Acute myeloid leukemia

Introduction to acute myeloid leukemia Acute myeloid leukemia (AML) or acute non-lymphocytic leukemia (ANLL) includes all non-lymphocytic-derived acute leukemias. It is a clonal malignant disease of the hematopoietic system caused by mutations in pluripotent stem cells or karyotypes of slightly differentiated precursor cells. People receiving large doses of radiation or prolonged exposure to benzene can increase the incidence of such diseases. AML is a highly heterogeneous disease group that can be transformed from malignant transformation of hematopoietic progenitor cells at different stages of normal myeloid cell differentiation and development. AML originating from different stages of progenitor cells has different biological characteristics. According to cell morphology and histochemical characteristics, AML is divided into different types, such as the biological characteristics of AML tumor cells with the application of M0M7 in FAB typing with immunology, cytogenetics and molecular biology. With a deeper understanding and understanding, it lays the foundation for the accurate classification of AML, the diagnosis of prognosis and the choice of the best treatment method. For the treatment of AML, in addition to acute promyelocytic leukemia, combined with chemotherapy is the main AML patient. The complete response rate is only 50% to 70%, and the long-term disease-free survival rate is 25% to 30%. basic knowledge The proportion of illness: 0.005% Susceptible people: no special people Mode of infection: non-infectious Complications: nosebleeds, central nervous system leukemia

Acute myeloid leukemia

First, the cause of the disease

1. Chemical substances

Long-term close contact with organic solvents, the risk of AML increased, a group of epidemiological surveys in China showed that workers in the benzene factory are 5 to 6 times more likely to develop leukemia than the general population, from exposure to onset, ie latency, average For 11 and 4 years, experimental mice inhaled high concentrations of benzene continuously, and AML occurred in 11% of female rats and 19% of male rats after 80 days.

The risk of leukemia in smokers is 2 to 3 times higher than that in the general population. Tobacco contains benzene, urethane, nitrosamines, and radioactive substances. If there are more than 40 cigarettes per day, AML is found to have abnormalities of chromosome 5 or 7. .

The risk of leukemia in tumors and non-tumor patients with longer-term application of alkylating agents or podophyllotoxins is 250 times higher than that of normal people. Domestic psoriasis patients use cytotoxic drugs such as bis-morpholine and ethylimine. After 7 years (average 30 months), more than 200 cases of leukemia have occurred, mostly in AML.

2. Ionizing radiation

Ionizing radiation-induced leukemia has been confirmed. In 1984, 26 provinces, municipalities and autonomous regions surveyed more than 20,000 clinical X-ray workers within 30 years. The standardization rate of leukemia was 3 or 5 times that of the control group, and AML accounted for 34%. 4%, patients with ankylosing spondylitis who received X-ray treatment, the incidence of leukemia was 9 or 5 times that of the same age group. The population affected by atomic bomb radiation in Japan, the incidence of leukemia was 4 to 40 times that of the normal population. And linearly related to the dose of radiation, a total of 766 cases of leukemia occurred in the above-mentioned irradiated population, of which 48% were AML, and the risk of leukemia increased by two times after radiotherapy of various solid tumors.

3. Genetics

Genetics has been shown to be one of the important risk factors for the onset of leukemia. After one of the monozygotic twins, the chance of developing leukemia within one year is five times that of the normal population. High leukemia in the high-risk family of leukemia The rate is 16 times that of the normal family. The genetic diseases with special chromosomal abnormalities, such as Down syndrome, Fanconi anemia, Bloom syndrome, neurofibromatosis, etc., are much higher than the normal population.

Some acquired diseases can be transformed into AML. The most common is the conversion of myelodysplastic syndrome (MDS) to AML. In the past, MDS before transformation was called pre-leukemia, and most of the leukemia transformed by MDS was AML. Such as polycythemia vera, primary myelofibrosis and other myeloproliferative diseases may be converted to AML in the later stages of the disease, a few atypical aplastic anemia, paroxysmal nocturnal hemoglobinuria can also be converted into AML .

Second, the pathogenesis

How the above various possible causes are triggered or transformed into AML is not clear.

Discussed from the chromosome and gene level.

1, chromosomal abnormalities

AML chromosomal abnormalities, like acute lymphoblastic leukemia, can be divided into two broad categories:

1 abnormal chromosome structure, such as a part of the chromosome structure is missing (del), repeat (dup), inversion (inv), or a certain structure (gene) breaks in two chromosomes, mutual translocation (t), forming a fusion gene;

2 changes in the number of chromosomes, such as the long or short arm of a chromosome (-p, -q), or increase (p, q).

2. The relationship between chromosome and genetic abnormalities and the pathogenesis of AML molecules

Most AML is caused by genetic mutations in acquired hematopoietic stem or progenitor cells. Only a few are genetic or familial, hematopoietic stem, and progenitor cell mutations, most of which are unknown. The known causes are radiation exposure, some The role of chemical substances, especially chemotherapeutic drugs such as alkylating agents, topoisomerase II inhibitors (such as etoposide), etc., due to the treatment of AML called t-AML, has been reported in recent years, a small number of AML The pathogenesis is due to accelerated gene mutation, DNA repair defects, and DNA replication errors.

Mutations in the gene can be expressed as chromosomal abnormalities, such as the chromosomal abnormalities listed in Tables 1 and 2, the nature of which is the cleavage or mutation of a certain nucleotide sequence of the genome.

(1) Fusion gene: Among the chromosomal abnormalities listed in Table 1 and the genes involved therein, there are three types of genes and fusion genes which have been studied more well and have a clearer understanding of the pathogenesis of AML.

1 q23 of chromosome 11: the gene involved is called MLL (myeloid-leukemia gene), MLL is normally expressed in the spleen, liver, lung, heart, brain, T and B lymphocytes, due to its trithorax protein with Drosophila There is homology, so it is also called HTRX or HRX gene. There are no fewer than 30 genes that are fused to MLL through gene translocation. Normally, MLL is a transcription factor. In AML, MLL is fused with its paired gene. It has been cloned, and the fusion gene makes the transcriptional regulation of MLL's normal gene disorder, which may be the mechanism that causes the characteristics of AML and its phenotype (common M4, M5 type).

2 chromosome 21 q22: the gene involved is called AML1, AML1 is normally expressed in hematopoietic cells, which is a subunit of core binding protein (CBL), which forms a complex with CBF through a rhd (runt homologous region). The latter facilitates the binding of CBF to DNA. The AML1-CBF complex is a transcription factor that forms a complex with the coactivators ATEF/CREB and P300/CBP and the DNA binding protein LEF-1 and its linker protein ALY. A transcription factor that regulates IL-3, myeloperoxidase, T cell receptor, and GM-CSF receptor (CSF-1R). These receptors bind to DNA via AML1 and function as transcriptional activation, if Grocho Or the binding of Ear-2 protein, which plays a role in transcriptional inhibition. Under normal conditions, ETO is expressed in certain cells in the brain, CD34 hematopoietic progenitor cells, in t(8;21)(q22;q22), AML1 and ETO Combining the formation of fusion genes, ETO recruits nuclear co-inhibitors Sin3A, N-CoR and histone deacetylase (HDAC), which inhibits the transcriptional activation of AML1, a complex of AML1-ETO and nuclear inhibitors. Object, not only can inhibit the normal function of AML-1, but also inhibit the function of ETO AML-1 and thus disturb the regulation of transcription, which may be the pathogenesis of AML type M2b.

3-dimensional A-acid receptor alpha (RAR) and promyelocytic leukemia (PML) genes.

(2) Non-fusion genes:

1p53 gene: p53 gene is located on human chromosome 17p13, 1, encoding 53kD protein, human P53 protein is composed of 393 amino acids, contains four functional regions, wild-type P53 protein is a phosphorylation protein in the nucleus, as a transcription factor Can be combined with specific DNA sequences, certain external stimuli such as DNA damage, stress can cause elevated levels of intracellular p53 protein, activate transcription of a series of downstream target genes, inhibit cell cycle progression or induce apoptosis, currently There are at least 7 known target genes, and the loss of p53 gene tumor suppressor function is one of the most common phenomena of malignant tumors. In hematological malignancies, the relationship between p53 gene inactivation and CML blast crisis has been paid attention to. Recently, researchers have found CML. The structure and expression of the p53 gene is abnormal, allele deletion and recombination, or point mutation, is found in 25% of CML patients.

2nm23 gene: nm23 gene exists in nm23-H1 and nm23-H2 subtypes, located in human chromosome 17q21, 3 is 4kb apart, both contain 5 exons, and the two subtypes are located in the exon-intron junction region. Most of the cleavage sites are identical. The nm23 gene encodes a 17kD protein. The proteins encoded by the two gene subtypes correspond to the A and B subunits of nucleosi dediphos phate kinase (NDPK), respectively. Cell development, proliferation, differentiation and regulation of cells, and the inactivation of an allele of nm23-H1 and nm23-H2 may lead to an imbalance of the ratio of NDPK A and B subunits, causing changes in cell activity and promoting tumor invasion and metastasis. In the process, the expression of nm23 gene in some tumors is related to the high metastatic potential. In blood diseases, it is involved in the occurrence and development of disease as a differentiation inhibitor gene. However, it has not been clarified how nm23 gene participates in leukemia and promotes it. Proliferation of leukemia cells and regulation of cell differentiation.

3BCL-2: BCL-2 is a member of a family of genes that control apoptosis. It is located on human chromosome 18q21, 3 and consists of three exons. It encodes a membrane protein consisting of 229 amino acids and has anti-apoptotic effects. BCL-2 can form a heterodimer with BAX. The BCL-2/BAX ratio is the key factor affecting apoptosis. If BCL-2 expression is high, it will inhibit apoptosis. Conversely, if BAX expression is high, it will promote cell apoptosis. In vitro, in vitro experiments showed that increased expression of BCL-2 enabled leukemia cells to resist apoptosis induced by glucocorticoids, VP-16, daunorubicin, mitoxantrone, etc., and the researchers found that BCL-2 was high. The expression significantly prolongs the survival time of leukemia cells, inhibits or blocks various factors including p53, c-myc, chemotherapy drugs, removal of growth factors, etc., and the BCL-2 family is associated with leukemia resistance and high expression. Leukemia cells of BCL-2 are not sensitive to chemotherapeutic drugs and have a poor prognosis.

4p16: p16 gene is an important tumor suppressor gene, located on chromosome 7p21, encoding 16kD protein, also known as multi-tumor suppressor gene, p16 protein inhibits cyclin-dependent kinase (CDK) 4 and 6, is a G1/S phase transition of cells Key regulatory genes, Hebert et al reported that the p16 gene was deleted, and the mutation rate was the highest in acute T-lymphocytic leukemia (T-ALL), reaching 22/24, while the detection rate of p16 gene deletion in pre-B-cell leukemia was 11/53. However, in the AML, the deletion of p16 gene, structural changes and other abnormalities are rare, suggesting that p16 has different effects in the occurrence and evolution of hematopoietic malignancies.

5WT-1: WT-l gene is associated with Wilm's tumor (WT). It has been confirmed by experiments that WT-l is a functional antagonist protein of human early growth response gene (EGR1), and WT-1 expression is restricted to kidney and urinary tract. Progenitor cells of the reproductive system may inhibit cell proliferation by inhibiting the proliferative effect of ERG1. The relationship between WT-l gene and hematological malignancies is not clear, but it is found that leukemia cells often express WT-l. .

6 Other genes: FMS encodes CSFI receptor, its mutation and allelic deletion may play an important role in the pathogenesis of certain leukemias, such as the high incidence of FMS mutation in M5 AML and the occurrence of ras gene mutation in AML. The rate of up to 30%, the incidence of tumor suppressor gene RB gene inactivation in various types of leukemia is about 10% to 30%, but the relationship between the above various single gene abnormalities and the molecular mechanism of AML has yet to be further clarified.

Acute myeloid leukemia prevention

1. Reduce or avoid harmful substances: such as ionizing radiation, chemical substances, chemical substances.

2. Active treatment should be given early for certain acquired diseases that may be converted to AML.

Acute myeloid leukemia complications Complications, episodes, central nervous system leukemia

1, infection

Fever is the most common complication of acute leukemia. About half of the patients have fever. When the body temperature is >38, 5°C is often caused by infection. The heat type is different and the heat is different. The main cause of fever is the main bacteria. And bone pain.

2, bleeding

In the whole process of acute leukemia, almost all patients will have different degrees of bleeding, 40% to 70% of patients have bleeding onset, in the absence of DIC, the incidence of bleeding is 67% to 75%, died of bleeding 38% to 44%, concurrent with DIC, almost all have bleeding, of which 20% to 25% died of DIC, bleeding site with skin, mucous membranes most common, manifested as skin bleeding spots, ecchymosis, nosebleeds, gingival bleeding Oral tongue blood blisters and menorrhagia, and the center of the plaque often induration, severe cases can have a variety of visceral bleeding, such as digestive tract, respiratory and urinary tract bleeding, intracranial hemorrhage can often be fatal, retinal hemorrhage can cause vision Decreased or even blind, subarachnoid hemorrhage often causes sudden death, intraocular hemorrhage can cause dizziness, tinnitus, hearing loss, etc., acute leukemia with AML-M3 and AML-M5 hemorrhage, easy to merge with DIC.

3, extramedullary complications of leukemia

Because leukemia cells can invade various tissues and organs, or affect the function of various systems, it can cause a variety of complications. Sometimes these system complications become the main clinical manifestations of patients, which can be seen in adult respiratory distress syndrome, sarcoidosis, chest cavity. Fluid, pulmonary fibrosis, pericardial effusion, arrhythmia, hypertension, heart failure, acute abdomen, portal hypertension, renal insufficiency, etc.

4, blood system complications

Found in thrombocytopenia, DIC, thrombosis, hemolytic anemia, high white blood cell status and leukocyte stasis syndrome.

5, endocrine and metabolic complications

It is characterized by diabetes, diabetes insipidus, and electrolyte imbalance.

6, nervous system complications

Intracranial hemorrhage is a serious complication of leukemia patients and is one of the leading causes of death in patients. Central nervous system leukemia AML is more common in M4M5 type.

7, skin damage

Leukemia complicated by skin damage is more common, can be divided into specific skin damage (more related to leukemia skin infiltration) and non-specific skin damage, specific skin lesions expressed as erythema, nodules, masses, M5, M3 type is relatively more.

8, bone and joint disease

Osteoarthritis is a common complication of leukemia. Other osteophyte complications include skull defect and femoral head necrosis.

9, eye complications

Omental hemorrhage, optic disc edema is a common manifestation of leukemia patients, other ocular complications include conjunctival hyperemia, edema, anterior chamber empyema, choroidal infiltration, iris infiltration, vitreous opacity, vision loss, eyelid lumps, eyeballs, acute glaucoma, etc. Mainly found in the M5 type.

10, green tumor

It is the manifestation of extramedullary infiltration of AML or CML. It is mainly composed of primitive or immature granulocytes. Monocytes form tumors. The more common sites are skin, eyelids, other parts along the paranasal sinus, bone, chest wall, breast, Gastrointestinal tract, respiratory or urinary tract, CNS or lymph node, T(8;21) AML has extramedullary infiltration characteristics, green tumors are more common, and leukemia with green tumor is generally considered to have poor therapeutic effect and poor prognosis.

11, oral complications

(1) gingival hyperplasia: common gingival hyperplasia of M4, M5 subtype in AML, leukemia gingival hyperplasia along the lip side

And the development of the lingual side, the congestion is sponge-like, the quality is soft, the local may have necrosis, hemorrhage, gingival hyperplasia after chemotherapy can be alleviated and disappeared.

(2) oral mucosal lesions: can be expressed as bleeding, erosion, ulcers, erythema, blood blister, etc., and leukemia

Patients with thrombocytopenic hemorrhage, oral infections, and chemotherapy are associated with mucosal damage. The importance of oral mucosal lesions is that it may be the gateway to bacterial invasion.

12. Leukemia-associated paraneoplastic syndrome

Some clinical syndromes associated with leukemia patients have nothing to do with extramedullary infiltration of leukocyte cells, called paraneplastic syndromes associated with leukemia. The main leukemia-associated paraneoplastic syndrome is Sweets syndrome, gangrenous. Pyoderma, arthritis and vasculitis syndrome.

Clinically, AML antibiotics with skin lesions and fever are ineffective. Skin lesions or blood cultures do not find pathogens. Sweet's syndrome should be considered. The diagnosis depends on skin biopsy, dermal layer neutrophil infiltration, pathogen infection, leukemia Cell infiltration and vasculitis can be diagnosed.

Pyoderma gangraenosum is an ulcerative skin disease of unknown etiology. 50% to 80% is related to systemic diseases. Nearly 1% of gangrenous pyoderma is associated with blood diseases. AML and CML are the most Common types, ALL and HCL with gangrenous pyoderma are occasionally reported, gangrenous pyoderma can be used as a primary diagnosis of leukemia, and some even earlier than the diagnosis of leukemia.

Symptoms of acute myeloid leukemia Common symptoms Hemorrhagic tendency Nose bleeding Heart palpitations Hematuria Leukopenia Reduces appetite and clotting disorders Osteolysis nodules

Anemia

Such as pale, powerless, palpitations, shortness of breath, etc., anemia in elderly patients is more common, a few cases can appear refractory anemia (RA) several months before the diagnosis, and then gradually develop into AML (but Rarely developed as ALL), the cause of anemia is: because normal hematopoietic stem cells are inhibited by leukemic clonal proliferation, erythroid progenitor cells have reduced reactivity to erythropoietin (EPO), bone marrow microenvironment is destroyed, and red blood cells are made. Reduced production; ineffective red blood cell formation; combined (rare) or recessive hemolysis, shortened red blood cell life; combined acute, chronic blood loss, or hypersplenism.

2, fever and infection

Fever is a common symptom in patients with newly diagnosed bone marrow suppression, especially in chemotherapy. The main cause is infection. Infection can occur on the body surface, and any part of the body, neutropenia (when <1, 0×109/L, the infection chance is obvious. Increased) with functional defects, chemotherapy and corticosteroid application to reduce the body's immune function, skin, mucous membrane (oral, gastrointestinal, etc.) bleeding, ulceration caused by barrier damage is the main cause of infection.

3, bleeding

About 60% of newly diagnosed AML have different degrees of bleeding, skin mucosa (nose, mouth and gums) bleeding is the most common, fundus, conjunctival hemorrhage is easier to see, women may have more menstruation, hematuria is less common, but microscopic hematuria is not easy to be It is found that severe gastrointestinal, respiratory and intracranial hemorrhage, although rare, is often the cause of death. The mechanism of acute leukemia bleeding is more complicated: thrombocytopenia is the most important cause of bone marrow failure, usually when platelets <20×109/L More with high-risk bleeding tendency, if combined with systemic infection or severe anemia can aggravate bleeding; chemotherapy, bacterial endotoxin and leukemia cell infiltration damage vascular endothelium and coagulopathy are all factors that cause bleeding.

Hemorrhage of AML-M3 subtype (acute promyelocytic leukemia) is more severe than other subtypes of ALL and AML, and its obvious bleeding is often incompatible with the degree of thrombocytopenia, because leukemia cells are destroyed (especially After the start of chemotherapy, a large amount of procoagulant substances and tissue factor release can cause disseminated intravascular coagulation (DIC) with fibrinolysis in 50% to 75% of M3 cases, occasionally DIC Appears in other subtypes of AML such as M5 (acute monocytic leukemia).

4, leukemia infiltration performance

Extramedullary infiltration of AML can occur in various subtypes of this disease, but M5 and M4 (acute granulocyte monocytic leukemia) are more common.

(1) skin infiltration: more common in M5 and M4, appearance of maculopapular rash, nodular or mass, purple-red color, can be multiple and cloth and a whole body or a few scattered on the body surface, and sensitive to radiotherapy, and occasionally In the blood picture, the skin infiltration before the leukemia changes, the benign skin damage associated with AML and erythema multiforme, Sweet syndrome, abscess, gangrene, etc., can be identified by skin biopsy.

(2) eye changes: AML retina, choroidal infiltration is less common than ALL, may be combined with bleeding or blindness, fundus infiltration often suggest a combined CNS involvement.

(3) Oral gingival changes: 25% to 50% of patients with M5 and M4 may develop gingival hyperplasia due to leukemia infiltration, severe gingival swelling such as spongy, surface rupture and bleeding, but other subtypes of AML are rare in gingival hyperplasia, oral and nasal mucosa Infiltration of tonsils or tongues is rare.

(4) Liver, spleen, and lymphadenopathy are seen in about 40% of cases (M5 type is more common): compared with ALL, the incidence is lower, and the degree of swelling is also lighter (the liver and spleen usually touched under the ribs) Under the ribs <4cm), the obvious incidence of liver, spleen and lymphadenopathy is generally 10%. Patients with significant hepatosplenomegaly should be distinguished from acute phase of chronic granulocytic leukemia (CGL).

(5) osteoarthritis: the incidence is about 20%, less common than ALL, bone and joint pain is easy to occur in the ribs, vertebrae, or long bones of the limbs and elbows, ankles and other large joints, occasionally osteonecrosis, but the joint exudate is rare Chest tenderness is a common sign that contributes to the diagnosis of leukemia.

(6) Central nervous system involvement (CNSL): The incidence of newly diagnosed AML is unknown, but the total incidence of CNSL in the total course of recurrence is 5% to 20% in children, and about 15% in adults, significantly lower than ALL, young (especially <2 years old), the number of peripheral blood leukocytes and primordial cells increased, significant hepatosplenomegaly, M4 or M5 subtype, and with chromosome monomer 7 or inv (16) (p13; q22) is a risk factor for CNSL, survival The longer the time, the higher the incidence of CNS involvement, the patient can be asymptomatic, and can also show symptoms such as increased intracranial pressure or cranial nerve palsy (V, VII is mainly for cranial nerves), and CNS prevention of AML. Treatment is generally not routine, but there are claims that patients with M5 or leukocytes >100×109/L should be given prophylactic treatment.

(7) granulocyte sarcoma: an extramedullary tumor composed of primary granules or proto-mononuclear cells. Because the tumor cells contain a large amount of myeloperoxidase, the tumor surface is green, so it is also known as chloroma. The incidence is 2% to 14% of AML, and more common in patients with t (8; 21) chromosomal abnormalities, granulocyte sarcoma often involving bone, periosteum, soft tissue, lymph nodes and skin, occurs in the eyelids, paranasal sinus , chest wall, breast, parotid gland, mediastinum, nerve, gastrointestinal tract and genitourinary system, tumor mass can be found in the diagnosis of AML, can also appear before the diagnosis of AML, and is sensitive to radiotherapy.

AML can also occur in the heart, pericardium, lung, pleura, kidney and gastrointestinal organs, tissue infiltration, but generally rarely lead to clinical symptoms, possible symptoms associated with infiltrating organs, signs with arrhythmia , anterior systolic murmur, pericardium, pleural hemorrhage and effusion, lung X-ray changes, renal enlargement, proteinuria, red urine, white blood cells, loss of appetite, nausea and vomiting, abdominal pain, diarrhea, gastrointestinal bleeding or performance For appendicitis, testicular, prostate, ovary, uterine infiltration is less common.

Examination of acute myeloid leukemia

1. Peripheral blood

Peripheral blood leukocytes can be normal, elevated or decreased, each accounting for 1/3 of the proportion, but regardless of the total number of white blood cells, which account for 85% of leukemia cells, 10% to 15% of AML cases of peripheral blood leukocytes More than 100 × 109 / L, that is, high white blood cell disease, more common in patients with M4 or M5 type, often accompanied by lung, central nervous system infiltration, tumor lysis syndrome and leukocyte viscerosis, is a high-risk type, poor prognosis, extreme A small number of patients with peripheral blood leukemia cells greater than 30%, and less than 30% of the bone marrow, did not meet the diagnostic criteria for acute leukemia, called peripheral blood type acute leukemia, in some cases, the number of myeloid leukemia cells may be high in the following months For these patients, especially in elderly patients with AML, chemotherapy can be temporarily stopped when peripheral blood platelets and granulocytes are reduced and have significant risk (platelets <20×109/L, granulocytes <1×109/L).

2, bone marrow

Most patients are extremely hyperplasia, normal hematopoietic cells are replaced by leukemia cells; a few patients with low bone marrow hyperplasia, but the original cells are still more than 30%, leukemia cells often have morphological abnormalities and nuclear, pulp development imbalance, such as the discovery of Auer bodies in the cytoplasm It is more helpful to exclude ALL and diagnosed as AML. Sometimes it can be caused by bone marrow dryness. The reason is that the leukemia cells are extremely accumulated, the bone marrow is too thick, or combined with myelofibrosis. At this time, bone marrow biopsy should be confirmed.

Based on morphological and cytochemical characteristics, the FAB Collaboration Group designated diagnostic criteria for acute leukemia typing in 1976 and revised and expanded in 1985.

3. Cytochemical staining

Cytochemical staining can complement morphological insufficiency and play an important role in the identification of acute leukemia types. Commonly used cytochemical staining methods include myeloperoxidase staining (MPO), Sudan black B staining (SBB), and chloroacetic acid AS. -D naphthol esterase staining (NAS-DCE), -butyric acid naphthol esterase staining (-NBE), -naphthyl acetate esterase staining (-NAE), periodic acid-Schiff staining (sugar Original staining, PAS), acid phosphatase staining (ACP), alkaline phosphatase staining (NAP), lysozyme, etc., if necessary, can be done by esterase double staining and Phl () small body, etc., according to the above method, The FAB types were initially classified (Table 4).

4, electron microscopy

Electron microscopy can improve the morphological classification of acute leukemia by observing the ultrastructure of cells. The differentiation of leukocytes between acute myeloid leukemia, acute monocytic leukemia, acute lymphoblastic leukemia and megakaryoblastic leukemia can be determined by electron microscopy. Cytochemical staining to confirm the diagnosis, the current electron microscope cytochemical staining has MPO staining and platelet peroxidase (PPO), etc., its advantages are high sensitivity, high specificity, can reveal some early differentiation characteristics of leukemia cells, such as MPO reaction is very Naive myeloblastic leukemia has the most diagnostic value. AML protoblasts are strongly positive for MPO (reaction). The response of protoplasts to MPO is not limited to granules, but also found in endoplasmic reticulum, nuclear membrane and Golgi; acute mononuclear Cellular leukemia primordial cells are weakly positive ( ), some cells are negative; while acute lymphoblastic leukemia and megakaryocyte primordial cells are unresponsive, PPO positive reaction is a unique marker of megakaryocytes and platelets, and megakaryocytes are positive for PPO ( ) And acute myeloid leukemia, acute monocytic leukemia and acute lymph The original cells of the cell leukemia were negative.

5. Cellular immunophenotype

Commonly used myeloid cell antibodies are MPO, CD33, CD13, CD11b, CDl5, CD14, and other myeloid-associated antibodies are CD34, HLA-DR, etc., anti-glycoprotein monoclonal antibody and anti-platelet glycoprotein IIb/IIIa, Ib (CD41a, CD41b, CD61, CD42a, CD42b) are considered to identify sensitive and specific monoclonal antibodies of M6 and M7 type ANLL, respectively. More than 90% of M3 type ANLL are characterized by CD33 and HLA-DR, and CDl4 is mononuclear specific. Antibodies, however, are not sensitive enough. In M4 and M5 type ANLL, the positive rate is about 70%. The relationship between acute myeloid mesangial markers and FAB typing can be seen in Table 5. The above myeloid immunophenotyping also contributes to chronic granules. Identification of acute types of cellular leukemia.

6, cytogenetic examination

By traditional methods, 50% ± 10% of AML cases have abnormal karyotypes, while chromosomal banding analysis, fluorescence in situ hybridization (FISH) and other cytogenetic techniques and polymerase chain reaction (PCR), Northern, The development and application of molecular biology techniques such as Southern and Western blotting have led to a deeper understanding of cytogenetics and molecular biology of acute leukemia, including structural and quantitative abnormalities.

(1) Abnormal chromosome structure:

1t(8;21)(q22;q22) and inv(16)(p13;q22): are the most common cytogenetic abnormalities in patients with newly diagnosed AML, and t(8;21) accounts for the onset of AML in young and children. The rate of 5% to 10% is mainly related to M2 type. It can also be seen in cases of M1 and M4. In adult leukemia, the presence of t(8;21) indicates that the patient has a good response to chemotherapy and has a high remission rate. The median survival time is long, but in childhood leukemia, the presence of t(8;21) indicates poor response to treatment, and AML cases with inv(16) and t(16;16) have their unique morphological manifestations: Acute granulocyte leukemia and M4E0, accounting for 10% to 12% of adult and young AML, eosinophils >5%, most cases of AML with inv(16), especially in the morphology of AML-M4-E0 type The change indicates a better prognosis, and this abnormal chromosomal expression may also be present in other AML cases such as M2, M4, and M5 typing.

2t(9;22)(q34;q11): The incidence of newly diagnosed AML is 1%, and t(9;22) usually appears alone without complex chromosome changes, but sometimes with t(9;22) Translocation AML can occur -7 and different triploids.

3t(15;17)(q22;q21): is a specific chromosomal change of M3 (APL), found in more than 90% of M3 cases, 1% to 2% of patients with APL have t(11;17) translocation, individual patients There is a t(5;17) translocation, and patients with a typical t(15;17) have a good therapeutic response to all-trans retinoic acid (ATRA), while the other two have no response to ATRA.

411q23 rearrangement: involving 11q23 strips in the rearrangement form more common in AML (M4), ALL, MDS and secondary to AML caused by topoisomerase II inhibitors, currently found about 30 different chromosomes The zone can be translocated with 11q23. For example, t(11;19) is common in infant leukemia. After differentiation and treatment, it has dual phenotypic characteristics of myeloid and lymphoid cells, indicating that chromosomal translocation may occur in the pluripotent hematopoietic stem cell stage; More than 90% of leukemia patients with 11q23 abnormalities can affect different genes. It is generally believed that the MLL (ALL-1, HRX, Ht-2X) genes involved in 11q23 usually have a poor prognosis.

5inv(3)(q2l;q26): AML with inv(3)(q2l;q26) is a unique subpopulation, often associated with micronuclear cell growth and abnormal platelet hyperplasia. These hematological abnormalities can also be seen in t(3; 3) In the case of (q2l; q26), the prognosis of patients with hematologic diseases involving 3q abnormalities is usually poor.

(2) Abnormal chromosome number:

1+8: is the most common karyotype change in AML, accounting for about 20% of karyotype abnormalities in AML patients. +8 as the primary change is more common in M1, M4 and M5, less common in M3 type, and as secondary Change, more common in the M3 type, but also occasionally in the M2 type.

2+21: There is a 1% incidence, and it occurs mostly in AML patients with del(5q) and -7 chromosome changes.

3-7: The incidence of 1% to 3% in AML patients may be related to exposure to certain chemicals, and AML patients with -7 are not sensitive to treatment and represent a poor prognosis of the disease.

4-5: Related to toxic exposure, common in treatment-related AML (t-AML).

5 sex chromosome reduction: common in M2 type, accompanied by t (8; 21), as a single karyotype abnormality, -X is significantly less than -Y, clinically, bone marrow cells -Y often represent normal male aging, but sometimes It is the only karyotype change in tumor cells.

7, molecular biology testing

Some fusion genes such as PML-RAR, AMLl-ETO need to be diagnosed by molecular biology techniques (so-called MCIM typing), or to observe residual leukemia, and some as described above, single genes such as N-RAS, Abnormal expression or expression of oncogenes such as K-RAs and BCL-2 and tumor suppressor genes RB1 and p53 may be associated with the development of certain AML. These gene tests have certain value in predicting the prognosis of AML.

(1) p53: The expression of p53 in AML is low, which often indicates poor prognosis.

(2) nm-23: nm-23-H1, nm-23-H2 mRNA increased in AML, CML-BC, normal in CML-CP, nm-23-H1 and nm-23-H2 in chromosome Expression in abnormal AML-M2 and AML-M3 was lower than other types of AML subtypes without chromosomal aberrations; whereas in AML-M6 cases, nm-23 expression levels were extremely high.

(3) BCL-2: In AML, the expression of BCL-2 of M1 and M2 subtypes is higher than that of M3, M4, M5, and the high expression survival time is short, and the chemotherapy effect is poor.

(4) p16: The functional inactivation rate of p16 homologous gene p15 in AML was as high as 86%. In addition, the p16 expression activity of bone marrow cells in newly diagnosed and relapsed AML was significantly lower than that of normal control and bone marrow cells in long-term remission of AML.

(5) WT-1: The WT-1 gene in the bone marrow of the leukemia patients was highly expressed at the early stage of diagnosis, and the WT-1 gene disappeared after the patient was clinically relieved. Some researchers successfully observed 33 cases of leukemia patients. WT-I gene expression in peripheral blood of 26 patients with AML, 7 patients with ALL, and 6 normal controls, and found that 6 normal individuals did not detect the lowest level of WT-1 transcription (<10-4). WT-1 of 3 patients (93, 9%) of leukemia patients showed different levels of expression in the early stage of the disease (10-4101), and the expression of WT-l gene was not different between AML and ALL. The researchers followed up and tested. Peripheral blood and WT-1 levels were expressed in 31 patients with leukemia after CR, and 5 cases recurred (of which 2/18 patients could not detect WT-1 expression, while 3/13 patients detected low levels) WT-1 expression), 3 of the 5 patients had an increase in WT-1 expression during relapse, suggesting that T-1 is a sensitive tumor marker that can be used to monitor the small amount of leukemia patients after chemotherapy or CR Residual lesions.

8. Lactate dehydrogenase (LDH) and lysozyme increase

In some patients with AML, lactate dehydrogenase (LDH) and lysozyme are elevated in serum and urine, and the increase in these indicators indicates the corresponding load of the tumor. It is more common in patients with M5 and M4, and calcium metabolism disorder is relatively rare. , manifested as hypercalcemia or hypocalcemia, may be related to the production and release of some parathyroid hormone-like substances in leukemia cells.

9, bone marrow pathology

The leukemia cells of the leukemia patients have hyperplasia of leukemia cells. The bone marrow is brown or grayish green with a purp-like color. If there is bleeding, it is dark red or reddish brown. When the leukemia cells are proliferated, the yellow pulp in the long bones can also be Red pulp is replaced (ie, occupied by leukemia cell proliferation), leukemia is often accompanied by trabecular bone reduction or worm-like defects, which is related to increased intraosseous pressure and insufficient trabecular blood supply, reticular fiber enlargement or collagen Fiber proliferation.

10, abnormal blood coagulation

Thrombocytopenia may occur in the presence of DIC, prolonged prothrombin and partial thromboplastin, decreased plasma fibrinogen, increased fibrin degradation products, and a deficiency in coagulation factors V, VII, VIII, X, and the like.

11, metabolic abnormalities

Hyperuricemia is common in patients with increased white blood cell count and induction chemotherapy, and is associated with tumor lysis, but the incidence of hyperuricemia in AML is lower than ALL; serum lactate dehydrogenase (LDH) can be elevated, especially M4, M5 subtype, its elevation is generally lighter than ALL; serum lysozyme (1ysozyme) increased by M4, M5 type; excessive lysozyme can damage renal proximal convoluted tubules, plus metabolic abnormalities of leukemia itself, antibiotics, diuretic The effects of treatments such as agents can lead to hypokalemia; the presence of hyperkalemia is associated with tumor lysis and hyperuricemia; sometimes low calcium or hypercalcemia can occur.

Diagnosis and differentiation of acute myeloid leukemia

Diagnostic criteria

According to clinical manifestations, peripheral blood, bone marrow morphology, acute myeloid leukemia is not difficult to diagnose.

1, acute myeloid leukemia undifferentiated (M1) blasts in the bone marrow type I (typically myeloblasts, no granules in the cytoplasm) + type II (with granulocyte characteristics, small cell mass, a small number of fine particles) > 90%, promyelocytes are few, neutral neutrophils and granulocytes in the following stages are absent or rare, at least 3% of primordial cells are positive for peroxidase or Sudan black, and M1 accounts for 10% to 20% of AML. The median age is 40 to 50 years old. Only 1/3 of the liver, spleen or edema are swollen. Most of the blood is red blood cells and thrombocytopenia, half of the white blood cells are increased, 1/4 white blood cells are reduced, and no special cytogenetic abnormalities are found. Usually sensitive to chemotherapy, the prognosis is better.

2, acute myeloid leukemia differentiation type (M2) bone marrow blast cells I + II type accounted for 30% ~ 89%, promyelocytes and the following stages of granulocytes > 10%, M2 type accounted for 30% ~ 45% of AML, the average Age is 30 years old, common cytogenetic abnormalities, of which 29% to 40% are t(8;21), and Auer bodies are often positive. The immunophenotype may be associated with CD56 and CD19 in addition to myeloid characteristics.

t(8;21) involves two genes, namely AML1 (21q22) and ETO (8q22), which form the fusion gene AMLl/ETO, which can still be detected in long-term CR, so it is not suitable as an indicator of recurrence, t(8) ;21) mainly occurs in M2 type without MDS history, good treatment response, high CR rate, long survival, but children, with extramedullary lesions still have a higher recurrence rate, shorter life, male M2 Patients often have Y chromosome loss, and women often have X chromosome loss.

3(M3) (APL)>30%(M3a);(M3b);(M3v)Auer

APLAML5%10%30381090%DICA(ATRA)M3aM3bM3vAuer

17q21A(RAR)15q24(PML)95%t(15;17)PML/RARa15P RAR/PML17P-M32/3M3PML 153ATRAATRAAPLt(1 5;17)t(5;17)(NPM/RARt(11;17)(PLZF/RARa)APLATRA

4-(AMMOLM4) -M4a>20%;M4b>20%;M4c>30%;M4E5%30%

AMMOLAML5%10%404520%25%>100×109/LCNS-L

M4Einv(16)(p13;q22)(MYH11)(CBF)MYH11/CBF10%M4MYH11/CBFCRM4EMYH11/CBF

M4ECNSCNS-LM4ECR

M4t(6;9)

5(AMOLM5) 80%M5a<30%M5b

AMOLAML2%10%M5a75%<25M511t(11;9)t(11;17)t(11;19)11q23(MLL)MLL9AF919DNL

50%AMOLCNSCNS-L3%22%10%30%DICAPLATRADICAMLAMOLAMOLCR

6(M6) >50%>30%15%30%()

M6AML5%>50MDS1/3

7(AMKLM7) 30%

M7AML5%AMLAML30%>100×109/L(LDH)

M0AuerAMLCD13CD33CD345q-7q-

Differential diagnosis

AML

1(ALL)

ALLAMLALL()

2

>30%()Auer

3(AA)

AMLAML()

4(IM)

IMALLAMLEBIM4

5(MH)

AMLM6AML>30%VitBl234

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