Secondary Autoimmune Hemolytic Anemia Research Articles

Autoimmune haemolytic anaemia in mantle cell lymphoma : an insidious complication associated with leukemic disease

Autoimmune haemolytic anaemia in mantle cell lymphoma : an insidious complication associated with leukemic disease

Surface localization of high-mobility group nucleosome-binding protein 2 on leukemic B cells from patients with chronic lymphocytic leukemia is related to secondary autoimmune hemolytic anemia

Chronic lymphocytic leukemia (CLL) is the main cause of autoimmune hemolytic anemia (AHA). However, the cellular basis underlying this strong association remains unclear. We previously demonstrated that leukemic B cells from patients with CLL recognize the erythrocyte protein Band 3, a prevalent autoantigen in AHA. Here we show that the major binding site of Band 3 on leukemic cells is an extrinsic protein identified as high-mobility group nucleosome binding protein 2 (HMGN2), a nucleosome-interacting factor which has not been previously reported at the cell surface. T lymphocytes do not express HMGN2 or bind Band 3. Removal of HMGN2 from the cell membrane abrogated the capacity of Band 3-pulsed CLL cells to induce CD4 + T cell proliferation. We conclude that surface HMGN2 in leukemic B cells is involved in Band 3 binding, uptake and presentation to CD4 + T lymphocytes, and as such may favor the initiation of AHA secondary to CLL.

Long Term Outcomes of Warm and Cold Antibody-Mediated Autoimmune Hemolytic Anemia Treated with Rituximab from a 13 Year Retrospective Cohort

Background and objective: Autoimmune hemolytic anemia (AIHA) is mediated by warm and cold-reactive autoantibodies, with the treatment approach depending on the type of antibody. Corticosteroids, immunosuppressive agents and splenectomy are the commonly used therapies for AIHA. Over the last decade, rituximab has emerged as a preferred second line agent for treatment of AIHA, though evidence supporting its use in AIHA, especially cold antibody-mediated AIHA, is limited to case reports and small case series. We therefore conducted a 13 year retrospective cohort study of patients treated for AIHA at the Cleveland Clinic to evaluate the outcomes of patients with this disorder treated with rituximab.Methods: Adult patients presenting with newly-diagnosed diagnosis or relapsed AIHA were included.The clinical presentations, type of AIHA (warm, cold, mixed), treatment and outcomes were recorded. Frequencies of complete responses (CR) (non-transfused hemoglobin of ≥ 12 mg/dL, hemoglobin increase ≥ 2 mg/dL, and normalization of hemolytic markers), and partial responses (PR) (non-transfused hemoglobin of ≥ 10 mg/dL with hemoglobin increase of ≥ 2 mg/dL) were recorded. Time to relapse was estimated using the Kaplan Meier method. A p value of ≤ 0.05 was considered significant for all analyses.Results: We identified 180 patients with AIHA of which 50 patients (31 with warm AIHA and 19 with Cold AIHA) were treated with rituximab. The rates of primary and secondary AIHA (associated with autoimmune disease, malignancy or drugs) were similar in patients with warm and cold AIHA (p=0.660). Rituximab was used as first line therapy in combination with steroids in 15 patients and as second/third line treatment in 35 patients. Only 17 patients received rituximab monotherapy while 33 received combination therapy with steroids. Overall response rates for Rituximab were 74% (17% CR, 57% PR) and 80% (27% CR, 53% PR) for patients with warm and cold AIHA respectively (p =0.877). Median time to response was 0.7 months in warm AIHA and 1.1 months in cold AIHA (p=0.112). Seven (22.5%) patients with warm AIHA but none with cold AIHA required maintenance steroids after Rituximab treatment. Relapses occurred in 9 (29%) patients with warm and 5 (26%) patients with cold antibody-mediated AIHA after rituximab treatment (p=0.154). The median time to relapse was 8.5 months for warm and 55.2 months for cold AIHA (p=0.044) (Figure 1).Patients who received rituximab with or without concomitant steroids demonstrated lower rates of relapse (26%) than those who received corticosteroids alone (32.3%) [Relative Risk 1.35 (1.09-2.82), p=0.047] (Figure 2). There were no major adverse events due to Rituximab over a median follow up of 54 months.Conclusion: Rituximab is highly effective in both warm and cold AIHA with higher response rates and lower relapse rates than corticosteroid therapy alone. In this cohort, there was a high incidence of durable responses, especially in cold antibody-mediated AIHA. [Display omitted] [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Clinical Characteristics and Long Term Outcomes of Warm Type Autoimmune Hemolytic Anemia

Back groundWarm type autoimmune hemolytic anemia (AIHA) is the disease which antibody reacts with self-antigen on red blood cell. Due to the uncommon of this disease, there is a little data about long term outcomes and response to therapy especially second line treatment.MethodsThis is a retrospective single center study from 2002 to 2013. The diagnosis of AIHA was made by positive direct Coombs’ test with clinical hemolysis and confirmed by Hematologist. Clinical data and long term outcome were reviewed and analyzed.ResultsDuring that period, 101 patients were reviewed, 77% were female, median age was 43 (15-83) years. The median hemoglobin level at diagnosis was 5.4 (2-10) g/dl. Primary AIHA was found in 61%. The secondary causes were SLE (64%), solid malignancy (13%), lymphoma (10%), drug (8%) and infection (5%). The secondary cause from SLE was commonly found in female (96%) (P<0.001). There was the difference of age between secondary cause from SLE (<50 years) and malignancy (>50 years) (p=0.013). These results showed the interesting data that secondary cause of AIHA needed to be searching especially SLE in young female and secondary cancer in elderly patients. Not only cause could be identified but also the specific treatment needed to be given according to secondary cause.Interestingly, most patients (96%) were initially response to steroid which was not different between primary and secondary AIHA. Second line treatments were required in 33 patients (33%). The indications were steroid dependent (58%), relapse (30%) and others (12%). The second line treatments were including cyclophosphamide (52%), azathioprine (21%), cyclosporine (6%), splenectomy (6%), danazol (6%) and others (9%). The overall response rate for second line was 93%. SLE group received second line therapy more than non SLE group (p<0.001). In the light of data from this study showed that this disease had a good prognosis in both frontline steroid and second line treatment. Relapse was occurred in 50 patients (50%). Most relapse occurred > 3 years after diagnosis (58%) and more common in SLE group (p<0.001). These findings illustrated the importance nature of the disease that need long follow up due to high relapse rate around half of patients.At the median follow up 53 months, the overall survival (OS) and event free survival (relapse and death) were 84% and 48%, respectively. The independent factor for decreasing OS was age >50 years with HR 3.09 (95% CI 1.09-8.73, p=0.03) and malignancy with HR 4.06 (95% CI 1.18-13.97, p=0.03). The only significant factor for relapse is age >50 years with HR 2.08 (95% CI 1.21-3.57, p = 0.008). Twenty patients were death. The common cause of death was sepsis (30%) due to heavily immunosuppressive treatment.ConclusionAIHA has good prognosis and long term survival especially in young patient without secondary malignancy. The search for secondary cause especially malignancy is important. Most patients have responded initially to steroid and high response rate to second line therapy. The most common cause of death was sepsis which related to treatment side effect. Carefully adjust and rapid taper immunosuppressant is considerable to avoid serious complication. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Autoimmune Hemolytic Anemia Following Influenza Virus Infection or Administration of Influenza Vaccine

Autoimmune hemolytic anemia (AIHA) is caused by hemolysis induced by the reaction of autoantibodies with red blood cells. AIHA is categorized as warm, cold, and mixed types and as primary or secondary. Certain viral infections lead to secondary AIHA; however, AIHA induced by influenza virus infection or the administration of influenza vaccine is infrequent. Here, we review relevant case reports in the English and Japanese literature.

Thirteen Year Retrospective Analysis Of Adult Patients With Autoimmune Hemolytic Anemia At The Cleveland Clinic: Responses To Therapy

Background and ObjectiveTreatment of autoimmune hemolytic anemia (AIHA) is complicated by disease heterogeneity and a high propensity for relapse. Most cases of AIHA are mediated by warm and cold-reactive autoantibodies, as defined by the direct antiglobulin test (DAT), and the treatment approach differs depending on the subtype. Evidence supporting use of specific AIHA treatments is limited to retrospective studies, small series, or case studies. To address this issue, a retrospective analysis of all patients with AIHA treated at the Cleveland Clinic from January 2000 to April 2013 was performed. MethodsPatients were included if they were ≥ 18 years old and presented with a new diagnosis or relapse of AIHA. Frequencies of complete responses (CR) or partial responses (PR) were recorded, and the median time to relapse measured using the Kaplan-Meier method. PR was defined as a nontransfused hemoglobin of ≥ 10 mg/dL with a hemoglobin increase of ≥ 2 mg/dL, while CR was defined as a nontransfused hemoglobin of ≥ 12 mg/dL, hemoglobin increase ≥ 2 mg/dL, and normalization of hemolytic markers. The duration of high dose and total corticosteroid therapy was recorded. Results180 patients were identified. 122 (69%) presented with warm antibody-mediated AIHA, 42 (24%) with cold antibody-mediated AIHA, 6 (3%) with mixed AIHA, and 8 (4%) with DAT negative AIHA. 97 (54%) were females. 61% of patients were between the ages of 50 and 80. Steroids were used in 82 patients with warm AIHA, 14 patients with cold AIHA, 3 patients with mixed AIHA, and 5 patients with DAT negative AIHA. Steroid response rates were 81% (27% CR, 54% PR) in warm AIHA, 85% (21% CR, 64% PR) in cold AIHA, 66% (33% CR, 33% PR) in mixed AIHA, and 80% (40% CR, 40% PR) in DAT negative AIHA. Median time to relapse was 14.3 months in warm AIHA, 3.6 months in cold AIHA, and 13 months in mixed AIHA; median time to relapse could not be determined in DAT negative AIHA. The mean duration of steroid use was 6.3 months in warm AIHA, 4.3 months in cold AIHA, 5.4 months in mixed AIHA, and 1.5 months in DAT negative AIHA. Rituximab was used in 23 patients with warm AIHA and 14 patients with cold AIHA, with overall response rates of 74% (17% CR, 57% PR) and 80% (27% CR, 53% PR), respectively. The median time to relapse was 8.5 months for warm and 55.2 months for cold AIHA after Rituximab treatment. In 15 patients with warm AIHA, splenectomy induced responses in 83% (33% CR, 50% PR) with a median time to relapse of 37.8 months. In 24 patients with warm AIHA and 7 patients with cold AIHA, treatment of the underlying disorder induced responses in 87% (33% CR, 54% PR) and 86% (29% CR, 57% PR), respectively. Median time to relapse was 22.1 months in warm AIHA and 16.5 months in cold AIHA. Other less commonly used treatments included immunosuppressants, intravenous immunoglobulin, and erythropoietin derivatives, with bortezomib and cold avoidance used in the cold AIHA group. When comparing warm and cold AIHA, no significant difference was found in total response rates to various treatments, including steroids (81% vs. 85%, p = 0.486), Rituximab (74% vs. 80%, p = 0.49), and treatment of the underlying condition (87% vs. 86%, p = 0.662). ConclusionsThis analysis demonstrated a surprisingly high response rate for corticosteroids in all subtypes of AIHA, though most responses in cold AIHA were partial and of relatively short duration. Rituximab was effective in both warm and cold antibody-mediated AIHA, with a high incidence of durable responses in the latter. Definitive treatment of the underlying condition was used less commonly, but was a highly effective approach for treating secondary AIHA. Splenectomy yielded durable remissions in most patients with warm AIHA. Disclosures:No relevant conflicts of interest to declare.

Serological characteristics and transfusion efficacy evaluation in 61 cases of autoimmune hemolytic anemia

This study was aimed to analyze the serological characteristics, efficacy and safety of incompatible RBC transfusion in patients with autoimmune hemolytic anemia (AIHA). The patients with idiopathic or secondary AIHA were analyzed retrospectively, then the serological characteristics and the incidence of adverse transfusion reactions were investigated, and the efficacy and safety of incompatible RBC transfusion were evaluated according to the different autoantibody type and infused different RBC components. The results showed that out of 61 cases of AIHA, 21 cases were idiopathic, and 40 cases were secondary. 8 cases (13.1%) had IgM cold autoantibody, 50 cases (82.0%) had IgG warm autoantibody, and 3 cases (4.9%) had IgM and IgG autoantibodies simultaneously. There were 18 cases (29.5%) combined with alloantibodies. After the exclusion of alloantibodies interference, 113 incompatible RBC transfusions were performed for 36 patients with AIHA, total efficiency rate, total partial efficiency rate and total inefficiency rate were 56.6%, 15.1% and 28.3%, respectively. Incompatible RBC transfusions were divided into non-washed RBC group and washed RBC group. The efficiency rate, partial efficiency rate and inefficiency rate in non-washed RBC group were 57.6%, 13.0% and 29.4%, respectively. The efficiency rate, partial efficiency rate and inefficiency rate in washed RBC group were 53.6%, 21.4% and 25.0%, respectively. There was no significant difference of transfusion efficacy (P > 0.05) in two groups. Incompatible RBC transfusions were also divided into IgM cold autoantibody group and IgG warm autoantibody group. The efficiency rate, partial efficiency rate and inefficiency rate in IgM cold autoantibody group were 46.2%, 30.8% and 29.4%, respectively. The efficiency rate, partial efficiency rate and inefficiency rate in IgG warm autoantibody group were 56.7%, 13.4% and 29.9%, respectively. There was no significant difference of transfusion efficacy (P > 0.05 ) in two groups. Hemolytic transfusion reaction was not observed in all incompatible RBC transfusions. It is concluded that the same ABO type of non-washed RBC transfusion and O type washed RBC transfusion are all relatively safe for the AIHA patients with severe anemia after the exclusion of alloantibodies interference. There is no significant difference of transfusion efficacy in two groups. The same ABO type of non-washed RBC transfusion is more convenient and efficient than washed RBC transfusion, and excessive use of type O RBCs can also be avoided.

Current Approaches for the Treatment of Autoimmune Hemolytic Anemia

Autoimmune hemolytic anemia (AIHA) is an infrequent group of diseases defined by autoantibody mediated red blood cell destruction. Correct diagnosis and classification of this condition are essential to provide appropriate treatment. AIHA is divided into warm and cold types according to the characteristics of the autoantibody involved and by the presence of an underlying or associated disorder into primary and secondary AIHA. Due to its low frequency, treatment for AIHA is largely based on small prospective trials, case series, and empirical observations. This review describes in detail the different treatment approaches for autoimmune hemolytic anemia. Warm antibody type AIHA should be treated with steroids, to which most patients respond, although relapse can occur and maintenance doses are frequently required. Splenectomy is an effective second line treatment and can provide long-term remission without medication. Rituximab is a useful alternative for steroid refractory patients, those requiring high maintenance doses and unfavorable candidates for surgery. Promising therapeutic modifications with this monoclonal antibody are emerging including drug combinations, lower doses, and long-term use. Primary cold agglutinin disease has been recognized as having a lymphoproliferative monoclonal origin. It is unresponsive to both steroids and splenectomy. Rituximab is currently the best therapeutic alternative for this condition, and several treatment regimens are available with variable responses.

Treatment of autoimmune hemolytic anemia at the departement of hematology of the UMC Ljubljana in the period from 2000–2011

Background: Autoimmune hemolytic anemia (AIHA) is an acquired hemolytic anemia and can be treated as an idiopathic or primary disease or can be associated with some other hematologic diseases (secondary). AIHA is a disease characterized by the presence of auto-antibodies directed against antigens on the red cell membrane, rare can the result of Coombs test be negative although there are all signs of AIHA present. Depending on the temperature at which auto-antibodies bind to the surface of an erythrocyte, we talk about AIHA with warm agglutinins and AIHA with cold agglutinins. Treatment is diverse as are also the causes of AIHA. The most important thing is to decrease the production of antibodies or to prevent the erythrocyte from decomposing with bound antibodies and to treat the disease symptomatically. Patients and methodes: With a retrospective analysis we searched through database of 70 patients with idiopathic (90 %) and secondary (10 %) autoimmune hemolytic anemia with warm (84.3 %) and cold (10 %) type agglutinin, who were treated at the Hematologic Department of the UMC Ljubljana during the period from 2000–2011. I processed the data with the SPSS program system. Results: Methylprednisolone was the first choice of treatment in 92. 5 % patients with primary and secondary AIHA with response rate of 79 % and 70.9 % complete remission rate. 22.7 % of the patients with complete remission after corticosteroids treatment , relapsed during the period of time and received a second-line treatment with cyclosporine (87 % response rate), rituximab or underwent splenectomy. Another attempt was made with methylprednisolone. The patients, who were refractory to the initial methylprednisolone treatment or required a higher maintenance dose, were treated in second line with cyclosporine (69 % response rate), rituximab (57 % responsee rate). One patient was treated successfully with mycophenolate mofetil and two patients, who were refractory to all other treatments, achieved a stable state of disease with splenectomy. The effective treatment for patients with cold agglutinin AIHA were corticosteroids and rituximab. We achieved an improvement of the condition in secondary AIHA when we treated the underlying disease. 6 % of all patients were refractory to any kind of treatment. Conclusions: Treatment with glucocorticoids is the most efficient treatment for patients with AIHA with warm and cold agglutinin. If the patients are refractory to the first-line therapy, we switch to a second-line therapy, which depends on etiology and concomitant diseases. Patients who are resistant to standard available treatments generally present with severe complications.

B‐cell receptor configuration and adverse cytogenetics are associated with autoimmune hemolytic anemia in chronic lymphocytic leukemia

The development of autoimmune hemolytic anemia (AIHA) in patients with chronic lymphocytic leukemia (CLL) is associated with specific biological features. The occurrence of AIHA was hereby investigated in a retrospective series of 585 CLL patients with available immunoglobulin heavy chain variable (IGHV) gene status. AIHA occurred in 73 patients and was significantly associated with an IGHV unmutated (UM) status (P < 0.0001) and unfavorable [del(17)(p13) and del(11)(q23)] cytogenetic lesions (P < 0.0001). Stereotyped HCDR3 sequences were identified in 29.6% of cases and were similarly represented among patients developing or not AIHA; notably, subset #3 was associated with a significantly higher risk of AIHA than the other patients (P = 0.004). Multivariate analysis showed that UM IGHV, del(17)(p13) and del(11)(q23), but not stereotyped subset #3, were the strongest independent variables associated with AIHA. Based on these findings, we generated a biological risk score for AIHA development according to the presence of none (low risk), one (intermediated risk), or two (high risk) of the independent risk factors. Overall, our data indicate that UM IGHV status and/or unfavorable cytogenetic lesions are associated with the risk of developing secondary AIHA in CLL patients and suggest a possible role of specific stereotyped B-cell receptor subsets in a proportion of cases.

Classification and therapeutic approaches in autoimmune hemolytic anemia: an update

Autoimmune hemolytic anemia (AIHA) is an uncommon autoantibody-mediated immune disorder that affects both children and adults. The diagnosis of AIHA relies mainly on the direct antiglobulin test, which is a highly sensitive and relatively specific test. The classification of AIHA is based on the pattern of the direct antiglobulin test and on the immunochemical properties of the autoantibody (warm or cold type), but also on the presence or absence of an underlying condition or disease (secondary vs primary AIHAs) that may have an impact on treatment and outcome. The distinction between AIHAs due to warm antibody (wAIHA) and AIHAs due to cold antibody is a crucial step of the diagnostic procedure as it influences the therapeutic strategy. Whereas corticosteroids are the cornerstone of treatment in wAIHA, they have no or little efficacy in cold AIHA. In wAIHA that is refractory or dependent to corticosteroids, splenectomy and rituximab are both good alternatives and the benefit–risk ratio of each option must be discussed on an individual basis. In chronic agglutinin disease, the most common variety of cold AIHA in adults, beyond supportive measures, rituximab given either alone or in combination with chemotherapy may be helpful. In this article, the classification of AIHA and the recent progress in therapeutics are discussed.

Clinical features and outcomes of autoimmune hemolytic anemia: a retrospective analysis of 32 cases

BackgroundThere has been no report on the clinical features or natural history of autoimmune hemolytic anemia (AIHA) in the Korean adult population. This study retrospectively analyzed the clinical characteristics and long-term outcomes of AIHA in the Korean adults.MethodsPatients newly diagnosed with AIHA between January 1994 and December 2010 at Chungnam National University Hospital were enrolled. Patient characteristics at diagnosis, response to treatment, and the natural course of the disease were documented.ResultsThirty-two patients (31 females and 1 male) with a median age of 48 years (range, 17-86) were enrolled. Of these, 21.9% were initially diagnosed with secondary AIHA. Thirteen patients (40.6%) were initially diagnosed with Evans' syndrome. Of the 29 patients who were placed on therapy, 27 (93.1%) showed a partial response or better. Nevertheless, 1 year after initiating treatment, 80% of the patients were still treatment-dependent. During follow-up (median length 14 months; range, 0.5-238), 14 of 25 patients (56.0%) who were initially diagnosed with primary warm antibody AIHA were found to have systemic lupus erythematosus (SLE). Median time to conversion to SLE was 8.0 months (95% CI, 4.3-11.7), and the probabilities of conversion at 12 and 24 months were 63% and 91%, respectively. Younger age (<60 years) and a positive fluorescent anti-nuclear antibody test were associated with a higher probability of SLE conversion (P=0.01 and P<0.001, respectively).ConclusionPrimary AIHA is rare. Regular, vigilant testing for SLE is required in patients initially diagnosed with AIHA.

Clinical Patterns and Hematological Spectrum in Autoimmune Hemolytic Anemia

Background:Autoimmune hemolytic anemia (AIHA) results from red cell destruction due to circulating autoantibodies against red cell membrane antigens. They are classified etiologically into primary and secondary AIHAs. A positive direct antiglobulin test (DAT) is the hallmark of diagnosis for AIHA.Methods and Results:One hundred and seventy-five AIHA cases diagnosed based on positive DAT were included in the study. The cases showed a female predilection (M: F = 1:2.2) and a peak incidence in the third decade. Forty cases were found to be due to primary AIHA, while a majority (n = 135) had AIHA secondary to other causes. The primary AIHA cases had severe anemia at presentation (65%) and more often showed a blood picture indicative of hemolysis (48%). Forty-five percent of primary AIHAs showed positivity for both DAT and indirect antiglobulin test (IAT). Connective tissue disorders were the most common associated etiology in secondary AIH A0 (n = 63).Conclusion:AIHAs have a female predilection and commonly present with symptoms of anemia. AIHA secondary to other diseases (especially connective tissue disorders) is more common. Primary AIHAs presented with severe anemia and laboratory evidence of marked hemolysis.

Expression of CD55 and CD59 on peripheral blood cells from systemic lupus erythematosus (SLE) patients

CD55 and CD59 are glycosylphosphatidylinositol-anchored proteins with complement inhibitory properties. CD55 inhibits the formation of C3 convertases, and CD59 prevents the terminal polymerisation of the membrane attack complex. It has been reported that SLE patients seems to have an acquired deficiency of these proteins associated with secondary autoimmune haemolytic anaemia and lymphopenia. The aim of this study was to evaluate the presence of altered CD55 and CD59 expression on peripheral blood cells from SLE patients. Flow cytometric analyses were performed on red and white blood cells from 23 SLE patients and 23 healthy controls. We observed more CD55- and CD59-lymphocytes ( p = 0.005 and p = 0.019, respectively), and CD59-granulocytes ( p = 0.045) in SLE patients than in controls. These results suggest there is an altered pattern of CD55 and CD59 expression on the peripheral blood cells of SLE patients, and it may play a role in the cytopenias in these patients.

Autoimmune hemolytic anemia

To study the clinico-hematological profile and treatment outcome in children suffering from auto immune hemolytic anemia (AIHA). Twelve children were diagnosed with auto immune hemolytic anemia over a period of four years. Direct antiglobulin test was positive in all the cases. Other causes of hemolytic anemia like thalassemia syndromes, hereditary spherocytosis, G6PD deficiency were excluded by appropriate tests. The children were followed up for 6 months to 4 years. The age ranged from 7 mth to 9 yr with a mean age of 4.51 yr. All patients had pallor as the presenting complaint followed by splenomegaly (83.3%), jaundice (66.7%), fever (50%) and bleeding manifestations (16.7%). 9 patients had primary disease and 3 had secondary disease. Tubercular infection was seen in 2 patients with secondary disease. Jaundice was seen equally in both the groups. Oral prednisolone produced remission in 83.3% cases. 4 patients (3 in primary and one in secondary group) had relapse after initial response. All responded to a second course of steroids but had subsequent relapses and developed a chronic course. Autoimmune hemolytic anemia is an uncommon cause of hemolytic anemia in children. Tubercular infection is an underlying pathology in cases of secondary autoimmune hemolytic anemia. Although oral steroids induce remission in most of the cases, relapses are common.

Monoclonal Antibodies: New Therapeutic Agents for Autoimmune Hemolytic Anemia?

Conventional treatment of autoimmune hemolytic anemia (AIHA) comprises corticosteroids and splenectomy and/or other immunosuppressive drugs for refractory/relapsed patients. Monoclonal antibodies (MoAbs) rituximab and alemtuzumab have gained widespread acceptance in the management of B-cell malignancies. More recently, they have been used to treat a number of autoantibody-mediated diseases, such as both idiopathic and secondary AIHA, with encouraging results. Herein we report an overview of the medical literature on the use of MoAbs to treat AIHA. The therapeutic mechanism of action of rituximab in the treatment of autoimmune diseases such as rheumatoid arthritis and lupus is currently a subject of considerable investigation. We have proposed that cell-associated IgG immune complexes, generated by the binding of rituximab to CD20 on B cells, may serve as decoys that attract FcgammaR-expressing effector cells and downregulate effector cell pathogenic action, thus reducing inflammation and tissue destruction in these diseases. We briefly review evidence that suggests that this immune complex decoy hypothesis plays a role in the therapeutic action of rituximab in AIHA, and we propose new measurements that should allow for a more complete evaluation of the importance of this mechanism in AIHA.

Diagnosis and treatment of autoimmune haemolytic anaemias in adults: a clinical review

Autoimmune haemolytic anaemia (AIHA) is an immune disorder caused by antibodies directed against unmodified autologous red cells. The disorder may be a primary (idiopathic) or a secondary disease. The diagnosis is based on the presence of anaemia, signs of haemolysis with reticulocytosis, low haptoglobin, increased lactate dehydrogenase, elevated indirect bilirubin, and a positive direct antiglobulin test (Coombs test). Sometimes, not all of these typical features are present. Most AIHA are caused by warm antibodies, whereas cold antibodies are less commonly detected. While half of the warm antibody-based AIHA are idiopathic anaemias, almost all cold antibody AIHA are secondary anaemias. Underlying diseases are Non Hodgkin's lymphomas and systemic autoimmune disorders, and less frequently organ transplantation, infections, or solid tumors. Moreover, AIHA is an important complication of treatment with nucleoside analogs. Most patients with AIHA require therapy. In warm antibody AIHA, standard first line therapy are glucocorticosteroids with or without high dose immunoglobulins, whereas splenectomy is considered second-line therapy. Response rates of primary AIHA to corticosteroid therapy are high. After initial remission, the dose should be tapered down slowly and with caution, and in some cases, low-dose maintenance therapy is required. The efficacy of standard therapy is low in secondary AIHA that develops in lymphoma patients, posttransplant patients, or tumor patients. Among other immunosuppressive treatments, rituximab (anti-CD20) appears to be highly effective in patients with warm antibody AIHA refractory to standard therapy. Mycophenolate mofetil is quite effective in AIHA patients with an underlying autoimmune or lymphoproliferative disease. Patients with cold agglutinins are refractory to steroids and splenectomy. Half of these patients may respond to rituximab, although responses usually are short-lived. Sometimes, AIHA that is associated with malignant lymphomas or tumors, disappears after successful anti-lymphoma or anti-tumor therapy.

Expression of CD47, CD35, CD55 and CD59 on Red Cells from Patients with Warm Autoimmune Hemolytic Anemia.

Autoimmune hemolytic anemia (AIHA) is defined as an increased destruction of red cells (RBC) in the presence of anti-RBC autoantibodies. CD47 is an integrin-associated protein expressed on all cells including RBCs. Animal models show that CD47 deficiency contributes to accelerated development of AIHA, while CD35 (CR1- complement receptor 1), CD55 (decay accelerating factor), and CD59 (membrane inhibitor of reactive lysis) are complement inhibitory proteins. Using flow cytometry analysis, in this study we evaluated the expression of CD47, CD35, CD55, and CD59 on RBCs of patients with warm AIHA before any treatment had been initiated. The study population consisted of 12 patients with active AIHA [M:F = 6:6, median age: 32 yrs (3 – 73)], and 20 healthy controls [M:F = 9:11, median age: 36 yrs (25 – 71)]. Ten patients presented idiopathic AIHA while 2 subjects had secondary AIHA (systemic lupus erythematosus and non-Hodgkin's lymphoma). At presentation the median Hb level was 6.6 mg/dL (range: 2.9 to 10 mg/dL), and the median absolute reticulocyte count was 324 × 109/L (range: 215 to 756 × 109/L). At the time of the analyses, all 12 patients had a positive direct antiglobulin test (DAT), 12 (100%) had IgG on their RBCs, 5 (41.7%) had IgG plus C3, and none had C3 alone. The strength of agglutination of all positive DATs showed a strong reaction. The RBC eluates prepared by a dichloromethane technique from the cell samples were positive in all 12 patients, but the retrieved autoantibodies were pan-reactive showing no specific reactivity. The mean fluorescence intensity (MFI) of the expression of CD47, CD35 and CD55 on RBCs of AIHA patients and healthy individuals were not statistically different (CD47 = 464.4 and 464.4; CD35 = 186.8 and 194.3; CD55 = 396.9 and 381.1, respectively). Four patients with life-threatening AIHA were treated with high dose of steroids and RBC transfusions, but 3 patients evolved to death. Two patients who died presented low CD55 expression on their RBCs at diagnosis. AIHA patients showed significant lower CD59 expression on RBCs than healthy controls (MFI = 512.3 ± 28.0 and 553.7 ± 36.6, P = .03). Although CD59 expression in patients that evolved to remission was not significantly different from healthy controls (MFI = 538.5 ± 14.4 and 553.7 ± 36.6), the expression of CD59 on RBCs of 3 AHAI patients who died were significantly lower than that seen on RBCs of healthy controls (MFI = 433.6 ± 69.6 and 553.7 ± 36.6, P = .0001). Although experimental studies have suggested that CD47 has a profound influence on the severity of AIHA in mice, our preliminary data on 12 patients with AIHA did not demonstrate difference on the expression of CD47 on RBCs of patients with warm AIHA or healthy indibiduals. On the other hand, complement regulatory proteins (CD35, CD55, and CD59) may play an important role in protecting RBC destruction through the activation of complement. Our results suggest that patients with life-threatening warm AIHA may present significant CD59 deficiency on their RBCs that may increase the susceptibility of cells to complement-mediated lysis resulting in severe clinical hemolysis.

Activity of Rituximab Monotherapy in Refractory Splenic Marginal Zone Lymphoma Complicated with Autoimmune Hemolytic Anemia

We describe the case of a 61-year-old patient with refractory splenic marginal zone lymphoma and secondary autoimmune hemolytic anemia, both successfully treated with rituximab. This case demonstrates that rituximab monotherapy might also be a valid therapeutic approach in marginal zone lymphoma and autoimmune hemolytic anemia after failure of first-line treatment. Maintenance therapy, although expensive, could be useful to improve event-free survival in patients with unfavorable clinical behavior.

Deficiency of red cell bound CD55 and CD59 in patients with systemic lupus erythematosus

CD55 and CD59 are glycosylphosphatidylinositol-anchored proteins with complement inhibitory properties. Autoimmune hemolytic anemia (AIHA) has been associated with antiphospholipid antibodies (APLA). The aim of this study was to evaluate the presence of APLA and its possible correlation with diminished CD55 and CD59 in red blood cells from patients with primary AIHA or secondary to systemic lupus erythematosus (SLE). Flow cytometric analyses were performed on CD55 and CD59 stained erythrocytes from 24 patients (primary AIHA, n=8; AIHA plus SLE, n=11; and SLE without AIHA, n=5) and 20 healthy controls. Antibodies to several phospholipids were detected in the sera by ELISA. Most patients with AIHA plus SLE and few with primary AIHA showed deficiency of either or both CD55 and CD59 expression and was not associated to the presence of APLA, while SLE patients exhibited a normal expression of these molecules. Although our findings showed CD55 and CD59 deficiency in primary or secondary AIHA, it appears that this defect plays a facilitator rather than a triggering role for the hemolytic process. Additionally, a role of anti-phospholipid antibodies as causative of this acquired defect is questionable.