Autoimmune Hemolytic Anemia Patients Research Articles

Transfusion support and pre-transfusion testing in autoimmune haemolytic anaemia.

Autoimmune haemolytic anaemia (AIHA) is characterized by an increased destruction of red blood cells due to immune dysfunction and auto-antibody production. Clinical manifestations are mainly related to anaemia, which can become life-threatening in case of acute haemolysis. Aiming at counterbalancing severe anaemia, supportive treatments for these patients frequently include transfusions. Unfortunately, free serum auto-antibodies greatly interfere in pre-transfusion testing, and the identification of compatible red blood cell units for AIHA patients can be challenging or even impossible. Problems faced in pre-transfusion testing often lead to delay or abandonment of transfusions for AIHA patients. In this review, we discuss publications concerning global transfusion management in AIHA, with a focus on pre-transfusion testing, and practical clues to manage the selection of transfusion units for these patients. Depending on the degree of transfusion emergency, we propose an algorithm for the selection and laboratory testing of units to be transfused to AIHA patients.

A national survey of current immunohematologic testing practices for the diagnosis of autoimmune hemolytic anemia in India.

Autoimmune hemolytic anemia (AIHA) is a common term for several disorders that differ from one another in terms of etiology, pathogenesis, clinical features, and treatment. Management of patients with AIHA has become increasingly evidence-based in recent years. While this development has resulted in therapeutic improvements, it also carries increased requirements for optimal diagnosis using more advanced laboratory tests. Unfortunately, limited data are available from developing countries regarding the testing and transfusion management of patients with AIHA. The main objective of this survey was to explore the current immunohematologic testing practices for the diagnosis of AIHA in India. This online survey consisted of 30 questions, covering the place of work, the number of AIHA cases encountered in the 3 preceding years, testing method(s), transfusion management, and so forth. Individuals representing 89 laboratories completed the survey; only 78 of which responded that AIHA testing was performed in their facility's laboratory. The majority of respondents agreed that the most commonly affected age-group comprised individuals of older than 20 years, with a female preponderance. Regarding transfusion management, respondents indicated that transfusion with "best-match" red blood cell units remains the most common practice. Column-agglutination technology is used by 92 percent of respondents as the primary testing method. Although a monospecific direct antiglobulin test is available at 73 percent of the sites, most of them have limited access to other resources that could diagnose cold or mixed AIHA. Merely 49 percent of responding laboratories have the resources to perform adsorption studies for the detection of alloantibodies. Furthermore, three-cell antibody screening reagents are unavailable at 32 percent of laboratories. In 72 percent of centers, clinical hematologists would prefer to consult a transfusion medicine specialist before administering treatment to AIHA patients. There is unanimous agreement regarding the need for a national registry. The survey data indicate wide variability in testing practices for patients with AIHA in India. Future studies are needed to focus on the feasibility and cost-effectiveness of different testing strategies for developing countries.

Autoimmune Hemolytic Anemia Associated with Mature Ovarian Cystic Teratoma Containing Monoclonal Immunoglobulin G: A Case Report and Review of Literature

Background. Autoimmune hemolytic anemia (AIHA) associated with solid tumors such as mature cystic teratomas is rare and poorly understood. Here, we report a successfully treated case of secondary AIHA in a mature cystic teratoma containing antibodies against red blood cells. Case description. A 22-year-old woman was referred to our hospital with progressive anemia. Laboratory findings revealed hemolysis with a positive direct and indirect antiglobulin test. Imaging studies identified a left ovarian mass, suspected to be a mature cystic teratoma, which was later confirmed by histopathology after laparoscopic oophorocystectomy. The patient was treated with prednisolone, resulting in improved anemia. To examine the relationship between the tumor and AIHA, an indirect antiglobulin test was performed on the tumor contents. Stronger aggregations were observed at any concentration diluted by 10 times from 10 to 10,000 times of the tumor contents compared to the patient’s serum. Additionally, immunofixation electrophoresis of the tumor contents revealed the presence of monoclonal immunoglobulin G-κ. Conclusion. The presence of monoclonal IgG-κ in the tumor suggests intratumoral antibody production as a possible mechanism. Further research is necessary to elucidate the pathogenic relationship between such tumors and AIHA. The report also highlights the importance of considering secondary AIHA in patients with unexplained anemia and solid tumors.

Clinical profile and serological correlation with haemolysis in DAT-positive autoimmune haemolytic anaemia patients in Bangladesh

Discerning the type of autoimmune haemolytic anaemia (AIHA) is crucial for transfusion support and initiation of treatment. This study aimed to establish the clinical profile and serological character of red cell autoantibodies and to investigate the relationship with haemolysis in AIHA patients who were direct antiglobulin test (DAT)-positive. A total of 59 DAT-positive AIHA patients were included in this study. Clinical, laboratory and serological findings were evaluated to find the gradation of haemolysis and to investigate its correlation with age, sex, type of autoantibody and level of autoantibody. Study findings revealed that most patients (89.8%) had haemolysis, wherein moderate haemolysis (67.8%) was predominant. Weakness, palpitations, fever, pallor, tachycardia and splenomegaly were common among patients with severe and moderate haemolysis. The majority (66.1%) had an associated disorder. Warm autoantibody was the most common, followed by cold and mixed cases. The severity of haemolysis correlated strongly with the strength of the DAT reaction (Cramer V 0.636, p<0.001). These findings may be useful to clinicians while determining a treatment plan. The direct relationship between severity of haemolysis and strength of DAT needs further exploration in a large population to establish whether it can be used as a tool to formulate a treatment plan when assessing AIHA patients in low resourced countries.

Evaluation of hepatic toxicity in autoimmune hemolytic anemia (AIHA) and Evans syndrome patients: a single-center Egyptian study

IntroductionBenign auto-immune illnesses include Evans syndrome (ES) and auto-immune hemolytic anemia (AIHA). Despite being benign in nature, the patients’ livers are burdened by the disease’s chronicity and the accompanying problems beyond the course of treatment. An additional burden stems from HCV infection, of which a significant proportion of Egyptians are positive. The purpose of this study was to identify the hepatotoxicity risks and the variables that influence the prognosis and survival of patients with AIHA/ES. There are 126 AIHA patients in this observational study, which is retrospective. From June 2009 to March 2021, patients visited the Haematology Unit of the Oncology Centre in Egypt. One hundred and sixteen patients have available data.ResultsThere was no significant difference between primary and secondary AIHA groups as regards baseline hemoglobin (Hb), bilirubin, LDH, or reticulocyte count. Thirty-four patients (29.31%) had HCV-positive tests and 1 patient (0.9%) had HBV. There was no difference between HCV-positive and negative cases as regards mean Hb concentration, mean platelet, or immune markers (P > 0.05). AIHA patients with HCV-positive showed a significantly higher relapse rate (56%) than HCV-negative patients (32%) (P = 0.034). HCV positivity and low platelet counts at diagnosis were poor predictors for overall survival (OS) (P 0.022 and 0.04, respectively). Median OS was significantly better in patients with no viral hepatitis infection (1101 days, 95% CI 592–2068) than in patients with positive HCV infection (521, 95% CI 326–1325) (P = 0.019).ConclusionsAzathioprine is the least hepatotoxic in AIHA patients under treatment. Viral hepatitis represents a superadded damage to the liver besides AIHA concerning clinical characteristics and outcomes.

Molecular typing of Kell, Kidd, and Duffy antigens in direct antiglobulin test-positive autoimmune hemolytic anemia patients.

In autoimmune hemolytic anemia (AIHA) patients, conventional pretransfusion testing is difficult to interpret due to the presence of autoantibodies which may show panreactivity. Molecular phenotyping of red cell antigens could potentially be used to precisely match blood units, thereby reducing the need to perform intensive serologic laboratory testing, hence time delay in providing transfusion to such patients. The aim of this study is to perform the molecular typing for Kell, Kidd, and Duffy blood group antigens in direct antiglobulin test (DAT)-positive red blood cells of AIHA patients and provide corresponding antigen-matched blood for transfusion therapy. Blood samples from 50 normal blood donors and 30 DAT-positive AIHA patients were tested using standard serological techniques and polymerase chain reaction-based methods for Kell (K/k), Kidd (Jka/Jkb), and Duffy (Fya/Fyb) blood group systems. Five patients requiring blood transfusion were given donor blood units identical for Kell, Kidd, and Duffy antigens and followed up. Genotyping and phenotyping results were 100% concordant for normal blood donors. Serological phenotyping of minor red cell antigens showed varied degree of agglutination for AIHA patients. The molecular typing was able to detect the antigen frequency accurately in all samples. The results of genotyping were used to provide Kell-, Kidd-, and Duffy-matched blood for transfusion therapy to AIHA patients with no adverse reaction. Molecular blood group typing has proved immensely useful in the determination of actual antigen profile and hence in providing appropriate transfusion support in patients with AIHA reduced risk of transfusion reactions and alloimmunization.

A Single Center Experience for Clinical Evaluation of Paroxysmal Cold Hemoglobinuria and Donath-Landsteiner Testing

Introduction: Paroxysmal cold hemoglobinuria (PCH) is a rare form of autoimmune hemolytic anemia (AIHA), mainly affecting children. The diagnosis and management is challenging due to similarities to other causes for AIHA and limited availability to Donath-Landsteiner (DL) testing. Methods: In this single-center retrospective study, we aimed to characterize the clinical presentation and outcomes of PCH patients, defined as having positive Donath-Landsteiner antibodies, compared to a cohort of AIHA patients. Results: DL-positive patients were observed to have higher lactose dehydrogenase levels and lower reticulocyte counts compared to DL-negative patients, although this was not statistically significant. We also observed that using steroids in DL-positive patients did not significantly impact their recovery. Conclusions: Our findings support the limited published data on PCH patients and further prompt prompting larger multicenter studies to further characterize these patients so that they are more readily identified, especially in centers where DL antibody testing is not readily available.

Comparison of Time to Relapse between Low-Fixed Dose Versus Standard-Dose Rituximab in the Treatment of ITP, TTP, and AIHA

Background: The optimal Rituximab dosing regimen for the treatment of immune thrombocytopenia purpura (ITP), autoimmune hemolytic anemia (AIHA), or thrombotic thrombocytopenia purpura (TTP) has not been well established. To our knowledge, there has not been a randomized trial examining the time to relapse with the different Rituximab dosing regimens (low-fixed dose of 100 mg x 4 weekly doses versus standard dose of 375 mg/m2 x 4 weekly doses) in the treatment of ITP, TTP, and AIHA. Previous comparative studies have shown that the weekly low-fixed Rituximab dosing regimen has been shown to be just as effective in treating these diseases as demonstrated by similar response and duration of response. Therefore, we conducted a comparative analysis to evaluate the time to first recurrence after being treated with Rituximab. Methods: We collected clinical data from a single center of patients with diagnosis of ITP, TTP, or AIHA and were treated with 4 weekly low-fixed or standard dose Rituximab. Time to first recurrence was measured to compare if there was a significant difference between the two Rituximab dosing regimens. Kaplan-Meier time to recurrence estimates were used to generate time to recurrence curves. Results: Of the 30 patients analyzed, 10 patients were diagnosed with AIHA, 12 patients with ITP, and 8 with TTP. All patients had a complete response (CR) per the specific disease CR definition prior to first disease recurrence. 17 patients were treated with standard dose Rituximab and 13 patients were treated with low-fixed dose Rituximab. 17 patients did not have a recurrence in the selected time frame of the study. Recurrence was observed in 40% of the AIHA patients, 50% of the TTP patients, and 37.5% of TTP (P=0.8297). 47% females had a recurrence compared to 36% males (P=0.7084). Recurrence was observed in 61% patients who received the low-fixed dose Rituximab and 29% of patients who received the standard dose Rituximab (P=0.1376). The median time of recurrence was 16 and 27 months among patients who received low-fixed dose vs standard dose Rituximab, respectively (P=0.1914). Conclusions: The use of low-fixed dose Rituximab versus standard dose Rituximab for treatment of ITP, TTP, and AIHA appears to have a higher recurrence rate but did not meet statistical significance. The median time difference in recurrence was 9 months. This could potentially be significant in a larger study population. Further investigation through large, randomized controlled trials is needed to assess if there is a significant difference in recurrence rate and time to recurrence between the two Rituximab dosing regimens.

Transfusions in autoimmune hemolytic anemias: Frequency and clinical significance of alloimmunization.

Autoimmune hemolytic anemia (AIHA) may be associated with transfusion reactions and risk of alloimmunization. To evaluate the transfusion policy and rate of alloimmunization and its clinical significance in AIHA. Data from 305 AIHA patients followed at a reference hematologic Center in Milan, Italy from 1997 to 2022 were retrospectively/prospectively collected (NCT05931718). Overall, 33% patients required transfusions with a response rate of 83% and eight transfusion reactions (7%), none hemolytic. Alloantibodies were detected in 19% of patients, being associated with higher transfusion burden (p=0.01), lower Hb increase post-transfusion (p=0.05), and transfusion reactions (p=0.04). Along decades, the rate of RBC transfusions decreased from 53% to 20% and that of alloimmunization dropped from 30% to 6% likely due to the adoption of prestorage leukoreduction, the use of more restrictive Hb thresholds, and the implementation of molecular typing. Severe symptomatic AIHA may be safely transfused provided appropriate matching of patients and donors.

Safety and efficacy of least incompatible red cell units in autoimmune hemolytic anemia: A prospective analysis of hemoglobin increment and hemolysis after transfusion

Abstract BACKGROUND: Red blood cell (RBC) transfusion is a challenge in autoimmune hemolytic anemia (AIHA) patients due to pan reactivity and crossmatch incompatibility. Apprehensions about the safety and efficacy of least incompatible (best-matched) red cells are common among treatment providers. AIM: A primary objective was to study the effect of RBC transfusion on hemolysis parameters (hemoglobin [Hb], serum bilirubin, serum lactate dehydrogenase [LDH], and reticulocyte count) in AIHA patients. SETTINGS AND DESIGN: This was a hospital-based prospective observational study conducted on 40 AIHA patients attending the department of internal medicine from January 2020 to July 2021 who received RBC Transfusions. METHODOLOGY: Blood samples were collected for evaluating hemolysis parameters: Hb, reticulocyte count, serum bilirubin, and serum LDH before transfusion and compared with the same parameters within 12 h after transfusion. STATISTICAL ANALYSIS: Analysis was done by SPSS software Version 16. Paired t-test was used to find the effect of RBC transfusion on hemolysis parameters and independent t-test was used to compare the effect of compatible and incompatible RBC transfusions. RESULTS: The median age at presentation was 42 years with a female preponderance (67.5%). Majority of the patients belong to warm AIHA (73%) and Secondary AIHA (60%). Compatible RBC units could be provided to 57% of cases and 43% were transfused with the least incompatible units. The mean pretransfusion Hb in AIHA was 4.3 mg/dl and showed a statistically significant increase after transfusion (P &lt; 0.001). A significant difference between reticulocyte levels of compatible and incompatible transfusions was noted with a P = 0.025. No statistically significant difference noticed in Hb, serum LDH, serum bilirubin levels between compatible and incompatible RBC transfusions. CONCLUSION: RBC transfusions in AIHA patients provide Hb increment similar to other anemic patients. RBC transfusions should not be denied in AIHA patients in view of hemolysis and best-matched units also may be transfused in indicated cases.

Insights into Large Granular Lymphocytic Leukemia-Associated Hemolytic Anemia: Clinical Associations, Therapeutic Responses, and Optimal Management Strategies from a Large Institutional Study

Introduction Large granular lymphocytic leukemia (LGLL) is characterized by a clonal proliferation of cytotoxic CD8+ T or CD3− natural killer (NK) cells. The disease typically presents with neutropenia in about 39-62% of patients, and anemia in up to 50% 1. While most cases of anemia in LGLL resemble pure red cell aplasia and present as reticulocytopenic and malproductive, we have also observed rare instances of hemolytic anemia (HA) with a high reticulocyte count. This unique and atypical presentation has prompted us to investigate the clinical features of LGLL with HA, aiming to gain insights into the pathogenesis of both conditions. In light of this, we conducted a comprehensive and systematic study of hemolysis within the context of LGLL. Methods We retrospectively examined clinical and molecular features of a large series of LGLL cases (n=262) diagnosed and managed at the Cleveland Clinic Foundation from 1998 to 2023 to identify those experiencing hemolysis. LGLL diagnosis was based on the presence of i) elevated LGL count (&amp;gt;0.5 × 10^9/L), ii) clonal TCR rearrangement, iii) VB expansion, iv) flow cytometric detection of aberrant CTL or NK cell proliferation and v) STAT3/5 mutation and vi) LGLL infiltration of the marrow. A diagnosis was established with &amp;gt;4/6 criteria fulfilled. HA diagnosis was based on evidence at any time during clinical course of laboratory signs of hemolysis. Results Overall, the median age at diagnosis was 63 years (IQR: 55-72) with a M:F ratio of 0.5. Majority of patients had been diagnosed with T-LGLL (n=225), whereas 22 had NK-LGLL. In 32/262 cases (12%), clinical and laboratory features were asserted to establish the diagnosis of HA. Of these, 22 (68%) had T-LGLL and 8 (25%) had NK-LGLL (Table 1). When comparing HA patients to the rest of the cohort, we observed a higher proportion of NK-LGLL cases with HA (25% vs 8%, p &amp;lt; 0.001). HA presented as the initial sign of the disease in majority of patients (88%), and 40% of them required transfusion support based on the degree of anemia and hemodynamics. The direct anti-globin test was positive in 30% of cases. Warm autoimmune HA (AIHA) was observed in 23% of patients, cold agglutinin disease in 7%, and one patient had both. Among 7 patients with IgG AIHA, 5 were also positive for anti-C3b, C3d antibodies. Two-thirds of the patients had multilineage cytopenia. Coexisting B-cell dyscrasia was identified in 13 cases, more frequently in HA than in those without (40% vs 26%, p=0.048), and autoimmune disorders in 8 cases (25%). HA in LGLL was also more likely to be associated with presence of splenomegaly (59% vs 21%, p&amp;lt;0.00001) and polyclonal hypergammaglobulinemia (22% vs 8%, p=0.02). Notably, STAT3 mutations were present in a higher proportion of HA patients (38% vs 22%, p=0.02), whereas median LGLL clone size (%) was similar between groups (68% vs 53%, p=0.5). Overall, 77% of HA patients received treatment, and 16% had still evidence of hemolysis at a median follow-up of 82 months. The majority (47%) were treated with steroids with a positive, albeit transient response (7 out of 15 treated). Other first-line treatments and their corresponding median duration of response (months) included cyclosporine (n=7, 72 months), cyclophosphamide (n=5, 72 months), IVIG (n=1, 16 months), and methotrexate (n=11, 21 months). Subsequent lines of therapy included campath (n=9), cyclosporine (CSA) (n=4), cyclophosphamide (n=9), intravenous immunoglobulin (IVIG) (n=2), MTX (n=4), rituximab (n=1), sirolimus (n=1), tacrolimus (n=2), and tofacitinib (n=2). Splenectomy was performed as definitive treatment for refractory cytopenia in 9 patients, with a durable response in 5 patients at last follow-up ( Fig.1). Conclusions Based on this large series, our study illustrates that LGLL represents a clonal lymphoproliferative disorder that is closely linked to HA. Notably, NK-LGLL cases exhibited a stronger association with HA. Our observations indicate that treatment with steroids and other therapeutic agents resulted in positive responses in a fraction of patients, while splenectomy demonstrated the most enduring response. These significant findings contribute substantially to advancing our comprehension of LGLL-associated HA and its optimal management strategies. AIHA in patients with LGLL points towards a global immune dysfunction in this disease beyond clonal cytotoxic T/NK cell expansion.

Clinical, immunological features, treatments, and outcomes of autoimmune hemolytic anemia in patients with RAG deficiency

Clinical, immunological features, treatments, and outcomes of autoimmune hemolytic anemia in patients with RAG deficiency

Severe autoimmune hemolytic anemia; epidemiology, clinical management, outcomes and knowledge gaps.

Autoimmune hemolytic anemia (AIHA) is an acquired hemolytic disorder, mediated by auto-antibodies, and has a variable clinical course ranging from fully compensated low grade hemolysis to severe life-threatening cases. The rarity, heterogeneity and incomplete understanding of severe AIHA complicate the recognition and management of severe cases. In this review, we describe how severe AIHA can be defined and what is currently known of the severity and outcome of AIHA. There are no validated predictors for severe clinical course, but certain risk factors for poor outcomes (hospitalisation, transfusion need and mortality) can aid in recognizing severe cases. Some serological subtypes of AIHA (warm AIHA with complement positive DAT, mixed, atypical) are associated with lower hemoglobin levels, higher transfusion need and mortality. Currently, there is no evidence-based therapeutic approach for severe AIHA. We provide a general approach for the management of severe AIHA patients, incorporating monitoring, supportive measures and therapeutic options based on expert opinion. In cases where steroids fail, there is a lack of rapidly effective therapeutic options. In this era, numerous novel therapies are emerging for AIHA, including novel complement inhibitors, such as sutimlimab. Their potential in severe AIHA is discussed. Future research efforts are needed to gain a clearer picture of severe AIHA and develop prediction models for severe disease course. It is crucial to incorporate not only clinical characteristics but also biomarkers that are associated with pathophysiological differences and severity, to enhance the accuracy of prediction models and facilitate the selection of the optimal therapeutic approach. Future clinical trials should prioritize the inclusion of severe AIHA patients, particularly in the quest for rapidly acting novel agents.

The Role of the Spleen and the Place of Splenectomy in Autoimmune Hemolytic Anemia-A Review of Current Knowledge.

Autoimmune hemolytic anemia (AIHA) is a rare, very heterogeneous, and sometimes life-threatening acquired hematologic disease characterized by increased red blood cell (RBC) destruction by autoantibodies (autoAbs), either with or without complement involvement. Recent studies have shown that the involvement of T- and B-cell dysregulation and an imbalance of T-helper 2 (Th2) and Th17 phenotypes play major roles in the pathogenesis of AIHA. AIHA can be primary (idiopathic) but is more often secondary, triggered by infections or drug use or as a part of other diseases. As the location of origin of autoAbs and the location of autoAb-mediated RBC clearance, as well as the location of extramedullary hematopoiesis, the spleen is crucially involved in all the steps of AIHA pathobiology. Splenectomy, which was the established second-line therapeutic option in corticosteroid-resistant AIHA patients for decades, has become less common due to increasing knowledge of immunopathogenesis and the introduction of targeted therapy. This article provides a comprehensive overview of current knowledge regarding the place of the spleen in the immunological background of AIHA and the rapidly growing spectrum of novel therapeutic approaches. Furthermore, this review emphasizes the still-existing expediency of laparoscopic splenectomy with appropriate perioperative thromboprophylaxis and the prevention of infection as a safe and reliable therapeutic option in the context of the limited availability of rituximab and other novel therapies.

A single center experience for clinical evaluation of paroxysmal cold hemoglobinuria and Donath-Landsteiner testing.

Paroxysmal cold hemoglobinuria (PCH) is a rare form of autoimmune hemolytic anemia (AIHA), mainly affecting children. The diagnosis and management are challenging due to similarities to other causes for AIHA and limited availability to Donath-Landsteiner (DL) testing. In this single-center retrospective study, we aimed to characterize the clinical presentation and outcomes of PCH patients, defined as having positive Donath-Landsteiner antibodies, compared to a cohort of AIHA patients. DL-positive patients were observed to have higher lactate dehydrogenase levels and lower reticulocyte counts compared to DL-negative patients, although this was not statistically significant. We also observed that using steroids in DL-positive patients did not significantly impact their recovery. Our findings support the limited published data on PCH patients and further prompt larger multicenter studies to further characterize these patients so that they are more readily identified, especially in centers where DL antibody testing is not readily available.

Genome-wide DNA methylation profiles analysis in primary warm autoimmune hemolytic anemia patients

ABSTRACTBackgroundAutoimmune hemolytic anemia (AIHA) is caused by auto-antibodies, secreted by overactivated B cells, directed against self-red blood cells, resulting in hemolysis. It found that aberrant DNA methylation in B cells can induce the production of autoantibodies. Therefore, we attempted to explore if similar aberrant DNA methylation occur in AIHA patients.MethodsA 49-year-old female wAIHA patient and a 47-year-old female healthy control (HC) were enrolled. Peripheral blood (PB) B cells DNA was extracted. After constructing genomic libraries, bisulfite genomic sequencing (BSP) and DNA methylation profiles were analyzed. BSP was verified using PB B cells from 10 patients with hemolysis, 10 patients with hemolytic remission, and 10 healthy controls (HCs) by Methylation-specific PCR.ResultsTotal DNA methylation of whole-genome C bases (4.8%) and CG type bases (76.8%) in wAIHA patient were lower than those in the HC (5.3 and 82.5%, respectively) (p = 0.022 and p < 0.001). DNA methylation of C bases and CG type bases in whole-genome regulatory elements, such as coding sequence, up2Kb and down2Kb in the patient were also lower than those in the HC (p = 0.041, p = 0.038, and p = 0.029). 30,180 DNA-methylated regions (DMRs) on all 23 chromosomes were identified. DMR-related genes were mainly involved in the Rap1, phospholipase D, HIF-1, calcium, vascular endothelial growth factor (VEGF) and Ras signaling pathways.ConclusionThe DNA methylation spectrum of B cells in AIHA patients is different from that of HC, and the proportion of hypo-methylation regions is higher than that of HC. DMR-related genes are mainly related to some signaling pathways.

Infrequent Thrombotic Complications in Japanese Patients with Warm Autoimmune Hemolytic Anemia.

Objective Patients with autoimmune hemolytic anemia (AIHA) are considered to be at an increased risk of thrombosis, and prophylaxis for venous thromboembolism (VTE) is often recommended. However, the occurrence of thrombosis in Asian patients has not been specifically studied. Thrombotic complications and features of Japanese warm AIHA (WAIHA) patients were studied to see if Japanese patients were at an increased risk of thrombosis and should receive prophylaxis for VTE. Patients and Methods Forty-seven consecutive patients with warm WAIHA were retrospectively studied. Twenty-nine patients were diagnosed as primary cases and 18 as secondary cases, and 10 patients were diagnosed with Evans syndrome. Results No patient presented with thrombosis, and over a median observation period of 15 months, 3 patients had ischemic cerebral vascular accidents. However, all three of those patients had other known risks for thrombosis, with only one taking thrombotic prophylaxis. No venous thrombosis occurred in any patients during the follow-up period. There was no mortality associated with thrombosis. D-dimer levels were often elevated in patients with WAIHA, indicating that the coagulation was activated in a considerable number of patients, but not to such a level as to be associated with clinically overt thrombosis. Conclusion Thrombotic complications occur infrequently in Japanese WAIHA patients, and these individuals do not appear to be at a particularly increased risk of thrombosis because of WAIHA. The indication of VTE prophylaxis should be determined individually, considering other risks.

Role of direct antiglobulin test in assessing the severity of extravascular hemolysis in autoimmune hemolytic anemia – analysis from a cross-sectional study

Background: Autoimmune hemolytic anemia (AIHA) is an immune hemolytic disease characterized by hemolysis and anemia which results from increased red cell destruction due to auto antibodies directed against self-antigens on red cells. Clinical characteristics and potential associated hemolysis in AIHA can greatly depend on the serological characteristics. Aims and Objectives: This study was done to find out the association of Grade of polyspecific Direct Antiglobulin test (DAT), complement involvement and immunoglobulin G (IgG) subclass with severity of hemolysis in an AIHA patients. Materials and Methods: This was a cross-sectional study conducted for a period of 18 months from March 1, 2012, to August 31, 2013. Fifty consecutive AIHA patients diagnosed by a positive DAT in EDTA anticoagulated blood samples using poly specific anti human globulin reagent were followed up and results of various immunohematological tests such as polyspecific and monospecific DAT, IgG subtyping, and thermal amplitude were performed. Hematological and biochemical parameters such as hemoglobin, percentage of reticulocyte, total serum bilirubin, and serum lactate dehydrogenase also were recorded. Data were analyzed using SPSS v17. Results: Majority of patients were belonging to 31–40 year age group and there was a remarkable female predilection. Secondary AIHA was more common (56%) than primary. SLE was identified as the most common underlying disorder in secondary AIHA. Majority (46%) were Grade 4 DAT positive. Predominant autoantibody identified was IgG (52%). Of the total IgG positive cases, IgG1 was the predominant subclass. C3d alone was detected in 18% of cases and C3d and IgG together in 30%. About 48% of our patients were of warm type, 32% mixed type, and 20% cold type. About 80% of the study population were treated with steroids alone. A small percentage of cases (16%) needed immunosuppressant in addition to steroids and still a smaller percentage (4%) needed splenectomy. Higher grades of DAT positivity were associated with more severe degree of anemia and hyperbilirubinemia. The study also demonstrated a positive correlation between DAT grade and severity of hemolysis. Conclusion: AIHA patients in this study were predominantly of Warm AIHA with more of IgG1 involvement. A significant association is found between higher grades of DAT results and severity of anemia and jaundice in this study group. A positive correlation exists between grades of DCT and hemolysis as well.

The potential of metabolomics as a predictive guide for clinical management in autoimmunity against red blood cells.

Autoimmune-responses leading to increased destruction of red blood cells occur in autoimmune haemolytic anaemia (AIHA). The pathophysiology of AIHA is multifactorial and not fully understood, and clinically it remains challenging to manage relapsed and treatment-refractory cases. Rabelo and colleagues conduct metabolomic profiling in plasma of 26 patients with primary warm AIHA, with consideration of haemolytic activity and relapse occurrence. They identify distinct metabolites to be increased in primary warm AIHA patients, thereby providing an encouraging basis for further validation and exploration of metabolomic profiling as a predictive tool for the management of AIHA. Commentary on: Rabelo et al. Metabolomic profile in patients with primary warm autoimmune haemolytic anaemia. Br J Haematol 2023;200:140-149.

The contribution of the alternative pathway in complement activation on cell surfaces depends on the strength of classical pathway initiation.

The complement system is an important component ofinnate immunity. The alternative pathway (AP) amplification loop is considered an essential feed forward mechanism for complement activation. However, the role of the AP in classical pathway (CP) activation has only been studied in ELISA settings. Here, we investigated its contribution on physiologically relevant surfaces of human cells and bacterial pathogens and in antibody-mediated complement activation, including in autoimmune haemolytic anaemia (AIHA) setting with autoantibodies against red blood cells (RBCs). We evaluated the contribution of the AP to complement responses initiated through the CP on human RBCs by serum of AIHA patients and recombinant antibodies. Moreover, we studied complement activation on Neisseria meningitidis and Escherichia coli. The effect of the AP was examined using either AP-depleted sera or antibodies against factor B and factor D. We show that the amplification loop is redundant when efficient CP activation takes place. This is independent of the presence of membrane-bound complement regulators. The role of the AP may become significant when insufficient CP complement activation occurs, but this depends on antibody levels and (sub)class. Our data indicate that therapeutic intervention in the amplification loop will most likely not be effective to treat antibody-mediated diseases. The AP can be bypassed through efficient CP activation. The AP amplification loop has a role in complement activation during conditions of modest activation via the CP, when it can allow for efficient complement-mediated killing.