Severe autoimmune hemolytic anemia following immunotherapy with checkpoint inhibitors in two patients with metastatic melanoma: a case report.

Introduction: Over the past decade, immune checkpoint inhibitors such as antibodies against cytotoxicity T-lymphocyte-associated protein 4 (CTLA-4) and programmed cell death protein 1 (PD-1) have become an important armamentarium against a broad spectrum of malignancies. However, these specific inhibitors can cause adverse autoimmune reactions by impairing self-tolerance. Hematologic side effects of immune checkpoint inhibitors, including autoimmune hemolytic anemia (AIHA), are rare but can be life-threatening. Case report: Herein, we report two patients on immune checkpoint inhibitors for metastatic melanoma who developed AIHA with symptoms of dyspnea and fatigue. In the first patient, symptoms alleviated after discontinuation of combined anti CTLA-4 and anti-PD-1 therapy, initiation of corticosteroids and application of a single red blood cell transfusion. Due to subsequent progress of melanoma, combinational anti-PD-1 and tyrosine kinase inhibitor therapy was initiated based on multidisciplinary tumor board decision. After two months, she again developed the described hematological and clinical signs of AIHA leading to cessation of anti-PD-1 therapy and initiation of corticosteroids, which again resulted in an alleviation of her symptoms. Due to further progression, the patient received dacarbazine for several months before she decided to stop any therapy other than palliative supportive care. In the second patient, discontinuation of anti-PD-1 therapy and initiation of corticosteroids entailed a complete alleviation of his symptoms. After refusing chemotherapy due to subsequent melanoma progression, he received radiotherapy of bone metastases and is currently enrolled in a clinical trial. The patient did not develop AIHA ever since. Conclusion: Hematologic immune-related adverse events due to treatment with immune checkpoint inhibitors are rare but can have life-threatening consequences. If dyspnea and other clinical symptoms are present, AIHA should be considered as a potential cause and treated promptly in a multidisciplinary setting. An expanded comprehension of risk factors and pathogenesis of AIHA is needed to identify high-risk patients beforehand, leading to more effective predictive and reactive treatment approaches.

Autoimmune cytopenias in children: When to think of primary immunodeficiency?

Autoimmune cytopenias are defined by autoantibodies' immune destruction of one or more blood elements. Most often it is autoimmune hemolytic anemia or immune thrombocytopenia or both that define Evans syndrome. It may be secondary to infection or to underlying pathology such as systemic autoimmune disease or primary immunodeficiency, especially when it becomes chronic over several years. Primary Immunodeficiencies or inborn errors of immunity (IEI) are no longer defined solely by infections: autoimmunity is part of the clinical features of several of these diseases. It is dominated by autoimmune cytopenias, in particular, immune thrombocytopenia (ITP) and autoimmune hemolytic anaemia (AIHA). The challenges for the clinician are the situations where autoimmune cytopenias are chronic, recurrent and/or refractory to the various long-term therapeutic options. Most of these therapies are similar in action and generally consist of non-mediated immune suppression or modulation. In these situations, primary Immunodeficiencies must be diagnosed as soon as possible to allow the initiation of a targeted treatment and to avoid several ineffective therapeutic lines.

IgA plasma cell myeloma presenting as cold agglutinin-induced haemolytic transfusion reaction.

Cold agglutinins produced in the setting of B cell neoplasms, such as lymphoplasmacytic lymphoma and plasma cell myeloma, can mediate autoimmune haemolytic anemia. Transfusion of these patients can exacerbate cold agglutinin-mediated haemolysis. Moreover, the workup for these reactions represents a diagnostic challenge due in part to false negative direct antiglobulin tests (DATs). Here, we report an anaemic patient who after a red blood cell (RBC) transfusion performed without blood warming, experienced a DAT-negative haemolytic transfusion reaction, and was later diagnosed with IgA-multiple myeloma, which showed an uncommon granular pattern by CD138 immunohistochemistry. Extensive workup excluded other diagnostic possibilities, including the presence of Donath-Landsteiner antibodies and cryoglobulins. Successful treatment with CyBorD (cyclophosphamide, bortezomib and dexamethasone) achieved complete remission, and additional RBC transfusions using warmers were completed uneventfully.

Treatment with plasma exchange of a pregnant woman with anti-PP1Pk alloimmunization: A case report.

The histo-blood group antigens P, P1 and Pk are a closely related set of glycosphingolipid structures expressed by red blood cells and other tissues. None of these three characters is expressed on p cells, a null phenotype that arises in the context of homozygous mutation of the A4GALT gene. Subjects with p phenotype spontaneously develop a natural alloantibody named anti-PP1Pk, which is a mixture of IgG and IgM against P1, P and Pk. While anti-P1 is a weak cold antibody with poor clinical significance, anti-P and anti-Pk antibodies are potent haemolysins responsible for severe hemolytic transfusion reactions. The rare anti-PP1Pk alloantibodies are associated with recurrent spontaneous abortion in the first trimester of gestation. P and Pk antigens are expressed at high levels on the placenta and antibodies directed against both these structures are deleterious to placental trophoblasts. Here we describe the use of plasma exchange (PEX) in a nulliparous 39-year-old woman with anti-PP1Pk antibodies and a history of repeated spontaneous early abortions and hypofertility. The patient underwent apheresis starting from the third week throughout the pregnancy and a healthy child was delivered by cesarean section at 35 WG. The newborn required only phototherapy within a few days of life. We can state that an early treatment with the only PEX has proven to be effective and safe in the management of a fetomaternal P-incompatibility caused by a high anti-PP1Pk titer (256).

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

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

Cold agglutinin disease in childhood: a case series with review of literature.

Cold agglutinins are autoantibodies that target RBC antigens at temperatures below average core body temperature. They produce RBC agglutination and cold agglutinin disease (CAD), a rare form of autoimmune haemolytic anaemia. Due to it's under recognition, there is a delay between the start of symptoms and the diagnosis. With an emphasis on the laboratory approach, we provide the clinical and analytical findings from five cases of childhood CAD.

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.

Total arch replacement for an aortic arch aneurysm with cold agglutinin disease after rituximab and plasmapheresis.

BACKGROUND: Cold agglutinin disease can lead to significant complications, especially for patients undergoing arch repair requiring hypothermic circulatory arrest. Rituximab and plasmapheresis are treatments for cold agglutinin disease. However, its use in patients with Stanford type A dissection has not been reported. Therefore, after consultation with hematologists, we used rituximab and plasmapheresis before mild hypothermic aortic arch surgery to maintain the body temperature above the thermal altitude. CASE PRESENTATION: This report describes an 86-year-old male patient with acute type A aortic dissection who received outpatient treatment for rheumatoid arthritis and a 55-mm thoracic aortic aneurysm. The patient was scheduled to undergo urgent surgery for a type A intramural hematoma and progressive aortic aneurysm; however, laboratory test results indicated blood clotting and cold agglutinin. Consequently, urgent surgery was rescheduled. After consulting with hematologists, rituximab was initiated 3 months before surgery, and plasmapheresis was performed 2 days before surgery for cold agglutinin disease. Under mild hypothermia conditions, total arch replacement using the frozen elephant trunk technique was performed while maintaining cerebral and lower body perfusion. The postoperative course was uneventful. On postoperative day 42, the patient was discharged without any neurological deficits. CONCLUSIONS: This case involving total arch replacement with mild hypothermia for an aortic arch aneurysm with cold agglutinin disease after rituximab treatment and plasmapheresis resulted in a successful outcome.

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.

Paroxysmal cold hemoglobinuria: A diagnostic dilemma in a paediatric patient.

BACKGROUND: Autoimmune hemolytic anaemia is rare in the paediatric population. Differentiation of the underlying aetiology is complicated by heterogeneity in diagnostic criteria and testing strategies. Paroxysmal cold hemoglobinuria (PCH) is an uncommon form of paediatric autoimmune hemolytic anaemia. Identification of the causative biphasic hemolysin requires clinical recognition and access to the Donath-Landsteiner (DL) test. CASE PRESENTATION: We report a young paediatric patient with no significant past medical history who presented with severe anaemia, jaundice, and dark urine following a respiratory illness. Initial laboratory evaluation showed a haemoglobin of 3.6 g/dL with plasma free haemoglobin 170 mg/dL (reference range <5 mg/dL), 3+ hemoglobinuria (reference range = 0), and direct antiglobulin testing (DAT) positive for complement component 3 (C3) only. Haemoglobin continued to decline following RBC transfusions using a blood warmer for presumed cold agglutinin syndrome. Subsequent testing at the reference laboratory revealed a DAT positive for C3 and immunoglobulin isotype G (IgG) and an eluate pan-agglutinin most consistent with a warm autoantibody, but the patient's anaemia was non-responsive to glucocorticoids and blood warmer cessation. However, a maximum cold agglutinin titre of 4 and absent thermal amplitude substantially weakened the evidence for the clinical significance of the cold autoantibodies. Consultation with the institutional transfusion medicine specialist prompted collection for the DL test, which demonstrated a definitive biphasic hemolysin consistent with PCH. DISCUSSION: Conflicting clinical and immunohematologic evidence can obscure the aetiology of autoimmune hemolysis, including concurrent warm and/or cold autoantibodies. Clinical correlation, consultation with the institutional transfusion service, and access to specialised testing are essential to establish the correct diagnosis.

Outcomes of therapeutic plasma exchange in severe autoimmune hemolytic anemia hospitalizations: An analysis of the National Inpatient Sample.

BACKGROUND: Autoimmune hemolytic anemia (AIHA) is characterized by humoral and/or cellular immune-mediated hemolysis of red blood cells. The role of therapeutic plasma exchange (TPE) in AIHA is unclear. STUDY DESIGN AND METHODS: We queried the National Inpatient Sample (NIS) for 2002-2019 to identify hospitalizations with the primary diagnosis of AIHA. We included hospitalizations with the highest severity subclass identified by All Patient Refined Disease Related Group (APR-DRG). We used multivariate regression analysis to compare in-hospital mortality and other relevant in-hospital outcomes between hospitalizations that received TPE and those that did not. RESULTS: We identified 255 weighted hospitalizations in the TPE group and 4973 in the control group. Those in the control group were older (median age 67 vs. 48 years, p < .001) and had a higher prevalence of most comorbidities. The TPE group had higher odds of all-cause in-hospital mortality (odds ratio [OR], 1.59; 95% confidence interval [CI], 1.19-2.11). They also had higher rates of many secondary outcomes, including requiring mechanical ventilation, developing circulatory shock, acute stroke, urinary tract infections, intracranial hemorrhage, acute kidney injury, and requiring new hemodialysis. No significant differences were noted in the rates of acute myocardial infarctions, bacterial pneumonia, sepsis/septicemia, thromboembolic events, and other bleeding events. Furthermore, the TPE group had a higher median length of hospital stay (19 vs. 9 days, p < .001). CONCLUSION: Hospitalizations with severe AIHA that received TPE had higher rates of adverse in-hospital outcomes.

Plasmodium falciparum-Induced Autoimmune Hemolytic Anemia in a Pregnant Patient with Sickle Cell Disease.

BACKGROUND Sickle cell disease (SCD) is an autosomal recessive hereditary condition characterized by chronic hemolytic anemia and painful vaso-occlusive episodes. Homozygous sickle cell patients are at increased risk of morbidity and mortality from malaria. Autoimmune hemolytic anemia (AIHA) secondary to, or in the setting of, malarial infection is rare. In our case, the concurrence of Plasmodium falciparum malarial parasitemia and AIHA led to severe hemolytic anemia with an extensive packed red blood cell transfusion requirement. The patient's underlying SCD also contributed to the severity of the anemia and persistence of the malarial infection. CASE REPORT We report the case of a 29-year-old woman in the second trimester of pregnancy, with a history of SCD, who presented with severe anemia beyond her typical baseline in the setting of P. falciparum malaria. Hemolysis markers, including lactate dehydrogenase and bilirubin, were elevated. Direct Coombs testing was positive for IgG and C3 antibodies. Treatment with antimalarial agents and steroids led to clinical improvement and eventual clearance of the parasitemia. CONCLUSIONS Our patient's clinical course was most compatible with P. falciparum malaria-induced AIHA. Although she received a short course of steroids, it was treatment and clearance of the parasitemia that led to resolution of the hemolysis and a return to baseline hemoglobin levels. While the exact mechanism of AIHA in malaria is not well characterized, several unique mechanisms have been proposed and should be considered in cases of P. falciparum malaria manifesting with particularly severe hemolytic anemia.

C1-inhibitor treatment in patients with severe complement-mediated autoimmune hemolytic anemia.

Complement-mediated (CM) autoimmune hemolytic anemia (AIHA) is characterized by the destruction of red blood cells (RBCs) by autoantibodies that activate the classical complement pathway. These antibodies also reduce transfusion efficacy via the lysis of donor RBCs. Because C1-inhibitor (C1-INH) is an endogenous regulator of the classical complement pathway, we hypothesized that peritransfusional C1-INH in patients with severe CM-AIHA reduces complement activation and hemolysis, and thus enhances RBC transfusion efficacy. We conducted a prospective, single-center, phase 2, open-label trial (EudraCT2012-003710-13). Patients with confirmed CM-AIHA and indication for the transfusion of 2 RBC units were eligible for inclusion. Four IV C1-INH doses (6000, 3000, 2000, and 1000 U) were administered with 12-hour intervals around RBC transfusion. Serial blood samples were analyzed for hemolytic activity, RBC opsonization, complement activation, and inflammation markers. Ten patients were included in the study. C1-INH administration increased plasma C1-INH antigen and activity, peaking at 48 hours after the first dose and accompanied by a significant reduction of RBC C3d deposition. Hemoglobin levels increased briefly after transfusion but returned to baseline within 48 hours. Overall, markers of hemolysis, inflammation, and complement activation remained unchanged. Five grade 3 and 1 grade 4 adverse event occurred but were considered unrelated to the study medication. In conclusion, peritransfusional C1-INH temporarily reduced complement activation. However, C1-INH failed to halt hemolytic activity in severe transfusion-dependent-CM-AIHA. We cannot exclude that posttransfusional hemolytic activity would have been even higher without C1-INH. The potential of complement inhibition on transfusion efficacy in severe CM-AIHA remains to be determined.

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

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

Autoimmune hemolytic anemia during pregnancy and puerperium: an international multicenter experience.

Relapsing or occurring de novo autoimmune hemolytic anemia (AIHA) during pregnancy or puerperium is a poorly described condition. Here, we report 45 pregnancies in 33 women evaluated at 12 centers from 1997 to 2022. Among the 20 women diagnosed with AIHA before pregnancy, 10 had a relapse. An additional 13 patients developed de novo AIHA during gestation/puerperium (2 patients had AIHA relapse during a second pregnancy). Among 24 hemolytic events, anemia was uniformly severe (median Hb, 6.4 g/dL; range, 3.1-8.7) and required treatment in all cases (96% steroids ± intravenous immunoglobulin, IVIG, 58% transfusions). Response was achieved in all patients and was complete in 65% of the cases. Antithrombotic prophylaxis was administered to 8 patients (33%). After delivery, rituximab was administered to 4 patients, and cyclosporine was added to 1 patient. The rate of maternal complications, including premature rupture of membranes, placental detachment, and preeclampsia, was 15%. Early miscarriages occurred in 13% of the pregnancies. Fetal adverse events (22% of cases) included respiratory distress, fetal growth restriction, preterm birth, AIHA of the newborn, and 2 perinatal deaths. In conclusion, the occurrence of AIHA does not preclude the ability to carry out a healthy pregnancy, provided close monitoring, prompt therapy, and awareness of potential maternal and fetal complications.

Anemia hemolítica autoinmune / Autoimmune haemolytic anaemia

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

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