Anemia

Introduction Anemia refers to the amount of hemoglobin, red blood cell count, and hematocrit in a circulating blood per unit volume that is lower than the normal pathological state. According to the World Health Organization, there are about 3 billion people with varying degrees of anemia worldwide, and tens of millions of people die each year from various diseases caused by anemia. The probability of population suffering from anemia in China is higher than that in Western countries. In the population with anemia, women are significantly higher than men, and the elderly and children are higher than the young and middle-aged. This should be taken seriously. In production workers exposed to hazardous substances, labor protection should be strengthened to not abuse drugs in daily life and to strictly control indications.

Cause

(a) erythropoiesis-reducing anemia:

Abnormalities in hematopoietic cells, bone marrow hematopoietic microenvironment, and hematopoietic materials affect erythropoiesis, which can reduce erythropoiesis-deficient anemia.

1. Anemia caused by abnormal hematopoietic stem cells

(1) Aplastic anemia (AA): AA is a bone marrow hematopoietic failure associated with primary and secondary hematopoietic stem cell damage. The pathogenesis of partial pancytopenia is related to the production of anti-myeloid autoantibodies by B cells, which in turn destroy or inhibit bone marrow hematopoietic cells.

(2) pure red cell anemia (PRCA): PRCA refers to the damage of bone marrow erythroid hematopoietic stem and progenitor cells, which in turn causes anemia. According to the cause, the disease can be divided into two categories: congenital and acquired. Congenital PRCA, the Diamond-Blackfan syndrome, is caused by heredity; acquired PRCA includes both primary and secondary. Some scholars have found that some patients with primary PRCA have their own EPO or young red blood cell antibodies in their serum. Secondary PRCA mainly has drug-related, infection-related types (bacteria and viruses, such as parvovirus B19, hepatitis virus, etc.), autoimmune disease-related types, lymphoproliferative disease-related types (such as thymoma, lymphoma, plasma). Cytopathic and lymphocytic leukemia, etc.) and acute aplastic crisis.

(3) congenital erythrocytic anemia (congenital dyserythropoieticanemia, CDA): CDA is a type of hereditary erythroid stem progenitor cells caused by abnormal clonal abnormalities, refractory anemia characterized by erythroid ineffective hematopoiesis and morphological abnormalities . According to hereditary methods, the disease can be divided into autosomal concealed hereditary and dominant hereditary.

(4) Hematopoietic malignant clonal diseases: These diseases have abnormalities in hematopoietic stem and progenitor cells, including myelodysplastic syndromes and various hematopoietic neoplastic diseases such as leukemia. The former is due to pathological hematopoiesis, hyperproliferation, high apoptosis, and in situ hemolysis; the latter has tumoric hyperplasia, low apoptosis and poor differentiation, and hematopoietic regulation is also affected, thereby reducing normal mature red blood cells and causing anemia.

2. The hematopoietic microenvironment caused by abnormalities in hematopoietic microenvironment includes bone marrow stroma, stromal cells and cytokines.

(1) Anemia caused by damage of bone marrow stroma and stromal cells: bone marrow necrosis, myelofibrosis, myelosclerosis, marble disease, bone marrow metastasis of various extramedullary neoplastic diseases, and various infections or non-infectious osteomyelitis The hematopoietic microenvironment may be abnormal due to damage to the bone marrow stroma and stromal cells, which may affect blood cell formation.

(2) Anemia caused by abnormal levels of hematopoietic regulators: stem cell factor (SCF), interleukin (IL), granule-mono-column colony-stimulating factor (GM-CSF), granulocyte colony-stimulating factor (G-CSF) ), erythropoietin (EPO), thrombopoietin (TPO), platelet growth factor (TGF), tumor necrosis factor (TNF) and interferon (IFN) have positive and negative regulation of hematopoiesis. Insufficient EPO occurs in renal insufficiency, liver disease, and pituitary or hypothyroidism; neoplastic diseases or certain viral infections induce more hematopoietic negative regulators such as TNF, IFN, and inflammatory factors, which can cause chronic disease. Anemia of chronic disease (ACD).

3. Anemia of hematopoietic raw materials or utilization of anemia. Hematopoietic raw materials refer to substances necessary for the proliferation, differentiation and metabolism of hematopoietic cells, such as proteins, lipids, vitamins (folic acid, vitamin B12, etc.), trace elements (iron, copper, zinc). and many more. Any deficiency or utilization of hematopoietic materials may result in reduced erythropoiesis.

(1) Anemia caused by deficiency of folic acid or vitamin B12 or utilization disorder: megaloblastic anemia caused by absolute or relative deficiency or utilization of folic acid or vitamin B12 due to various physiological or pathological factors.

(2) Iron deficiency and iron utilization of anemia: This is the most common anemia in the clinic. Iron deficiency and iron utilization disorders affect heme synthesis, and this type of anemia is called hemoglobin synthesis abnormal anemia. The erythrocyte morphology of this type of anemia is small, and the central light-stained area is enlarged, belonging to small cell hypochromic anemia.

(2) Hemolytic anemia (HA), that is, red blood cells destroy excessive anemia.

(3) Hemorrhagic anemia:

According to the rate of blood loss, acute and chronic, chronic hemorrhagic anemia often combined with iron deficiency anemia. Can be divided into coagulopathy (such as idiopathic thrombocytopenic purpura, hemophilia and severe liver disease) and non-clotting diseases (such as trauma, tumors, tuberculosis, bronchiectasis, peptic ulcer, sputum and Two types of gynecological diseases, etc.).

an examination

Related inspection

Determination of trace elements in human body by blood morphological examination of various bone marrow cells

In addition to red blood cells, hemoglobin, and red blood cell ratio, the most basic hematology should include:

(1) Net red blood cell count, corrected reticulocyte count = patient's hematocrit / 0.45 / L × reticulocyte (%).

(2) Determination of MCV and MCHC.

(3) Peripheral blood smear, observe whether red blood cells have abnormal red blood cells, such as spherical red blood cells, target red blood cells, fission cells, with or without red blood cell size, low pigment and polychromatic red blood cells, eosinophilic spot color, Kabo Terry's ball, Hao's body and so on. Changes in the number and morphology of white blood cells and platelets, with or without abnormal cells.

(4) Bone marrow puncture for bone marrow smear examination, which is indispensable for diagnosis, and bone marrow biopsy should be performed if necessary. Bone marrow examination must include staining to confirm or rule out iron deficiency anemia and iron granulocyte anemia.

Urine routine, fecal occult blood and parasite eggs, blood urea nitrogen, serum creatinine and lung X-ray examination can not be ignored.

Differential diagnosis

Indicators for identifying the nature of anemia are often used to calculate the mean red blood cell volume (MCV), mean red blood cell hemoglobin (MCH), and mean red blood cell hemoglobin concentration (MCHC) calculated from the number of red blood cells, hematocrit, and hemoglobin.

Increased MCV, seen in aplastic anemia, reduced, seen in iron deficiency anemia. Increased, is the indication of hemolysis, decreased with small cell hyperplasia, is iron deficiency anemia; reduced with large cell hyperplasia, aplastic anemia.

Comprehensive changes in MCV, MCH, and MCHC can identify anemia as hypoxic small erythrocyte anemia and hyperchromic large cell anemia (MCV increases, MCHC is higher than normal).

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