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.

Laparoscopic excision of accessory spleen for recurrent autoimmune hemolytic anemia after splenectomy: a case report

BACKGROUND

Splenectomy is indicated in cases of autoimmune hemolytic anemia (AIHA), which are refractory to medical management. In post-splenectomy, there exists a theoretical risk of AIHA recurrence, especially if an accessory spleen undergoes compensatory hypertrophy. In this context, we present a unique case of recurrent AIHA managed through laparoscopic excision of the accessory spleen (LEAS).

CASE PRESENTATION

A 60-year-old male underwent laparoscopic splenectomy (LS) for AIHA refractory to standard medical therapies. Following the surgery, there was a marked improvement in hemolytic anemia symptoms, and oral steroid therapy was terminated 7 months post-LS. Nonetheless, a year after the LS, the patient exhibited a marked decline in hemoglobin levels, dropping to a concerning 5.8 g/dl, necessitating the reintroduction of oral steroids. A subsequent contrast-enhanced computed tomography (CT) scan unveiled an enlarged accessory spleen. The patient then underwent LEAS, during which the accessory spleen, obscured within adipose tissue, proved challenging to visualize laparoscopically. This obstacle was surmounted utilizing intraoperative ultrasonography (US), enabling successful excision of the accessory spleen. The post-surgical period progressed without complications, and the steroid dosage was reduced to one-twelfth of its initial preoperative quantity.

CONCLUSIONS

Recurrent AIHA can be instigated by post-splenectomy compensatory hypertrophy of the accessory spleen. Ensuring comprehensive splenic tissue excision is crucial in AIHA management to obviate recurrent stemming from hypertrophic remnants. In scenarios of AIHA recurrence tied to an enlarged accessory spleen, LEAS stands as a viable and effective therapeutic modality.

Autoimmune Hemolytic Anemias: Classifications, Pathophysiology, Diagnoses and Management

Autoimmune hemolytic anemias (AIHAs) are conditions involving the production of antibodies against one's own red blood cells (RBCs). These can be primary with unknown cause or secondary (by association with diseases or infections). There are several different categories of AIHAs recognized according to their features in the direct antiglobulin test (DAT). (1) Warm-antibody AIHA (wAIHA) exhibits a pan-reactive IgG autoantibody recognizing a portion of band 3 (wherein the DAT may be positive with IgG, C3d or both). Treatment involves glucocorticoids and steroid-sparing agents and may consider IVIG or monoclonal antibodies to CD20, CD38 or C1q. (2) Cold-antibody AIHA due to IgMs range from cold agglutinin syndrome (CAS) to cold agglutin disease (CAD). These are typically specific to the Ii blood group system, with the former (CAS) being polyclonal and the latter (CAD) being a more severe and monoclonal entity. The DAT in either case is positive only with C3d. Foundationally, the patient is kept warm, though treatment for significant complement-related outcomes may, therefore, capitalize on monoclonal options against C1q or C5. (3) Mixed AIHA, also called combined cold and warm AIHA, has a DAT positive for both IgG and C3d, with treatment approaches inclusive of those appropriate for wAIHA and cold AIHA. (4) Paroxysmal cold hemoglobinuria (PCH), also termed Donath-Landsteiner test-positive AIHA, has a DAT positive only for C3d, driven upstream by a biphasic cold-reactive IgG antibody recruiting complement. Although usually self-remitting, management may consider monoclonal antibodies to C1q or C5. (5) Direct antiglobulin test-negative AIHA (DAT-neg AIHA), due to IgG antibody below detection thresholds in the DAT, or by non-detected IgM or IgA antibodies, is managed as wAIHA. (6) Drug-induced immune hemolytic anemia (DIIHA) appears as wAIHA with DAT IgG and/or C3d. Some cases may resolve after ceasing the instigating drug. (7) Passenger lymphocyte syndrome, found after transplantation, is caused by B-cells transferred from an antigen-negative donor whose antibodies react with a recipient who produces antigen-positive RBCs. This comprehensive review will discuss in detail each of these AIHAs and provide information on diagnosis, pathophysiology and treatment modalities.

Autoimmune cytopenias in patients with malignant lymphoma: A multicenter report by the Polish Lymphoma Research Group

BACKGROUND

Autoimmune cytopenias (ACs), including immune thrombocytopenia (ITP), autoimmune hemolytic anemia (AIHA) and autoimmune granulocytopenia, are rare complications observed in lymphoma patients. They may appear before, during or after lymphoma diagnosis, whether the patients had disease progression or not.

OBJECTIVES

This study aims to correlate ACs with lymphoma type, disease course and prognosis. We performed a multicenter retrospective analysis of adult patients with malignant lymphoma and ACs coexistence diagnosed and treated in centers aligned with the Polish Lymphoma Research Group (PLRG).

MATERIAL AND METHODS

The analysis covers the years 2016-2022 and included 51 patients comprised of 23 women and 28 men. Of these, 35 patients were diagnosed with AIHA, 15 patients with ITP and 1 patient with both AIHA and ITP.

RESULTS

The most common type of lymphoma was Hodgkin lymphoma (HL) (12 patients) and diffuse large B-cell lymphoma (DLBCL) (14 patients). At the time of diagnosis, 31 (61%) of patients had stage 4 of HL or DLBCL, according to Ann Arbor classification. In total, the response to treatment was evaluated in 50 patients, with 25 being in complete remission and 6 in partial remission. We observed that B cell symptoms (p = 0.036), bone marrow involvement (p = 0.073), splenomegaly (p = 0.025), and more than 2 lines of treatment were more common in AIHA compared to ITP patients. Conversely, eucopenia (p = 0.056) and ACs without lymphoma progression (p = 0.002) were more often diagnosed in ITP patients.

CONCLUSIONS

In the study group, relapsed and refractory disease was observed more often, and shorter overall survival (OS) was noted in patients with DLBCL. We found that AC is associated with a worse prognosis in comparison to the general population of lymphoma patients. There were no differences in response to AC therapy. To have more accurate data, a larger group, as part of a multicenter study, should be evaluated.

Paediatric-onset Evans syndrome: Breaking away from refractory immune thrombocytopenia

Since its first description by Evans in 1951, this syndrome has been linked to chronic immune thrombocytopenia with the concurrent or delayed onset of autoimmune haemolytic anaemia or neutropenia. For decades, the evolution of Evans syndrome (ES) has carried a poor prognosis and often resulted in chronic steroid exposure, multiple immune suppressing medications directed against T or B lymphocytes, and splenectomy. This paper presents a new view of ES based on recent advances in genomics which begin to classify patients based on their underlying molecular variants in previously described primary immune disorders. This has opened up new avenues of targeted therapy or bone marrow transplant at rather than broad long-term immune suppression or splenectomy. Importantly, recent studies of the full lifespan of ES suggest that at least 80% of those paediatric patients will progress to various clinical or biological immunopathological manifestations with age despite the resolution of their cytopenias. Those patients merit long-term follow-up and monitoring in dedicated transition programs to improve outcome at the adult age.

Case report: Autoimmune hemolytic anemia caused by warm and cold autoantibodies with complement activation-etiological and therapeutic issues

Introduction

Research on mixed warm and cold autoantibodies in autoimmune hemolytic anemia (AIHA) targeting erythrocytes [red blood cells (RBCs)] and platelets is scarcely reported.

Case presentation

In this study, we present the case of a 5-year-old boy with positive direct [anti-IgG (1+), anti-IgG-C3d (3+)], and indirect antiglobulin (Coombs) tests. The RBCs were coated with polyspecific-positive, warm IgG autoantibodies alongside activated complement components. Plasma-containing immunoglobulin M (IgM) class autoantibodies were found in 1:64 titers with a wide temperature range of 4°C-37°C. The platelets were also coated with IgM autoantibodies. There was a reduction in the levels of the classical and alternative complement pathways, such as C3, C4, ADAMTS13 metalloprotease activity, factor H antigen, complement factor B antigen, and C1q antigen alongside the elevated sC5b-9 terminal complement complex. Hematuria and/or proteinuria, reduced diuresis, and elevated levels of serum creatinine were absent. The kidney ultrasound report was normal. A recent combination of Epstein-Barr virus (EBV) and cytomegalovirus (CMV) infection was found. The first-line treatment consisted of intravenous methylprednisolone [4 mg/kg/body weight for the first 72 h (q12 h), followed by 2 mg/kg body weight for 21 consecutive days with a slow steroid reduction until plasmapheresis (PLEX)]. After the patient showed limited response to corticosteroid therapy, rituximab (375 mg/m2) was administered once a week (five doses in total), with vitamins B9 and B12. These strategies also showed limited (partial) therapeutic benefits. Therefore, the treatment was switched to PLEX (five cycles in total) and intravenous immunoglobulin (IVIg) (1 g/kg/5 days). This combination significantly improved RBC count and platelet levels, and C3 and C4 levels returned to normal. A follow-up of 2.5 years after treatment showed no sign of relapse. A genetic analysis revealed a rare heterozygous intronic variation (c.600-14C > T) and heterozygous Y402H polymorphism of the CFH gene. c.600-14C > T mutation was located near the 5' end of exon 6 in the gene encoding the complement C3 protein of unknown significance. We presumed that the complement regulators in our patient were sufficient to control complement activation and that complement blockade should be reserved only for devastating, life-threatening complement-related multiorgan failure.

Conclusion

We believe that EBV and CMV triggered AIHA, thus activating the complement cascade. Hence, we used corticosteroids, rituximab, vitamins B9 + B12, PLEX, and fresh frozen plasma (FFP) as treatment. Final remission was achieved with PLEX and FFP. However, an additional late effect of B12 rituximab and the disappearance of long-lived circulating plasma cells should not be completely ignored. Complement activation with a genetic background should be assessed in severe warm and cold hemolytic anemias caused by autoantibodies.

A nanobody-based complement inhibitor targeting complement component 2 reduces hemolysis in a complement humanized mouse model of autoimmune hemolytic anemia

C2 is an attractive therapeutic target for many complement-mediated diseases. We developed Nab1B10, a new anti-C2 nanobody that potently and selectively inhibits both the classical and lectin pathways of complement activation. Mechanistically, Nab1B10 binds to the C2a portion of C2 and inhibits the assembly of C3 convertase C4b2a. Nab1B10 cross-reacts with monkey but not rodent C2 and inhibits classical pathway-mediated hemolysis. Using a new complement humanized mouse model of autoimmune hemolytic anemia (AIHA), we demonstrated that Nab1B10 abolished classical pathway complement activation-mediated hemolysis in vivo. We also developed C2-neutralizing bi- and tetra-valent antibodies based on Nab1B10 and found these antibodies significantly more potent than the other anti-C2 monoclonal antibody that is already in clinical trials. These data suggest that these novel C2-neutralizing nanobodies could be further developed as new therapeutics for many complement-mediated diseases, in which pathogenesis is dependent on the classical and/or lectin pathway of complement activation.

A Peculiar CLL Case with Complex Chromosome 6 Rearrangements and Refinement of All Breakpoints at the Gene Level by Genomic Array: A Case Report

INTRODUCTION

Chronic lymphocytic leukemia (CLL), the most common leukemia in Western countries, is a mature B-cell chronic lymphoproliferative disorder characterized by the accumulation of neoplastic CD5+ B lymphocytes, functionally incompetent and usually monoclonal in origin, in bone marrow, lymph nodes and blood. Diagnosis occurs predominantly in elderly patients, with a median age reported between 67 and 72 years. CLL has a heterogeneous clinical course, which can vary from indolent to, less frequently, aggressive forms. Early-stage asymptomatic CLL patients do not require immediate therapeutic intervention, but only observation; treatment is necessary for patients with advanced disease or when "active disease" is observed. The most frequent autoimmune cytopenia (AIC) is autoimmune haemolytic anaemia (AHIA). The main mechanisms underlying the appearance of AIC in CLL are not fully elucidated, the predisposition of patients with CLL to suffering autoimmune complications is variable and autoimmune cytopenia can precede, be concurrent, or follow the diagnosis of CLL.

CASE PRESENTATION

A 74-year-old man was admitted to the emergency room following the finding of severe macrocytic anaemia during blood tests performed that same day, in particular the patient showed a profound asthenia dating back several months. The anamnesis was silent and the patient was not taking any medications. The blood examination showed an extremely high White Blood Cell count and findings of AIHA in CLL-type mature B-cell lymphoproliferative neoplasia. Genetic investigations: Conventional karyotyping was performed and it obtained a trisomy 8 and an unbalanced translocation between the short arm of chromosome 6 and the long arm of chromosome 11, concurrent with interstitial deletions in chromosomes 6q and 11q that could not be defined in detail. Molecular cytogenetics (FISH) analyses revealed Ataxia Telangiectasia Mutated (ATM) monoallelic deletion (with loss of ATM on derivative chromosome 11) and retained signals for TP53, 13q14 and centromere 12 FISH probes. TP53 and IGHV were not mutated. Array-CGH confirmed trisomy of the entire chromosome 8 and allowed us to resolve in detail the nature of the unbalanced translocation, revealing multiple regions of genomic losses on chromosomes 6 and 11.

DISCUSSION

The present case report is an unusual CLL case with complex karyotype and refinement of all breakpoints at the gene level by the genomic array. From a genetic point of view, the case under study presented several peculiarities.

CONCLUSIONS

We report the genetic findings of a CLL patient with abrupt disease onset, so far responding properly to treatments despite the presence of distinct genetic adverse traits including ATM deletion, complex karyotype and chromosome 6q chromoanagenesis event. Our report confirms that interphase FISH alone is not able to provide an overview of the whole genomic landscape in selected CLL cases and that additional techniques are required to reach an appropriate cytogenetic stratification of patients.

Possible role of IL-23 inhibitor in autoimmune hemolytic anemia

Rituximab and prednisone are commonly used treatments for autoimmune hemolytic anemia (AIHA), where the body's immune system attacks and destroys its red blood cells. However, some AIHA patients may become refractory to rituximab treatment, and this can result in continued hemolysis and persistent anemia, making it challenging for affected individuals to manage their symptoms. The underlying causes of rituximab refractoriness in AIHA patients can be complex and vary from patient to patient. Herein, we present a case of newly diagnosed warm and cold AIHA that remained in remission with an interleukin-23 inhibitor.

Monoclonal antibodies for treatment of cold agglutinin disease

INTRODUCTION

Cold agglutinin disease (CAD) is a difficult-to-treat autoimmune hemolytic anemia and B cell lymphoproliferative disorder associated with fatigue, acrocyanosis and a risk of thromboembolic events. Cold-induced binding of autoantibodies agglutinates red blood cells and triggers the classical complement pathway, leading to predominantly extravascular hemolysis.

AREAS COVERED

This review summarizes clinical and experimental antibody-based treatments for CAD and analyzes the risks and benefits of B cell and complement directed therapies, and discusses potential future treatments for CAD.

EXPERT OPINION

Conventional treatment of CAD includes a B cell targeted treatment approach with rituximab, yielding only limited treatment success. Addition of a cytotoxic agent (e.g. bendamustine) increases efficacy but this is accompanied by an increased risk of neutropenia and infection. Novel complement-directed therapies have emerged and were shown to have a good efficacy against hemolysis and safety profile but are expensive and unable to address circulatory symptoms. Complement inhibition with sutimlimab may be used as a bridging strategy until B cell directed therapy with rituximab takes effect or continued indefinitely if needed. Future antibody-based treatment approaches for CAD involve the further development of complement-directed antibodies, combination of rituximab and bortezomib, and daratumumab. Non-antibody based prospective treatments may include the use of Bruton tyrosine kinase inhibitors.

Autoimmune hemolytic anemia, a rare disease in newborns: a case report

Autoimmune hemolytic anemia (AIHA) is a type of hemolytic anemia in which autoantibodies attack the membrane antigens of red blood cells, causing cell rupture (lysis). Hemolysis stimulates compensatory RBC production by boosting erythropoietin levels; however, this response is often insufficient to restore normal hemoglobin blood levels, resulting in anemia. It is a rare disease, with an annual incidence of one case in every 80 000 live births. Infants of any age can be affected, though neonatal incidence is unusual. Here, the authors report a rare case of AIHA in the neonatal period with concomitant atrial septal defect, ventricular septal defect, and patent ductus arteriosus.

Case presentation

A one-hour-old male neonate weighing 3 kg who was born at 38 weeks of gestation presented to the pediatric department with the complaint of respiratory distress. Examination revealed obvious respiratory distress with subcostal and intercostal recessions and a continuous grade 2 murmur at the left upper chest; the liver was palpable 1 cm below the right subcostal margin with a palpable splenic tip. Laboratory investigations were ordered, which showed hemoglobin was decreasing continuously and bilirubin was raised, suspecting AIHA. A positive blood culture, tachycardia, tachypnea, and a raised leukocyte count showed that the baby was in sepsis. The baby improved clinically, and the complete blood count showed improved Hb. Cardiac examination findings and a second-grade continuous murmur at the left upper chest were further investigated through echocardiography, which showed a grade 2 atrial septal defect, a muscular ventricular septal defect, and a patent ductus arteriosus.

Clinical discussion

Childhood AIHA is a rare and underrated disease that differs from the adult form. The disease's initial manifestation and subsequent course are both poorly understood. It affects mostly young children, and a high prevalence (21%) is found in infants. In some patients, there is a genetic predisposition to the development of this disease, and there is underlying immune deregulation in more than half of the cases, necessitating long-term homogeneous multidisciplinary follow-up. It is of two types, primary and secondary, and according to the study conducted in France, AIHA is associated not only with other autoimmune diseases but with some systemic diseases as well, like neurological, digestive, chromosomal abnormalities, and cardiac diseases, as in our case.

Conclusion

There is a scarcity of data on clinical management and treatment strategies. More research should be done to know the environmental factors that can trigger the immune response against red blood cells. Moreover, a therapeutic trial is essential for a better outcome and helps prevent serious complications.

Three different pathways of IgM-antibody-dependent hemolysis are mainly regulated by complement

Antibodies to red blood cells (RBCs) may hemolyze erythrocytes via Fc-mediated phagocytosis or complement-dependent. Complement activation on RBCs can be detected by C3d-direct antiglobulin test (DAT), which is the only test in immune hematology that directly targets complement. However, a positive DAT with anti-C3d cannot distinguish between C3b-mediated extravascular hemolysis, C5b-C9-mediated intravascular hemolysis and C5b-C8-mediated eryptosis. Furthermore, DAT is not suitable to estimate the strength of hemolysis. Autoimmune hemolytic anemia (AIHA) is a rare disease that is caused by autoantibodies to red blood cells that is divided in warm AIHA and in cold agglutinin disease (CAD). The causative antibodies in CAD and sometimes in warm AIHA are from the IgM class. Depending on strength of complement activation they can induce extravascular hemolysis, intravascular hemolysis and eryptosis. We studied the three types of hemolysis by use of sera from patients with CAD under various conditions. We found that additionally to the routinely applied C3d-DAT, indirect tests for complement activity (free hemoglobin and Annexin V-binding to phosphatidylserine-exposing RBCs) should be used to determine the portion of extravascular, intravascular and eryptotic hemolysis. Eryptotic hemolysis may have a significant share in clinical relevant CAD or IgM warm AIHA, which should be considered for successful treatment.

Real-world data from India on clinical practices in the management of autoimmune haemolytic anaemia: A survey-based cross-sectional assessment

BACKGROUND

Autoimmune haemolytic anaemia (AIHA) is a decompensated acquired haemolysis caused by the host's immune system acting against its own red cell antigens. The aim of this national survey is to capture real-world data of clinical practices in AIHA by collecting responses from clinical haematologists across India.

METHODOLOGY

In this cross-sectional study, a structured, 26-question online survey was conducted in India by few members of the special interest group in immunohaematology between January and March, 2022. The final survey consisted of questions covering place of work, amount of AIHA cases being evaluated by the haematologist over preceding years, basic demographic, clinical and laboratory features of the patients being treated under them etc. Descriptive statistical analysis was performed during the assessment.

RESULTS

The survey response rate was 48.2% (53/110), 69.8% (37/53) have diagnosed and managed more than 10 AIHA cases in the last 3 years with a female preponderance. There was considerable variability in response. While 56.6% (30/53) of respondents do have the access to the facilities to subtype AIHA cases; 32.1% (17/53) of clinicians would prefer administering high dose steroids for 6 weeks or more in non-responding patients, and only 45.3% (24/53) would assess the risks of thrombosis in AIHA. There is unanimous agreement among the participants that health-related quality of life should be taken into consideration in patients and the need for a national registry of patients with AIHA in India.

CONCLUSION

The current national survey showed that some aspects of AIHA management were consistent; others were less so, but also significant variations were observed in certain clinical practices, where the evidence base is limited. A joint effort is needed to establish a national patient registry by including both clinical haematologists and transfusion medicine specialists which could potentially standardise AIHA management and future research in India.

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 2022 (Online ahead of print). doi: 10.1111/bjh.18584.

[Autoimmune hemolytic anemia following the third dose of the COVID-19 vaccine]

The development and exacerbation of autoimmune diseases following coronavirus disease 2019 (COVID-19) vaccination have been reported; however, there are few reports of autoimmune hemolytic anemia (AIHA). A 75-year-old woman was admitted to the emergency department 46 days after receiving her third dose of the mRNA-1273 COVID-19 vaccine because of fatigue and general weakness. Initial laboratory analyses revealed severe hemolytic anemia with positive direct and indirect Coombs test and elevation of serum indirect bilirubin and lactate dehydrogenase. The patient had no underlying disease after a close examination and was diagnosed with warm AIHA, which was thought to be associated with COVID-19 vaccination. The anemia improved daily after the administration of prednisolone. Clinicians should be aware of the possibility of AIHA being caused by COVID-19 vaccination, and monotherapy with prednisolone should be considered in cases of severe anemia.

Thymoma With Triple Threat: Pure Red Cell Aplasia, Autoimmune Hemolytic Anemia, and T-Cell Large Granular Lymphocytic Leukemia

Thymomas are a rare neoplasm of the anterior mediastinum and often associated with paraneoplastic syndromes. Though myasthenia gravis is the most common and well-known, the list of reported paraneoplastic syndromes occurring with thymoma is extensive and ever-growing. Paraneoplastic syndromes can involve nearly every organ system, including hematologic abnormalities affecting any or all cell lines. This can present challenges to the clinician in terms of diagnosis, prognostic impact, and management. We present the case of a previously healthy 41-year-old female who was diagnosed with thymoma and three rare hematologic paraneoplastic syndromes: pure red cell aplasia (PRCA), autoimmune hemolytic anemia (AIHA), and T-cell large granular lymphocytic leukemia (T-LGLL). To the best of our knowledge, there have been only four other reported cases of PRCA and AIHA in a single patient with thymoma, all of which were treated with thymectomy. Upfront surgical resection was not possible in the present case and thus the patient was alternatively treated with corticosteroids and octreotide, which proved successful in resolving the anemia. The authors present this case to share these findings of an alternative treatment strategy for thymoma-associated PRCA and AIHA and to highlight the importance of careful monitoring with routine blood work for these complex patients.

Enterovirus 71-Induced Autoimmune Hemolytic Anemia in a Boy

Autoimmune hemolytic anemia (AIHA) can be induced by recent or concomitant infections. Many infectious agents are postulated to be associated with this condition. Treatment of infection induced AIHA still varies. This report describes a previously healthy Thai boy who developed AIHA associated with enterovirus-71 infection. He was successfully treated with oral prednisone.

The effect of HLA matching and donor relatedness on the risk of autoimmune haemolytic anaemia in haematopoietic stem cell transplant recipients: A systematic review and meta-analysis

Recent studies have identified autoimmune haemolytic anaemia (AIHA) as a haematopoietic stem cell transplant (HSCT) complication that represents a significant cause of morbidity and mortality for these patients. In order to understand this autoimmune phenomenon, emerging research has focused on the prognostic factors associated with the development of the disorder. These studies have identified numerous possible associations with often contrasting and conflicting results. A systematic review and meta-analysis were performed in order to determine the effect of human leucocyte antigen (HLA) matching and donor relatedness on the risk of AIHA post-HSCT. PubMed, SCOPUS and ProQuest were searched from 1 January 1995 to 1 August 2021 using a range of keywords. Meta-analysis was performed using OpenMeta-Analyst software using a random effects model and arcsine risk difference (ARD). Eight eligible articles were identified, and meta-analysis showed an increased risk of AIHA in those who received HLA-mismatched transplants (ARD -0.082; 95% confidence interval [CI] -0.157, -0.007; p = 0.031) and those who received donations from unrelated donor sources (ARD -0.097; 95% CI -0.144, -0.051; p < 0.001). Patients who receive HSCT from HLA-matched and related donor sources have a reduced risk of developing AIHA. Healthcare practitioners should be mindful of the risk of AIHA, especially in those who receive HLA-mismatched and unrelated donor-sourced stem cells. While these findings provide further evidence for researchers investigating the pathogenesis of this HSCT complication, more studies are needed to fully understand the cause.

Splenectomy in the management of primary immune-mediated hemolytic anemia and primary immune-mediated thrombocytopenia in dogs

Background

Current reports about the use of splenectomy for the management of immune‐mediated hemolytic anemia (IMHA) or immune‐mediated thrombocytopenia (ITP) or both in dogs are limited.

Objectives

To retrospectively describe the use of splenectomy as part of the management for IMHA, ITP, and concurrent IMHA and severe thrombocytopenia (CIST) in dogs. It was hypothesized that splenectomy would be beneficial in allowing for reduction of dose of immunosuppressive drugs or discontinuation in 1 or more of these groups.

Animals

Seventeen client‐owned dogs (7 with IMHA, 7 with ITP, and 3 with CIST) were identified across 7 UK‐based referral hospitals from a study period of 2005 to 2016.

Methods

Data were collected retrospectively via questionnaires and included information about diagnosis, management and treatment response before and after splenectomy. Based on clinical outcome, treatment with splenectomy as part of the management protocol was classified as either successful or unsuccessful.

Results

Six of 7 dogs with ITP were managed successfully with splenectomy as part of their management protocol (3 complete and 3 partial responses), although 1 subsequently developed suspected IMHA. Of the 7 dogs with IMHA, splenectomy was part of a successful management protocol in 4 dogs (2 complete and 2 partial responses). In the CIST group, 1 case (1/3) responded completely to management with splenectomy as part of the management protocol.

Conclusions and Clinical Importance

Splenectomy was considered successful and well tolerated in most cases of isolated ITP. Whether there is a benefit of splenectomy in cases of IMHA and CIST could not be determined in the current study.

The role of neutrophils in antibody-driven autoimmune cytopenias

Autoimmune cytopenias are a consequence of autoantibodies that target blood cell lineages and mark them for their accelerated destruction, mostly through phagocytosis by monocytes and macrophages and complement activation. Neutrophils, although equipped with Fc and complement receptors and effector mechanisms that are critical in other autoimmune conditions, remained long overlooked. Recent reports, however, propose a new and possibly critical role of neutrophils. In this review, we gathered available evidence on the contribution of neutrophils to the development, onset, and consequences of autoantibody-dependent cytopenias.

Bruton's Kinase Inhibitors for the Treatment of Immunological Diseases: Current Status and Perspectives

The use of Bruton’s tyrosine kinase (BTK) inhibitors has changed the management of patients with B-cell lymphoid malignancies. BTK is an important molecule that interconnects B-cell antigen receptor (BCR) signaling. BTK inhibitors (BTKis) are classified into three categories, namely covalent irreversible inhibitors, covalent reversible inhibitors, and non-covalent reversible inhibitors. Ibrutinib is the first covalent, irreversible BTK inhibitor approved in 2013 as a breakthrough therapy for chronic lymphocytic leukemia patients. Subsequently, two other covalent, irreversible, second-generation BTKis, acalabrutinib and zanubrutinib, have been developed for lymphoid malignancies to reduce the ibrutinib-mediated adverse effects. More recently, irreversible and reversible BTKis have been under development for immune-mediated diseases, including autoimmune hemolytic anemia, immune thrombocytopenia, multiple sclerosis, pemphigus vulgaris, atopic dermatitis, rheumatoid arthritis, systemic lupus erythematosus, Sjögren’s disease, and chronic spontaneous urticaria, among others. This review article summarizes the preclinical and clinical evidence supporting the role of BTKis in various autoimmune, allergic, and inflammatory conditions.

Life-saving transfusion in autoimmune hemolytic anemia: a case report and procedure review of the dilution method

A woman with autoimmune hemolytic anemia (AIHA) presented in the emergency department with life-threatening anemia (hemoglobin 3 g/dL). Exaggeration of preexisting chronic anemia to severe anemia after a recent red blood cell (RBC) transfusion led to suspicion of delayed hemolytic transfusion reaction. Given the urgency for transfusion along with a stronger suspicion for coexistence of an alloantibody, the dilution method proposed by Lawrence Petz and George Garratty was used to find an RBC unit for transfusion. An alloantibody with Fy^b specificity was identified, which was masked by the coexistent autoantibody. This method is based on the assumption that the titers of an alloantibody are higher than that of autoantibody. Diluting the autoantibody would reveal the alloantibody and, for this purpose, a serial doubling dilution of serum is performed. This method has an important limitation of missing any alloantibodies with titers less than that of the autoantibody. In spite of this, this method may be of use at a resource-poor setting, where trained personnel and other reagents intended for advanced immunohematology methods are unavailable.

[Advances in understanding the pathogenesis and treatment of autoimmune hemolytic anemia]

Autoimmune hemolytic anemia (AIHA) is caused by damaged red blood cells due to auto-antibodies targeting its membrane proteins. The heterogeneous group of diseases is divided into two types depending on the thermal amplitude of autoantibodies: warm and cold AIHA. Cold AIHA includes cold agglutin disease and paroxysmal nocturnal hemoglobinuria. AIHA is also divided into primary and secondary AIHA depending on its etiology. Recent advances in understanding the pathogenesis have revealed that AIHA brings not only anemia but also thromboembolic risk or impaired quality of life (QOL). This review describes its pathogenesis, diagnostic approach, and treatment strategies based on the latest information.

[Thrombotic risk in autoimmune hemolytic anemia]

Autoimmune hemolytic anemia (AIHA) is a type of anemia caused by the destruction of red blood cells due to autoantibodies targeting membrane proteins. AIHA is divided into two types based on the thermal amplitude: warm AIHA (at 37°C) and cold AIHA (at <37°C). Anemia and jaundice are the major symptoms of AIHA, and in cold agglutinin disease the peripheral circulation disturbance deteriorates patients' quality of life. Cumulative evidence has revealed that both types of AIHA increase the risk of thrombosis and intravascular hemolysis appears to be the most critical factor in the pathogenesis. Complement activation plays an important role in the intravascular hemolysis of AIHA, though the coagulation and hemostatic systems and the crosstalk between these systems also contributes significantly to the pathogenesis of thrombosis. Future treatment of AIHA should be targeted at not only alleviating anemia but also reducing thrombotic risk.

Autoimmune Hemolytic Anemia in Chronic Lymphocytic Leukemia: A Comprehensive Review

Simple Summary

This review analyzes the occurrence, clinical characteristics, and prognostic impact and treatment of autoimmune hemolytic anemia (AIHA) in chronic lymphocytic leukemia (CLL). Autoimmune hemolytic anemia is observed in about 10% of CLL. Pathogenesis is multifactorial involving humoral, cellular, and innate immunity, so the different mechanisms are well described in this review which also focuses on drugs associated to CLL-AIHA and on difficulties to diagnose it. There is a comprehensive revision of the main published casistics and then of the treatments; in particular the paper analyzes the main chemo-immunotherapeutic agents used in this setting. Since the therapy depends on the presence and severity of clinical symptoms, disease status, and comorbidities, treatment is nowadays more individualized in CLL and also in CLL-AIHA. Patients not responding to corticosteroids and rituximab are treated with CLL-specific drugs as per current guidelines according to age and comorbidities and new targeted agents against BCR and BCL-2 which can be given orally and have few side effects, are very effective both in progressive CLL and in situations such as AIHA.

Abstract

Chronic lymphocytic leukemia (CLL) patients have a greater predisposition to develop autoimmune complications. The most common of them is autoimmune hemolytic anemia (AIHA) with a frequency of 7–10% of cases. Pathogenesis is multifactorial involving humoral, cellular, and innate immunity. CLL B-cells have damaged apoptosis, produce less immunoglobulins, and could be responsible for antigen presentation and releasing inflammatory cytokines. CLL B-cells can act similar to antigen-presenting cells activating self-reactive T helper cells and may induce T-cell subsets imbalance, favoring autoreactive B-cells which produce anti-red blood cells autoantibodies. Treatment is individualized and it depends on the presence and severity of clinical symptoms, disease status, and comorbidities. Corticosteroids are the standardized first-line treatment; second-line treatment comprises rituximab. Patients not responding to corticosteroids and rituximab should be treated with CLL-specific drugs as per current guidelines according to age and comorbidities. New targeted drugs (BTK inhibitors and anti BCL2) are recently used after or together with steroids to manage AIHA. In the case of cold agglutinin disease, rituximab is preferred, because steroids are ineffective. Management must combine supportive therapies, including vitamins; antibiotics and heparin prophylaxis are indicated in order to minimize infectious and thrombotic risk.

[Development of autoimmune hemolytic anemia after BNT162b2 mRNA COVID-19 vaccination]

A 75-year-old woman with a history of postoperative chemotherapy for lung adenocarcinoma and a history of Helicobacter pylori eradication for idiopathic thrombocytopenic purpura (ITP) was admitted to the department of hematology and oncology for the treatment of anemia 2 weeks after BNT162b2 mRNA COVID-19 vaccination. Her blood examination revealed direct and indirect Coombs test-positive hemolytic anemia and elevation of serum LDH and indirect bilirubin levels. No obvious trigger other than BNT162b2 mRNA COVID-19 vaccination was found. She was diagnosed with autoimmune hemolytic anemia (AIHA), and oral prednisolone therapy was administered. The anemia improved soon after the administration of prednisolone. Although vaccination is considered to be very important for suppressing the spread of COVID-19, there have been reports of increasing risk of ITP development and deterioration caused by BNT162b2 mRNA COVID-19 vaccination. Because the number of vaccinated people is increasing rapidly, hematologists must be vigilant to the development of AIHA after BNT162b2 mRNA COVID-19 vaccination although case reports of this phenomenon have been very rare thus far.

New-onset Evans syndrome associated with systemic lupus erythematosus after BNT162b2 mRNA COVID-19 vaccination

Evans syndrome presents as concurrent autoimmune hemolytic anemia (AIHA) and immune thrombocytopenia (ITP). Systemic lupus erythematosus (SLE) is the most frequent autoimmune disorder associated with Evans syndrome. We herein report a case of new-onset Evans syndrome associated with SLE after BNT162b2 mRNA coronavirus disease 2019 (COVID-19) vaccination in a 53-year-old woman. Blood examination at diagnosis showed hemolytic anemia with a positive Coombs test and thrombocytopenia. Hypocomplementemia and the presence of lupus anticoagulant indicated a strong association with SLE. Prednisolone administration rapidly restored hemoglobin level and platelet count. This case suggests that mRNA COVID-19 vaccination may cause an autoimmune disorder. Physicians should be aware of this adverse reaction by mRNA COVID-19 vaccination and should consider the benefits and risks of vaccination for each recipient.

Thromboembolic complications in autoimmune hemolytic anemia: Retrospective study

Introduction

A small number of retrospective studies suggest AIHA to be associated with an increased risk to suffer from thromboembolic events. However, based on these studies it remains unclear whether the complement activation per is a risk factor to develop thromboembolic events in AIHA patients. The aim of this retrospective study is to investigate the incidence of thromboembolic events and the relation to complement activation in a cohort of AIHA patients.

Patients and Methods

We included 77 patients in this study with a positive DAT and hemolytic parameters or with AIHA diagnosis based on the medical report. The included patients were screened for thromboembolic events (TEE) and have been stratified in groups with and without complement activation based on the positivity for complement in the DAT.

Results

Of the 77 included patients, 51 (66%) had warm AIHA, 13 (17%) cold‐AIHA, 5 (7%) mixed AIHA, and 8 (10%) atypical AIHA, respectively. Primary and secondary AIHA was diagnosed in 44% and 56%, respectively. Twenty patients (26%) suffered from TEE. The majority (80%) of these patients suffered from warm AIHA and 10% from cold‐AIHA. Hemolysis parameters did not differ in patients with and without TEE. There was no correlation with complement activation as evidenced by a positivity for complement in the monospecific DAT with the occurrence of TEE.

Conclusion

AIHA is associated with an increased risk of TEE. Based on these results prophylactic anticoagulation might be considered as soon as the diagnosis of AIHA is confirmed.

Autoimmune hemolytic anemia associated with vitamin B12 deficiency and viral illness in DiGeorge syndrome. Case report and literature review

Vitamin B12 plays a crucial role in cell maturation and differentiation. Its deficiency can lead to cytopenias and even hemolysis. We suggest regular monitoring and maintenance of Vit B12 levels in DiGeorge syndrome patients to prevent such triggers.

A fluorometric erythrophagocytosis assay using differentiated monocytic THP-1 cells to assess the clinical significance of antibodies to red blood cells

BACKGROUND AND OBJECTIVES

The significance of antibodies to red blood cells (RBCs) is variable and cannot be predicted solely by serological testing. A flow cytometry-based erythrophagocytosis assay was established using phorbol 12-myristate 13-acetate (PMA)-treated THP-1 cells and RBCs labelled with PKH26 to assess allo- and autoantibodies to RBCs.

MATERIALS AND METHODS

THP-1 cells were differentiated into macrophage-like cells by treatment with PMA. RBC samples coated with alloantibodies or autoantibodies were obtained from 16 patients with autoimmune haemolytic anaemia of warm type (wAIHA) as well as from five pregnant women with warm autoantibodies. RBCs from healthy blood donors were used as controls. RBCs were labelled with the red lipophilic fluorescent dye PKH26 and incubated with PMA-treated THP-1 cells. After removal of nonadherent RBCs by washing and haemolysis of adherent RBCs, erythrophagocytosis was quantified by flow cytometry.

RESULTS

We observed significant phagocytosis of RBCs coated with clinically relevant alloantibodies (i.e. anti-D and anti-K) or autoantibodies from patients with active wAIHA, but not of those coated with alloantibodies (anti-Ch) or autoantibodies from patients and pregnant women without haemolysis.

CONCLUSION

The flow cytometry-based erythrophagocytosis test described here is quantitative, highly reliable, and may be helpful for the assessment of the clinical significance of antibodies to RBCs.

Daratumumab therapy for post-HSCT immune-mediated cytopenia: experiences from two pediatric cases and review of literature

Background

Immune-mediated cytopenias (AIC) are challenging complications following allogeneic hematopoietic stem cell transplantation (HSCT). While broad-acting immunosuppressive agents like corticosteroids are often standard of care, several novel therapies which target specific immunological pathways have recently been developed and provide hope for patients with steroid-refractory courses and may limit long-term toxicity. The successful off-label use of the plasma cell depleting anti-CD38 antibody daratumumab was published in several case reports, suggesting efficacy, i.e., in patients with antibody-mediated AIC refractory to previous B cell depletion. We want to share our experience with two children, whom we treated with daratumumab, including one fatal course with uncontrolled disease. Given the absence of substantial data from HSCT registries or prospective trials, we furthermore provide a critical review of the literature on daratumumab treatment of AIC.

Case presentations

Patient 1 (P1), an 11-year-old girl with lipopolysaccharide-responsive and beige-like anchor protein (LRBA) deficiency who developed immune-mediated thrombocytopenia (AIT) from day +58 after HSCT, showed a complete response to daratumumab after the fourth of six total daratumumab doses. She remains transfusion independent for over a year of follow-up. Previously, her thrombocytopenia was refractory to corticosteroids, rituximab, intravenous immunoglobulins (IVIG), eltrombopag, cyclosporine A, and sirolimus. Patient 2 (P2), a 6-year-old boy with CD40 ligand (CD40L) deficiency, developed both AIT and hemolytic anemia (AIHA) after HSCT on days +58 and +83, respectively, and was also treated with daratumumab after being previously refractory to prednisolone, rituximab, and IVIG. Yet, he did neither respond to daratumumab nor the concomitantly administered methyprednisolone pulse, plasmapheresis, and eculizumab and succumbed due to refractory disease.

Conclusion

Reviewing the literature on the use of daratumumab for refractory AIC post-HSCT, we consider daratumumab a promising agent for this life-threatening disorder: ten of the twelve patients reached transfusion independency in the literature. However, treatment failures are likely to be underreported. Thus, controlled trials are needed to explore the safety and efficacy of daratumumab in this rare post-HSCT complication.

[Diagnosis and treatment of autoimmune hemolytic anemia: the role of B-1 cells in secondary AIHA]

Autoimmune hemolytic anemia (AIHA) is a rare disease with an unknown etiology. Although the diagnosis of a typical case is expected to be easy, the actual diagnosis is often challenging due to the diversity of conditions. Prednisolone treatment continues for a long period and causes several adverse events, including infection and osteoporosis. Therefore, a solid understanding of the pathophysiology, depending on the disease type, is necessary to avoid ineffective and unnecessary treatment and achieve a good outcome. Previously, we reported two studies concerning colorectal cancer that ectopically expresses band 3 erythrocyte membrane protein, leading to cancer-related anemia without bleeding through an immune response identical to or resembling AIHA. In this article, the methods of laboratory examination for the diagnosis of AIHA are summarized to serve as physicians' reference. Furthermore, points for conventional management and emerging treatments against specific targets are briefly described. In addition, due to the increasing knowledge on B-1 cells' participation in malignant and autoimmune diseases, the pathophysiological role of B-1 cells in AIHA is scrutinized through their physiological function in innate and adaptive immunity, in terms of the production of anti-band 3 antibodies. The screening and analysis of primary disease in AIHA should improve clinical outcomes.

Late-onset myocardial infarction and autoimmune haemolytic anaemia in a COVID-19 patient without respiratory symptoms, concomitant with a paradoxical increase in inflammatory markers: a case report

BACKGROUND

In December 2019, a new coronavirus (named severe acute respiratory syndrome coronavirus 2, SARS-CoV-2) spread from China, causing a pandemic in a very short time. The main clinical presentation of SARS-CoV-2 infection (COVID-19, coronavirus disease-2019) is pneumonia, but several cardiovascular complications may also occur (e.g., acute coronary syndromes, pulmonary embolism, stroke, arrhythmias, heart failure and cardiogenic shock). Direct or indirect mechanisms induced by SARS-CoV-2 could be implicated in the pathogenesis of these events.

CASE PRESENTATION

We report herein the third case of COVID-19 autoimmune haemolytic anaemia (AIHA) reported so far, which occurredwithout any other possible explanations in a Caucasian patient. The patient also suffered from ST-elevation myocardial injury.

CONCLUSIONS

Both complications occurred quite late after COVID-19 diagnosis and were probably precipitated by systemic inflammation, as indicated by a significant delayed increase in inflammatory markers, including interleukin-6 (IL-6).

Role of therapeutic plasma exchanges in refractory severe warm autoimmune hemolytic anemia: Presentation of two case reports

BACKGROUND

Warm autoimmune hemolytic anemia (WAIHA) is a disorder with a usually good response to corticosteroid treatment, whereas in some cases first-line treatment's response is poor and other therapies such as intravenous immunoglobulins (IVIGs), rituximab, or splenectomy must be applied.

STUDY DESIGN AND METHODS

Herein, we describe two patients with severe WAIHA treated at our center, who obtained a response after therapeutic plasma exchanges (TPEs) combined with low doses of IVIG.

RESULTS

The first patient was an 18-year-old man with no relevant past medical history who was diagnosed with WAIHA. The patient presented a progressive clinical worsening despite treatment with prednisone, IVIG, and rituximab. After starting TPEs, signs of hemolysis rapidly improved and hemoglobin started to recover. The second patient was a 38-year-old man with a past history of immune thrombocytopenia and WAIHA. The patient presented a new flare of WAIHA, with no response after 2 weeks of treatment with corticosteroids, IVIG, and rituximab. After initiation of TPEs, the patient had an improvement in hemolysis biomarkers and recovery of hemoglobin concentration.

CONCLUSION

Combination of TPEs with rituximab and IVIG might be considered as a therapeutic option in patients with severe WAIHA without response to corticosteroid and IVIG treatment.

Prognostic significance of hemoglobin level and autoimmune hemolytic anemia in SARS-CoV-2 infection

Higher levels of D-dimer, LDH, and ferritin, all have been associated with the poor prognosis of COVID-19. In a disease where there are acute inflammation and compromised oxygenation, we investigated the impact of initial hemoglobin (Hgb) levels at Emergency Department (ED) triage on the severity and the clinical course of COVID-19. We conducted a cross-sectional study on 601 COVID-19 patients in a COVID-19 national referral center between 13 and 27 June 2020. All adult patients presented at our hospital that required admission or hotel isolation were included in this study. Patients admitted to the intensive care unit (ICU) had a lower initial Hgb than those admitted outside the ICU (12.84 g/dL vs. 13.31 g/dL, p = 0.026) and over the course of admission; the prevalence of anemia (Hgb < 12.5 g/dL) was 65% in patients admitted to ICU, whereas it was only 43% in non-ICU patients (odds ratio of 2.464, 95% CI 1.71-3.52). Anemic ICU patients had a higher mortality compared with non-anemic ICU patients (hazard ratio = 1.88, log-rank p = 0.0104). A direct agglutination test (DAT) for all anemic patients showed that 14.7% of ICU patients and 9% of non-ICU patients had autoimmune hemolytic anemia (AIHA). AIHA patients had significantly longer length of hospital stay compared with anemic patients without AIHA (17.1 days vs. 14.08 days, p = 0.034). Lower Hgb level at hospital presentation could be a potential surrogate for COVID-19 severity.

Rare case of Auto immune haemolytic anaemia in an infant with auto "f & kidd antibodies"

BACKGROUND

"f" antigen is a compound antigen in Rh blood group system. Anti f has haemolytic potential as described in literature. Its occurrence in an infant as autoantibody with another blood group system ie Jka is very rare. Case report We report a case of 10-month-old infant diagnosed with AIHA with autoantibodies directed towards "f" and Jka antigen. Antibody identification was done and antigen negative blood units were crossmatched & transfused with demonstrable haemoglobin rise and subsequent decrease in DAT grading.

RESULT

Auto anti f + Jka was identified in a 10 months old infant. Autoantibodies were identified by identification 3 & 11 cell panel and select cell panel. Results were later confirmed by allogenic adsorption & elution. Patient was transfused antigen negative blood unit which lead to haemoglobin rise & gradual decrease in direct coombs test grading CONCLUSION: To our knowledge, this is the first case report of auto anti f + Jka having haemolytic potential in an infant which shows the importance of extensive immmunohaematology workup in providing compatible blood unit in patients with autoantibody.

Pregnancy-associated immune-mediated hemolytic anemia in a dog

OBJECTIVE

To describe the clinical presentation, diagnostic investigations, and outcome of a dog with pregnancy-associated immune-mediated hemolytic anemia.

CASE SUMMARY

A 6-year-old, pregnant Bichon Frise was presented due to lethargy, inappetence, and progressive regenerative anemia with spherocytosis. The dog had been recently receiving ranitidine and amoxicillin/clavulanate. An in-house saline agglutination test identified marked agglutination and a urinalysis identified hemoglobinuria. Thoracic and abdominal imaging, as well as infectious diseases testing, was unremarkable. The bitch started whelping shortly following hospitalization, and the anemia progressively resolved without any other intervention. Ranitidine and amoxicillin/clavulanate were re-introduced within the following 2 months but the anemia did not reoccur. In light of these findings, a diagnosis of pregnancy-associated immune-mediated hemolytic anemia was made.

NEW OR UNIQUE INFORMATION PROVIDED

Pregnancy-associated immune-mediated hemolytic anemia should be considered in female dogs that develop severe hemolytic anemia during pregnancy and may resolve spontaneously following parturition.

Efficacy and safety of second-line treatment in Thai patients with primary warm-type autoimmune hemolytic anemia

Objectives:: To investigate the efficacy and safety of second-line treatment in Thai patients with primary warm-type autoimmune hemolytic anemia (AIHA) that failed corticosteroid treatment. Methods:: This descriptive retrospective study included patients aged >14 years who were diagnosed with and treated for primary warm-type AIHA at the Division of Hematology, Department of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand, during January 2007 to December 2016. All 54 included patients failed first-line corticosteroid treatment after which second-line treatment was prescribed. Baseline clinical characteristics, laboratory results at diagnosis and at start of second-line treatment, type of second-line treatment, treatment outcome, and complications of treatment including death were collected. Results:: Included patients had a mean age at onset of 55.8 years (14.5-87.4) and 83.3% of patients were female. Most patients (63%) were refractory to steroids, and the rest of them relapsed while on steroids. The second-line medications were azathioprine (61.1%), cyclophosphamide (31.5%), chlorambucil (1.9%), danazol (3.7%), and rituximab (1.9%), with respective response rates of 78.8%, 58.8%, 1/1 patient, 2/2 patients, and 0/1 patient. Strong positive direct Coombs' test (3+-4+) was the only predictive factor of treatment response (p = 0.008). Males had better relapse-free survival than females (not reached vs. 20.6 months) (p = 0.023). Approximately 40% of the patients who responded to second-line treatment relapsed at a median of 7.4 months. Conclusion:: Immunosuppressive drugs are the most common second-line treatment for primary warm-type AIHA in Thailand; however, relapse was common. Additional therapies are needed to reduce the relapse rate and prolong remission.

AIHA and Pancytopenia as Complications of Pembrolizumab Therapy for Metastatic Melanoma: A Case Report

Immunotherapy has been an emerging treatment for metastatic melanoma and several other malignancies since 2015. Hematological immune-mediated adverse effects from immunotherapy are rarely reported but they can cause serious harm to patients. Antibodies such as ipilimumab, nivolumab and pembrolizumab target different immune checkpoints to promote T cell anti-tumour response. In particular, pembrolizumab is an antibody that inhibits programmed cell death receptor 1 (PD-1) to upregulate tumour suppression. In this report, we present a case of pembrolizumab-induced autoimmune hemolytic anemia and pancytopenia in a patient who was receiving pembrolizumab treatment for metastatic melanoma. This patient has a history of chronic lymphocytic leukemia and was diagnosed with metastatic melanoma in 2017. He developed symptomatic AIHA and pancytopenia after receiving 8 cycles of pembrolizumab in 2018. Pembrolizumab treatment was discontinued and he was treated with blood transfusion and prednisone. After 5 months of tapering prednisone treatment, his anemia and pancytopenia have improved toward successful recovery. Cancer patients already face an increased risk of immunosuppression with conventional chemotherapy. This case report also summarized all reported cases of PD-1 inhibitor hematological adverse effects in the treatment of oncological diseases. These incidents reflect the risk of immune-mediated hematologic adverse effects, which should be considered in all patients using immunotherapy.

Primary and Secondary Immune Cytopenias: Evaluation and Treatment Approach in Children

This review summarizes the evaluation and management of the autoimmune cytopenias, a heterogeneous group of conditions including, but not limited to, autoimmune hemolytic anemia, immune thrombocytopenia, and multilineage disorders in Evans syndrome. These diseases can be challenging to treat and there are limited data comparing second-line therapeutics. The understanding of the molecular cause of these conditions is improving with the goal of advancing therapies and making them more targeted.

ACVIM consensus statement on the treatment of immune-mediated hemolytic anemia in dogs

Immune‐mediated hemolytic anemia (IMHA) causes severe anemia in dogs and is associated with considerable morbidity and mortality. Treatment with various immunosuppressive and antithrombotic drugs has been described anecdotally and in previous studies, but little consensus exists among veterinarians as to the optimal regimen to employ and maintain after diagnosis of the disease. To address this inconsistency and provide evidence‐based guidelines for treatment of IMHA in dogs, we identified and extracted data from studies published in the veterinary literature. We developed a novel tool for evaluation of evidence quality, using it to assess study design, diagnostic criteria, explanation of treatment regimens, and validity of statistical methods. In combination with our clinical experience and comparable guidelines for humans afflicted with autoimmune hemolytic anemia, we used the conclusions of this process to make a set of clinical recommendations regarding treatment of IMHA in dogs, which we refined subsequently by conducting several iterations of Delphi review. Additionally, we considered emerging treatments for IMHA in dogs and highlighted areas deserving of future research. Comments were solicited from several professional bodies to maximize clinical applicability before the recommendations were submitted for publication. The resulting document is intended to provide clinical guidelines for management of IMHA in dogs. These guidelines should be implemented pragmatically, with consideration of animal, owner, and veterinary factors that may vary among cases.

Diagnosis and management of chronic and refractory immune cytopenias in children, adolescents, and young adults

Children, adolescents, and young adults with chronic refractory autoimmune cytopenias represent a rare but challenging group of patients, who are managed frequently by pediatric hematologists. Novel diagnostic tests and genomic discoveries are refining historical diagnoses of Evans syndrome and common variable immunodeficiency, while also elucidating the cellular and molecular basis for these disorders. Genetic characterization of chronic and refractory autoimmune cytopenias has led to targeted therapies with improved clinical outcomes and fewer off-target toxicities. In this review, we focus on the appropriate diagnostic workup, expanded genetic testing, and novel treatment opportunities that are available for these challenging patients.

Successful treatment of tacrolimus-related pure red cell aplasia and autoimmune hemolytic anemia with rituximab in a pediatric cardiac transplant patient

Acquired pure red cell aplasia (PRCA) and autoimmune hemolytic anemia (AIHA) are rare complications of immunosuppression in pediatric solid organ transplant patients. We report a 14-month-old female child who developed Coombs positive hemolytic anemia and reticulocytopenia while on tacrolimus after cardiac transplantation. She was successfully treated with rituximab after failing treatment with corticosteroids and intravenous immunoglobulins. Clinicians should consider PRCA differential diagnosis in a patient presenting with reticulocytopenia and hemolysis. In addition, the coexistence of PRCA with AIHA, and the response to therapy with rituximab, supports a common immune-mediated pathogenesis for both disorders.

Eryptosis in autoimmune haemolytic anaemia

OBJECTIVE

Haemolysis and anaemia related to autoimmune haemolytic anaemia (AIHA) of warm type (wAIHA) and of cold type (cAIHA) are believed to be solely due to antibody and/or complement-mediated destruction and clearance of red blood cells (RBCs). There is evidence that RBCs of affected patients may also undergo eryptosis, the suicidal death of RBCs.

METHOD

RBCs from 24 patients with wAIHA, 7 patients with chronic cAIHA and one patient with AIHA of mixed type were analysed for exposed phosphatidylserine (PS) by treatment with phycoerythrin-labelled Annexin V, and cell-associated fluorescence was measured using a MACSQuant flow cytometer.

RESULTS

PS-exposing RBCs were detected in 7 of 13 patients with clinically significant wAIHA. Haemolysis was mostly related to IgM or IgA autoantibodies (aab) in those patients. In contrast, PS exposure in 11 patients with wAIHA in complete remission was comparable to that in healthy blood donors. All patients with chronic cAIHA and the patient with AIHA of mixed type showed haemolytic activity and high numbers of PS-exposing RBCs. Patients with decompensated AIHA appear to respond to treatment with erythropoietin, which is a known inhibitor of eryptosis.

CONCLUSION

Eryptosis may frequently occur in AIHA related to IgM or IgA aab. Inhibition of eryptosis with erythropoietin may represent a new therapeutic option in the treatment of AIHA.

Evidence Suggesting Complement Activation and Haemolysis at Core Temperature in Patients with Cold Autoimmune Haemolytic Anaemia

BACKGROUND

It is unclear why haemolysis may somewhat persist in patients with cold autoimmune haemolytic anaemia (cAIHA) at 37 °C (core temperature).

METHODS

Seven patients with cAIHA were included in this study. Serological testing was performed using standard techniques. Bound autoantibodies (aab) on patients' RBCs were analysed by the direct antiglobulin test (DAT), dual antiglobulin test (DDAT) and flow cytometry (FC) using pre-warmed RBCs (37 °C). Temperature-dependent complement binding was determined by incubation of patients' serum samples with group O RBCs and fresh serum complement.

RESULTS

The DAT was strongly positive with anti-C3d in all cases, independent of season and outside temperature. Haemolysis usually improved during warm periods of time, but decompensated following febrile infections, and persisted throughout the year, though exposure to the cold was strictly avoided. In addition, trace amounts of IgM aab were infrequently detectable on patients' RBCs even at 37 °C, and complement activation was demonstrated following incubation of RBCs with the causative aab at 37 °C.

CONCLUSIONS

Binding of trace amounts of IgM aab at 37 °C may provide an explanation for the durable C3d-positive DAT and haemolysis in patients with cAIHA.

Autoimmune Hemolysis: A Journey through Time

The existence of autoimmune diseases in humans has been known for almost 100 years. Currently, autoimmune pathogenesis has been attributed to more than 40 human diseases; yet it is still not clear what immune abnormalities conclusively prove underlying autoimmune pathogenesis. Hence, although much has been learned, research is still needed for complete elucidation of the mechanisms of the immune dysregulation in AIHA. Better understanding of the underlying mechanism(s) may allow for development of more specific therapies of these not uncommon and often difficult-to-treat disorders.

Clinically and/or Serologically Misleading Findings Surrounding Immune Haemolytic Anaemias

Autoimmune haemolytic anaemias (AIHAs) are well-characterized disorders. They can be differentiated from one another and from other non-immune haemolytic anaemias by clinical, laboratory and serological testing. However, several misleading clinical presentations and/or serological findings may result in misinterpretation, delay and/or misdiagnosis. Such failures are avoidable by adequate clinical and serological experience of the responsible physicians and serologists or, at least, by an optimised bidirectional communication. As long as this has not been achieved, unpleasant failures are to be expected. A true diagnosis of AIHA can neither be verified by clinical nor serological findings alone. Thus, a collective clinical and serological picture remains obligatory for fulfilling the criteria of optimal diagnosis and therapy. Ultimately, the majority of pioneer scientific and practical work in this field stems from scientists who were simultaneously involved in both the clinic and serology.

Treatment Options for Primary Autoimmune Hemolytic Anemia: A Short Comprehensive Review

Until now, treatment of primary autoimmune hemolytic anemia of the warm type (wAIHA) is primarily based on immunosuppression. However, many patients do not respond adequately to treatment, and treated patients may develop severe side effects due to uncontrolled, mixed and/or long-lasting immunosuppression. Unfortunately, the newly used therapeutic monoclonal antibodies are unspecific and remain frequently ineffective. Thus, development of a specific therapy for AIHA is necessary. The ideal therapy would be the identification and elimination of the causative origin of autoimmunization and/or the correction or reprogramming of the dysregulated immune components. Blood transfusion is the most rapidly effective measure for patients who develop or may develop hypoxic anemia. Although some effort has been made to guide physicians on how to adequately treat patients with AIHA, a number of individual aspects should be considered prior to treatment. Based on my serological and clinical experience and the analysis of evidence-based studies, we remain far from any optimized therapeutic measures for all AIHA patients. Today, the old standard therapy using controlled steroid administration, with or without azathioprine or cyclophosphamide, is, when complemented with erythropoiesis-stimulating agents, still the most effective therapy in wAIHA. Rituximab or other monoclonal antibodies may be used instead of splenectomy in therapy-refractory patients.