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.

Management of autoimmune haemolytic anaemia in low-to-middle income countries: current challenges and the way forward.

Autoimmune haemolytic anaemia (AIHA) is a common term for several disorders that differ from one another in terms of aetiology, pathogenesis, clinical features, and treatment. Therapy is becoming increasingly differentiated and evidence-based, and several new established and investigational therapeutic approaches have appeared during recent years. While this development has resulted in therapeutic improvements, it also carries increased medical and financial requirements for optimal diagnosis, subgrouping, and individualization of therapy, including the use of more advanced laboratory tests and expensive drugs. In this brief Viewpoint review, we first summarize the diagnostic workup of AIHA subgroups and the respective therapies that are currently considered optimal. We then compare these principles with real-world data from India, the world's largest nation by population and a typical low-to-middle income country. We identify major deficiencies and limitations in general and laboratory resources, real-life diagnostic procedures, and therapeutic practices. Incomplete diagnostic workup, overuse of corticosteroids, lack of access to more specific treatments, and poor follow-up of patients are the rule more than exceptions. Although it may not seem realistic to resolve all challenges, we try to outline some ways towards an improved management of patients with AIHA.

Collage of cases and brief review of the laboratory diagnosis and molecular testing in autoimmune haemolytic anaemia.

Autoimmune haemolytic anaemia (AIHA) is an acquired heterogenous clinical entity with variable presentations like acute haemolysis or mild, chronic haemolysis compounded with acute exacerbation in winters or fatal uncompensated haemolysis. A step-wise approach to the diagnosis and characterisation of AIHA should be undertaken, firstly the diagnosis of haemolysis followed by the establishment of immune nature with the aid of direct agglutination tests (DAT). Simultaneously the other causes of immune haemolysis need to be excluded too. In light of advancements in diagnostics, a wide array of investigations can be used like absolute reticulocyte count, bone marrow responsiveness index to establish the evidence of haemolysis, sensitive gel technology, enhanced DAT assays, e.g., modified DAT with low ionic strength saline solution (LISS) at 4°C, DAT assays utilizing reagents such as anti-IgA and anti-IgM and DAT by flowcytometry, to detect RBC bound autoantibodies (Abs) and monospecific DAT to establish immune causes of haemolysis and characterisation of the autoantibodies. The compensatory role of bone marrow and synchronous pathologies like clonal lymphoproliferation, dyserythropoiesis, fibrosis are important factors in the evolution of the disease and aid in the customisation of treatment modalities. The laboratory work up should aim to diagnose underlying diseases like chronic lymphoproliferative disorders, autoimmune disorders and infectious diseases. Also, tests like autoimmune lymphoproliferative syndromes (ALPS) screening panel and Next-generation sequencing (NGS) panel for RBC membrane disorders, RBC enzymopathies, and congenital dyserythropoietic aneamia have found their place. It is incumbent upon the clinicians to use the all-available diagnostic modalities for the accurate diagnosis, prognostication and customisation of the therapy.

End-organ damage due to iron overload related to blood transfusion in an 11-year-old male.

Introduction and importance: Iron overload is an abnormal accumulation of iron in parenchymal organs that leads to end-organ damage which could be either primary or secondary to repeated blood cell transfusion, its manifestations usually start in middle age and rarely in childhood. Case presentation: The authors present a rare case of an 11-year-old male with iron overload secondary to repeated packed blood transfusion for autoimmune haemolytic anaemia. He developed type 1 diabetes, pituitary atrophy, and hepatic injury. It was difficult to maintain good control of his diabetes. He had a fatal acute circulatory collapse due to multiple organ failure. Clinical discussion: Iron overload is a clinical consequence of repeated blood transfusion that could result in end-organ damage, usually occurring in adolescence and is less likely at a young age as in our case. The accumulation of iron in the tissues causes diabetes mellitus due to the destruction of ß cells in the pancreas, and the increase in insulin resistance in the peripheral tissues. Conclusion: Iron overload is a serious complication of repeated blood transfusion, which could be prevented by early treatment with iron chelators at maximum tolerated doses.

A pilot study of orelabrutinib treatment in three cases of refractory/relapsed autoimmune haemolytic anaemia/Evans syndrome.

Currently, there is no effective treatment for refractory/relapsed (R/R) autoimmune haemolytic anaemia (AIHA), associated with poor quality of life. Bruton tyrosine kinase inhibitors have begun to be used in some autoimmune diseases. We initiated the clinical trial of orelabrutinib treatment on R/R AIHA/Evans Syndrome, which is in progress. The preliminary results showed that nine of the 12 enrolled patients responded to orelabrutinib treatment. Here, we reported three cases who have completed the treatment and were followed up for 6 months, achieving complete or partial remission. Orelabrutinib is expected to become a new second-line treatment for R/R AIHA/Evans syndrome.

'A kiss that took my legs away': a rare presentation of Epstein-Barr virus in the older population.

We present the case of a 70-year-old woman presenting with nausea, diarrhoea and a generalised rash. Initial blood tests revealed obstructive deranged liver function tests and low haemoglobin. A haemolysis screen revealed raised reticulocytes, low haptoglobin and a positive direct antiglobulin test. 6 days into her admission, she developed lower limb weakness and loss of sensation. MRI spine showed no significant findings. Cerebrospinal fluid showed raised white blood cell count and raised protein. Nerve conduction studies were normal. The clinical picture was in keeping with transverse myelitis. Autoimmune and viral screens were negative except for a single result which provided the unifying diagnosis: Epstein-Barr virus (EBV). She responded to high dose intravenous corticosteroids and her rehabilitation is ongoing. EBV should be considered even in the older population.

Sirolimus is effective for primary refractory/relapsed warm autoimmune haemolytic anaemia/Evans syndrome: a retrospective single-center study.

BACKGROUND: Some patients with warm autoimmune haemolytic anaemia (wAIHA) or Evans syndrome (ES) have no response to glucocorticoid or relapse. Recent studies found that sirolimus was effective in autoimmune cytopenia with a low relapse rate. METHODS: Data from patients with refractory/relapsed wAIHA and ES in Peking Union Medical College Hospital from July 2016 to May 2022 who had been treated with sirolimus for at least 6 months and followed up for at least 12 months were collected retrospectively. Baseline and follow-up clinical data were recorded and the rate of complete response (CR), partial response (PR) at different time points, adverse events, relapse, outcomes, and factors that may affect the efficacy and relapse were analyzed. RESULTS: There were 44 patients enrolled, with 9 (20.5%) males and a median age of 44 (range: 18-86) years. 37 (84.1%) patients were diagnosed as wAIHA, and 7 (15.9%) as ES. Patients were treated with sirolimus for a median of 23 (range: 6-80) months and followed up for a median of 25 (range: 12-80) months. 35 (79.5%) patients responded to sirolimus, and 25 (56.8%) patients achieved an optimal response of CR. Mucositis (11.4%), infection (9.1%), and alanine aminotransferase elevation (9.1%) were the most common adverse events. 5/35 patients (14.3%) relapsed at a median of 19 (range: 15-50) months. Patients with a higher sirolimus plasma trough concentration had a higher overall response (OR) and CR rate (p = 0.009, 0.011, respectively). At the time of enrolment, patients were divided into two subgroups that relapsed or refractory to glucocorticoid, and the former had poorer relapse-free survival (p = 0.032) than the other group. CONCLUSION: Sirolimus is effective for patients with primary refractory/relapsed wAIHA and ES, with a low relapse rate and mild side effects. Patients with a higher sirolimus plasma trough concentration had a higher OR and CR rate, and patients who relapsed to glucocorticoid treatment had poorer relapse-free survival than those who were refractory.

Detection of red cell alloantibody prior to overflow phenomenon in a case of warm AIHA secondary to Chronic Lymphocytic Leukemia and Myasthenia Gravis: A case report.

INTRODUCTION: Defects in the lymphoid system have been linked to immune dysregulation, which might explain why lymphoid neoplasms and immunological disorders tend to occur concurrently. Chronic Lymphocytic Leukemia (CLL), characterised by the accumulation of dysfunctional lymphocytes, is associated with autoimmune cytopenias such as autoimmune haemolytic anaemia (AIHA). Detection of underlying alloantibody in warm AIHA, is challenging for any transfusion medicine specialist. This report highlights the significance of overflow phenomenon in detection of alloantibody in a case of warm AIHA secondary to CLL and myasthenia gravis. CASE REPORT: A 56-year-old male with a history of myasthenia gravis and thymoma progressed to B-cell CLL presented with severe anaemia and thrombocytopenia leading to multiple red blood cell (RBC) transfusions in the last two months. Clinical profile and laboratory workup suggested features of AIHA, and subsequent immunohaematological workup hinted towards an impending overflow phenomenon due to differential reactivity pattern observed between serum and eluate with antibody screen/identification panel. The eluate was pan-reactive with an antibody screen/ identification panel, while the serum showed a discrete anti-C alloantibody pattern. A compatible and antigen-negative RBC unit was successfully transfused, followed by medical management. DISCUSSION: The overflow phenomenon in AIHA depends on antibody titre and its affinity for RBC antigens. In the index case, the impending 'overflow or spillover' of autoantibodies into the patient's serum allowed us to detect underlying alloantibody without performing allogeneic adsorption and transfuse antigen-negative and crossmatch compatible PRBC unit. CONCLUSION: This case emphasises the significance of understanding the overflow phenomenon in AIHA as it can guide a transfusion medicine specialist in the early detection and identification of underlying alloantibodies, which is crucial for appropriate transfusion management in AIHA. However, early presentation and timely workup, along with a high level of suspicion, is crucial to identify this phenomenon.

Risk of venous thromboembolism in autoimmune diseases: A comprehensive review.

Autoimmune diseases have specific pathophysiologic mechanisms leading to an increased risk of arterial and venous thrombosis. The risk of venous thromboembolism (VTE) varies according to the type and stage of the disease, and to concomitant treatments. In this review, we revise the most common autoimmune disease such as antiphospholipid syndrome, inflammatory myositis, polymyositis and dermatomyositis, rheumatoid arthritis, sarcoidosis, Sjogren syndrome, autoimmune haemolytic anaemia, systemic lupus erythematosus, systemic sclerosis, vasculitis and inflammatory bowel disease. We also provide an overview of pathophysiology responsible for the risk of VTE in each autoimmune disorder, and report current indications to anticoagulant treatment for primary and secondary prevention of VTE.

Anemia hemolítica autoinmune después de la infección por Covid 19 / Autoimmune Haemolytic Anaemia After Covid 19 Infection

Since its emergence in Wuhan province in late 2019, SARS-CoV-2 infection has affected more than 520 million people and caused the death of more than 6.2 million individuals. Despite rare, several haematological disorders have been observed and associated with SARS-CoV-2 infection, in particular, autoimmune haemolytic anaemia (AIHA). We present the case of a 71-year-old man with recent SARS-CoV-2 infection, presenting with 5 weeks evolution of asthenia and loss of 10% of body weight. From the initial study, normochromic normocytic anaemia stands out with haptoglobin consumption. Direct Coombs test was positive, with positive direct antiglobulin test for IgG4. The patient was admitted and started corticosteroids therapy with prednisolone 1 mg / kg. Given that the extended etiologic study was negative, covid 19 was assumed to be the trigger of the current clinical picture. During hospitalization, the patient presented a favourable evolution with recovery of haemoglobin value and absence of haemolysis. (AU)

Desde su aparición en la provincia de Wuhan a finales de 2019, la infección por SARS-CoV-2 ha afectado a más de 520 millones de personas y ha causado la muerte de más de 6,2 millones de individuos. A pesar de ser poco frecuentes, se han observado varios trastornos hematológicos asociados a la infección por SARS-CoV-2, en particular la anemia hemolítica autoinmune (AIHA). Presentamos el caso de un varón de 71 años con infección reciente por SARS-CoV-2, que presenta astenia de 5 semanas de evolución y pérdida del 10% del peso corporal. Del estudio inicial destaca anemia normocítica normocrómica con consumo de haptoglobina. El test de Coombs directo fue positivo, con antiglobulina directa positiva para IgG4.El paciente fue ingresado y se inició tratamiento con corticosteroides con prednisolona 1 mg / kg. Dado que el estudio etiológico ampliado fue negativo, se asumió que el covid 19 era el desencadenante del cuadro clínico actual. Durante la hospitalización, el paciente presentó una evolución favorable con recuperación del valor de hemoglobina y ausencia de hemólisis. (AU)

A case of cold agglutinin syndrome associated with chronic lymphocytic leukaemia harbouring mutations in CARD11 and KMT2D.

Cold agglutinin disease (CAD) is a rare cold autoimmune haemolytic anaemia (cAIHA) caused by IgM antibodies recognizing I antigens on erythrocytes. cAIHA is now mainly classified into two types: primary CAD and cold agglutinin syndrome (CAS). CAS develops in association with the underlying disease, which is most commonly malignant lymphoma. Recent studies have identified gene mutations in CARD11 and KMT2D in a high proportion of patients with CAD, which has led to recognition of CAD as an indolent lymphoproliferative disorder. We herein report a case of cAIHA without lymphocytosis or lymphadenopathy in whom bone marrow was infiltrated by a small population of clonal lymphocytes (6.8%) expressing cell surface markers consistent with chronic lymphocytic leukaemia (CLL). Whole-exome sequencing of bone marrow mononuclear cells revealed mutations in the CARD11 and KMT2D genes. This patient also had somatic hypermutation with overrepresentation of IGHV4-34, which is prevalent in CLL harbouring the KMT2D mutation. These observations suggest that CAS caused by early-phase CLL could be misinterpreted as primary CAD.

Maintenence rituximab following induction in autoimmune cytopenias.

About 50% of immune thrombocytopenia (ITP) patients respond to rituximab induction, but most relapse. The effectiveness of rituximab maintenance remains untested. This study included autoimmune cytopenia patients who had previously responded to rituximab induction but subsequently relapsed. After re-induction, patients received rituximab maintenance regimen consisting of a single 375 mg/m2 dose administered at 4 month intervals, with a maximum of 6 doses. Primary endpoints were duration of response and safety. Sixteen patients: ITP (9), autoimmune haemolytic anaemia (2), and Evans syndrome (5) received rituximab maintenance. 15/16 achieved complete response (CR); 8/15 CR + 1 partial reponse remain in remission. Median response: 43 months; estimated 5-year relapse-free >50%. Three developed hypogammaglobulinemia. Rituximab maintenance led to prolonged remissions in patients with autoimmune cytopenias who had previously responded to rituximab induction.

Uncovering the Unusual: A Case of Mixed Connective Tissue Disease With Rare Presentation, Atypical Complications, and Therapeutic Dilemmas.

Mixed connective tissue disease (MCTD) is an overlap syndrome characterized by features of systemic lupus erythematosus, scleroderma, and polymyositis, along with the presence of the U1RNP antibody. A 46-year-old female patient presented with severe anemia, cough, and breathlessness, and was diagnosed with cold agglutinin disease, a type of autoimmune hemolytic anemia (AIHA). Autoimmune workup revealed MCTD by positive antinuclear and U1RNP antibodies. She had bilateral miliary mottling on X-ray and a tree-in-bud appearance on high-resolution computed tomography of the thorax, which were suggestive of pulmonary tuberculosis. Standard therapy with steroids was not advisable. She was subsequently started on anti-tuberculosis treatment (anti-Koch's therapy), followed by steroid therapy and immunosuppressive therapy after three weeks. The patient responded well to treatment, but after two months, she developed cytomegalovirus (CMV) retinitis. Adult-onset CMV disease may occur as a result of primary infection, reinfection, or activation of a latent infection. Although not directly related, it can occur as an atypical association in the setting of immunosuppressive therapy. Morbidity and mortality are significantly increased in this population secondary to infectious potentiation: immunosuppression causes infections, and infections cause AIHA. The management of MCTD and secondary AIHA and immunosuppression poses a therapeutic challenge.

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

Objectives: The complement system is an important component of innate 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). Methods: 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. Results: 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. Conclusion: 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.

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.

Anemia hemolítica autoinmune / Autoimmune haemolytic anaemia

Las anemias hemolíticas autoinmunes (AHAI) son trastornos hematológicos adquiridos ocasionados por una destrucción periférica de eritrocitos incrementada, mediada por autoanticuerpos dirigidos frente a antígenos eritrocitarios. Se clasifican según etiología en primarias y secundarias, y según el tipo de anticuerpo detectado y temperatura de reacción en AHAI por anticuerpos calientes (AHAI-C) y AHAI por anticuerpos fríos (AHAI-F).El pilar del manejo en AHAI-C continúa siendo el tratamiento con glucocorticoides, y la adición precoz de rituximab ha demostrado buenos resultados en los últimos estudios. Las AHAI-F primarias se tratan principalmente con rituximab, solo o combinado con quimioterapia.En fase de desarrollo avanzado encontramos nuevos fármacos como los inhibidores de Syk, Ig anti-FcRn e inhibidores del complemento, que permitirán ampliar el arsenal terapéutico, especialmente en casos refractarios o recidivantes. (AU)

Autoimmune haemolytic anaemias (AIHA) are acquired haematological disorders caused by increased peripheral erythrocyte destruction mediated by autoantibodies against erythrocyte antigens. They classified according to aetiology into primary and secondary, and according to the type of antibody and reaction temperature into AIHA due to warm antibodies (w-AIHA) and AIHA due to cold antibodies (c-AIHA).The mainstay of management in w-AIHA remains glucocorticoid therapy, and the early addition of rituximab has shown good results in recent studies. Primary c-AIHA is mainly treated with rituximab, alone or in combination with chemotherapy.New drugs such as Syk inhibitors, anti-FcRn Ig and complement inhibitors are in advanced development and will expand the therapeutic arsenal, especially in refractory or relapsed cases. (AU)

Metabolomic profile in patients with primary warm autoimmune haemolytic anaemia.

Autoimmune haemolytic anaemia (AIHA) is a rare clinical condition with immunoglobulin fixation on the surface of erythrocytes, with or without complement activation. The pathophysiology of AIHA is complex and multifactorial, presenting functional abnormalities of T and B lymphocytes that generate an imbalance between lymphocyte activation, immunotolerance and cytokine production that culminates in autoimmune haemolysis. In AIHA, further laboratory data are needed to predict relapse and refractoriness of therapy, and thus, prevent adverse side-effects and treatment-induced toxicity. The metabolomic profile of AIHA has not yet been described. Our group developed a cross-sectional study with follow-up to assess the metabolomic profile in these patients, as well as to compare the metabolites found depending on the activity and intensity of haemolysis. We analysed the plasma of 26 patients with primary warm AIHA compared to 150 healthy individuals by mass spectrometry. Of the 95 metabolites found in the patients with AIHA, four acylcarnitines, two phosphatidylcholines (PC), asymmetric dimethylarginine (ADMA) and three sphingomyelins were significantly increased. There was an increase in PC, spermine and spermidine in the AIHA group with haemolytic activity. The PC ae 34:3/PC ae 40:2 ratio, seen only in the 12-month relapse group, was a predictor of relapse with 81% specificity and 100% sensitivity. Increased sphingomyelin, ADMA, PC and polyamines in patients with warm AIHA can interfere in autoantigen and autoimmune recognition mechanisms in a number of ways (deficient action of regulatory T lymphocytes on erythrocyte recognition as self, negative regulation of macrophage nuclear factor kappa beta activity, perpetuation of effector T lymphocyte and antibody production against erythrocyte antigens). The presence of PC ae 34:3/PC ae 40:2 ratio as a relapse predictor can help in identifying cases that require more frequent follow-up or early second-line therapies.

Autoimmune haemolytic anaemia and immune thrombocytopenia following SARS-CoV-2 and non-SARS-CoV-2 vaccination: 32 Years of passive surveillance data.

Autoimmune haemolytic anaemia (AIHA) and immune thrombocytopenia (ITP) are two uncommon haematologic autoimmune conditions that can rarely arise secondary to vaccination. Prior studies using the US Centers for Disease Control's (CDC) Vaccine Adverse Event Reporting System (VAERS) have demonstrated this infrequency, but contemporary data as well as comparison with current information regarding SARS-CoV-2 vaccination has not been assessed. In this study, we reviewed VAERS database reports from 1990 to 2022 to characterize the incidence and clinical and laboratory findings of non-SARS-CoV-2-associated AIHA and ITP and SARS-CoV-2 vaccine-associated AIHA and ITP. We discovered a total of 863 AIHA and ITP reports following vaccination with 15 non-SARS-CoV-2 and four SARS-CoV-2 vaccines submitted to the CDC VAERS database. AIHA and ITP reporting was low for both groups, with a large proportion excluded due to a lack of clinical details. ITP was reported the most frequently in both groups and was significantly more common with measles-mumps-rubella (MMR) vaccination (p < 0.001) in the non-SARS-CoV-2 group. AIHA and ITP cases were higher in the SARS-CoV-2 vaccine group, though ultimately still very infrequent. Autoimmune haematologic disease is vanishingly rare after immunization and rates are lower than in the general population according to passive reporting.

Diffuse large B-cell lymphoma and red cell autoimmunity: clinical role and pathogenesis.

Diffuse large B-cell lymphoma (DLBCL) is the most common form of B-cell non-Hodgkin lymphoma (B-NHL) with significant morbidity and mortality despite advancements in treatment. Lymphoma and autoimmune disease both result from breakdowns in normal cell regulatory pathways, and epidemiological studies have confirmed both that B-NHL is more likely to develop in the setting of autoimmune diseases and vice versa. Red cell immunity, as evidenced by direct antiglobulin test (DAT) positivity, has been linked to DLBCL and more recently the pathogenic causes of this association have begun to be better understood using molecular techniques. This project aimed to explore the relationship between red cell autoimmunity and DLBCL. DAT positivity was more common in DLBCL as compared to healthy controls (20.4% vs 3.7%, p=0.0005). Univariate analysis found a non-significant trend towards poorer overall survival in the DAT positive (DAT+) compared to the DAT negative (DAT-) groups (p=0.087). High throughput sequencing was used to compare mutations in DLBCL from DAT+ and DAT- patients. The most frequently mutated genes in 15 patient samples were KMT2D (n=13), MYOM2 (n=9), EP300 (n=8), SPEN (n=7), and ADAMTSL3 (n=7), which were mutated in both DAT+ and DAT- groups. BIRC3 (n=3), FOXO1 (n=3) and CARD11 (n=2) were found to be mutated only in samples from the DAT+ group. These gene mutations may be involved in disease development and progression, and potentially represent targets for future therapy. The immunoglobulin genotype IGHV4-34 is seen more frequently in DLBCL clones than in normal B cells and has intrinsic autoreactivity to self-antigens on red cells, which is largely mediated by two motifs within the first framework region (FR1); Q6W7 and A24V25Y.26 These motifs form a hydrophobic patch which determines red cell antigen binding and are frequently mutated away from self-reactivity in normal B cells. If this does not occur this may provide constant B cell receptor signalling which encourages lymphoma development, a theory known as antigen driven lymphomagenesis. As with previous studies, IGHV4-34 was over-represented (15.6%) in our DLBCL cohort. Furthermore, of 6 IGHV4-34-expressing DLBCL samples five had unmutated hydrophobic patch mutations providing further evidence for antigen-driven lymphomagenesis. Mutation analysis of these five samples demonstrated high frequency of mutations in several genes, including CREBBP and NCOR2. Further research could explore if mutations in CREBBP and NCOR2 work in conjunction with the preserved QW and AVY motifs to promote lymphomagenesis in IGHV4-34-expressing B cells, and if so, could guide future targeted therapy.

[Autoimmune haemolytic anaemia]. / Anemia hemolítica autoinmune.

Autoimmune haemolytic anaemias (AIHA) are acquired haematological disorders caused by increased peripheral erythrocyte destruction mediated by autoantibodies against erythrocyte antigens. They classified according to aetiology into primary and secondary, and according to the type of antibody and reaction temperature into AIHA due to warm antibodies (w-AIHA) and AIHA due to cold antibodies (c-AIHA). The mainstay of management in w-AIHA remains glucocorticoid therapy, and the early addition of rituximab has shown good results in recent studies. Primary c-AIHA is mainly treated with rituximab, alone or in combination with chemotherapy. New drugs such as Syk inhibitors, anti-FcRn Ig and complement inhibitors are in advanced development and will expand the therapeutic arsenal, especially in refractory or relapsed cases.