Hypoproliferative acute leukemia

Introduction to hypoproliferative acute leukemia Hypoproliferative acuteleukemia (HAL) is a rare type in acute leukemia (AL). The majority of acute leukemia patients have a higher degree of myeloproliferation, and about 10% of acute leukemias have a complete blood cell reduction. Peripheral blood can be free of naive cells, no hepatosplenomegaly, and bone marrow biopsy is reduced, and the proportion of naive cells accounts for 5% to 75%. basic knowledge The proportion of illness: 0.001% Susceptible people: no specific people Mode of infection: non-infectious Complications: anemia

Causes of hypoproliferative acute leukemia

(1) Causes of the disease

The exact cause of human leukemia is still unknown, and many factors are thought to be associated with leukemia. The virus may be the main factor, in addition to genetics, radiation, chemical poisons or drugs.

1. Virus It has been confirmed that leukemia virus can be isolated from spontaneous leukemia tissues of animals such as chicken, mouse, cat, cow and gibblet. It is a retrovirus and most of them are C-form under electron microscope, retrovirus It is an RNA virus that releases RNA after entering the cytoplasm to remove the membrane. Under the action of reverse transcriptase, it is transcribed into complementary DNA (ie, precursor viral DNA) using viral RNA as a template, and then formed by DNA-dependent DNA polymerase. Proviral DNA, proviral DNA can be integrated into the DNA of the host cell for replication, but does not affect the survival of the host cell. The viral etiology of human leukemia has been studied for decades, but so far only adult T cell leukemia has been Caused by the virus, in 1976, Japan's Gao Yueqing first reported adult T-cell leukemia/lymphoma (ATL). Later epidemiological surveys found that the southwestern part of Japan, the Caribbean region and Central Africa were high-risk areas, and in 1980 in the ATL cell line. ATL-associated antigens were found, and virus particles were found under electron microscope. Gallo of the United States and Rizhao Reif of Japan isolated C-type reverse transcribed RNA from patient cultured cell lines, respectively. The viruses, named HTLV-1 and ATLV, were confirmed to be consistent in the future, which is a major contribution to the etiology of human leukemia virus. The high-incidence area of ATL is also a high-risk area of HTLV-1 infection, and the Japanese sero-epidemiological survey indicates The positive rate of HTLV-1 antibody in the healthy population over 40 years old is 6% to 37%, and the positive rate of non-endemic area antibody is only 0-0.015%. HTLV-1 is infectious and can be transmitted through mother-to-child transmission through lactation. And blood transfusion, China Zeng Yi and other people in 28 provinces, municipalities, autonomous regions for sero-epidemiological survey, found that 8 cases of HTLV-1 antibody-positive people are mostly Japanese or close contact with them, in 1989, Lu Lianhuang in Fujian coastal areas The relationship between other viruses such as HTLV-2 and hairy cell leukemia, Epstein-Barr virus and ALL-L3 subtype (Burkitt leukemia/lymphoma) has not been fully established, and other types of leukemia have not been able to confirm the cause of the virus. It is not contagious.

2. Radiation ionizing radiation has leukemia effect, its effect is related to the radiation dose size and irradiation site. One large dose or multiple small doses have leukemia effect, and whole body irradiation, especially bone marrow irradiation, can cause bone marrow suppression and immunosuppression. Chromosomal breaks and aberrations were observed several months after irradiation. In 1945, after survivors of atomic bombs in Hiroshima and Nagasaki, Japan, the number of leukemias was 30 and 17 times higher than that of unirradiated areas. Radiation therapy for ankylosing spondylitis and 32P treatment The incidence of leukemia and leukemia was higher than that of the control group. According to the survey from 1950 to 1980 in China, the incidence of leukemia in clinical X-ray workers was 9.61/100,000 (standardized rate 9.67/100,000), while others The medical staff is 2.74/100,000 (standardized rate is 2.77/100,000). The radiation can induce AML, ALL and CML, but no CLL is seen, and there is often a period of myelosuppression before the onset, and the incubation period is about 2 to 16 years. There is no clear basis for whether diagnostic radiation will cause leukemia, but intrauterine irradiation can increase the risk of leukemia in infants after birth.

3. The role of chemical substance benzene-induced leukemia is relatively certain, it can cause chromosomal damage at 1~10ppm, leukemia effect from 124 to 200ppm, AML and AEL are the main cause of acute leukemia caused by benzene, the latter accounts for a considerable proportion, which deserves attention, and There is often a stage of myelosuppression before the clinical manifestations of leukemia, similar to MDS, benzene-induced chronic leukemia is mainly CML, no CLL, alkylating agent, topoisomerase II inhibitor and cytotoxic drugs can cause secondary leukemia It is also more certain that treatment-related leukemia (t-AL), especially the first two drugs, most t-AL occurs in the original lymphatic malignant tumor and malignant tumors that are prone to immunodeficiency after long-term alkylating agent treatment. At intervals of 2 to 8 years, secondary leukemia caused by chemotherapy is mainly AML, and there is often a period of complete cytopenia before onset. In recent years, nearly 100 cases of secondary leukemia caused by bis-morpholine have been reported in China. For the treatment of psoriasis, it is a very strong chromosomal aberration substance. Leukemia occurs after 1 to 7 years after taking B-morpholine (median 4 years). The leukemia caused by B-morpholine is mainly AML. M3 majority, have been reported related to smoking and the incidence of leukemia.

4. Genetic factors The incidence of certain leukemias is related to genetic factors. Single-oval twins such as one person with leukemia have another 20% chance of leukemia, familial leukemia accounts for 7% of the total number of leukemia cases, occasionally congenital leukemia, part Infant leukemia is thought to be associated with genetic factors, often accompanied by 11q23 (MLL) abnormalities, and some hereditary diseases are often associated with higher rates of leukemia, including Down, Bloom, Klinefeher, Fan-

Coni and Wiskott Aldrich syndrome, such as Down syndrome, the incidence of acute leukemia is 20 times higher than the general population. Most of the above hereditary diseases have chromosomal aberrations and ruptures, but most leukemias are not hereditary diseases.

(two) pathogenesis

Leukemia is a malignant clonal disease of a group of hematopoietic stem cells and progenitor cells. The levels of hematopoietic cells are different. For example, AML can be pluripotent stem cells or granulocyte-monocyte progenitor cells. Leukemia cells lose further differentiation. The ability of maturity is blocked at an early stage. ALL mainly affects the lymphoid system. The myeloid system is almost non-malignant. The block occurs in the early stage of lymphoid system. The mechanism of leukemia in hematopoietic cells remains unclear. Some chromosomal abnormalities are related to There is a direct relationship between the occurrence of leukemia. Chromosomal breaks and translocations can shift the position of oncogenes and activate them. The changes in gene structure in chromosomes can directly cause mutations in cells. The chromosomal rearrangement of leukemia cells can cause the structure or regulation of cell oncogenes. Changes, the quality and quantity of the gene product changes, the latter may be related to the occurrence and maintenance of leukemia, such as APL (M3) with t (15; 17), making the retinoic acid receptor on chromosome 17 The (RAR) gene is fused to the promyelocytic leukemia (PML) gene located on chromosome 15, forming a PML/RAR fusion gene, and its protein product Blocking the differentiation of granulocytes, which is a molecular mechanism of APL pathogenesis and all-trans retinoic acid treatment, such as the Ph chromosome of CML, t(9;22), forming a BCR/ABL fusion gene, which encodes a protein High tyrosine kinase activity, which stimulates hematopoietic cell proliferation, such as ALL-L3 with t(8;14), causing the C-MYC gene on chromosome 8 to be juxtaposed with the immunoglobulin heavy chain gene on chromosome 14, chromosome Translocation changes the transcription of the C-MYC gene, thereby destroying the normal network associated with C-MYC protein. Activation or overexpression of C-MYC gene causes tumorigenesis. There may be a process of leukemia. Some acute leukemias are On the basis of myelodysplastic or myeloproliferative disorders, leukemia causes normal blood cell reduction, and the mechanism of hematopoietic failure is complicated, not only the exclusion of myeloid leukemia cells, but also cell and body fluid-mediated hematopoietic inhibition.

Low proliferative acute leukemia prevention

prevention:

1. Eat more natural foods and regular production foods that have undergone hygienic inspection, such as: fresh vegetables, whole grains, etc.;

Second, reduce contact with benzene, chronic benzene poisoning mainly damages the human hematopoietic system, causing leukemia, platelet count reduction to induce leukemia, some workers engaged in the production of benzene as chemical raw materials should strengthen labor protection, decoration should be chosen to be harmless to the human body Decoration materials;

Third, do not abuse drugs, use chloramphenicol, cytotoxic anticancer drugs, immunosuppressive drugs and other drugs should be careful, do not use for a long time;

Fourth, try to avoid radiation, personnel engaged in radiation work should do a good job of personal protection, infants and pregnant women should avoid contact with excessive emission lines.

Low proliferative acute leukemia complications Complications anemia

1. Infection, fever is the most common complication and can be repeated infection.

2. Anemia can be complicated by anemia.

3. Bleeding is more common in the skin, mucous membrane bleeding.

Symptoms of hypoplastic leukemia Common symptoms Shortness of breath, palpitations, fatigue, whole blood cells, skin mucous membrane bleeding, dizziness

Most of the patients are elderly, concealed onset, with dizziness, fatigue, palpitations, shortness of breath and other anemia symptoms are most common, skin, mucosal bleeding is common, with light, moderate bleeding, a small number of patients with fever, infection as a clinical feature, The signs of leukemia cell infiltration are mild, and the lymph nodes, liver and spleen are generally not enlarged.

Examination of hypoplastic acute leukemia

1. Blood: Most of the whole blood cells are reduced, and very obvious, but leukemia cells are rare, so it is non-leukemia leukemia.

2. Bone marrow hyperplasia is low, primordial cells 30%.

3. Bone marrow biopsy pathology: hematopoietic cell proliferation is low, but there is still evidence of leukemia cell infiltration, the diagnosis of hypoproliferative leukemia needs to be combined with bone marrow smear (multiple site puncture) and bone marrow biopsy, Howe et al. based on bone marrow biopsy hematopoietic cells Areas of low proliferative leukemia are divided into three cases: 1 severe hyperplasia: hematopoietic cell area <15%; 2 moderate hyperplasia: hematopoietic cell area is 15% to 30%; 3 hyperplasia is mildly reduced: hematopoietic cell area 30% to 40%.

4. B ultrasound: generally no hepatosplenomegaly, swollen lymph nodes.

5. X-ray can prompt lung infection.

Diagnosis and diagnosis of hypoplastic acute leukemia

1. Aplastic anemia (AA) Anemia, hemorrhage, pancytopenia and low myeloproliferation are the main features of AA, similar to HAL. The main distinguishing points are bone marrow smear and/or bone marrow biopsy to find leukemia cells. AA is mainly mature lymphocytes.

2. Myelodysplastic syndrome (MDS): refractory anemia in MDS with blast-producing (RAEB) and refractory anemia with blast-producing (RAEB-t) patients with bone marrow, with a low percentage The original cells, especially the MDS with low bone marrow hyperplasia, are easily confused with HAL. The identification points are: 1 The percentage of primordial cells is the most important, 30% is HAL, <30% is RAEB or RAEB-t, 2 pathological hematopoiesis, HAL is often absent For example, or to a lesser extent, MDS morbid hematopoiesis is a prerequisite for diagnosis.

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