immune hemolysis

Introduction
Cause
Examine
Diagnosis

Introduction

Introduction The disease produces autoantibodies due to immune dysfunction, binds to the surface of red blood cells or is freed in serum, sensitizing red blood cells, or activating complement, and premature destruction of red blood cells to cause hemolytic anemia. Autoimmune hemolytic activity is an abnormality in the dysfunction of a group of B lymphocytes, which produces anti-erythrocyte antibodies and increases the destruction of red blood cells. Sometimes the destruction of red blood cells can be compensated by the formation of bone marrow erythropoiesis, and there is no clinical anemia, that is, only autoimmune hemolysis (AIH). Others can only measure anti-self red blood cell antibodies (AI) without obvious signs of hemolysis. Evans is called when the body produces both anti-self-erythrocyte antibodies and anti-self-platelet antibodies (even leukocyte antibodies), which in turn causes anemia and thrombocytopenia (or whole cell reduction). The clinical manifestations of this disease are multi-terminal, warm antibody type AIHA is mostly chronic onset, easy to repeat, some patients have a history of acute attacks, chills, fever, jaundice, back pain, etc., hemoglobinuria is common in paroxysmal coldness Hemoglobinuria is rare in cold agglutinin disease, often repeated, and difficult to control later.

Cause

Cause

Hemolysis caused by the destruction of red blood cells by the production of antibodies against self-erythrocytes. It is the most common type of hemolytic anemia. When a person's immune surveillance function is abnormal and the antigenicity of red blood cells changes or foreign infections such as mycoplasma and red blood cells have the same antigenicity, autoantibodies are produced. According to the optimal temperature of antibody action, the disease is divided into two categories:

First, warm antibody type AIHA: warm antibodies are generally most active at 37 ° C, mainly IgG, a small number of IgM, is an incomplete antibody. According to its etiology, it can be divided into two reasons: unexplained (idiopathic) and secondary.

The warm antibody type AIHA can be secondary to:

1 hematopoietic tumors: such as chronic lymphocytic leukemia, lymphoma, myeloma and so on.

2 connective tissue diseases: such as systemic lupus erythematosus, rheumatoid arthritis and the like.

3 infectious diseases: especially children with viral infections.

4 immune diseases: such as hypogammaglobulinemia and immunodeficiency syndrome.

5 gastrointestinal diseases: such as ulcerative colitis.

6 benign tumors: such as ovarian dermoid cysts.

Second, cold antibody type AIHA: cold antibody is most active at 20 ° C, mainly IgM. Lectin IgM is more common in cold agglutinin syndrome, and can directly erythrocyte agglutination in the blood circulation, so it is a complete antibody. Another special cold antibody (17S, IgG), called DL antibody, is found in paroxysmal cold hemoglobinuria. Cold agglutinin syndrome can be secondary to pneumonia mycoplasma pneumonia and infectious mononucleosis; paroxysmal cold hemoglobinuria can be secondary to viral or syphilis infection.

The mechanism of the disease has not yet been elucidated, and there are many theories. In recent years, more emphasis has been placed on the destruction of immune function (such as lymphoid tissue infection or malignant lesions) and the loss of immune surveillance (recognition), leading to the production of autoantibodies, and some patients cannot rule out the possibility of innate immune deficiency.

Warm-type autoimmune hemolytic anemia: This disease can occur in men and women of different ages, but it is more common in adults. In recent years, a large number of cases reported in the literature, the primary only accounted for 45%, most cases are secondary to various diseases.

The patient's red blood cells are generally considered normal, but their surface is often adsorbed with incomplete antibodies - IgG and / or C3. The sensitized red blood cells do not hemolyze in the blood vessels, but are destroyed by macrophages in the mononuclear-macrophage system, and only a part of the membrane may be dragged and digested. Due to the continuous loss of the membrane, it eventually becomes a spherical cell, which is blocked and swallowed in the spleen cord. If both IgG and C3 are present on the membrane, the sensitized red blood cells are accelerated by the spleen. The destruction of sensitized cells by macrophages is determined by the two effects of "attachment" and "ingestion". The C3 receptor is associated with "attachment" and "ingestion" is dependent on the IgG-Fc receptor. The two receptors interact synergistically. If C3 is attached alone, hemolysis is not serious because it cannot be further ingested and does not cause phagocytosis. The red blood cells that adsorb C3 are mostly blocked and destroyed in the liver because of the abundant blood flow in the liver and more phagocytic cells.

Examine

an examination

Related inspection

Immunopathological examination of autoimmune antibody detection

(1) History and symptoms

(1) Question of medical history:

note:

1 with or without jaundice, blood transfusion history.

2 Is there any painful hand and foot cyanosis?

3 Whether it has lymphatic system tumors, myeloma, gastric adenocarcinoma, autoimmune diseases (systemic lupus erythematosus, rheumatoid arthritis, etc.) diseases such as mycoplasma, viral infection and syphilis.

4 Whether to use penicillin, quinidine, quinine, methyldopa and other drugs.

(2) Clinical symptoms: dizziness, fatigue, shortness of breath, palpitations; chills, fever, low back pain, chest tightness (acute hemolysis).

(2) Physical examination found

Anemia appearance, skin, sclera yellow staining, mild swelling of the spleen, some patients have hand and foot hair (cold antibody type).

(3) Auxiliary inspection

Blood: Hemoglobin is reduced, positive cells are pigmented anemia; white blood cells and platelets are normal; reticulocytes are increased, small spherical red blood cells are increased, and young red blood cells are seen.

Bone marrow: hyperplasia, with obvious proliferation of young red blood cells. The granulocyte and megakaryocyte cell lines are normal. Blood indirect erythropoietin increased, serum haptoglobin decreased or disappeared, and plasma free hemoglobin increased. Urine hemosiderin is negative. Direct anti-human globulin test positive, indirect anti-human globulin test positive or negative (warm antibody type autoimmune hemolytic anemia). The cold agglutinin test was positive (cold agglutinin syndrome). Positive cold and hot hemolysis test, urine hemosiderin test positive (paroxysmal cold hemoglobinuria).

Diagnosis

Differential diagnosis

Immune hemolysis needs to be differentiated from the following symptoms:

1. Hereditary spherocytosis: a family history; peripheral blood small spherical red blood cells > 10%; red blood cell osmotic fragility test positive; autolysis test: hemolysis > 5%.

2. Paroxysmal nocturnal hemoglobinuria: acid hemolysis test, venom factor hemolysis test positive, urine hemosiderin test positive.

3. Glucose-6-phosphate dehydrogenase deficiency: methemoglobin reduction test positive; fluorescent spot test, nitrotetrazolium basket method: G6PD activity decreased.