Fatal warm autoimmune hemolytic anemia resulting from IgM autoagglutinins in an infant with severe combined immunodeficiency

IgM Warm Autoantibodies Causing Autoimmune Hemolytic Anemia in a Pediatric Patient

Most often, IgM-mediated autoimmune hemolytic anemia (AIHA) presents as cold agglutinin disease in the pediatric population. The IgM warm agglutinins are rare, with few reports in the literature. This case study describes a 5 year old girl with nausea, abdominal pain and jaundice, and a hemoglobin of 5.5 g/dL who was diagnosed with a warm reactive IgM AIHA. The laboratory workup revealed a pan-reactive antibody and a direct antiglobulin test negative for IgG and C3. A thermal amplitude assay revealed reactive IgM antibodies at 37°C, 30°C, 25°C, and 4°C and an antibody titer of 1:8. An adsorption for IgM-specific autoantibodies exposed underlying anti-E and anti-Cw alloantibodies. Transfusion of phenotypically matched red blood cell units supported ongoing hemolysis. The AIHA treatment included steroids followed by rituximab with complete resolution. A literature review shows variable outcomes for warm AIHA in the pediatric population and often describes the presence of warm reactive IgM-mediated AIHA as an indicator for poor prognosis.

IgM-mediated Warm Autoimmune Hemolytic Anemia: An Autopsy Report

A 79-year-old man with Sjögren's syndrome and systemic lupus erythematosus developed acute impaired consciousness and hemolytic anemia. The patient's red blood cells agglutinated spontaneously at 25-37°C. The treatment of red blood cells with 2-mercaptoethanol resulted in the loss of spontaneous agglutination. A diagnosis of IgM-mediated warm autoimmune hemolytic anemia was made. The patient received steroid pulse and plasma exchange therapies. Rituximab was also administered. However, the patient died from multiple organ failure at six days from the symptom onset. The clinical progress of the patient and autopsy findings suggested that complement activation might have been associated with the pathology.

Fatal warm autoimmune hemolytic anemia in a child due to IgM-type autoantibodies

Herein is described a case of immunoglobulin M (IgM) warm autoimmune hemolytic anemia (AIHA) in a child who consequently died within 3 days of clinical onset. A previously healthy 11-year-old boy presented with fever, anemia, jaundice, and deteriorating consciousness. On direct agglutination test against group O red blood cells, agglutination was seen even at 37°C in saline, which was abolished on dithiothreitol treatment of the serum, indicating that the responsible autoantibody was IgM and had a warm-reactive capacity. A diagnosis of IgM warm AIHA was therefore made. Hemagglutination in the visceral capillaries was considered as the direct cause of organ dysfunction. The patient died due to respiratory failure. IgM warm AIHA is a very severe condition that is difficult to reverse in an advanced state. Both prompt, definite diagnosis and intervention are therefore vital to prevent severe multi-organ dysfunction in cases of IgM warm AIHA.

Severe Autoimmune Hemolytic Anemia in an Infant Caused by Warm-reactive IGM and IGA Autoantibodies: A Case Report and Review of the Literature

Warm-reactive IgM autoimmune hemolytic anemia is uncommon and carries a poor prognosis in adults. There have been rare reports in children, generally associated with an underlying immunologic deficiency, and outcomes are quite variable. Warm IgM in combination with other antibodies has not been reported in children. We report the first case of severe, steroid-responsive autoimmune hemolytic anemia caused by both warm-reactive IgM and IgA autoantibodies in an otherwise healthy 3-month-old.

Rituximab therapy for autoimmune haematological diseases

Autoimmune haematological diseases are characterized by the production of antibodies against blood proteins or cells, and comprise primary immune thrombocytopenia, autoimmune haemolytic anaemia, acquired haemophilia, and thrombotic thrombocytopenic purpura. Current treatments for these disorders include corticosteroids, cytotoxic drugs and splenectomy, which may be associated with significant systemic toxicity and/or morbility. B cells play a key role in both the development and perpetuation of autoimmunity, since they produce autoantibodies but also function as antigen-presenting cells, and release immunomodulatory cytokines. Rituximab, an anti-CD20 monoclonal antibody that specifically depletes B cells, may be an effective treatment strategy for patients with autoimmune disorders. This article reviews data of the literature, showing that patients with autoimmune haematological diseases can respond to rituximab irrespective of age and number or type of prior treatments. These data suggest that rituximab provides an effective and well-tolerated treatment option for these conditions.

Severe autoimmune hemolytic anemia in a liver transplanted child

AIHA can complicate solid organ and bone marrow transplantation early after transplant. We describe the first case report of a 16-month-old boy with mixed type warm-acting IgM and warm IgG autoantibodies AIHA, occurring eight months after liver transplantation. This case describes the complexity of this very rare form of AIHA. It also illustrates the efficacy of rituximab in this indication, as well as the transfusion support with extremely rare blood, along with the importance of international collaboration to provide it. In this report, the etiologies of HA occurring in post-transplant pediatric patients are reviewed and the different treatment strategies are discussed.

Membrane autoantibodies in systemic lupus erythematosus: a case of autoimmune hemolytic anemia, antiphospholipid antibodies, and transient acquired activated protein C resistance

BACKGROUND

Warm autoimmune hemolytic anemia and antiphospholipid antibodies (which include lupus anticoagulants and anticardiolipin [ACL] antibodies) are associated, respectively, with approximately 10 and 40 percent of cases of systemic lupus erythematosus (SLE). This study reports a case of SLE presenting with an unusual constellation of findings that included an immunoglobulin M (IgM) cold autoantibody of high thermal amplitude, high-titer ACL antibodies, and transient acquired activated protein C resistance.

CASE REPORT

A previously untransfused, nulligravid 17-year-old woman without a significant medical history presented with signs and symptoms of SLE and an extravascular hemolytic anemia. Spontaneous agglutination was noted in blood samples collected for testing. Serologic testing revealed a normal-titer, high-thermal-amplitude IgM red blood cell (RBC) autoantibody but no additional RBC antibodies in the patient's plasma. Additional testing was significant for a high-titer ACL IgM and a positive test for activated protein C resistance (a screening test for the Factor [F]V Leiden mutation), which prompted initiation of prophylactic anticoagulation. Confirmatory DNA testing for FV Leiden, however, was negative. The patient's symptoms, anemia, RBC autoagglutinins, ACL antibodies, and activated protein C resistance all resolved after 6 weeks of immunosuppression.

CONCLUSION

This case illustrates the wide range of clinical and laboratory findings that autoantibodies against cellular membranes may produce. IgM autoagglutinins of high thermal amplitude associated with a significant extravascular hemolytic anemia may be a presenting feature of SLE. Concomitant antiphospholipid antibodies may interfere with partial thromboplastin time-based tests of hypercoagulability such as that for activated protein C resistance.

Successful HLA-identical hematopoietic stem cell transplantation in a patient with purine nucleoside phosphorylase deficiency

PNP deficiency is an autosomal recessive metabolic disorder characterized by severe combined immunodeficiency, autoimmune hemolytic anemia, and by a complex of neurologic manifestations including ataxia, developmental delay, and spasticity. PNP protein catalyzes the phosphorolysis of deoxyinosine and deoxyguanosine. It is found in most tissues of the body but is expressed at the highest levels in lymphoid tissues. This tissue distribution explains why the lymphoid system is predominantly affected in PNP deficiency. We describe a five-yr-old boy with muscular hypertonia, impaired growth, autoimmune hemolytic anemia, and neutropenia who underwent HSCT from his HLA-identical sister. One yr post-HSCT, the boy developed normal immunological functions, and his neurological status improved.

Mouse models of IgG- and IgM-mediated hemolysis

Well-characterized mouse models of allo-immune antibody-mediated hemolysis would provide a valuable approach for gaining greater insight into the pathophysiology of hemolytic transfusion reactions. To this end, mouse red blood cells (mRBCs) from human glycophorin A transgenic (hGPA-Tg) donor mice were transfused into non-Tg recipients that had been passively immunized with IgG or IgM hGPA-specific monoclonal antibodies (mAbs). In this novel murine "blood group system," mRBCs from hGPA-Tg mice are "antigen positive" and mRBCs from non-Tg mice are "antigen negative." Passive immunization of non-Tg mice with the IgG1 10F7 and IgG3 NaM10-2H12 anti-hGPA mAbs each induced rapid clearance of incompatible transfused hGPA-Tg-mRBCs in a dose-response manner. Using various knockout mice as transfusion recipients, both the complement system and activating Fcgamma receptors were found to be important in the clearance of incompatible mRBCs by each of these IgG mAbs. In addition, the IgM E4 anti-hGPA mAb induced complement-dependent intravascular hemolysis of transfused incompatible hGPA-Tg-mRBCs accompanied by gross hemoglobinuria. These initial studies validate the relevance of these new mouse models for addressing important questions in the field of transfusion medicine.

Successful anti-CD20 monoclonal antibody treatment of severe autoimmune hemolytic anemia due to warm reactive IgM autoantibody in a child with common variable immunodeficiency

Autoimmune hemolytic anemia due to warm reactive IgM autoantibodies is unusual, severe, and often fails to respond to standard immunosuppressive therapies in both adults and children. A 6-year-old girl with common variable immunodeficiency had longstanding steroid dependent, splenectomy-unresponsive, warm IgM autoantibody-mediated autoimmune hemolytic anemia. Rituximab, a monoclonal antibody directed against CD20 antigen, was used to deplete B lymphocytes and reduce autoantibody production. She received a total of six doses of rituximab (375 mg/m2). Therapy was well tolerated, and B-lymphocytes were effectively depleted from the peripheral blood. The patient was completely tapered off glucocorticoids. The patient has remained off immunosuppressive agents for 16 months despite the return of B lymphocytes to the peripheral circulation. She continues to require IVIG. Early treatment with rituximab might be an option for patients with warm reactive IgM autoantibody-mediated autoimmune hemolytic anemia not responding to other treatments or experiencing untoward side effects from those treatments.

The use of rituximab, anti-CD20 monoclonal antibody, in pediatric transplantation

Rituximab, chimeric anti-human CD-20, is approved for treatment of B-cell lymphoma in adults. It is being used experimentally in other various immune-related disease such as immune thrombocytopenic purpura, myasthenia gravis, and rheumatoid arthritis. In transplant recipients it is used for treatment of post-transplant lymphoproliferative disease, and prevention and treatment of acute rejection. There are few data on its use in children. This paper reviews the use of rituximab in these disease states and provides hypotheses for its mode of action.

High incidence of graft failure in children receiving CD34+ augmented elutriated allografts for nonmalignant diseases

T-cell depletion of the marrow graft using counterflow centrifugal elutriation reduces the risk of graft-versus-host disease (GVHD). However, because of high rates of graft failure and relapse, elutriation alone has not improved survival. We have carried out a phase II clinical trial in 54 pediatric patients to determine if CD34+ selection to rescue pluripotent stem cells from the small lymphocyte fraction improves engraftment. The processed grafts contained a mean of 5.5 x 10(7) cells/kg IBW, 4.7 x 10(6) CD34+ cells/kg IBW, and 6.3 x 10(5) CD3+cells/kg IBW. Patients achieved an ANC >500 at a median of 16 days and platelet count >20 000 at a median of 28 days. The incidence of clinically significant GVHD was 19%. In total, 10 patients enrolled in this study experienced graft failure, with eight of the 14 patients transplanted for nonmalignant indications failing to engraft stably. Graft failure was statistically significantly associated with nonmalignant diagnosis (P<0.001), but was not associated with CMV seropositivity, donor gender, or cell counts of the allograft. We conclude that although time to engraftment is similar to that seen with unmanipulated grafts, graft failure remains a significant problem in patients with hereditary, nonmalignant diseases. Future efforts will seek to preserve the benefits of elutriation with CD34+ selection by increasing immune ablation of the preparative regimen and/or increasing posttransplant immune suppression.