Pathological mutations reveal the key role of the cytosolic iRhom2 N-terminus for phosphorylation-independent 14-3-3 interaction and ADAM17 binding, stability, and activity.

The protease ADAM17 plays an important role in inflammation and cancer and is regulated by iRhom2. Mutations in the cytosolic N-terminus of human iRhom2 cause tylosis with oesophageal cancer (TOC). In mice, partial deletion of the N-terminus results in a curly hair phenotype (cub). These pathological consequences are consistent with our findings that iRhom2 is highly expressed in keratinocytes and in oesophageal cancer. Cub and TOC are associated with hyperactivation of ADAM17-dependent EGFR signalling. However, the underlying molecular mechanisms are not understood. We have identified a non-canonical, phosphorylation-independent 14-3-3 interaction site that encompasses all known TOC mutations. Disruption of this site dysregulates ADAM17 activity. The larger cub deletion also includes the TOC site and thus also dysregulated ADAM17 activity. The cub deletion, but not the TOC mutation, also causes severe reductions in stimulated shedding, binding, and stability of ADAM17, demonstrating the presence of additional regulatory sites in the N-terminus of iRhom2. Overall, this study contrasts the TOC and cub mutations, illustrates their different molecular consequences, and reveals important key functions of the iRhom2 N-terminus in regulating ADAM17.

A pilot study of orelabrutinib treatment in three cases of refractory/relapsed autoimmune haemolytic anaemia/Evans syndrome.

Currently, there is no effective treatment for refractory/relapsed (R/R) autoimmune haemolytic anaemia (AIHA), associated with poor quality of life. Bruton tyrosine kinase inhibitors have begun to be used in some autoimmune diseases. We initiated the clinical trial of orelabrutinib treatment on R/R AIHA/Evans Syndrome, which is in progress. The preliminary results showed that nine of the 12 enrolled patients responded to orelabrutinib treatment. Here, we reported three cases who have completed the treatment and were followed up for 6 months, achieving complete or partial remission. Orelabrutinib is expected to become a new second-line treatment for R/R AIHA/Evans syndrome.

Autoimmune cytopenia and Kabuki syndrome in paediatrics: Insights in 11 patients.

Kabuki syndrome (KS) is now listed in the Human Inborn Errors of Immunity (IEI) Classification. It is a rare disease caused by KMT2D and KDM6A variants, dominated by intellectual disability and characteristic facial features. Recurrently, pathogenic variants are identified in those genes in patients examined for autoimmune cytopenia (AIC), but interpretation remains challenging. This study aims to describe the genetic diagnosis and the clinical management of patients with paediatric-onset AIC and KS. Among 11 patients with AIC and KS, all had chronic immune thrombocytopenic purpura, and seven had Evans syndrome. All had other associated immunopathological manifestations, mainly symptomatic hypogammaglobinaemia. They had a median of 8 (5-10) KS-associated manifestations. Pathogenic variants were detected in KMT2D gene without clustering, during the immunological work-up of AIC in three cases, and the clinical strategy to validate them is emphasized. Eight patients received second-line treatments, mainly rituximab and mycophenolate mofetil. With a median follow-up of 17 (2-31) years, 8/10 alive patients still needed treatment for AIC. First-line paediatricians should be able to recognize and confirm KS in children with ITP or multiple AIC, to provide early appropriate clinical management and specific long-term follow-up. The epigenetic immune dysregulation in KS opens exciting new perspectives.

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.

Familial autoimmunity and risk of developing immune thrombocytopenia and Evans syndrome.

BACKGROUND: Immune thrombocytopenia (ITP) and Evans syndrome (ES) are manifestations of immune dysregulation. Genetic variants in immune-related genes have been identified in patients with ITP and especially ES. We aimed to explore familial autoimmunity in patients with ITP and ES to understand possible contributions to chronicity. PROCEDURE: We assessed family history in two ways: via patient report for ITP and ES and by population-based analysis using the Utah Population Database (UPDB) for ITP. A total of 266 patients with ITP and 21 patients with ES were identified via chart review, and 252 of the 266 patients with ITP were also identified in the UPDB. RESULTS: Chart review showed familial autoimmunity in 29/182 (15.9%) and 25/84 (29.8%) of patients with newly diagnosed+persistent (nd+p) ITP and chronic ITP (cITP), respectively, (p = .009). The UPDB analysis revealed that autoimmunity in relatives of patients with nd+pITP was higher than in relatives of controls (odds ratio [OR]: 1.69 [1.19-2.41], p = .004), but was not significantly increased in relatives of patients with cITP (OR 1.10 [0.63-1.92], p = .734). Incomplete family history in medical records likely contributed to the observed discrepancy. CONCLUSIONS: The findings suggest that familial autoimmunity may have a stronger association with the development of ITP rather than its duration. Twelve (57.1%) patients with ES reported autoimmunity in their relatives. UPDB analysis was omitted due to the small number of patients with ES. The use of population databases offers a unique opportunity to assess familial health and may provide clues about contributors to immune dysregulation features within families.

Extremely Rare Case of Successful Treatment of Foot Ulcer Associated with Evans' Syndrome and Buerger's Disease.

Evans Syndrome (ES) is a rare autoimmune disorder characterized by the simultaneous occurrence of immune thrombocytopenia (ITP) and autoimmune hemolytic anemia (AIHA). Thrombotic complications in ES patients are uncommon, particularly involving Buerger's Disease (BD). We report a case of a 49-year-old male with ES and a history of diabetes and heavy smoking, presenting with a necrotic wound on his right great toe. Diagnostic evaluations revealed severe stenosis and thrombosis in the lower limb arteries, diagnosed as BD. The patient underwent successful popliteal-tibioperoneal artery bypass surgery and the subsequent disarticulation and revision of the distal phalanx, followed by the application of an acellular dermal matrix (ADM) to promote healing. Post-surgery, the patient showed significant improvement in blood flow and complete epithelialization without complications. This case highlights the importance of a multidisciplinary approach to managing complex wounds in ES patients, suggesting potential treatment pathways for future cases involving BD.

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.

Evans syndrome caused by a deleterious mutation affecting the adaptor protein SASH3.

Increasing evidence suggests multilineage cytopenias (also known as Evans syndrome) may be caused by inborn errors of immunity (IEI) with immune dysregulation. We studied a patient with autoimmune haemolytic anaemia and immune thrombocytopenia and identified a germline mutation in SASH3 (c.862C>T;p.Arg288Ter), indicating a recently identified IEI. Immunohistochemistry performed after clinically indicated splenectomy revealed severe hypoplasia/absence of germinal centres. The autoimmune phenotype was associated with an increased CD21low T-bet+ CD11c+ subset along with decreased regulatory T cells, impaired T-cell proliferation and T-cell exhaustion. The younger brother carries the same SASH3 mutation and shares immunophenotypic features but is currently clinical asymptomatic, indicating heterogeneity of SASH3 deficiency.

Maintenence rituximab following induction in autoimmune cytopenias.

About 50% of immune thrombocytopenia (ITP) patients respond to rituximab induction, but most relapse. The effectiveness of rituximab maintenance remains untested. This study included autoimmune cytopenia patients who had previously responded to rituximab induction but subsequently relapsed. After re-induction, patients received rituximab maintenance regimen consisting of a single 375 mg/m2 dose administered at 4 month intervals, with a maximum of 6 doses. Primary endpoints were duration of response and safety. Sixteen patients: ITP (9), autoimmune haemolytic anaemia (2), and Evans syndrome (5) received rituximab maintenance. 15/16 achieved complete response (CR); 8/15 CR + 1 partial reponse remain in remission. Median response: 43 months; estimated 5-year relapse-free >50%. Three developed hypogammaglobulinemia. Rituximab maintenance led to prolonged remissions in patients with autoimmune cytopenias who had previously responded to rituximab induction.

Clinical utility of measuring CD4+ T follicular cells in patients with immune dysregulation.

Mechanistic studies of autoimmune disorders have identified circulating T follicular helper (cTfh) cells as drivers of autoimmunity. However, the quantification of cTfh cells is not yet used in clinical practice due to the lack of age-stratified normal ranges and the unknown sensitivity and specificity of this test for autoimmunity. We enrolled 238 healthy participants and 130 patients with common and rare disorders of autoimmunity or autoinflammation. Patients with infections, active malignancy, or any history of transplantation were excluded. In 238 healthy controls, median cTfh percentages (range 4.8%-6.2%) were comparable among age groups, sexes, races, and ethnicities, apart from a significantly lower percentages in children less than 1 year of age (median 2.1%, CI: 0.4%-6.8, p < 0.0001). Among 130 patients with over 40 immune regulatory disorders, a cTfh percentage exceeding 12% had 88% sensitivity and 94% specificity for differentiating disorders with adaptive immune cell dysregulation from those with predominantly innate cell defects. This threshold had a sensitivity of 86% and specificity of 100% for active autoimmunity and normalized with effective treatment. cTfh percentages exceeding 12% distinguish autoimmunity from autoinflammation, thereby differentiating two endotypes of immune dysregulation with overlapping symptoms and different therapies.

Systemic lupus erythematosus mimicking retinal migraine: a case report.

BACKGROUND: Retinal migraine is a diagnosis of exclusion and is characterized by repeated episodes of transient monocular blindness associated with migraine. We report a case of systemic lupus erythematosus with acute episodes mimicking retinal migraines. CASE REPORT: A 46-year-old woman with a history of migraine with aura since her 20s and Evans syndrome presented with episodic transient monocular blindness. Retinal migraine was considered as the cause, and migraine prophylaxis initially reduced its frequency. After 5 months, the frequency increased, with chilblain-like lupus lesions on her extremities. Laboratory testing revealed lymphopenia and hypocomplementemia, fulfilling the diagnostic criteria for systemic lupus erythematosus, which may have caused Evans syndrome and transient monocular blindness, mimicking retinal migraines. After intravenous methylprednisolone and rituximab therapy, the transient monocular blindness episodes did not recur. CONCLUSION: Given the clinical presentation, systemic lupus erythematosus should be considered as a cause of transient monocular blindness and should be distinguished from retinal migraine.

Concurrent severe pulmonary tuberculosis with Evans syndrome: a case report with literature review.

BACKGROUND: Tuberculosis is a bacterial infection involving multiple organs and systems. Its hematological presentation mainly includes anemia and leukocytosis. Evans syndrome is a rare autoimmune disease characterized by autoimmune hemolytic anemia, immune thrombocytopenia, and neutropenia, with positive results for the direct Coombs test and platelet antibodies. The cooccurrence of tuberculosis and Evans syndrome is rarely reported. CASE PRESENTATION: A 69-year-old female presented with a fever and shortness of breath. Her chest computerized tomography scan showed extensive miliary nodules in the bilateral lung fields. She rapidly developed respiratory failure that required endotracheal intubation and mechanical ventilation. The acid-fast bacilli sputum smear results indicated a grade of 3+. Later on, blood testing revealed hemolytic anemia, a positive direct Coombs test result, and the presence of the platelet antibody IgG. This patient was diagnosed as having disseminated pulmonary tuberculosis and Evans syndrome. She successfully recovered after treatment with antituberculosis drugs and glucocorticoids. CONCLUSIONS: Tuberculosis can occur together with Evans syndrome. Affected patients should receive both antituberculosis and immunosuppressive drugs.

Refractory immune thrombocytopenia successfully treated with bortezomib in a child with 22q11.2 deletion syndrome, complicated by Evans syndrome and hypogammaglobulinemia.

Treatment of refractory autoimmune cytopenias (AICs) and Evans syndrome (ES) represent a great challenge in pediatric setting, where an underlying primary immunodeficiency is recurrent. Frequently, second or third line treatments are employed, with an increased risk of toxicity and infections. The advent of novel drugs is the object of research in order to modify the management of these patients.We report a case of successful use of bortezomib in a child with 22q11.2 deletion syndrome and CVID-like phenotype with a multi-refractory severe ES. Last flares were prolonged and dominated by severe and symptomatic ITP, refractory to different courses of high dose steroid and IVIG, mofetil mycophenolate, thrombopoietin receptor agonists, sirolimus, and rituximab. Persistence of AICs in subjects with depletion of CD20 + B-cells and IgG strengthens the hypothesis about the production of autoantibodies by terminally differentiated plasma-cells, not targetable from immunosuppressants and rituximab.In the attempt to enhance plasma-cells inhibition, the child was addressed to bortezomib, with a good response at 6 month follow-up without side effects. Nowadays, the use of bortezomib in ES/AICs is based only on small retrospective studies and case reports. Despite the lack of long term follow-up, our work highlights the potential role of bortezomib in the management of pediatric patients with multi-resistant AICs secondary to immune-system impairment.

Immune deficiency, autoimmune disease and intellectual disability: A pleiotropic disorder caused by biallelic variants in the TPP2 gene.

Four individuals from two families presented with a multisystemic condition of suspected genetic origin that was diagnosed only after genome analysis. The main phenotypic features were immune system dysregulation (severe immunodeficiency with autoimmunity) and intellectual disability. The four individuals were found to be homozygous for a 4.4 Kb deletion removing exons 20-23 (NM_003291.4) of the TPP2 gene, predicting a frameshift with premature termination of the protein. The deletion was located on a shared chromosome 13 haplotype indicating a Swiss founder mutation. Tripeptidyl peptidase 2 (TPP2) is a protease involved in HLA/antigen complex processing and amino acid homeostasis. Biallelic variants in TPP2 have been described in 10 individuals with variable features including immune deficiency, autoimmune cytopenias, and intellectual disability or chronic sterile brain inflammation mimicking multiple sclerosis. Our observations further delineate this severe condition not yet included in the OMIM catalog. Timely recognition of TPP2 deficiency is crucial since (1) immune surveillance is needed and hematopoietic stem cell transplantation may be necessary, and (2) for provision of genetic counselling. Additionally, enzyme replacement therapy, as already established for TPP1 deficiency, might be an option in the future.

Refractory autoimmune cytopenias in pediatric Evans syndrome with underlying systemic immune dysregulation.

Evans syndrome is a rare but challenging disorder in children; and despite rapidly growing evidence for targetable systemic immune dysregulation driving these "idiopathic" autoimmune cytopenias, precision diagnosis and management remains sub-optimal among these patients. We analyzed retrospective clinical data for 60 pediatric ES patients followed at 3 large tertiary referral centers in the United States over a recent 6-year period and found that definable underlying systemic immune dysregulation was identified in only 42% of these patients throughout the course of clinical care. Median time from ES diagnosis to identification of the underlying systemic immune dysregulation disorder was 1.3 years (<1 month for rheumatologic disease, 2.3 years for CVID, 3.4 years for ALPS, and 7.4 years for monogenic disorders of immune regulation). Notably, a significantly higher percentage of patients in whom a definitive immune dysregulation disorder was ultimately identified required ≥3 cytopenia-directed therapies (92%) and also second- and third-line immunomodulatory agents (84%), vs those in whom no unifying immune dysregulation was diagnosed (65%, and 35%, respectively)-indicating that autoimmune cytopenias as a manifestation of systemic immune dysregulation are more treatment-refractory and severe. These data underline the importance of identifying the underlying systemic immune dysregulation and providing targeted therapy in pediatric ES.

ADEM post-Sars-CoV-2 infection in a pediatric patient with Fisher-Evans syndrome.

INTRODUCTION: Sars-CoV-2 is a single-strained RNA virus belonging to Coronaviridae's family. In pediatric age, the majority of patients is asymptomatic; however, several neurological manifestations associated with Sars-CoV-2 infection have been detected in a percentage of cases ranging from 17.3 to 36.4%. Acute disseminated encephalomyelitis (ADEM) has been recently included among the potential complications of Sars-Cov2 infection. The available data regarding pediatric patient show only one case. CASE REPORT: We present a case regarding a 6-year-old patient suffering from Fisher-Evans syndrome who was given sirolimus and thalidomide therapy. After 10 days since the first positive nasopharyngeal swab for Sars-CoV-2, in which he had no symptoms, he presented an episode of generalized tonic-clonic seizure with spontaneous resolution. The patient underwent MRI which showed the typical picture of acute disseminated encephalomyelitis. His clinical course was favorable, with a good response to cortisone therapy and a progressive improvement of the neuroradiological and electroencephalographic picture. CONCLUSIONS: According to our knowledge, this is the second case of an acute disseminated encephalomyelitis following SARS-CoV-2 infection in a pediatric patient, characterized by monosymptomatic onset, in which the immunosuppressive therapy practiced for the Fisher-Evans syndrome has probably contributed to a favorable evolution of ADEM, in contrast to other case described in the literature.

Immune dysregulation and multisystem inflammatory syndrome in children (MIS-C) in individuals with haploinsufficiency of SOCS1.

BACKGROUND: We studied 2 unrelated patients with immune thrombocytopenia and autoimmune hemolytic anemia in the setting of acute infections. One patient developed multisystem inflammatory syndrome in children in the setting of a severe acute respiratory syndrome coronavirus 2 infection. OBJECTIVES: We sought to identify the mechanisms underlying the development of infection-driven autoimmune cytopenias. METHODS: Whole-exome sequencing was performed on both patients, and the impact of the identified variants was validated by functional assays using the patients' PBMCs. RESULTS: Each patient was found to have a unique heterozygous truncation variant in suppressor of cytokine signaling 1 (SOCS1). SOCS1 is an essential negative regulator of type I and type II IFN signaling. The patients' PBMCs showed increased levels of signal transducer and activator of transcription 1 phosphorylation and a transcriptional signature characterized by increased expression of type I and type II IFN-stimulated genes and proapoptotic genes. The enhanced IFN signature exhibited by the patients' unstimulated PBMCs parallels the hyperinflammatory state associated with multisystem inflammatory syndrome in children, suggesting the contributions of SOCS1 in regulating the inflammatory response characteristic of multisystem inflammatory syndrome in children. CONCLUSIONS: Heterozygous loss-of-function SOCS1 mutations are associated with enhanced IFN signaling and increased immune cell activation, thereby predisposing to infection-associated autoimmune cytopenias.

Bortezomib treatment of steroid-refractory Evans syndrome in children.

Treatment of refractory Evans syndrome (ES) remains a challenge in hematology practice. Due to rarity of this condition, evidence-based approaches are limited and often treatment choices stem from small case series or anecdotal experiences. There is mounting evidence that some patients have genetic defects that could be targeted with promising preliminary results. Here, we describe three very refractory pediatric ES cases treated on bortezomib without adverse effects. Two of the three patients had dramatic and long-lasting recovery that started following the initial doses of the drug. Clinical trials to assess the role of bortezomib in ES treatment are warranted.

A Rare Clinical Manifestation of Graves' Disease: Evans Syndrome and a Review of the Literature.

Evans syndrome is a rare combination of autoimmune hemolytic anemia and immune thrombocytopenia. Evans syndrome in cases of Graves' disease is extremely rare. The coexistence of these autoimmune diseases suggests that they may share a common pathogenic pathway. The case here presented is of a 36-year old female patient who was admitted for anemia and thrombocytopenia and was diagnosed with Evans syndrome associated with Graves' disease, and was then treated with methimazole and methylprednisolone (MPSL). During follow-up, MPSL was discontinued gradually over the course of two months. Interestingly, while Evans syndrome is characterized by frequent relapses, this patient has been in remission of Evans syndrome for approximately 1 year without MPSL therapy. The remission of Evans syndrome associated with Graves' disease in the absence of immunosuppressive therapy suggests that these 2 diseases have a common pathogenetic mechanism.

Relapsing Evans syndrome and systemic lupus erythematosus with antiphospholipid syndrome treated with Bortezomib in combination with plasma exchange.

Relapsing Evans syndrome (ES) and systemic lupus erythematosus (SLE) with secondary antiphospholipid syndrome (APS) is very rare association. Coexistence of these syndromes is potentially fatal and require high-dose combined immunosuppressive therapy. We describe a case of successful use of Bortezomib and plasma exchange in a patient with ES and APS refractory to standard therapy. Thirty-two-year-old male who presented episodes of relapsing hemolytic anemia, pancytopenia and multiple thrombosis with positive direct and indirect antiglobulin test result, lupus anticoagulant and medium titer of anti-beta-2-glycoprotein 1 and anti-cardiolipin antibodies was diagnosed with ES and SLE with secondary APS. High-dose therapy by steroids and Cyclosporin A were started with temporary improvement. There was also no stable improvement with Rituximab and Cyclophosphamide. Bortezomib in combination with cyclosporine A and plasma exchange was introduced. He had stable improvement in hematological parameters with no evidence of relapse of hemolytic crisis or thrombosis during a follow-up for 1 year.