Severe Relapsing Autoimmune Encephalitis with GABAA Receptor, Titin, and AchR Antibodies in a Patient with Thymoma: A Case Report.

Introduction: We report a challenging case of autoimmune encephalitis in a patient with a thymoma harboring titin and acetylcholine receptor antibodies, who experienced multiple relapses despite thymectomy and aggressive first-line immunotherapy, and for whom GABAA receptor antibodies were ultimately identified. Case Presentation: This 40-year-old man presented with headaches, weakness, diplopia, hearing loss, and seizures progressing to status epilepticus. Brain MRI showed multifocal cortical and subcortical T2/fluid attenuated inversion recovery hyperintense lesions without enhancement. Initial neural antibody testing identified only acetylcholine receptor and titin antibodies. He presented multiple severe relapses despite complete thymoma resection, intravenous methylprednisolone with immunoglobulins or plasmapheresis, and mycophenolate mofetil. Second-line immunotherapy with rituximab was successful to alleviate symptoms and normalize the EEG and MRI after identification of anti-GABAA receptor antibodies on more comprehensive neural antibody testing for autoimmune encephalitis. Conclusion: This case demonstrates the complexity and importance of identifying pathogenic antibodies and selecting 2nd line treatment accordingly in patients with autoimmune encephalitis when multiple antibodies coexist. Despite tumor resection, aggressive immunotherapy may be needed to prevent further deterioration in anti-GABAA receptor encephalitis.

Acute central nervous system graft-versus-host-disease after liver transplantation.

Acute Central Nervous System (CNS) Graft Versus Host Disease (GvHD) is a rare form of GvHD, only described in case reports. Knowledge about this condition is extrapolated from chronic CNS GvHD cases occurring mostly after hematopoietic stem cell transplantation. GvHD following solid organ transplantation is an unexpected complication. GvHD after liver transplantation has a poor prognosis, and the optimal management is not yet known. Here we describe the case of a 63-year-old man who underwent deceased donor liver transplantation and subsequently developed skin rash, colitis and pancytopenia followed by refractory status epilepticus. Following the identification of lymphocytes of donor origin in the cerebrospinal fluid of the patient, he was diagnosed with acute CNS GvHD. He was treated with an intensive immunosuppressive regimen, but care was withdrawn due to lack of improvement and worsening neurologic prognosis. It is the second known case of acute CNS GvHD following liver transplantation. Clinicians should be aware of this possible, although rare, complication of liver transplantation, especially when there is refractory status epilepticus of unknown origin.

Chronic granulomatous disease presenting at age 52 with fulminant mulch pneumonitis.

Chronic granulomatous disease should be considered in adults of any age in the presence of refractory and/or atypical or fulminant pulmonary infections. This case of new large deletions in NCF1 was presented with mulch pneumonitis without a significant history of infections.

Therapeutic options for CTLA-4 insufficiency.

BACKGROUND: Heterozygous germline mutations in cytotoxic T lymphocyte-associated antigen-4 (CTLA4) impair the immunomodulatory function of regulatory T cells. Affected individuals are prone to life-threatening autoimmune and lymphoproliferative complications. A number of therapeutic options are currently being used with variable effectiveness. OBJECTIVE: Our aim was to characterize the responsiveness of patients with CTLA-4 insufficiency to specific therapies and provide recommendations for the diagnostic workup and therapy at an organ-specific level. METHODS: Clinical features, laboratory findings, and response to treatment were reviewed retrospectively in an international cohort of 173 carriers of CTLA4 mutation. Patients were followed between 2014 and 2020 for a total of 2624 months from diagnosis. Clinical manifestations were grouped on the basis of organ-specific involvement. Medication use and response were recorded and evaluated. RESULTS: Among the 173 CTLA4 mutation carriers, 123 (71%) had been treated for immune complications. Abatacept, rituximab, sirolimus, and corticosteroids ameliorated disease severity, especially in cases of cytopenias and lymphocytic organ infiltration of the gut, lungs, and central nervous system. Immunoglobulin replacement was effective in prevention of infection. Only 4 of 16 patients (25%) with cytopenia who underwent splenectomy had a sustained clinical response. Cure was achieved with stem cell transplantation in 13 of 18 patients (72%). As a result of the aforementioned methods, organ-specific treatment pathways were developed. CONCLUSION: Systemic immunosuppressants and abatacept may provide partial control but require ongoing administration. Allogeneic hematopoietic stem cell transplantation offers a possible cure for patients with CTLA-4 insufficiency.

Partial Purine Nucleoside Phosphorylase Deficiency Helps Determine Minimal Activity Required for Immune and Neurological Development.

Introduction: Complete or near complete absence of the purine nucleoside phosphorylase (PNP) enzyme causes a profound T cell immunodeficiency and neurological abnormalities that are often lethal in infancy and early childhood. We hypothesized that patients with partial PNP deficiency, characterized by a late and mild phenotype due to residual PNP enzyme, would provide important information about the minimal PNP activity needed for normal development. Methods: Three siblings with a homozygous PNP gene mutation (c.769C>G, p.His257Asp) resulting in partial PNP deficiency were investigated. PNP activity was semi-quantitively assayed by the conversion of [14C]inosine in hemolysates, mononuclear cells, and lymphoblastoid B cells. PNP protein expression was determined by Western Blotting in lymphoblastoid B cells. DNA repair was quantified by measuring viability of lymphoblastoid B cells following ionizing irradiation. Results: A 21-year-old female was referred for recurrent sino-pulmonary infections while her older male siblings, aged 25- and 28- years, did not suffer from significant infections. Two of the siblings had moderately reduced numbers of T, B, and NK cells, while the other had near normal lymphocyte subset numbers. T cell proliferations were normal in the two siblings tested. Hypogammaglobulinemia was noted in two siblings, including one that required immunoglobulin replacement. All siblings had typical (normal) neurological development. PNP activity in various cells from two patients were 8-11% of the normal level. All siblings had normal blood uric acid and increased PNP substrates in the urine. PNP protein expression in cells from the two patients examined was similar to that observed in cells from healthy controls. The survival of lymphoblastoid B cells from 2 partial PNP-deficient patients after irradiation was similar to that of PNP-proficient cells and markedly higher than the survival of cells from a patient with absent PNP activity or a patient with ataxia telangiectasia. Conclusions: Patients with partial PNP deficiency can present in the third decade of life with mild-moderate immune abnormalities and typical development. Near-normal immunity might be achieved with relatively low PNP activity.

Hiding in plain sight: A case of fever, rash, and jaundice.

A 25-year-old man presented to the emergency department with a 3-day history of fever, anorexia, jaundice, and a generalized skin eruption. His liver function tests showed marked cholestatic and cytolytic abnormalities without liver insufficiency. A liver biopsy was performed, and morphology with routine stains was considered non-specific. Because of the dermatological findings, the non-specific biopsy morphology, and the absence of an identified infectious etiology, a diagnosis of Kawasaki disease was presumed. However, additional colorations on liver biopsy with Warthin-Starry stain revealed multiple thin and coiled microorganisms compatible with spirochetes. His serology for leptospirosis was found to be positive for IgM, supporting the diagnosis of acute leptospirosis with liver involvement. Our case illustrates the diagnostic challenge of leptospirosis and highlights the utility of conventional laboratory tests to confirm the diagnosis. Exceptionally, Warthin-Starry stain allowed the identification of leptospires in liver biopsy and confirmed liver involvement of systemic leptospirosis.

Un homme de 25 ans a consulté à l'urgence parce qu'il faisait de la fièvre depuis trois jours, de l'anorexie, un ictère et une éruption cutanée généralisée. Les tests de fonction hépatique ont révélé des anomalies cholestatiques et cytolytiques marquées, sans insuffisance hépatique. La coloration standard de la biopsie hépatique a révélé une morphologie cellulaire considérée comme non spécifique. Compte tenu des observations dermatologiques, de la morphologie non spécifique de la biopsie et de l'absence d'étiologie infectieuse établie, un diagnostic de maladie de Kawasaki a été présumé. Cependant, l'ajout d'une coloration de Warthin-Starry a révélé de multiples microorganismes minces et torsadés compatibles avec des spirochètes. La sérologie pour la leptospirose s'est avérée positive pour les anticorps IgM, appuyant un diagnostic de leptospirose aiguë avec atteinte hépatique. Ce cas illustre les difficultés diagnostiques de la leptospirose et fait ressortir l'utilité des tests de laboratoire traditionnels pour confirmer le diagnostic. Exceptionnellement, la coloration de Warthin­Starry a permis d'observer des leptospires à la biopsie hépatique et confirmé la leptospirose systémique avec atteinte hépatique.

Ectopic jejunal pancreas with pancreatitis mistaken for a post-transplant lymphoproliferative disease in an immunosuppressed kidney transplant patient.

An ectopic pancreas, also known as pancreatic rest or heterotopic pancreas, consists of pancreatic tissue found in a location with no continuity with the anatomic pancreas. This lesion can occasionally cause gastrointestinal obstruction, ulceration or become inflamed and cause ectopic pancreatitis. We present the case of a 29-year-old immunocompromised female patient due to a previous kidney transplant. She presented with nausea and vague abdominal discomfort and was admitted for investigation and treatment of an acute kidney injury. A small bowel mass of unknown etiology was incidentally found on abdominal computed tomography imaging. Due to the high suspicion of a post-transplant lymphoproliferative disease, a surgical exploration took place and revealed the presence of a pancreatic rest with chronic pancreatitis. Ectopic pancreas diagnosis is challenging and surgical exploration is warranted when a neoplastic process is suspected.

Phenotype, penetrance, and treatment of 133 cytotoxic T-lymphocyte antigen 4-insufficient subjects.

BACKGROUND: Cytotoxic T-lymphocyte antigen 4 (CTLA-4) is a negative immune regulator. Heterozygous CTLA4 germline mutations can cause a complex immune dysregulation syndrome in human subjects. OBJECTIVE: We sought to characterize the penetrance, clinical features, and best treatment options in 133 CTLA4 mutation carriers. METHODS: Genetics, clinical features, laboratory values, and outcomes of treatment options were assessed in a worldwide cohort of CTLA4 mutation carriers. RESULTS: We identified 133 subjects from 54 unrelated families carrying 45 different heterozygous CTLA4 mutations, including 28 previously undescribed mutations. Ninety mutation carriers were considered affected, suggesting a clinical penetrance of at least 67%; median age of onset was 11 years, and the mortality rate within affected mutation carriers was 16% (n = 15). Main clinical manifestations included hypogammaglobulinemia (84%), lymphoproliferation (73%), autoimmune cytopenia (62%), and respiratory (68%), gastrointestinal (59%), or neurological features (29%). Eight affected mutation carriers had lymphoma, and 3 had gastric cancer. An EBV association was found in 6 patients with malignancies. CTLA4 mutations were associated with lymphopenia and decreased T-, B-, and natural killer (NK) cell counts. Successful targeted therapies included application of CTLA-4 fusion proteins, mechanistic target of rapamycin inhibitors, and hematopoietic stem cell transplantation. EBV reactivation occurred in 2 affected mutation carriers after immunosuppression. CONCLUSIONS: Affected mutation carriers with CTLA-4 insufficiency can present in any medical specialty. Family members should be counseled because disease manifestation can occur as late as 50 years of age. EBV- and cytomegalovirus-associated complications must be closely monitored. Treatment interventions should be coordinated in clinical trials.

Sirolimus in Refractory Cronkhite-Canada Syndrome and Focus on Standard Treatment.

Cronkhite-Canada syndrome is a rare syndrome consisting of extensive gastrointestinal polyposis and ectodermal changes including cutaneous hyperpigmentation, alopecia, and onychodystrophy. We report the case of a 45-year-old Caucasian male patient who failed multiple treatments over 2 years including steroids, azathioprine, adalimumab, and cyclosporine. He had recurrent and prolonged hospitalizations because of diarrhea, abdominal pain, weight loss, and malnutrition. Sirolimus was initiated with a significant clinical and endoscopic benefit apparent within, respectively, 2 and 8 weeks. An ongoing remission was achieved and maintained for over 6 months after prednisone tapering. We review the current evidence on treatment of Cronkhite-Canada syndrome and suggest the incorporation of sirolimus in that algorithm.

Natural history and treatment of cutaneous and systemic mastocytosis.

INTRODUCTION: Mastocytosis, a heterogeneous group of disorders, is characterized by an abnormal increase in the number of mast cells that is limited to the skin (cutaneous mastocytosis), involving extracutaneous tissues (systemic mastocytosis), or presenting as solid tumours (mastocytoma and mast cell sarcoma). Recent studies estimate that 1 in 10,000 people are diagnosed with mastocytosis. Although prompt diagnosis and appropriate management are crucial, little is known about the natural history and currently there are no established management guidelines. We have conducted a systematic review to assess the natural history and management of different mastocytosis subtypes. METHODS: A systematic review and meta-analysis were conducted using the PubMed and Ovid database of studies published in English and French over the last fifteen years, from January 2001 to December 2016. Keywords 'Cutaneous mastocytosis', 'Systemic mastocytosis', 'pathophysiology', 'clinical course', 'prognosis', 'drug therapy', and 'therapy' were searched. Rate of complete resolution was subjected to pooled analysis for different mastocytosis subtypes. Meta-analysis was conducted using Stata version 12.0. RESULTS: We reviewed 634 papers, of which 5 were included in the analysis of resolution, and 138 were included in the assessment of management. Pooled estimate for rate of complete resolution varied depending on the mastocytosis subtype. In cutaneous mastocytosis, the complete resolution rate for mastocytoma was 10% per year (95% CI: 4.8%, 15.1%) while the rate for urticaria pigmentosa was 1.9% per year (95% CI: -0.5%, 4.3%). Diffuse cutaneous mastocytosis and systemic mastocytosis subtypes did not show evidence of complete resolution in the studies reviewed. Treatment of cutaneous and systemic mastocytosis is purely symptomatic with topical corticosteroids, antihistamines, omalizumab and imatinib being common choices. CONCLUSION: Rate of resolution of mastocytosis is only shown in urticaria pigmentosa and mastocytoma. Better management guidelines are required to improve the health of these patients.

DRESS syndrome: cerebral vasculitic-like presentation.

INTRODUCTION: DRESS (drug reaction with eosinophilia and systemic symptoms) syndrome is a severe adverse drug-induced reaction. It manifests with pyrexia, eosinophilia, and lymphadenopathy, with multiple organ involvement, mainly the skin, liver, and kidneys. The purpose of this article is to demonstrate that DRESS syndrome can be associated with cerebral manifestations, a concept not well known in the neuroradiological literature. METHODS: We describe three cases of DRESS syndrome associated with cerebral vasculitic-like lesions and realize a review of the literature to demonstrate that this association represents a very rare entity. RESULTS: Acute ischemic lesions were found among two patients. In all cases, perivascular enhancement was present. Magnetic resonance angiography (MRA) sequence was normal. Although no cerebral biopsy was performed, this enhancement pattern is strongly suggestive of a vasculitic process associated with DRESS syndrome. CONCLUSION: Diagnosis of cerebral vasculitic-like associated lesions must be considered in patients with DRESS syndrome since it can be reversed completely by withdrawing the causal medication and instigating corticosteroid treatment in a timely fashion.

HTLV-1-associated arthropathy treated with anti-TNF-alpha agent.

Human T cell leukemia virus type 1 or HTLV-1 infection is a public health problem in endemic regions like Japan, Central America or Africa. Although the majority of HTLV-1 carriers remain asymptomatic throughout their lives, some patients could develop neurological disorder, inflammatory arthropathy also called HTLV-1-associated arthropathy or T-cell malignancy, the adult T-cell leukemia/lymphoma or ATL with a very poor prognosis. Described to be very close to rheumatoid arthritis, HTLV-1-associated arthropathy patients have few or no response to the first line therapy with corticosteroids and disease modifying antirheumatic drugs or DMARDs. The use of anti-TNF-α agents in these patients is an interesting alternative but asks the question of risk of developing an adult T-Cell leukemia/lymphoma. We reported an exceptional case of a smoldering ATL patient with an HTLV-1-associated arthropathy, refractory to corticosteroid, DMARDs and rituximab therapy, treated successfully with etanercept, without progression to aggressive ATL after 5 years.