Epidemiology of Secondary Warm Autoimmune Haemolytic Anaemia-A Systematic Review and Meta-Analysis

Role of IRF4 in mediating plasmablast differentiation in diffuse large B-cell lymphomas via mTORC1 pathway

Autoimmune haemolytic anaemia (AIHA) is common secondary to diffuse large B-cell lymphoma (DLBCL). However, there are no reports on tumour B-cells differentiating into plasmablasts in DLBCL secondary AIHA. To state impact of the interferon regulatory factor 4 (IRF4) on DLBCL and explore the mechanism of IRF4 on plasmablast differentiation.We analysed the expression of immunity-related genes from the Gene Expression Omnibus and correlated predictors from clinical and laboratory data using R package and various statistical tools. Western blotting (WB) was used to detect protein levels in DLBCL cell lines of different subtypes to investigate the plasmablast and activation of mTORC1. To furtherly validate mTOR regulation of plasmablast differentiation, mTOR-activated and -inhibited cell models were constructed by CCK8 and flow cytometry (FCM) was used to assess the proportion of CD38 positive cells. We found that IRF4 was highly expressed in activated B-cell-like (ABC) DLBCL vs. germinal centre B-cell-like (GCB) DLBCL. Positive MUM-1and low haemoglobin values were corrected to non-CGB patients. Plasmablast indictors (BLIMP-1, ARF4, IRE1α, and IRF4) and mTORC1 pathway indictors (mTOR, p70S6K and phosphorylated-p70S6K) were different level in ABC cell lines. After successfully constructing cell models, the proportion of CD38+ cells changed in mTOR-activated and -inhibited ABC-DLBCL cell models. We first pointed out that the role of the IRF4 invovling in DLBCL cell plasmablast differentiation via mTORC1 pathway. These findings could be extended to provide experimental evidence for novel treatments of secondary AIHA in ABC-DLBCL.

Sovleplenib in patients with primary or secondary warm autoimmune haemolytic anaemia: results from phase 2 of a randomised, double-blind, placebo-controlled, phase 2/3 study

BACKGROUND

Spleen tyrosine kinase inhibitors are potential treatment options for warm autoimmune haemolytic anaemia. This study aimed to assess the preliminary efficacy and safety of sovleplenib-an oral spleen tyrosine kinase inhibitor-in patients with warm autoimmune haemolytic anaemia in China. Here we report on the phase 2 results.

METHODS

This randomised, double-blind, placebo-controlled, phase 2 part from the phase 2/3 study was conducted at 13 centres in China. Eligible patients, aged 18-75 years, with an Eastern Cooperative Oncology Group (ECOG) performance status of no more than 2, had primary or secondary warm autoimmune haemolytic anaemia (stable underlying disease not requiring drug intervention) with no response to previous glucocorticoid treatment, haemoglobin of less than 100 g/L with active haemolysis, and a positive direct antiglobulin test. The study comprised two periods; patients were randomly assigned (3:1) to receive sovleplenib or placebo at 300 mg orally once a day in the 8-week double-blind period. Upon completion, all patients entered an open-label treatment period for at least 16 weeks and received sovleplenib 300 mg once a day until 24 weeks after the last patient was randomly assigned. The primary endpoint for phase 2 of the trial was overall haemoglobin response rate (haemoglobin ≥100 g/L with an increase of ≥20 g/L from baseline at least once, and haemoglobin not affected by rescue therapy, such as red blood cell transfusions, intravenous immunoglobulin, and glucocorticoids) by week 24. Efficacy analyses in the 0-8 week double-blind period included all patients who were randomly assigned, analysed by intention-to-treat. Safety analysis in the double-blind period included patients in the intention-to-treat population who received at least one dose of the study medication. This phase 2/3 study is registered with ClinicalTrials.gov, NCT05535933, and the phase 3 part is ongoing.

FINDINGS

Between Sept 26, 2022, and May 9, 2023, 34 patients were screened and 21 patients (four [19%] male and 17 [81%] female) were enrolled in the study and randomly assigned to receive either sovleplenib (n=16) or placebo (n=5). All 21 patients completed the 0-8-week double-blind treatment and entered the open-label treatment period. The overall haemoglobin response rate was 67% (14 of 21 patients) by week 24, and durable haemoglobin response rate was 48% (ten of 21 patients) by week 24. During the 0-8-week double-blind treatment, 13 (81%) of 16 patients in the sovleplenib group versus five (100%) of five patients taking placebo reported treatment-emergent adverse events (TEAEs), and four (25%) of 16 patients versus four (80%) of five patients reported grade 3 adverse events. Although all 21 patients had a TEAE during the 24-week treatment with sovleplenib, only seven (33%) patients had grade 3 events. The most common grade 3 TEAE was anaemia (four [19%] patients), which was not related to treatment. There were no grade 4 or 5 TEAEs.

INTERPRETATION

Sovleplenib treatment achieved an encouraging overall haemoglobin response in Chinese patients with warm autoimmune haemolytic anaemia and was well tolerated. The phase 3 part of the study (ESLIM-02) is currently ongoing to further substantiate the efficacy and safety of sovleplenib in this setting.

FUNDING

HUTCHMED.

Parsaclisib for the treatment of primary autoimmune hemolytic anemia: Results from a phase 2, open-label study

Autoimmune hemolytic anemia (AIHA) is a group of acquired autoimmune disorders characterized by red blood cell hemolysis. In a phase 2, open-label, multicenter study, adults with warm AIHA, cold agglutinin disease, or mixed-type AIHA were administered once-daily 1.0 or 2.5 mg parsaclisib (selective phosphoinositide 3-kinase δ inhibitor) orally for 12 weeks, followed by an extension period. Dose increases (for AIHA worsening) or decreases (for tolerability) were permitted. Primary efficacy endpoint was the proportion of patients with complete (≥12 g/dL hemoglobin [Hgb]) or partial (10-12 g/dL Hgb or ≥2 g/dL increase from baseline) response at any visit during weeks 6-12 not attributable to transfusion. Among 25 enrolled patients (median age, 63 y), 16 (64%) achieved a partial or complete Hgb response during weeks 6-12. Responses were observed by week 1 in 52.0% of patients with incremental improvements during weeks 6-12 and sustained responses during the extension period. Responses were higher among patients with warm AIHA versus other types (75.0% vs. 44.4%). Clinically meaningful improvements in Functional Assessment of Chronic Illness Therapy-Fatigue scores were observed at weeks 6 and 12. All patients had treatment-emergent adverse events (TEAEs), most commonly diarrhea (32.0%) and pyrexia (28.0%). Grade ≥3 TEAEs occurred in 13 patients (52.0%). TEAEs considered possibly related to treatment occurred in 11 patients (44.0%). No dose reductions were required; six patients (24%) discontinued for a TEAE. In summary, parsaclisib was well tolerated and resulted in substantial improvements in Hgb response at week 1, with durable responses through the extension period. CLINICAL TRIAL REGISTRATION: This trial was registered at ClinicalTrials.gov (NCT03538041).

Autoimmune haemolytic anaemias

Adult autoimmune haemolytic anaemias (AIHAs) include different subtypes of a rare autoimmune disease in which autoantibodies targeting autoantigens expressed on the membrane of autologous red blood cells (RBCs) are produced, leading to their accelerated destruction. In the presence of haemolytic anaemia, the direct antiglobulin test is the cornerstone of AIHA diagnosis. AIHAs are classified according to the isotype and the thermal optimum of the autoantibody into warm (wAIHAs), cold and mixed AIHAs. wAIHAs, the most frequent type of AIHAs, are associated with underlying conditions in ~50% of cases. In wAIHA, IgG autoantibody reacts with autologous RBCs at 37 °C, leading to antibody-dependent cell-mediated cytotoxicity and increased phagocytosis of RBCs in the spleen. Cold AIHAs include cold agglutinin disease (CAD) and cold agglutinin syndrome (CAS) when there is an underlying condition. CAD and cold agglutinin syndrome are IgM cold antibody-driven AIHAs characterized by classical complement pathway-mediated haemolysis. The management of wAIHAs has long been based around corticosteroids and splenectomy and on symptomatic measures and non-specific cytotoxic agents for CAD. Rituximab and the development of complement inhibitors, such as the anti-C1s antibody sutimlimab, have changed the therapeutic landscape of AIHAs, and new promising targeted therapies are under investigation.

Mixed autoimmune hemolytic anemia as the initial presentation of systemic lupus erythematosus: A case report and review

Autoimmune hemolytic anemia (AIHA) is an acquired condition caused by autoantibody mediated destruction of erythrocytes. AIHA is classified as warm or cold depending on whether the autoantibodies involved react optimally at or below body temperature (37°C), respectively. Mixed AIHA, with features of both, is rare and clinically more severe. We report a case of mixed AIHA that was found to be the presentation of systemic lupus erythematosus (SLE). Treatment with rituximab and prednisone resulted in good response. Although more commonly associated with warm AIHA, SLE can present with mixed AIHA.

Mycophenolate Mofetil for the Treatment of Warm Autoimmune Haemolytic Anaemia Post-Rituximab Therapy: A Case Series

Background

Warm autoimmune haemolytic anaemia (wAIHA) is an acquired haemolytic disorder most commonly treated with a combination of corticosteroids, rituximab and/or splenectomy. Third-line therapies for refractory cases include immunosuppressive agents. Mycophenolate mofetil is frequently used in these scenarios, although its use is supported by small studies and anecdotal evidence rather than large-scale data.

Case description

We describe three cases of refractory warm autoimmune haemolytic anaemia successfully treated with mycophenolate mofetil. Case 1: A persistent case of autoimmune haemolytic anaemia in a 56-year-old was ultimately managed with mycophenolate mofetil, leading to successful steroid tapering and stable haemoglobin levels without relapse. Case 2: A woman with a complex oncological history, including lymphoma and breast cancer, achieved remission with mycophenolate therapy, maintaining stability post-steroid treatment. Case 3: Mycophenolate proved effective for a 63-year-old with cirrhosis after recurrent autoimmune anaemia and deep vein thrombosis, enabling cessation of steroids and maintaining remission.

Conclusion

Management of this condition can be challenging and balancing the available treatments is crucial to reduce potential complications from long-term therapies that appear to be ineffective. Our case series demonstrates anecdotal experience on successful use of mycophenolate mofetil for complex refractory cases of wAIHA.

LEARNING POINTS

Warm autoimmune haemolytic anaemia can be a challenging condition to manage. Refractory cases that are steroid-dependent can benefit from trialling steroid-sparing agents such as mycophenolate.Anti-CD20 agents such as rituximab can be very effective in refractory cases, however there is a small percentage of patients that might not be responsive to this monoclonal antibody.Autoimmune haemolytic anaemias can be frequently complicated by thrombotic events, and part of the backbone treatment is establishing good thromboprophylaxis.

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.

Healthcare resource utilization of patients with warm autoimmune hemolytic anemia initiating first line therapy of oral corticosteroids with or without rituximab

This retrospective cohort study described real-world treatment patterns and healthcare resource utilization (HCRU) of patients with warm autoimmune hemolytic anemia (wAIHA) initiating treatment with first-line (1L) oral corticosteroids (OCS) + rituximab (R) compared to 1L OCS. Patients with a wAIHA diagnosis code (D59.11) between 8/2020-3/2022 were identified using US pharmacy and medical claims databases. Patients initiating 1L OCS ± R were identified (date of initiation = 'index date') with a 1-year pre-index period and a variable (minimum 1-year) follow-up period. The final sample comprised 77 1L OCS + R patients and 400 1L OCS patients (~ 60% female, mean age > 64 years). Over the 1-year follow-up, HCRU was higher in the OCS + R cohort with higher mean number of physician office visits (22.9 and 14.4; p < 0.01), including hematology/oncology office visits, and higher utilization of rescue therapy (59.7% and 33.3%; p < 0.01), driven by higher use of injectable corticosteroids. Patients in OCS + R and OCS groups completed 1L therapy after a similar mean duration of 103.5 and 134.6 days, respectively (p = 0.24). In the majority of patients, second-line (2L) therapy was initiated at a similar timepoint: 66.2% OCS + R and 72.0% OCS cohorts (p = 0.31) initiated 2L in a mean of 218.3 and 203.2 days (p = 0.76) after the end of 1L treatment, respectively. The addition of rituximab in 1L did not extend the remission period, with most patients in both cohorts initiating 2L therapy within less than 1 year of completing 1L treatment. 1L OCS + R patients also had substantial HCRU burden. More effective novel therapies are needed to address the high unmet need in wAIHA.

Primary autoimmune haemolytic anaemia is associated with increased risk of ischaemic stroke: A binational cohort study from Denmark and France

Primary autoimmune haemolytic anaemia (AIHA) causes the destruction of red blood cells and a subsequent pro-thrombotic state, potentially increasing the risk of ischaemic stroke. We investigated the risk of ischaemic stroke in patients with AIHA in a binational study. We used prospectively collected data from nationwide registers in Denmark and France to identify cohorts of patients with primary AIHA and age- and sex-matched general population comparators. We followed the patient and comparison cohorts for up to 5 years, with the first hospitalization of a stroke during follow-up as the main outcome. We estimated cumulative incidence, cause-specific hazard ratios (csHR) and adjusted for comorbidity and exposure to selected medications. The combined AIHA cohorts from both countries comprised 5994 patients and the 81 525 comparators. There were 130 ischaemic strokes in the AIHA cohort and 1821 among the comparators. Country-specific estimates were comparable, and the overall adjusted csHR was 1.36 [95% CI: 1.13-1.65], p = 0.001; the higher rate was limited to the first year after AIHA diagnosis (csHR 2.29 [95% CI: 1.77-2.97], p < 10-9 ) and decreased thereafter (csHR 0.89 [95% CI: 0.66-1.20], p = 0.45) (p-interaction < 10-5 ). The findings indicate that patients diagnosed with primary AIHA are at higher risk of ischaemic stroke in the first year after diagnosis.

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

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

A Rare Association of Mixed Autoimmune Hemolytic Anemia with Gastric Carcinoma

This case report outlines a 70-year-old female patient who presented with a concurrent mixed autoimmune hemolytic anemia (AIHA) and a gastric adenocarcinoma. Her treatment course of these two diseases is summarized, which included supportive care, neoadjuvant chemotherapy for her gastric adenocarcinoma, steroids, rituximab, and surgical resection of the tumor. This approach ultimately led to the stabilization of her AIHA and primary cure for her solid malignancy. We briefly review both AIHA and gastric adenocarcinoma as clinical entities, propose working causes of hemolytic anemia including gastric adenocarcinoma, and outline a successful treatment pathway for these two concurrent conditions.

Warm autoimmune hemolytic anemia and the best treatment strategies

Warm autoimmune hemolytic anemia (wAIHA) is characterized by evidence of red blood cell (RBC) hemolysis and a direct antiglobulin test positive for IgG and sometimes complement. While varying with the extent of the compensatory increase in RBC production, symptoms of anemia predominate, as does jaundice, the latter often exacerbated by concurrent Gilbert's syndrome. Initial treatment with corticosteroids is highly effective, with over 85% of patients responding but with less than one-third maintaining that response upon weaning. Subsequent rituximab administration in those failing corticosteroids provides complete remission in over 75% of patients and may be long-lasting. Over 50% of patients failing rituximab respond to erythropoiesis-stimulating agents or immunosuppressive agents. Splenectomy is best deferred if possible but does offer long-term remission in over two-thirds of patients. A number of new treatments for wAIHA (fostamatinib, rilzabrutinib, and FcRn inhibitors) show promise. A treatment algorithm for wAIHA is proposed to avoid the excessive use of corticosteroids.

Diagnosis and Management of Autoimmune Hemolytic Anemias

Autoimmune hemolytic anemia (AIHA) is usually categorized, as other immune-mediated cytopenias, in so-called benign hematology, and it is consequently managed in various settings, namely, internal medicine, transfusion centers, hematology and, more rarely, onco-hematology departments [...].

Survival in autoimmune hemolytic anemia remains poor, results from a nationwide cohort with 37 years of follow-up

Introduction

Autoimmune hemolytic anemia (AIHA) is considered a chronic disease, with an overall good prognosis. However, recent reports indicate pre‐mature mortality. Causes of death have not been evaluated previously.

Methods

In a nationwide setting, we identified all patients with warm type AIHA or cold agglutinin disease (CAD), and age–sex‐matched comparators from Denmark, 1980–2016. We estimated overall survival and cause‐specific mortality from anemia, infection, cardiovascular causes, hematological or solid cancer, bleeding, or other causes, using cumulative incidence proportions.

Results

We identified 1460 patients with primary AIHA, 1078 with secondary AIHA, 112 with CAD, and 130 801 comparators. One‐year survival and median survival were, 82.7% and 9.8 years for primary AIHA, 69.1% and 3.3 years for secondary AIHA, and 85.5% and 8.8 years for CAD. Prognosis was comparable to the general population only in patients with primary AIHA below 30 years. In all other age and subgroups, the difference was considerable. Cumulated cause‐specific mortality at 1 year was increased among patients versus comparators.

Discussion

All groups of autoimmune hemolytic anemia are associated with increased overall and cause‐specific mortality compared to the general population. This probably reflects unmet needs in both treatment and follow‐up programs.

The Risk of Developing Osteoporosis in Hemolytic Anemia-What Aggravates the Bone Loss?

Hemolytic anemia (HA) renders erythropoietic stress on the bone marrow and has been linked to osteoporosis. In this nationwide retrospective cohort study, we examined this correlation by utilizing the Taiwan National Health Insurance Research Database (NHIRD). We identified two cohorts, matching population with and without HA in a 1:4 ratio. A total of 2242 HA patients and 8968 non-HA patients were enrolled. Patients with HA had a significantly higher cumulative incidence (log-rank test p = 0.0073), higher incidence density (5.11 vs. 3.76 per 1000 persons-years), and a 1.31-fold risk of developing osteoporosis than non-HA patients (aHR = 1.31, 95% C.I. 1.04-1.63, p = 0.01). After adjusting for age, sex, and comorbidities, patients with factors including female (aHR = 2.57, 95% C.I. 2.05-3.22, p < 0.001), age > 65 (aHR = 9.25, 95% C.I. 7.46-11.50, p < 0.001), diagnosis of cholelithiasis (aHR = 1.76, 95% C.I. 1.20-2.58, p = 0.003) and peptic ulcer disease (aHR = 1.87, 95% C.I. 1.52-2.29, p < 0.001) had significantly higher risk of osteoporosis. We propose that this correlation may be related to increased hematopoietic stress, increased consumption of nitric oxide (NO) by hemolysis, and the inhibitory effects of iron supplements on osteogenesis through the receptor activator of nuclear factor κB ligand (RANKL)/Osteoprotegerin pathway and the Runt-related transcription factor 2 (RUNX2) factor. Our findings suggest that patients with hemolytic anemia are at a higher risk of developing osteoporosis, and it would be in the patient's best interest for physicians to be aware of this potential complication and offer preventative measures.