Search Results (39)

Background: Non-associative immune-mediated hemolytic anemia (IMHA) is uncommon in cats and carries substantial mortality. Glucocorticoids are first-line treatment, and cyclosporin A (CsA) is frequently added, but data on the clinical course and long-term outcome are limited. We describe clinical findings, treatment, adverse events and outcome in cats with non-associative IMHA. Methods: In this retrospective observational single-center study (October 2014–October 2024), 37 cats diagnosed by the 2019 ACVIM consensus criteria were included; 15 received prednisolone alone (PG) and 22 prednisolone combined with CsA (CPG), allocated at the clinician’s discretion. Between-cohort comparisons are exploratory. Results: Cats in the CPG cohort presented with more severe anemia. Overall mortality was 24.3%, with all deaths within four weeks; survival to discharge was 13/15 (PG) and 19/22 (CPG). Median follow-up was 50 [8–430] and 70 days [12–330]. Two cats achieved sustained treatment-free remission of 4.2 and 1.9 years. Five cats relapsed, four while receiving ongoing immunosuppression. Conclusions: Most cats survived the acute phase but required prolonged immunosuppression, and sustained treatment-free remission was uncommon. Relapses occurred predominantly during ongoing therapy rather than after discontinuation. Because CsA was used preferentially in more severely affected cats, comparative efficacy cannot be assessed and remains to be addressed prospectively. Full article

Immune-mediated thrombotic thrombocytopenic purpura (iTTP) is a rare, life-threatening thrombotic microangiopathy caused by severe ADAMTS13 deficiency due to anti-ADAMTS13 autoantibodies. The resulting persistence of ultra-large von Willebrand factor (VWF) multimers promotes uncontrolled platelet adhesion and aggregation in the microcirculation, leading to thrombocytopenia, microangiopathic hemolytic anemia, and ischemic organ injury. Therapeutic plasma exchange (TPE) has transformed the prognosis of iTTP by removing circulating autoantibodies and replenishing functional ADAMTS13, and it remains a life-saving intervention in acute disease. However, TPE is invasive, resource-intensive, dependent on central venous access and plasma availability, and associated with catheter-related, hemodynamic, metabolic, infectious, and plasma-related adverse events. The therapeutic landscape has changed substantially with the incorporation of immunosuppression and the anti-VWF nanobody caplacizumab. Caplacizumab rapidly blocks VWF–platelet interactions at the effector level, whereas corticosteroids and B-cell-directed therapy target the autoimmune basis of iTTP. Triple therapy with TPE, immunosuppression, and caplacizumab accelerates platelet recovery and reduces unfavorable outcomes. At the same time, accumulating observational evidence and early prospective data suggest that selected patients may achieve remission with caplacizumab plus immunosuppression without routine first-line TPE. This perspective review critically re-evaluates the role of TPE in contemporary iTTP management. We propose that TPE should no longer be viewed exclusively as an obligatory universal first-line intervention, but rather as a contextualized component of individualized, response-adapted care. TPE remains indispensable for severe, unstable, or refractory disease and must be immediately available when TPE-free treatment is attempted. Safe implementation of TPE-free strategies requires experienced centers, rapid ADAMTS13 testing, immediate access to caplacizumab and immunosuppression, careful patient selection, and close clinical and laboratory monitoring. Defining which patients can be treated safely without TPE is a central challenge for future trials and guideline development. Full article

Background: Caplacizumab is a cornerstone in the management of immune-mediated thrombotic thrombocytopenic purpura (iTTP), in combination with plasma exchange (PEX) and immunosuppression. Pivotal trials and real-world data have demonstrated faster platelet count recovery and improved remission rates. Nevertheless, a subset of patients still experiences exacerbations or delayed response. Observational evidence suggests that unintended treatment interruptions may contribute to these unfavorable outcomes. Methods: We report on two patients with iTTP treated with caplacizumab and immunosuppression; PEX was used in Case 1 and as escalation therapy in Case 2. Laboratory parameters including platelet count, lactate dehydrogenase (LDH), ADAMTS13 activity, and anti-ADAMTS13 autoantibodies were monitored. Results: In the first case, a 29-year-old female experienced an exacerbation and ischemic complications after two individual caplacizumab doses were unintentionally missed on days 12 and 14. Subsequent continuous administration led to stabilization and recovery. In the second case, a 42-year-old male presented with hemolytic anemia, thrombocytopenia, and ADAMTS13 activity of 1% and was initially treated with prednisolone and caplacizumab without PEX. Two individual caplacizumab doses were unintentionally missed on days 3 and 5 and were followed by delayed treatment response and microembolic infarcts. Treatment escalation to PEX and rituximab and reinitiation of continuous caplacizumab administration led to clinical stabilization. Conclusions: Even brief interruptions of caplacizumab therapy may compromise outcomes in iTTP. Continuous administration and secured availability, together with serial monitoring of ADAMTS13 activity to guide treatment duration and discontinuation, are essential to improve patient care. Full article

Background/Objectives: Acute intravascular hemolysis is associated with the release of labile heme, which contributes to systemic inflammation and organ dysfunction. Galectin-3 (Gal-3) is a known modulator of inflammatory responses. However, its specific role in heme-induced organ injury remains to be fully elucidated. Methods: We used a phenylhydrazine (PHZ)-induced model of acute hemolysis in wild-type (WT) and Gal-3 knockout (KO) mice to investigate the influence of Gal-3 on tissue alterations and the inflammatory response. Results: Despite equivalent levels of hemolysis and anemia in both genotypes, Gal-3 deficiency was associated with reduced injury in the liver, kidneys, and pancreas. In WT mice, Gal-3 was associated with a pro-inflammatory splenic microenvironment. Conversely, Gal-3 KO mice exhibited a shift toward an immunoregulatory phenotype, characterized by an increased frequency of CD4 + CD25 + FoxP3+ regulatory T cells and IL-10+ macrophages. This shift correlated with preserved organ architecture and a more controlled inflammatory profile. Conclusions: Our findings suggest that Gal-3 may act as a mediator of heme-induced systemic inflammation. By influencing the splenic immune microenvironment and promoting a regulatory phenotype, the absence of Gal-3 appears to alleviate multi-organ stress, suggesting its potential as a target for modulating complications during acute hemolytic crises. Full article

Mesenchymal stromal/stem cells (MSCs) are increasingly explored for immune-mediated diseases, yet standardized analytical readouts that capture coordinated immunomodulatory output across complementary secretory pathways remain limited. Here, we report the feasibility of an HPLC-based multi-analyte secretome characterization panel that quantifies two small-molecule outputs—adenosine and kynurenine—alongside two immunomodulatory proteins—interleukin-10 (IL-10) and transforming growth factor-beta (TGF-β)—in conditioned media from canine adipose-derived MSCs (cAD-MSCs). Canine immune-mediated hemolytic anemia (IMHA) was used as a disease context to motivate the selection of these analytes, given the pro-inflammatory cytokine environment characteristic of this condition. Three independent cAD-MSC lines were evaluated under baseline conditions and following cytokine stimulation with recombinant interferon-gamma (IFN-γ; 100 ng/mL) and tumor necrosis factor-alpha (TNF-α; 50 ng/mL), referred to herein as inflammatory priming or licensing. Conditioned media were collected at 72 h for metabolite analysis and 48 h for protein analysis, and quantified by HPLC using external calibration and peak integration. Across all three lines, licensing produced directionally consistent increases: mean adenosine increased 2.3-fold, mean kynurenine increased 3.1-fold, mean IL-10 increased 1.6-fold, and mean TGF-β increased 1.7-fold compared with unlicensed controls. Metabolite measurements for adenosine and kynurenine are reported with full chromatographic selectivity data; IL-10 and TGF-β measurements by reversed-phase HPLC with UV detection are presented as exploratory/semi-quantitative outputs and will require orthogonal confirmation (e.g., immunoassay) in future work. These findings are preliminary, derived from three independent donor lines with no comparator group, and are intended to support feasibility of the analytical framework rather than establish definitive performance specifications. Collectively, the data support the potential of a multi-analyte HPLC-based characterization panel to capture licensing-responsive secretory shifts across mechanistically complementary pathways, providing a foundation for expanded development and validation. Full article

Background/Objectives: Immune-mediated thrombotic thrombocytopenic purpura (iTTP) is a rare but life-threatening thrombotic microangiopathy in children. Secondary forms, occurring in association with immune dysregulation, autoimmune disease, or other triggers, are particularly challenging to diagnose and manage, and pediatric-specific data remain limited. This study aimed to describe the clinical characteristics, diagnostic pathways, and management of pediatric iTTP and to contextualize these findings within the recent literature. Methods: We conducted a retrospective case series of pediatric patients diagnosed with iTTP at a tertiary referral center, between November 2021 and January 2026. Clinical presentation, laboratory findings, including ADAMTS13 activity and ADAMTS13 inhibitors, associated conditions, treatment strategies, and outcomes were reviewed. In parallel, a narrative literature review was performed focusing on pediatric immune-mediated secondary TTP published over the past five years. Results: Four pediatric patients (three females, one male; median age 14 years) met inclusion criteria. All presented with severe thrombocytopenia and microangiopathic hemolytic anemia, accompanied by prominent neurologic manifestations in three cases. Severe ADAMTS13 activity deficiency (≤10%) with positive inhibitors was documented in all patients. Secondary iTTP occurred in association with evolving systemic autoimmunity, systemic lupus erythematosus, common variable immunodeficiency, or without an identifiable trigger at presentation. High clinical probability scores facilitated early diagnosis. Management required plasma exchange, corticosteroids, and targeted and immunomodulatory therapy. Conclusions: Pediatric secondary iTTP is a heterogeneous condition that frequently presents with diagnostic ambiguity and severe neurologic involvement. Early recognition, prompt initiation of TTP-directed therapy, and comprehensive immunologic evaluation are critical for favorable outcomes. Case series combined with narrative reviews remain valuable for advancing understanding and optimizing individualized care in this rare pediatric disorder. Full article

A five-month-old, intact, female Miniature Schnauzer Terrier presented with persistent severe hemolytic anemia following an initial infection with Babesia gibsoni and B. vogeli. Despite treatment, severe regenerative anemia persisted, and the patient was unresponsive to antibiotics, as well as antiprotozoal and immunosuppressive agents. Subsequent laboratory tests and diagnostic imaging ruled out persistent hemiparasitic infections, immune-mediated diseases, or neoplasia. Genomic DNA and cDNA sequencing identified a point mutation in exon 8 (g.4978G>T) that introduced a premature termination codon, leading to exon 8 skipping and a single-nucleotide deletion at the exon 7–intron 7 boundary (c.966delG) during splicing. A 151 bp deletion in the coding region of the patient’s PKLR cDNA was subsequently detected, which ultimately resulted in pyruvate kinase deficiency. This missplicing results in a premature stop codon and disrupts PKLR tetramer formation owing to the partial loss of domain A and complete loss of domain C. Enzyme activity assays confirmed a complete loss of function in the mutant PKLR protein compared to the wild-type, supporting the causal role of this deletion in non-spherocytic hemolytic anemia. This is the first report as per our knowledge documenting truncated PKLR variant in a dog, and notably, the first such case in a Miniature Schnauzer breed. Full article

Background: Evans syndrome is a rare autoimmune disease characterized by immune thrombocytopenia (ITP), autoimmune hemolytic anemia (AIHA), and autoimmune neutropenia, typically triggered by an episode of immune dysregulation or multiple other factors. We present what appears to be the first reported case of Evans syndrome developing in a 66-year-old female following respiratory syncytial virus (RSV) vaccination. Case Presentation: A 66-year-old female presented with a petechial rash on her arms, legs, and face. Laboratory tests revealed a platelet count of 1 × 10⁹/L, significantly lower than her historical baseline of >200 × 10⁹/L. On hospital day 4, her hemoglobin declined from 14.3 g/dL to 9.9 g/dL, with laboratory evidence of hemolysis, including elevated bilirubin, low haptoglobin, and increased lactate dehydrogenase (LDH). Bone marrow biopsy revealed megakaryocytic hyperplasia consistent with ITP, along with a small polyclonal B-cell population lacking CD20 expression. Imaging was unremarkable, showing no interval changes aside from stable pre-existing pulmonary nodules and no lymphadenopathy. These findings supported a diagnosis of Evans syndrome. Initial therapy with dexamethasone and intravenous immunoglobulin (IVIG) for presumed ITP was ineffective. Due to refractory thrombocytopenia, the patient initially received one dose of rituximab, followed by one dose of romiplostim. Subsequently, the patient received rituximab infusions every week at a rate of 375 mg/m² for four doses, as well as prednisone at a dose of 1 mg/kg/day. Within five weeks, her blood count returned to normal. Conclusions: This case raises concern for a potential temporal association between RSV vaccination and the onset of Evans syndrome. It underscores the need for heightened clinical awareness and further investigation into immune-mediated hematologic complications following RSV immunization. Full article

Antibody-mediated autoimmune diseases are common, can involve any organ system, and pose a large burden for patients and healthcare systems. Most antibody-mediated diseases are mediated by IgG antibodies. Selective targeting of pathogenic antibodies is an attractive treatment option which has already proven to be effective in antibody-positive generalized myasthenia gravis, maternal-fetal alloimmune cytopenias, and immune thrombocytopenic purpura. Warm autoimmune hemolytic anemia (wAIHA) is an autoimmune disorder mediated by pathogenic antibodies mainly of the IgG class with no approved therapy. Current treatment includes non-specific immunosuppression with corticosteroids, rituximab, and other immunosuppressive agents. With most therapies, time to response can be delayed and transfusions may be needed. Neonatal Fc receptor (FcRN) therapies provide rapid and sustained reduction of pathogenic IgG levels providing potential for fast, effective therapy in antibody-mediated autoimmune diseases including warm autoimmune hemolytic anemia. This review focuses on the emerging role of FcRn inhibition in autoimmune hematologic diseases, and their therapeutic potential in wAIHA. Full article

Feline infectious peritonitis (FIP) is caused by mutated feline coronaviruses. Immune-mediated hemolytic anemia (IMHA) arises due to immune-mediated erythrocyte destruction and can be non-associative or associative with diseases such as FIP. Records of cats with FIP were reviewed to find those with associative IMHA based on exclusion of other causes of anemia and a positive saline agglutination test and/or Coombs test. The inclusion criteria were met for 45 cats (26 (58%) cats with effusive and 19 (42%) with non-effusive FIP). Median hematocrit was 18% (interquartile range [IQR] 13–20). Anemia was non-regenerative in 36 (80%) cats and regenerative in 5 (11%) cats; 4 (9%) cats had no reticulocyte count available. Concurrent thrombocytopenia was present in 18 (40%) cats. All 45 cats were treated with nucleoside analogs, and 44 (98%) cats with glucocorticoids; in 5 (11%) cats, glucocorticoids were added after starting antiviral treatment due to persistent anemia. Median follow-up was 72 days (IQR 14–246); at the time of last follow-up 33 (73%) cats had survived while 12 (27%) had died or were euthanized. Of the 33 surviving cats, 17 achieved remission of both FIP and IMHA. In three cats, FIP remission was achieved, but IMHA relapsed; in one of these, IMHA relapsed twice. FIP relapsed without IMHA in two cats, and both FIP and IMHA relapsed in one cat. In 9 cats the antiviral and glucocorticoid treatment is still ongoing at the time of the publication. Although FIP is likely an uncommon cause of associative IMHA, as more cats with FIP are treated with antiviral therapy, it is important to consider IMHA as a possible cause of anemia in cats with FIP. Full article

Thrombotic thrombocytopenia purpura is a serious disease that can involve complex symptomatology, prolonged hospitalization, and a high risk of mortality if treatment is delayed. This disease is rare, but it is even rarer among pediatric patients. Even though it was first described 100 years ago, the earliest documented case was a pediatric patient. The last three decades have seen the discovery of the pathological mechanisms responsible for its clinical presentation. Symptoms/signs characteristic of microangiopathic hemolytic anemia with significant thrombocytopenia characterize the vast majority of patients. Its pathology centers on the accumulation of ultra-large von Willebrand factor multimers due to an enzyme deficiency that prevents their breakdown. Currently, in pediatric patients, two forms of the disease are known: congenital due to a mutation in the enzyme’s gene and immune-mediated due to enzyme depletion or neutralization secondary to autoantibody formation. With the advent of therapeutic plasma exchanges, immunosuppression, and, more recently, a TTP-specific nanobody, there is reason for optimism that the disease does not necessarily equate to a bad outcome. Thus, the aim of this review is to contrast the congenital and immune-mediated forms of the disease in pediatric patients while presenting them in the context of their pathologic mechanisms, diagnosis, and treatment. Full article

Autoimmune liver diseases (AiLDs), including autoimmune hepatitis (AIH), primary biliary cholangitis (PBC), and primary sclerosing cholangitis (PSC), are immune-mediated conditions associated with significant hepatic and systemic manifestations. Among these, cytopenias—defined as reductions in blood cell counts affecting single or multiple lineages—represent a clinically important, though often under-recognized, complication. Cytopenias in AiLDs arise from diverse mechanisms, including immune-mediated destruction, hypersplenism due to portal hypertension, bone marrow suppression, and nutritional deficiencies. These abnormalities can exacerbate bleeding, infections, or fatigue, complicating the disease course and impacting therapeutic strategies. Immune-mediated cytopenias, such as autoimmune hemolytic anemia (AIHA), immune thrombocytopenic purpura (ITP), and autoimmune neutropenia (AIN), are more frequently associated with AIH, whereas cytopenias in PBC and PSC are largely attributed to hypersplenism. Diagnostic evaluation involves a systematic approach combining clinical history, laboratory testing (e.g., complete blood counts, Coombs tests, and nutritional assessments), imaging studies, and bone marrow evaluation in complex cases. Treatment strategies aim to address the underlying cause of cytopenias, including immunosuppressive therapy for autoimmune mechanisms, beta-blockers or splenectomy for hypersplenism, and supplementation for nutritional deficiencies. Challenges include distinguishing between immune- and hypersplenism-related cytopenias, managing drug-induced cytopenias, and optimizing care in transplant candidates. The recently recognized IgG4-related disease, often mimicking cholestatic AiLDs, adds another layer of complexity, given its association with autoimmune cytopenias and hypersplenism. This review aims to act as a guide for the clinician dealing with patients with AiLDs with respect to the occurrence of cytopenias, with a specific focus on pathophysiology and management of these cytopenias. Furthermore, there need to be enhanced multidisciplinary discussions about those patients between the hematologists and hepatologists, with a maintenance of a high index of suspicion for the rarer causes of cytopenias in AiLDs on the part of the treating physician, and there is a need for further studies to elucidate the mechanisms behind the occurrence of cytopenias in AiLDs. Full article

Background: In Epstein–Barr virus infectious mononucleosis, hemolytic anemia occasionally occurs. Methods: To characterize hemolytic anemia linked to Epstein–Barr virus infectious mononucleosis, we performed a systematic review (PROSPERO CRD42024597183) in the United States National Library of Medicine, Excerpta Medica, and Web of Science with no restrictions on language. Only reports published since 1970 were included. Eligible were reports describing hemolytic anemia in subjects with clinical signs and microbiological markers of Epstein–Barr virus mononucleosis. Results: In the literature, we detected 56 reports released between 1973 and 2024, documenting 60 individuals (32 females and 28 males; 27 children and 33 adults) with hemolytic anemia linked to Epstein–Barr virus infectious mononucleosis. The mechanism underlying anemia was categorized as cold-antibody-mediated (N = 31; 52%), warm-antibody-mediated (N = 18, 30%), mixed warm- and cold-antibody-mediated (N = 4; 6.7%), or paroxysmal cold hemoglobinuria (N = 2; 3.3%). The remaining 5 cases (8.3%) remained unclassified. Observation alone was the chosen approach in 23% of cases (N = 14). Steroids (67%; N = 40) and blood transfusions (38%; N = 23) were the most commonly used treatment, while plasma exchange, intravenous polyclonal immunoglobulin, rituximab, and splenectomy were used less frequently. Observation was slightly but significantly (p = 0.032) more common in cases of cold-antibody-mediated anemia compared to all other cases combined. Patients recovered a median of 28 [interquartile range 21–39] days after disease onset. Two patients with warm-antibody-mediated hemolytic anemia died. Conclusions: This literature review points out that Epstein–Barr virus, like Mycoplasma pneumoniae, cytomegalovirus, or severe acute respiratory syndrome coronavirus 2, may act as a trigger for immune-mediated hemolytic anemia. Full article

Background: Peripheral erythrophagocytosis appears to be a unique sign of acquired immune-mediated hemolytic anemia. It is said to be rare but its prevalence among patients with autoimmune hemolytic anemia has not been studied. Methods: In this retrospective study from July 2014 to June 2024, the clinical and laboratory features, treatment and outcomes of children diagnosed with autoimmune hemolytic anemia were described. The prevalence of peripheral erythrophagocytosis was compared to a group of children with hereditary spherocytosis at the time of first diagnosis seen in the same period. Results: Twelve consecutive children with autoimmune hemolytic anemia were included. There were four female patients. The mean age was 6.7 (range 0.8 to 16.6) years. The mean hemoglobin was 6.0 (range 2.5 to 8.1) g/dL. Seven patients were positive by a direct antiglobulin test, three were positive with cold agglutinins and two were positive on both tests. In seven cases, an acute infection appeared to be the precipitating factor. Mycoplasma pneumoniae infection was documented in three and suspected in another two cases. Peripheral erythrophagocytosis was present in five cases (42%) but was not found at diagnosis in any of the 16 cases of hereditary spherocytosis (p = 0.0081). Six children had pre-existing diseases, including two with hereditary hemolytic anemia. Conclusions: Peripheral erythrophagocytosis is a relatively common and characteristic finding in pediatric autoimmune hemolytic anemia and should be actively looked for in the evaluation of acute hemolysis, including in children with pre-existing hereditary hemolytic disorders. Full article

Background: Lupus podocytopathy (LP) is a non-immune complex-mediated glomerular lesion in systemic lupus erythematosus (SLE), characterized by the diffuse effacement of podocyte processes without immune complex deposition or with only mesangial immune complex deposition. LP is a rare cause of nephrotic syndrome in SLE patients with implications for prognosis and treatment. Case Report: We present the case of a 28-year-old woman with a medical history of type 1 diabetes mellitus (T1DM) who presented with lower limb edema, dyspnea, hypercholesterolemia, with nephrotic range proteinuria, without acute kidney injury, and laboratory findings compatible with auto-immune hemolytic anemia. They had negative infectious serology, positive antinuclear antibody (ANA), and an eye fundus examination showing diabetic retinopathy. A biopsy was performed to define the etiology of the renal involvement, which was compatible with LP. Following immuno-suppressive and antiproteinuric therapy, the patient evolved with the complete remission of the nephrotic syndrome. Conclusions: Lupus podocytopathy is an infrequent anatomopathological entity, so this case is presented as the first reported in Peru, and a literature review is made. Full article