Stretch-activated ion channel TMEM63B associates with developmental and epileptic encephalopathies and progressive neurodegeneration.

By converting physical forces into electrical signals or triggering intracellular cascades, stretch-activated ion channels allow the cell to respond to osmotic and mechanical stress. Knowledge of the pathophysiological mechanisms underlying associations of stretch-activated ion channels with human disease is limited. Here, we describe 17 unrelated individuals with severe early-onset developmental and epileptic encephalopathy (DEE), intellectual disability, and severe motor and cortical visual impairment associated with progressive neurodegenerative brain changes carrying ten distinct heterozygous variants of TMEM63B, encoding for a highly conserved stretch-activated ion channel. The variants occurred de novo in 16/17 individuals for whom parental DNA was available and either missense, including the recurrent p.Val44Met in 7/17 individuals, or in-frame, all affecting conserved residues located in transmembrane regions of the protein. In 12 individuals, hematological abnormalities co-occurred, such as macrocytosis and hemolysis, requiring blood transfusions in some. We modeled six variants (p.Val44Met, p.Arg433His, p.Thr481Asn, p.Gly580Ser, p.Arg660Thr, and p.Phe697Leu), each affecting a distinct transmembrane domain of the channel, in transfected Neuro2a cells and demonstrated inward leak cation currents across the mutated channel even in isotonic conditions, while the response to hypo-osmotic challenge was impaired, as were the Ca2+ transients generated under hypo-osmotic stimulation. Ectopic expression of the p.Val44Met and p.Gly580Cys variants in Drosophila resulted in early death. TMEM63B-associated DEE represents a recognizable clinicopathological entity in which altered cation conductivity results in a severe neurological phenotype with progressive brain damage and early-onset epilepsy associated with hematological abnormalities in most individuals.

Analysis of MRI-derived spleen iron in the UK Biobank identifies genetic variation linked to iron homeostasis and hemolysis.

The spleen plays a key role in iron homeostasis. It is the largest filter of the blood and performs iron reuptake from old or damaged erythrocytes. Despite this role, spleen iron concentration has not been measured in a large, population-based cohort. In this study, we quantify spleen iron in 41,764 participants of the UK Biobank by using magnetic resonance imaging and provide a reference range for spleen iron in an unselected population. Through genome-wide association study, we identify associations between spleen iron and regulatory variation at two hereditary spherocytosis genes, ANK1 and SPTA1. Spherocytosis-causing coding mutations in these genes are associated with lower reticulocyte volume and increased reticulocyte percentage, while these common alleles are associated with increased expression of ANK1 and SPTA1 in blood and with larger reticulocyte volume and reduced reticulocyte percentage. As genetic modifiers, these common alleles may explain mild spherocytosis phenotypes that have been observed clinically. Our genetic study also identifies a signal that co-localizes with a splicing quantitative trait locus for MS4A7, and we show this gene is abundantly expressed in the spleen and in macrophages. The combination of deep learning and efficient image processing enables non-invasive measurement of spleen iron and, in turn, characterization of genetic factors related to the lytic phase of the erythrocyte life cycle and iron reuptake in the spleen.

High Rate of Passenger Lymphocyte Syndrome after ABO Minor Incompatible Lung Transplantation.

Rationale: Passenger lymphocyte syndrome (PLS) may complicate minor ABO mismatched lung transplantation (LuTX) via donor-derived red cell antibody-induced hemolysis.Objectives: To ascertain the incidence and specificity of PLS-relevant antibodies among the study population as well as the dynamics of hemolysis parameters and the transfusion requirement of patients with or without PLS.Methods: In this cohort study, 1,011 patients who received LuTX between January 2010 and June 2019 were studied retrospectively. Prospectively, 87 LuTX (July 2019 to June 2021) were analyzed. Postoperative ABO antibody and hemolytic marker determinations, transfusion requirement, and duration of postoperative hospital care were analyzed. Retrospectively, blood group A recipients of O grafts with PLS were compared with those without.Measurements and Main Results: PLS affected 18.18% (retrospective) and 30.77% (prospective) of A recipients receiving O grafts, 5.13% of B recipients of O grafts, and 20% of AB patients receiving O transplants. Anti-A and anti-A1 were the predominant PLS-inducing antibodies, followed by anti-B and anti-A,B. Significantly lower hemoglobin values (median, 7.4 vs. 8.3 g/dl; P = 0.0063) and an approximately twice as high percentage of patients requiring blood transfusions were seen in PLS. No significant differences in other laboratory markers, duration of hospital stay, or other complications after LuTX were registered.Conclusions: Minor ABO incompatible LuTX recipients are at considerable risk of developing clinically significant PLS. Post-transplant monitoring combining red cell serology and hemolysis marker determination appears advisable so as not to overlook hemolytic episodes that necessitate antigen-negative transfusion therapy.

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.

PKLR mutations in pyruvate kinase deficient Polish patients: Functional characteristics of c.101-1G > A and c.1058delAAG variants.

Pyruvate kinase (PK) deficiency is a rare autosomal recessive disorder characterized by chronic hemolytic anemia of variable severity. Nine Polish patients with severe hemolytic anemia but normal PK activity were found to carry mutations in the PKLR gene encoding PK, five already known ones and one novel (c.178C > T). We characterized two of the known variants by molecular modeling (c.1058delAAG) and minigene splicing analysis (c.101-1G > A). The former gives a partially destabilized PK tetramer, likely of suboptimal activity, and the c.101-1G > A variant gives alternatively spliced mRNA carrying a premature stop codon, encoding a severely truncated PK and likely undergoing nonsense-mediated decay.

Clonal hematopoiesis and acquired genetic abnormalities of the red cell: An historical review.

Several syndromes affecting the red cell that mimic those induced by germline mutations may result from a somatic mutation that accompanies a myeloid malignancy. These syndromes are most notable in cases of myelodysplastic syndrome, but they are not limited to any one category of myeloid neoplasm. Their occurrence in males exceed the male predominance that is evident in myeloid neoplasms. The syndromes include disorders of globin chain synthesis (α- and ß-thalassemia), heme synthesis (erythropoietic porphyria and erythropoietic uroporphyria), red cell membrane structure (elliptocytosis and spherocytosis), red cell enzyme activity (pyruvate kinase deficiency, glucose-6-phosphate dehydrogenase deficiency) and lowered expression of red cell ABO blood group antigens. This historical review describes the path to uncovering these acquired syndromes and their causal somatic mutations, where known. These syndromes often go unrecognized because of the dominant concern of the primary neoplasm. They may add to the healthcare needs of the patient.

COL4A1-related disorder as a mimic of congenital TORCHES infection-Expanding the clinical, neuroimaging and genotype spectrum.

Pseudo-TORCH Syndrome (PTS) encompasses a heterogeneous group of genetic disorders that may clinically and radiologically resemble congenital TORCH infections. These mimickers present with overlapping features manifested as intracranial and systemic abnormalities. Collagen type IV alpha 1 chain (COL4A1)-related diseases, characterized by autosomal dominant inheritance, exhibit a diverse phenotypic spectrum involving cerebrovascular, renal, ophthalmological, cardiac, and muscular abnormalities. Cerebrovascular manifestations range from small-vessel brain disease to large vessel abnormalities, resulting in intracerebral hemorrhage, periventricular leukoencephalopathy, and ventriculomegaly. Additional features include cortical malformations, eye defects, arrhythmias, renal disease, muscular abnormalities, and hematological manifestations. Age of onset varies widely, and phenotypic variability exists even among individuals with the same variant. In this study, we present two cases of COL4A1-related disorder mimicking congenital TORCH infections, highlighting the importance of recognizing genetic mimics in clinical practice.

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.

The disease burden of paroxysmal nocturnal hemoglobinuria in Denmark: Epidemiology, survival, healthcare resource utilization, costs, treatment gaps, and labor market attachment.

OBJECTIVES: To establish epidemiology, healthcare costs, and labor market attachment in patients with paroxysmal nocturnal hemoglobinuria (Pt-PNH) in Denmark. METHODS: Data were from Statistics Denmark and the Danish Health Data Authority national population registers (2005-2021). Descriptive baseline statistics characterized the Pt-PNH analytic population; ordinary least squares and adjusted Cox proportional hazards regressions measured outcomes in the Pt-PNH versus Danish general population matched comparators. RESULTS: Overall PNH incidence in Denmark was n = 11 during 2007-2009, n = 25 during 2016-2018 and n = 7 during 2019-2020; prevalence increased from n = 13 in 2006 to n = 62 in 2021. Of the overall n = 85 Pt-PNH; n = 24 were treated with complement-5 inhibitors (Pt-C5i) and n = 61 not treated with C5i (Pt-nC5i). Versus respective comparators, all patients had significantly greater annual per-patient costs (from inpatient hospital admissions, outpatient contacts, PNH treatments; indirect costs from lost earnings + transfer payments; post-diagnosis for Pt-PNH and Pt-nC5i, post-treatment initiation for Pt-C5i). The Pt-C5i incurred the greatest healthcare and indirect cost differences (€709 119; €152 832, respectively) followed by the Pt-PNH (€189 323; €29 159, respectively) and Pt-nC5i (€95 548; €4713, respectively). The Pt-PNH versus comparators also had an increased hazard of death (2.71 [95% CI, 1.63 - 4.51]). CONCLUSION: Although a rare disease, PNH is associated with significant patient, healthcare system, and societal burdens in Denmark.

Identification of the molecular etiology in rare congenital hemolytic anemias using next-generation sequencing with exome-based copy number variant analysis.

OBJECTIVES: In congenital hemolytic anemias (CHA), it is not always possible to determine the specific diagnosis by evaluating clinical findings and conventional laboratory tests. The aim of this study is to evaluate the utility of next-generation sequencing (NGS) and clinical-exome-based copy number variant (CNV) analysis in patients with CHA. METHODS: One hundred and forty-three CHA cases from 115 unrelated families referred for molecular analysis were enrolled in the study. Molecular analysis was performed using two different clinical exome panels in 130 patients, and whole-exome sequencing in nine patients. Exome-based CNV calling was incorporated into the traditional single-nucleotide variant and small insertion/deletion analysis pipeline for NGS data in 92 cases. In four patients from the same family, the PK Gypsy variant was investigated using long-range polymerase chain reaction. RESULTS: Molecular diagnosis was established in 86% of the study group. The most frequently mutated genes were SPTB (31.7%) and PKLR (28.5%). CNV analysis of 92 cases revealed that three patients had different sizes of large deletions in the SPTB and six patients had a deletion in the PKLR. CONCLUSIONS: In this study, NGS provided a high molecular diagnostic rate in cases with rare CHA. Analysis of the CNVs contributed to the diagnostic success.

Evans syndrome: Disease awareness and clinical management in a nation-wide ITP-NET survey.

Evans syndrome (ES) is rare and mostly treated on a "case-by-case" basis and no guidelines are available. With the aim of assessing disease awareness and current management of adult ES, a structured survey was administered to 64 clinicians from 50 Italian participating centers. Clinicians had to be involved in the management of autoimmune cytopenias and were enrolled into the ITP-NET initiative. The survey included domains on epidemiology, diagnosis, and therapy of ES and was designed to capture current practice and suggested work-up and management. Thirty clinicians who had followed a median of 5 patients (1-45)/15 years responded. The combination of AIHA plus ITP was more common than the ITP/AIHA with neutropenia (p < .001) and 25% of patients had an associated condition, including lymphoproliferative syndromes, autoimmune diseases, or primary immunodeficiencies. The agreement of clinicians for each diagnostic test is depicted (i.e., 100% for blood count and DAT; only 40% for anti-platelets and anti-neutrophils; 77% for bone marrow evaluation). Most clinicians reported that ES requires a specific approach compared to isolated autoimmune cytopenias, due to either a more complex pathogenesis and a higher risk of relapse and thrombotic and infectious complications. The heterogeneity of treatment choices among different physicians suggests the need for broader harmonization.

Temporal trends of splenectomy in pediatric hospitalizations with hereditary spherocytosis from 2000 to 2019: A national survey.

BACKGROUND: Total and partial splenectomy are used in pediatric patients with hereditary spherocytosis to resolve anemia and hemolytic complications. PROCEDURE: Data from the Healthcare Cost and Utilization Project's Kid's Inpatient Database was used to profile and describe temporal trends in pediatric (≤18 years) hospital admissions in the United States from 2000 to 2019 data release years. Survey sampling methods were used to produce national estimates. RESULTS: From 2000 to 2019, the use of splenectomy declined overall, from 427 to 206 weighted procedures (difference = 222, 95% confidence interval [CI]: 124-320; p < .0001); the risk of undergoing splenectomy during admission also declined from 56.7% to 38.7% (risk difference = 17.9 percentage points [p.p.], 95% CI: 9.7-26.1; p < .0001). Total splenectomy was mostly used. Age at time of splenectomy increased 10.2 years (difference = 1.6 years, 95% CI: 0.6-2.7; p = .0018). The risk of splenectomy increased with age until 10 years, then leveled off until 18 years. The proportion of children aged ≤5 years undergoing splenectomy decreased from 27.7% to 11.2% in 2019 (risk difference: 16.5 p.p., 95% CI: 7.3-25.7; p = .0004). The strongest clinical predictors of splenectomy, adjusting for patient- and hospital-level characteristics, were a co-diagnosis of symptomatic cholelithiasis (adjusted odds ratio [aOR] = 3.18, 95% CI: 1.92-5.28; p < .0001) and splenomegaly or hypersplenism (aOR = 2.52, 95% CI: 1.74-3.65; p < .0001). Risk of splenectomy with splenomegaly or hypersplenism increased over time. CONCLUSION: Splenectomy was delayed until age greater than 10 years. Older age, co-diagnosis with splenomegaly or hypersplenism, or symptomatic cholelithiasis were strongest clinical predictors of splenectomy. Conservative management of hereditary spherocytosis appears to be more common.

Infantile pyknocytosis, a neonatal hemolytic anemia with Heinz bodies: A cohort study.

Infantile pyknocytosis (IP) is a rare, probably misestimated, cause of non-immune neonatal hemolytic anemia evolving in two phases: an initial phase with severe jaundice, followed by a second phase with hemolytic anemia, which may require neonatal intensive care. The diagnosis of IP is based on the transient presence on blood smear of hyperdense, contracted, and/or spiculated red blood cells (pyknocytes), associated with the spontaneous resolution of clinico-biological features and the exclusion of other causes. If the etiology remains undetermined, some contributing factors, such as oxidative stress, have been proposed. We report the description of 16 patients with IP aiming at clarifying the circumstances associated with the development of this acquired disorder. In the acute phase, the mean hemoglobin nadir and pyknocyte count were 7.8 g/dL and 11%, respectively, and strikingly, Heinz bodies were evident in 50% of the newborns, but in 100% after prolonged incubation (4 hours). A high proportion of Mediterranean or African ancestry was noted in newborns, as well as a significant number of peripartum events, such as respiratory distress. If the etiology of IP is certainly multifactorial, our series reinforces the role of oxidative stress, which may, at least in part, find origin in desaturation episodes in newborns.

Early diagnosis of sickle cell retinopathy by using ocular coherence tomography in pediatric population (7-18 years) in central India.

BACKGROUND: Sickle cell disease (SCD) is the commonest inherited blood disorder leading to complications occurring due to vaso-occlusion including sight-threatening retinopathy. Retinopathy can be managed if diagnosed early and vision loss can be prevented. Since, very less data are available from India, hence, this study was conducted in children (7-18 years) with SCD to diagnose retinopathy by using ocular coherence tomography (OCT) in subclinical stages. METHODS: This cross sectional single-center study was performed in 7-18 years age group children with SCD without any visual symptoms. Enrolled participants underwent complete ophthalmological examination including macula and optic disc thickness measurements using Cirrus HD-OCT and results were analyzed. RESULTS: Among 55 participants, none had visual impairment. Significant fundoscopy finding (nonproliferative sickle cell retinopathy/NPSR) was found in three patients (5.4%), thinning of central macula in four patients (7.27%), inner macula thinning in eight patients (14.5%), outer macula thinning in one patient (1.81%), retinal nerve fiber layer thinning in five patients (9%), ganglion cell layer to inner plexiform layer thinning in eight patients (14.54%). Overall NPSR was found in 5.4% patients detected with fundoscopy, whereas retinal layer thinning was found in 14 patients (25.4%) using OCT. CONCLUSION: Despite of the significant prevalence of SCR, it is still underdiagnosed complication, leading to thinning of the retina from early ages; thus, its early diagnosis by regular screening using newer diagnostic methods can prevent progression to sight-threatening complications and provide better quality of life for these patients.

Fatal co-infection by multiple pathogens in an indigenous woman with autoimmune hemolytic anemia and tuberculosis: a case report.

BACKGROUND: Tuberculosis (TB), one of the leading causes of death worldwide, has a higher incidence among indigenous people. Albeit uncommon, autoimmune hemolytic anemia (AIHA) has been deemed a risk condition to develop mycobacterial infection, as a result of the immunosuppressive treatments. TB, in turn, can be a predisposing factor for secondary infections. CASE PRESENTATION: Here we present a case of a 28-year-old indigenous woman from Colombia, previously diagnosed with AIHA and pulmonary TB. Despite various treatments, therapies and medical interventions, the patient died after severe medullary aplasia of multiple causes, including secondary myelotoxicity by immunosuppressive therapy and secondary disseminated infections, underlining infection by Staphylococcus aureus, Klebsiella pneumoniae and Candida glabrata, which were identified as drug-resistant microorganisms. Together, this led to significant clinical complications. Invasive aspergillosis was diagnosed at autopsy. CONCLUSIONS: This report presents a rarely finding of AIHA followed by TB, and highlights the great challenges of dealing with co-infections, particularly by drug resistant pathogens. It also aims to spur governments and public health authorities to focus attention in the prevention, screening and management of TB, especially among vulnerable communities, such as indigenous people.

A Real-World Disproportionality Analysis of Drug-Induced Immune Hemolytic Anemia in the FDA Adverse Event Reporting System.

BACKGROUND: Drug-induced immune hemolytic anemia (DIIHA) is a rare but potentially life-threatening pharmacogenic hematological adverse effect. Updating the risk of DIIHA among the currently available drugs based on spontaneously reported adverse event data is of great significance. OBJECTIVE: This study aimed to identify the top 50 drugs associated with immune hemolytic anemia in adults as well as common drugs that could cause immune hemolytic anemia in children based on the United States Food and Drug Administration Adverse Event Reporting System (FAERS) database. METHODS: We extracted adverse events (AE) in the FAERS database from Q1 2004 to Q3 2022 using Open vigil2.1. We use the high-level term "anaemias haemolytic immune" according to the Medical Dictionary for Regulatory Activities (MedDRA) Dictionary (version 24.0). The reported correlation between drugs and DIIHA risk was identified by reported odds ratio (ROR) and proportional reporting ratio (PRR). RESULTS: There were 10500309 AEs in FAERS from 2004Q1 to 2022Q3, of which 2326 (0.02%) were DIIHA cases. The incidence of DIIHA is comparable between males and females. The most common drugs associated with DIIHA in adults and children are summarized according to the number of AE reports. The top 3 categories in terms of quantity of drugs are antineoplastic agents, immunosuppressants, and antibiotics for systemic use. The top 5 drugs in terms of ROR and PRR are alemtuzumab, daclizumab, fludarabine, busulfan, and bendamustine in adults, with entecavir, treosulfan, vinorelbine, pegademase, and alemtuzumab for children. CONCLUSIONS: Our study identified the most common drugs that could induce DIIHA in adults and children, as well as the respective ROR and PRR value to discover new drug signals. This study provides references to clinicians for the management of rare DIIHA.

Practical approach to thrombocytopenia in patients with sepsis: a narrative review.

Thrombocytopenia frequently occurs in patients with sepsis. Disseminated intravascular coagulation (DIC) may be a possible cause of thrombocytopenia owing to its high prevalence and association with poor outcomes; however, it is important to keep the presence of other diseases in mind in sepsis practice. Thrombotic microangiopathy (TMA), which is characterized by thrombotic thrombocytopenic purpura, Shiga toxin-producing Escherichia coli hemolytic uremic syndrome (HUS), and complement-mediated HUS, is characterized by thrombocytopenia, microangiopathic hemolytic anemia, and organ damage. TMA has become widely recognized in recent years because of the development of specific treatments. Previous studies have reported a remarkably lower prevalence of TMA than DIC; however, its epidemiology is not well defined, and there may be cases in which TMA is not correctly diagnosed, resulting in poor outcomes. Therefore, it is important to differentiate DIC from TMA. Nevertheless, differentiating between DIC and TMA remains a challenge as indicated by previous reports that most patients with TMA can be diagnosed as DIC using the universal coagulation scoring system. Several algorithms to differentiate sepsis-related DIC from TMA have been suggested, contributing to improving the care of septic patients with thrombocytopenia; however, it may be difficult to apply these algorithms to patients with coexisting DIC and TMA, which has recently been reported. This review describes the disease characteristics, including epidemiology, pathophysiology, and treatment, of DIC, TMA, and other diseases with thrombocytopenia and proposes a novel practical approach flow, which is characterized by the initiation of the diagnosis of TMA in parallel with the diagnosis of DIC. This practical flow also refers to the longitudinal diagnosis and treatment flow with TMA in mind and real clinical timeframes. In conclusion, we aim to widely disseminate the results of this review that emphasize the importance of incorporating consideration of TMA in the management of septic DIC. We anticipate that this practical new approach for the diagnostic and treatment flow will lead to the appropriate diagnosis and treatment of complex cases, improve patient outcomes, and generate new epidemiological evidence regarding TMA.

The use of therapeutic plasma exchange in systemic loxoscelism induced treatment resistant hemolytic anemia: A case report.

Brown recluse spider bites can lead to severe reactions such as skin necrosis,hemolytic anemia, and multiorgan failure, which can be life-threatening. Therapeutic plasma exchange has been reported to provide clinical benefit for such cases. In thisreport, we present a case of a brown recluse spider bite that was successfully treated with therapeutic plasma exchange and compare it with previous case reports.

A Multicentric Castleman Disease Associated with Mixed Warm and Cold Antibody-Mediated AHA Responsive to Siltuximab.

Castleman disease is non-clonal lymphoproliferative disorders defined by hypertrophy of lymph nodes. The multicentric form (MCD), in which multiple lymph node stations are involved, is not associated with HHV8 infection, but considered idiopathic, although IL-6 appears to play a central role in its pathogenesis. Here, we report the case of a patient who presented with mixed autoimmune hemolytic anemia (AIHA) and adenopathy that was very challenging to diagnose due to very low values of hemoglobin and refractoriness of obtaining any improvement of AIHA with standard first and second lines of therapy (steroids, rituximab, immunoglobulin, erythropoietin, and cyclosporine). When we safely proceeded to lymph node biopsy, a diagnosis of MCD was established. This permitted the treatment with siltuximab, an anti-IL-6 monoclonal antibody. After only 1 week, hemoglobin raised and he was discharged. After 1 year, he was still in remission. This case underlines the challenges in diagnosis of MCD, and the first case of response to siltuximab after the failure of rituximab to relieve mixed AIHA.

Case presentation: a severe case of cobalamin c deficiency presenting with nephrotic syndrome, malignant hypertension and hemolytic anemia.

BACKGROUND: The etiology of nephrotic syndrome can vary, with underlying metabolic diseases being a potential factor. Cobalamin C (cblC) defect is an autosomal recessive inborn error of metabolism caused by mutations in the MMACHC gene, resulting in impaired vitamin B12 processing. While cblC defect typically manifests with hematological and neurological symptoms, renal involvement is increasingly recognized but remains rare. CASE PRESENTATION: We describe a 7-month-old male patient presenting with fatigue and edema. His first laboratory findings showed anemia, thrombocytopenia, hypoalbuminemia and proteinuria and further examinations reveals hemolysis in peripheric blood smear. During his follow up respiratory distress due to pleural effusion in the right hemithorax was noticed. And fluid leakage to the third spaces supported nephrotic syndrome diagnosis. The patient's condition deteriorated, leading to intensive care admission due to, hypertensive crisis, and respiratory distress. High total plasma homocysteine and low methionine levels raised suspicion of cobalamin metabolism disorders. Genetic testing confirmed biallelic MMACHC gene mutations, establishing the diagnosis of cblC defect. Treatment with hydroxycobalamin, folic acid, and betaine led to remarkable clinical improvement. DISCUSSION/CONCLUSION: This case underscores the significance of recognizing metabolic disorders like cblC defect in atypical presentations of nephrotic syndrome. Early diagnosis and comprehensive management are vital to prevent irreversible renal damage. While cblC defects are more commonly associated with atypical hemolytic uremic syndrome, this case highlights the importance of considering cobalamin defects in the differential diagnosis of nephrotic syndrome, especially when associated with accompanying findings such as hemolysis. Our case, which has one of the highest homocysteine levels reported in the literature, emphasizes this situation again.