Functional and surface characteristics of lymphocytes from patients with warm-antibody type autoimmunhemolytic anemia (AIHA)

Summary As part of an overall assessment of immunological function, several aspects of cellular immunity and circulating lymphocyte subpopulations were evaluated in a group of 10 patients with idiopathic autoimmunhemolytic anemia (AIHA). The absolute numbers of circulating T and B cells were reduced in the patient group compared to normals. A shift from corticosteroid-sensitive to corticosteroid-resistent and activated cells in the cytogram of clustered Fe-(III)-hydroxide-glucane saccharose labeled T lymphocytes was apparent. In vitro studies of cellular reactivity, as evaluated by PHA, ConA, PWM, antigens and allogeneic cell induced proliferation showed a blend of general or selective depression and sometimes a normal or increased activity with no definite correlation with both the number of circulating T cells and the extent of the hemolytic activity by the disease. The possible significance of the findings is discussed.This work was supported by the Minister für Wissenschaft und Forschung des Landes NRW II B8-FA 6438     

Promotion and prevention of autoimmune disease by CD8+ T cells

Until recently, little was known about the importance of CD8+ T effectors in promoting and preventing autoimmune disease development. CD8+ T cells can oppose or promote autoimmune disease through activities as suppressor cells and as cytotoxic effectors. Studies in several distinct autoimmune models and data from patient samples are beginning to establish the importance of CD8+ T cells in these diseases and to define the mechanisms by which these cells influence autoimmunity. CD8+ effectors can promote disease via dysregulated secretion of inflammatory cytokines, skewed differentiation profiles and inappropriate apoptosis induction of target cells, and work to block disease by eliminating self-reactive cells and self-antigen sources, or as regulatory T cells. Defining the often major contribution of CD8+ T cells to autoimmune disease and identifying the mechanisms by which they alter the pathogenesis of disease is a rapidly expanding area of study and will add valuable information to our understanding of the kinetics, pathology and biology of autoimmune disease.     

Successful Treatment with Cyclosporine and High-Dose Gamma Immunoglobulin for Persistent Parvovirus b19 Infection in a Patient with Refractory Autoimmune Hemolytic Anemia

We describe a patient with persistent pure red cell aplasia due to human parvovirus B19 (HPVB19) infection during immunosuppressive therapy for refractory autoimmune hemolytic anemia (AIHA). The patient had been given corticosteroid (CS) and/or azathioprine for AIHA. During the course of treatment, reticulocyte count and hemoglobin levels decreased suddenly. Bone marrow aspirate showed erythroid lineage-specific aplasia with a few giant proerythroblasts, suggesting the presence of HPVB19 infection. The diagnosis of aplastic crisis due to HPVB19 infection was based on positive test results by polymerase chain reaction for HPVB19 immunoglobulin M (IgM) antibody and B19 DNA. Although splenectomy followed by administration of high-dose gamma globulin (HDIG) and plasma exchange were performed, the crisis and hemolysis recurred. Aplastic crises occurred several times when the B19 IgG result became negative and the CD4+ lymphocyte count was less than 300/microL. The patient showed complete recovery from anemia after CS was switched to cyclosporin A (CsA) and intermittent administration of HDIG. The result for B19 IgG antibody was continuously positive, and the DNA result became negative after these treatments. The results in this case indicated that concomitant administration of CsA and intermittent administration of HDIG can lead to cure of chronic anemia due to HPVB19 infection in patients with refractory AIHA.     

IgA-mediated autoimmune hemolytic anemia in an infant

Autoimmune Hemolytic anemia (AIHA) a relatively uncommon form of hemolytic anemia in children, occurs due to the premature destruction of red blood cells caused by presence of autoantibodies directed against antigens on RBCs. Warm reactive AIHA is the most common form due to IgG isotype of immunoglobulin class binding to autologous RBCs at 37⁰C and confirmed with a positive DAT screening. We present a case of DAT-negative primary warm AIHA in an infant due to IgA antibody. A 10 month old male infant presented with dark colored urine and irritability for past two months, with associated history of fever, diarrhea and vomiting. He had received one red cell transfusion 10 days prior. On physical examination he had pallor with tachycardia without splenomegaly. On investigation his hemoglobin was 5.8 g/dl, WBC 25.9 × 10³/mm³ and normal platelets counts. Peripheral blood smear had spherocytes and biochemical values showed high bilirubin and LDH. Immunohematological work up revelaed polyspecific DAT was negative but monospecific DAT screening showed strong (4+) positivity for IgA and a weak IgG positivity. The patient was diagnosed as IgA-mediated Warm AIHA and was started on prednisolone at 2 mg/kg/day following which hemoglobin improved over the next 2 months. After 2 weeks, prednisolone was tapered and stopped by the end of 3 months. Patients with clinical and laboratory evidence of acute hemolysis, an additional screening for IgA antibody may be done even in cases where poly-specific DAT is negative. Early detection helps in avoiding further investigations and provide efficient management.