cold antibody autoimmune hemolytic anemia
Introduction
Introduction of cold antibody autoimmune hemolytic anemia Cold antibody type self-immunity hemolytic anemia is a type of autoimmune hemolytic anemia, and its optimal reaction temperature is below 30 ° C, especially 4 ° C autoantibodies. There are 3 subtypes: 1 self-erythrocyte antibody aggregates red blood cells (cold agglutinin) at 4 °C and activates complement, destroys red blood cell (colostin) cold agglutinin syndrome ie cold agglutinin/colmolysin syndrome (coldautoagglutininssyndrome) , CAS). At 24 ° C, the maximum amount of binding to red blood cells and fixation of complement, and activation of whole complement at 37 ° C leads to hemolysis of the two-way hemolysin (Donath-Land-steiner, DL antibody) type, that is, paroxysmalcoldhemoglobinuria (PCH). 3 cold aggregate and DL antibody mixed type. basic knowledge The proportion of illness: 0.001% Susceptible people: no special people Mode of infection: non-infectious Complications: renal failure
Cause
Cold antibody type autoimmune hemolytic anemia
Causes:
Cold antibody type hemolytic anemia can be divided into primary (unexplained) and secondary according to its etiology. The primary disease of secondary cold antibody type AIHA also takes lymphatic proliferative disease as the first place. Second, various infectious diseases, due to the improvement of diagnostic techniques, secondary cases gradually increased.
Pathogenesis:
The mechanism of production of anti-erythrocyte autoantibodies has not yet been elucidated, and the possible factors are as follows.
1. Viral infection can activate the binding of polyclonal B cells or chemicals to the erythrocyte membrane, and changing its antigenicity may lead to the production of autoantibodies.
2. Lymphoid tissue can cause the body to lose its immune surveillance function due to infection, tumor and immune deficiency, which is not conducive to the identification of its own cells, which is conducive to the production of autoantibodies.
3. T helper cell (Th) balance disorder, Th2 hyperfunction, mainly produce IL-4, IL-6 and IL-10, activate B lymphocytes to make their function abnormally hyperactive, produce their own red blood cell antibodies.
Prevention
Cold antibody type autoimmune hemolytic anemia prevention
Active treatment of the primary disease and warmth is the best preventive measure. The disease has a poor prognosis and lacks effective treatment, so it should focus on prevention, promote eugenics, and conduct pre-marital and prenatal examinations. The cold agglutinin test is positive, especially secondary CAS titers can be as high as 1:1000 or even 1:1.6 million (normal < 1:64). When the temperature rises to 30 ° C, the lectin titer is still increased in albumin or physiological saline, and has the diagnostic value of CAS. Prenatal diagnosis can be done early in pregnancy to prevent the birth of homozygous children.
Complication
Cold antibody type autoimmune hemolytic anemia complications Complications, renal failure
In severe cases, there may be significant hemoglobinuria complicated with transient renal failure. Renal failure is a pathological condition in which all kinds of chronic kidney diseases develop to the late stage and some or all of the renal function is lost. Renal failure can be divided into acute renal failure and chronic renal failure. The condition of acute renal failure progresses rapidly, usually due to insufficient blood supply to the kidney (such as trauma or burns), impaired function of the kidney due to some factors, or poison. The injury causes the production of acute kidney failure.
Symptom
Cold antibody type autoimmune hemolytic anemia symptoms common symptoms skin pale jaundice fatigue proteinuria diarrhea chills lymph node enlargement immune hemolysis
The peak age of primary CAS is about 70 years old, and the number of female patients is slightly more. The CAS caused by primary CAS and lymphoproliferative diseases is chronic, mainly pale and weak due to chronic hemolysis, usually stable. In cold conditions, the condition can be aggravated, so hemoglobinemia and hemoglobinuria caused by acute hemolysis occur in winter, often without chills, fever and renal insufficiency. Most patients have auricles, nose tips and fingers in cold environments. And toe cyanosis, disappeared as soon as it warms up, as the ambient temperature decreases, cold antibodies (IgM) in the blood flowing to the skin and subcutaneous tissue active, causing red blood cells to aggregate and combine with complement, red blood cell agglutination leads to local blood flow Stagnation, this is the main cause of hand and foot cyanosis. Unlike the Raynaud sign, all fingers can be affected, first turned dark gray, and the white light can be changed to white after a long time of exposure. In rare cases, agglutinated red blood cells block small blood vessels. The gangrene of the fingertips occurred, and the patient's signs were rare. Except for anemia and jaundice, the liver, spleen and lymph nodes were not obvious.
The course of CAS caused by infection is short-lived, often occurs 2 to 3 weeks after the infection occurs (at this time, the concentration of cold agglutinin peaks), after 2 to 3 weeks, spontaneous relief, typical symptoms are pale and jaundice, cold environment There are hands and feet in the bottom.
Examine
Cold antibody type autoimmune hemolytic anemia
When venous blood is drawn, red blood cells are self-coagulated. The disappearance of agglutination after heating often indicates the possibility of CAS, rather than the formation of red blood cells. The patient has relatively stable chronic mild to moderate anemia, and the reticulocyte is slightly elevated. Peripheral blood smear showed red blood cell agglutination, no obvious red blood cell malformation, white blood cells and platelet counts were normal, even if there was no obvious hemoglobinuria, hemosiderin urine may still be positive, often with mild bilirubinemia.
The cold agglutinin test is positive, especially the secondary CAS titer can be as high as 1:1000 or even 1:1.6 million (normal <1:64), when the temperature rises to 30 ° C, the lectin in albumin or saline The titer is still high, and it has the diagnostic value of CAS. The autoantibody is IgM type, which acts together with complement to cause agglutination of red blood cells.
Diagnosis
Diagnosis and identification of cold antibody autoimmune hemolytic anemia
Diagnostic criteria
Diagnosis of cold antibody type AIHA:
1 There is sufficient clinical and laboratory evidence to show that intravascular hemolysis occurs after the patient is cold.
2 cold type self-erythrocyte antibody test positive (CAS needs cold agglutinin test positive, PCH needs DL antibody test positive) and high titer or strong activity.
3 The direct Coombs test can be positive, showing C3 type. In addition, if a clear secondary cause can be found, the secondary cold antibody type AIHA should be diagnosed; secondary is excluded to diagnose the primary.
Differential diagnosis
Paralyzed with cold antibody type AIHA is paroxysmal nocturnal hemoglobinuria (PNH), especially CAS, because its hemolysis is caused by IgG binding to complement, so acid hemolysis test and saccharification hemolysis test may be positive, much like PNH, but patients with PNH do not have cold antibodies, and patients with cold antibodies do not have PNH cells (PNH cells lack GP1 anchor proteins such as CD55 and CD59), which can be identified.
