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.

Immune-mediated hemolytic anemia and pure red cell aplasia in a Jack Russell Terrier during treatment for hypoadrenocorticism.

An 11-year-old neutered male Jack Russell Terrier was presented to Yuki Animal Hospital for regenerative anemia during the treatment of hypoadrenocorticism. A blood smear examination showed spherocytes, polychromatic erythrocytes, and erythrocyte ghosts. The direct agglutination test was positive at 37°C. The dog was then diagnosed with immune-mediated hemolytic anemia (IMHA). Although prednisolone and mycophenolate mofetil were administered, the hematocrit and reticulocyte count decreased, and nonregenerative anemia developed. A bone marrow examination was performed to diagnose the cause of the nonregenerative anemia. Histologic and cytologic bone marrow examination revealed a normocellular to hypercellular medulla with severe erythroid hypoplasia. No proliferation of lymphocytes or lymphoblast-appearing cells was observed. This dog was diagnosed with pure red cell aplasia (PRCA). Despite treatment with immunosuppressive agents, the patient died of thrombosis. Although these associations were unclear, this is the first report of PRCA diagnosis following IMHA and while treating hypoadrenocorticism.

Passenger lymphocyte syndrome following minor ABO-mismatched liver transplantation.

Passenger lymphocyte syndrome is an immunologic disorder observed in solid organ and haematopoietic stem cell transplantation in which B lymphocytes within a donor graft are transferred to the recipient and subsequently produce circulating antibodies against host red blood cell antigens. The syndrome is most likely to occur in minor ABO blood group mismatched or Rh incompatible transplantation. Although generally mild and self-limited, the resulting haemolytic burden has the potential to increase the risk of infection, graft failure and death. The phenomenon is observed in the transplantation of any solid organ with lymphoid tissue, including the liver. We present a structured case report of passenger lymphocyte syndrome following minor ABO-mismatched liver transplantation, which was initially complicated by blood loss anaemia early in the postoperative period. By reviewing the limited literature of this disorder following liver transplantation, we emphasise common clinical findings and treatment strategies as well as introduce chimerism analysis to confirm resolution.

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.

Autoimmune hemolytic anemia and thrombocytopenia in a Chinese patient with heterozygous NBAS mutations: Case report.

RATIONALE: Neuroblastoma amplified sequence (NBAS)-associated disease is an autosomal recessive disorder and a broad spectrum of clinical symptoms has been reported. However, autoimmune mediated hemolytic anemia (AIHA) is rarely reported in NBAS disease. PATIENT CONCERNS: A now 21-year-old male harbors heterozygous variants of c.6840G>A and c.335 + 1G>A and was found had retarded growth, hypogammaglobulinemia, B lymphopenia, optic atrophy, horizontal nystagmus, slight splenomegaly and hepatomegaly since childhood. This case had normal hemoglobin level and platelet count in his childhood. He developed AIHA first in his adulthood and then thrombocytopenia during the treatment of AIHA. The mechanism underlying a case with pronounced hypogammaglobulinemia and B lymphopenia is elusive. In addition to biallelic NBAS mutations, a germline mutation in the ANKRD26 (c.2356C>T) gene was also detected. So either autoimmune or ANKRD26 mutation-mediated thrombocytopenia is possible in this case. INTERVENTION AND OUTCOME: He was initially managed with steroid and intermittent intravenous immunoglobulin supplement. After treatment, he responded well with a normalization of hemoglobin and serum bilirubin. But the patient subsequently experienced severe thrombocytopenia in addition to AIHA. He was then given daily avatrombopag in addition to steroid escalation. He responded again to new treatment, with the hemoglobin levels and platelet counts went back to the normal ranges. Now he was on de-escalated weekly avatrombopag and low-dose steroids maintenance. CONCLUSION: The phenotype of this case indicates that c.335 + 1G>A NBAS variant is probably a pathogenic one and c.2356C>T ANKRD26 variant is improbably a pathogenic one. AIHA may respond well to steroid even when happened in patients with NBAS disease.

ZAP-70 mutation: a case with familial autoimmune haemolytic anaemia and immune deficiency.

Zeta-chain associated protein kinase 70 kDa (ZAP-70) deficiency is one of the rare immunodeficiency disorders due to autosomal recessive homozygous or compound heterozygous loss-of-function mutations in the ZAP-70 GENE In the literature, patients with ZAP-70 deficiency have been reported with a broad spectrum of clinical manifestations including recurrent respiratory infections (81.8%), cutaneous involvement (57.9%), lymphoproliferation (32.4%), autoimmunity (19.4%), enteropathy (18.4%) and increased risk of malignancies (8.1%). The most common immunological phenotype in those patients was low CD8+ T cell counts (97.9%) and normal non-functioning CD4+ T cell. Haematopoietic stem cell transplantation was applied as a curative treatment for this disorder.

Transfusing children with sickle cell disease using blood group genotyping when the pool of Black donors is limited.

BACKGROUND: Red blood cell transfusion is an effective treatment for patients with sickle cell disease (SCD). Alloimmunization can occur after a single transfusion, limiting further usage of blood transfusion. It is recommended to match for the ABO, D, C, E, and K antigens to reduce risks of alloimmunization. However, availability of compatible blood units can be challenging for blood providers with a limited number of Black donors. STUDY DESIGN AND METHODS: A prospective cohort of 205 pediatric patients with SCD was genotyped for the RH and FY genes. Transfusion and alloimmunization history were collected. Our capacity to find RhCE-matched donors was evaluated using a database of genotyped donors. RESULTS: Nearly 9.8% of patients carried a partial D variant and 5.9% were D-. Only 45.9% of RHCE alleles were normal, with the majority of variants affecting the RH5 (e) antigen. We found an alloimmunization prevalence of 20.7% and a Rh alloimmunization prevalence of 7.1%. Since Black donors represented only 1.40% of all blood donors in our province, D- Caucasian donors were mostly used to provide phenotype matched products. Compatible blood for patients with rare Rh variants was found only in Black donors. A donor with compatible RhCE could be identified for all patients. CONCLUSION: Although Rh-compatible donors were identified, blood units might not be available when needed and/or the extended phenotype or ABO group might not match the patient. A greater effort has to be made for the recruitment of Black donors to accommodate patients with SCD.

Comparison of timing of relapse in dogs with nonassociative immune-mediated hemolytic anemia, thrombocytopenia, or polyarthritis.

BACKGROUND: Relapse is a clinical concern in dogs diagnosed with immune-mediated hemolytic anemia (IMHA), thrombocytopenia (ITP), or polyarthritis (IMPA). The average time to relapse is unknown, and evidence that vaccination is associated with disease relapse is lacking. HYPOTHESIS/OBJECTIVES: Compare the incidence of relapse in groups of dogs with IMHA, ITP, or IMPA over a 24-month period after diagnosis and compare proportions of dogs that received vaccines in those dogs that did and did not relapse. ANIMALS: One hundred sixty client-owned dogs (73 with IMHA, 55 with ITP, 32 with IMPA). METHODS: Medical records of dogs were reviewed with the goal of following cases for a minimum of 2 years. Incidence of relapse was calculated for each disease, and relapse rates in dogs that were or were not vaccinated after diagnosis were compared. RESULTS: Relapse rates at 12 months differed significantly among disease groups (P = .02), with a higher rate for IMPA (35%) compared to IMHA (11%) or ITP (11%). Relapse rate at 24 months was 41% for IMPA, 18% for IMHA, and 23% for ITP. Ninety percent of IMPA relapses occurred in the first 12 months after diagnosis, compared with 56% for IMHA and 50% for ITP. Vaccine administration after diagnosis was not associated with relapse (P = .78). CONCLUSIONS AND CLINICAL IMPORTANCE: Risk of disease relapse in IMPA is highest in the first year after diagnosis, with a higher relapse rate compared with IMHA and ITP. The role of vaccination in disease relapse remains unclear.

COVID-19 vaccine safety and immunogenicity in patients with cold agglutinin disease receiving concomitant sutimlimab.

Patients with cold agglutinin disease (CAD) are more vulnerable to infectious agents, thus the COVID-19 pandemic has posed a particular risk to this population. Sutimlimab Phase 3 studies CARDINAL and CADENZA spanned the period before and during the pandemic; investigators were advised to vaccinate enrolled patients without stopping treatment. Of 61 completers from both studies, 47 received ≥1 dose of a COVID-19 vaccine. In the immunogenicity analysis (n = 27) all patients developed an immune response post-COVID-19 vaccination, with detectable immunoglobulin G anti-spike antibodies. Analysis of six patients with booster vaccinations demonstrated increased immune responses pre- to post-booster. COVID-19 vaccines were well tolerated in patients with CAD receiving sutimlimab treatment, and no signs of hemolytic exacerbations were observed post-vaccination.

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.

Diagnostic evaluation of paediatric autoimmune lymphoproliferative immunodeficiencies (ALPID): a prospective cohort study.

BACKGROUND: Lymphoproliferation and autoimmune cytopenias characterise autoimmune lymphoproliferative syndrome. Other conditions sharing these manifestations have been termed autoimmune lymphoproliferative syndrome-like diseases, although they are frequently more severe. The aim of this study was to define the genetic, clinical, and immunological features of these disorders to improve their diagnostic classification. METHODS: In this prospective cohort study, patients were referred to the Center for Chronic Immunodeficiency in Freiburg, Germany, between Jan 1, 2008 and March 5, 2022. We enrolled patients younger than 18 years with lymphoproliferation and autoimmune cytopenia, lymphoproliferation and at least one additional sign of an inborn error of immunity (SoIEI), bilineage autoimmune cytopenia, or autoimmune cytopenia and at least one additional SoIEI. Autoimmune lymphoproliferative syndrome biomarkers were determined in all patients. Sanger sequencing followed by in-depth genetic studies were recommended for patients with biomarkers indicative of autoimmune lymphoproliferative syndrome, while IEI panels, exome sequencing, or genome sequencing were recommended for patients without such biomarkers. Genetic analyses were done as decided by the treating physician. The study was registered on the German Clinical Trials Register, DRKS00011383, and is ongoing. FINDINGS: We recruited 431 children referred for autoimmune lymphoproliferative syndrome evaluation, of whom 236 (55%) were included on the basis of lymphoproliferation and autoimmune cytopenia, 148 (34%) on the basis of lymphoproliferation and another SoIEI, 33 (8%) on the basis of autoimmune bicytopenia, and 14 (3%) on the basis of autoimmune cytopenia and another SoIEI. Median age at diagnostic evaluation was 9·8 years (IQR 5·5-13·8), and the cohort comprised 279 (65%) boys and 152 (35%) girls. After biomarker and genetic assessments, autoimmune lymphoproliferative syndrome was diagnosed in 71 (16%) patients. Among the remaining 360 patients, 54 (15%) had mostly autosomal-dominant autoimmune lymphoproliferative immunodeficiencies (AD-ALPID), most commonly affecting JAK-STAT (26 patients), CTLA4-LRBA (14), PI3K (six), RAS (five), or NFκB (three) signalling. 19 (5%) patients had other IEIs, 17 (5%) had non-IEI diagnoses, 79 (22%) were unresolved despite extended genetics (ALPID-U), and 191 (53%) had insufficient genetic workup for diagnosis. 16 (10%) of 161 patients with a final diagnosis had somatic mutations. Alternative classification of patients fulfilling common variable immunodeficiency or Evans syndrome criteria did not increase the proportion of genetic diagnoses. INTERPRETATION: The ALPID phenotype defined in this study is enriched for patients with genetic diseases treatable with targeted therapies. The term ALPID might be useful to focus diagnostic and therapeutic efforts by triggering extended genetic analysis and consideration of targeted therapies, including in some children currently classified as having common variable immunodeficiency or Evans syndrome. FUNDING: Deutsche Forschungsgemeinschaft under Germany's Excellence Strategy. TRANSLATION: For the German translation of the abstract see Supplementary Materials section.

Decreasing alloimmunization-specific mortality in sickle cell disease in the United States: Cost-effectiveness of a shared transfusion resource.

Red blood cell alloimmunization and consequent delayed hemolytic transfusion reaction (DHTR) incidence and mortality in patients with sickle cell disease (SCD) are high. A shared transfusion resource has decreased both in other countries, while in the United States cost concerns persist. We conducted a Markov cohort simulation of a birth cohort of alloimmunized patients with SCD to estimate lifetime DHTR incidence, DHTR-specific mortality, quality-adjusted life expectancy (QALE), and costs with the implementation of a shared transfusion resource to identify antibody history versus without (i.e., status quo). We conducted our analysis using a lifetime analytic time horizon and from a United States health system perspective. Implementation of shared transfusion resource projects to decrease cumulative DHTR-specific mortality by 26% for alloimmunized patients with SCD in the United States, relative to the status quo. For an average patient population of 32 000, this intervention would generate a discounted increment of 4000 QALYs at an incremental discounted cost of $0.3 billion, resulting in an incremental cost-effectiveness ratio of $75 600/QALY [95% credible interval $70 200-81 400/QALY]. The results are most sensitive to the baseline lifetime medical expenditure of patients with SCD. Alloantibody data exchange is cost-effective in 100% of 10 000 Monte Carlo simulations. The resource would theoretically need a minimum patient population of 1819 patients or cost no more than $5.29 million annually to be cost-effective. By reducing DHTR-specific mortality, a shared transfusion resource in the United States projects to be a life-saving and cost-effective intervention for patients with SCD in the United States.

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.

Compound heterozygosity induces a rare Gerbich-negative phenotype in an immunized blood donor.

BACKGROUND: Antibodies to Gerbich blood group antigens are exceedingly rare and can cause moderate transfusion reactions. Several deletional variants of the GE-gene, that harbors long sequence repeats, enable alloimmunization and formation of naturally occurring antibodies. SUBJECT AND METHODS: A female blood donor and soldier of the German Army without history of pregnancy or transfusion showed an antibody reactive with all test cells except for GE:-2-3 RBC. Thus, anti-Ge2 was suspected. Molecular analysis including fragment length specific PCR, Sanger sequencing and NGS should reveal the molecular background of the deficiency. Segregation of the variant alleles should be demonstrated by family analysis. RESULTS: Compound heterozygosity for GYPC exon 2 (GE*01.-02) and exon 3 (GE*01.-03) deletion was detected in the donor and her sister. The mother had one exon 3 amplicon of reduced length, while the father heterozygously exhibited a truncated GYPC exon 2. NGS clearly demonstrated reduced coverages within the deletional fragments within each family member. The donor and her sister showed the complete absence of a 640 bp fragment. DISCUSSION AND CONCLUSION: Rare GE deletion variants can induce naturally occurring anti-Ge2 in Caucasians. Because of an enhanced risk of injury as soldier autologous RBC of the donor were cryopreserved. The donor and her sibling can give blood for each other because of identical ABO, Rh, and K antigen blood types.

Successful management of severe Kell alloimmunization in pregnancy with intravenous immune globulin.

Hemolytic Disease of the Fetus and Newborn (HDFN) is a condition that affects 1 to 2 out of 1000 patients during pregnancy (1). When an alloantibody is present, it is essential to identify its nature in order to organize appropriate follow-up. Kell-mediated HDFN is rare; it occurs in about 5% of Kell alloimmunized pregnant women. It is important to note that in case of anti-Kell immunization, the severity of HDFN is not correlated with maternal antibody titers, and anemia tends to occur earlier and more severely. Therefore, early diagnosing and management of this condition is crucial. In the management of severe fetal anemia due to Kell immunization, available treatments include in utero transfusion (IUT), immunoglobulin therapy. Other alternative treatments exist, such as plasmapheresis. Intravenous immunoglobulin (IVIG), a noninvasive therapeutic approach, acts through multiple mechanisms. IVIG has been evaluated in cases of RhD immunization with high maternal antibody titers and a history of pregnancies involving early hydrops or intrauterine death. Regarding the potential benefits of intravenous IgG therapy, it may delay the need for early IUT, reduce the overall reliance on IUT, and have a positive impact on obstetric outcomes. This case of IV IgG therapy of anti-Kell immunization offers a thought-provoking avenue for future exploration.

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).

Risk of new alloimmunization in patients on anti-CD38 treatment using tube LISS-IAT method.

BACKGROUND: Daratumumab is a monoclonal antibody that targets CD38, a transmembrane protein expressed on many cells including RBCs and to a greater extent on myeloma cells. It has been used for treatment of multiple myeloma and autoimmune diseases. Transfusion management of patients on such therapy can be challenging as these drugs cross-react with RBC surface antigens and cause panreactivity. MATERIAL AND METHODS: A retrospective study of the 68 patients treated with anti-CD38 from 2018-2023 was carried out. Data regarding transfusion history and antibody screens were analyzed. Depending whether they had immunohematological work-up before or during the treatment- DAT, antibody screen (CAT and tube), RBC pheno/genotyping and serologic cross-matches (CAT and tube) were performed for each patient. All cases with positive CAT IAT were retested in LISS-tube and cross-matches were performed with phenotypically matched units in LISS-tube. RESULTS: Antibody screen has shown panagglutination with all panel cells with low and variable agglutination intensity (weak to 2 +). Panagglutination remained positive for 1 - 6 months after drug cessation. Positive DAT was seen in 60,6% patients, while autocontrol was negative. Ficin treated panel-cells eliminated nonspecific reactivity. LISS-tube antibody screen and cross-matches were negative for all patients, apart from 3 patients who had preexisting antibodies. No new antibodies were detected during the course of the study. CONCLUSION: Among study group there were no newly identified alloantibodies, meaning that the policy of transfusing them with matched RBCs and performing IAT/cross-matches in tube is a safe and effective policy according to the findings of this study.