Autoimmune Hemolytic Anemia in Systemic Lupus Erythematosus and Primary Antiphospholipid Syndrome
The prevalence of AIHA in patients with SLE is 7.5% (average of seven studies; range: 5.2% to 12.5%). AIHA may occur at any time during the course of SLE, but two-thirds of cases of AIHA occur at diagnosis or soon thereafter. Almost half of the patients are already taking steroids. Most patients are women and have wAIHA. Evans syndrome is common. Compared with SLE patients without AIHA, those with AIHA are younger; have a higher prevalence of thrombocytopenia, APAs, renal disease, serositis, and central nervous system involvement; and have a higher risk of venous thrombosis.
The prevalence of AIHA in primary antiphospholipid syndrome (PAPS) is about 10%. AIHA precedes PAPS in 25% of cases, but in others occurred after a median time of 4.4 years after the diagnosis of PAPS. Patients with PAPS and AIHA have an increased risk for the development of SLE.
Autoimmune Hemolytic Anemia in Inflammatory Bowel Disease
In the only larger study, the prevalence of AIHA in ulcerative colitis was 1.7%. The mean time from diagnosis of colitis to AIHA was 17 months. Three-quarters of these patients had total colitis. AIHA may also be associated with Crohn disease, but the prevalence is lower than in ulcerative colitis.
Autoimmune Hemolytic Anemia in Other Immune Diseases
A few or single cases of an association of wAIHA with Sjögren syn drome, dermatomyositis, biliary cirrhosis, Graves disease, Churg Strauss syndrome, crescentic glomerulonephritis, polymyalgia rheumatica, scleroderma, autoimmune pancreatitis, and cAIHA with rheumatoid arthritis have been reported. A high prevalence of AIHA was found in small children with giant-cell hepatitis.
Autoimmune Hemolytic Anemia in Transplanted Patients
AIHA is a rare but important and dangerous complication of allogeneic hematopoietic stem-cell transplantation (HSCT). Aside from AIHA, causes of hemolytic anemia in transplanted patients may be lymphocyte passenger syndrome and ABO incompatibility. AIHA may be caused by severe immunosuppression by drugs to prevent rejection, graft-versus-host disease (GVHD), viral infections, EBV lymphoproliferative disorder (LPD), or the recurrence of an immune disorder after transplantation (biliary cirrhosis).
The highest rate of AIHA occurred in small children after unrelated cord HSCT for inborn metabolic defects (44%) and in children with severe combined immune deficiency after haploidentical HSCT with T-cell–depleted stem cell grafts.
In adults, the incidence of AIHA ranges from 3.0% to 4.4% after allogeneic HSCT. The median time from HSCT to AIHA is 4 to 10 months. Most patients have wAIHAs. Risk factors for AIHA are unrelated donors, T-cell depletion, and extensive GVHD. In most cases, AIHA occurred in patients in CR of the underlying disease. However, in one study AIHA was associated with a relapse of chronic myeloid leukemia in the majority of patients.
After transplantation of solid organs, the highest risk of AIHA was in patients with pancreatic transplantation. A number of patients with AIHA or cAIHA were observed after liver transplantation, but only a small number were observed after cardiac, lung, intestinal, and renal transplantation. The most likely cause of AIHA in these patients is severe drug-induced immunosuppression.
Autoimmune Hemolytic Anemia in Pregnancy and After Blood Transfusion
Very few cases of AIHA and Evans syndrome—with wAIHAs— occurred during pregnancy. In these patients, there seems to be a higher risk for pre-eclampsia. AIHA responds well to steroids and resolves in most cases after delivery. In two cases, the newborns had mild hemolysis.
Development of RBC autoantibodies is common in multitransfused patients and is associated with the presence of alloantibodies. However, anemia is rare.
