Dominant negative OTULIN-related autoinflammatory syndrome.

OTU deubiquitinase with linear linkage specificity (OTULIN) regulates inflammation and cell death by deubiquitinating linear ubiquitin chains generated by the linear ubiquitin chain assembly complex (LUBAC). Biallelic loss-of-function mutations causes OTULIN-related autoinflammatory syndrome (ORAS), while OTULIN haploinsuffiency has not been associated with spontaneous inflammation. However, herein, we identify two patients with the heterozygous mutation p.Cys129Ser in OTULIN. Consistent with ORAS, we observed accumulation of linear ubiquitin chains, increased sensitivity to TNF-induced death, and dysregulation of inflammatory signaling in patient cells. While the C129S mutation did not affect OTULIN protein stability or binding capacity to LUBAC and linear ubiquitin chains, it did ablate OTULIN deubiquitinase activity. Loss of activity facilitated the accumulation of autoubiquitin chains on LUBAC. Altered ubiquitination of LUBAC inhibits its recruitment to the TNF receptor signaling complex, promoting TNF-induced cell death and disease pathology. By reporting the first dominant negative mutation driving ORAS, this study expands our clinical understanding of OTULIN-associated pathology.

Novel Presentation of Major Histocompatibility Complex Class II Deficiency with Hemophagocytic Lymphohistiocytosis.

PURPOSE: Major histocompatibility complex (MHC) class II deficiency is one of the combined immune deficiency disorders caused by defects in the MHC class II regulatory genes leading to abnormal T cells development and function. Therefore, patients mainly present with increased susceptibility to infections, diarrhea, and failure to thrive. In this report, we present one MHC class II deficient patient with a novel presentation with Hemophagocytic Lymphohistiocytosis (HLH). METHODS: Immunophenotyping of lymphocyte subpopulations and HLA-DR expression was assess by flow cytometry. Gene mutational analysis was performed by whole exome and Sanger sequencing. RESULTS: We reported a 7-year-old girl, who was diagnosed at age of 2 years with MHC class II deficiency by genetic testing and flow cytometry. Two years later, she developed disseminated BCGitis which was treated with proper antimicrobial agents. At the age of 7 years, she presented with clinical features fulfilling 6 diagnostic criteria of HLH including evidence of hemophagocytic activity in bone marrow aspiration. Accordingly, the diagnosis of HLH was established and the patient was started on IV Dexamethasone, Anakinra and IVIG. Eventually, patient started to improve and was discharged in good condition. Few months later, the patient was readmitted with severe pneumonia and sepsis leading to death. CONCLUSION: Patients with MHC class II deficiency might present with disseminated BCGitis especially if the patient has severe T cell lymphopenia. Additionally, this immune defect might be added to the list of inborn errors of immunity that can be complicated with HLH.

Reactive Arthritis in Children: Case report and Narrative Review and Proposed therapy.

Reactive arthritis is an acute inflammatory aseptic arthritis that is preceded by an infectious process in genetically predisposed individuals. It has been associated with gastrointestinal or genitourinary infection. Reactive arthritis is rare in children. In this review, we present two index cases that need biologic treatment followed by a thorough review of reactive arthritis in children and adolescents with proposed treatment algorithm.

Genotype and Phenotype of Adenosine Deaminase 2 Deficiency: a Report from Saudi Arabia.

Adenosine deaminase 2 deficiency (DADA2), a rare and potentially fatal systemic autoinflammatory disease, is characterized by low or lack of ADA2 activity due to ADA2 mutations. DADA2 symptoms are variable and include vasculitis, immunodeficiency, and cytopenia. Minimal data are available from Saudi Arabia. This retrospective study conducted at seven major tertiary medical centers examined the phenotypic and genotypic variabilities, clinical and diagnostic findings, and treatment outcomes among 20 Saudi patients with DADA2 from 14 families. The median age of the study cohort was 9.5 years (4-26 years). The clinical presentation was before the age of 5 months in 25% of patients. Homozygous c.1447-1451del mutation was the most frequent ADA2 alteration (40%), followed by c.882-2A:G (30%). All tested patients exhibited absent or near-absent ADA2 activity. Phenotypic manifestations included stroke (40%), hematological abnormalities (95%), lymphoproliferation (65%), and recurrent infection (45%). Five and three patients had extracranial vasculitis features and Hodgkin lymphoma, respectively. Atypical manifestations included growth retardation (30%) and transverse myelitis. Anti-tumor necrosis factor (anti-TNF) therapy was the main treatment. Some patients underwent blood transfusion, splenectomy, cyclosporine and colony-stimulating factor therapies, and hematopoietic stem cell transplantation due to anti-TNF therapy failure. Fulminant hepatitis and septic multiorgan failure caused mortality in three patients. Thus, this study revealed the variability in the molecular and clinical characteristics of DADA2 in the study cohort with predominant aberrant hematological and immunological characteristics. Consensus diagnostic criteria will facilitate early diagnosis and treatment. Additionally, disease registries or large prospective studies are needed for evaluating rare disease complications, such as cancer.

Combined endoscopic-laparoscopic surgery (CELS) can avoid segmental colectomy in endoscopically unremovable colonic polyps: a cohort study over 10 years.

BACKGROUND: Combined-Endoscopic-Laparoscopic-Surgery (CELS) was developed for benign colonic polyps, endoscopically unresectable, to avoid segmental colectomy. This observational study aims to compare surgical outcomes of endoscopically unresectable colonic polyps treated laparoscopically before and since the institutional introduction of CELS. Primary endpoint was postoperative morbidity and mortality; secondary endpoints were time of hospitalization and histopathological findings. METHODS: Charts of all patients with preoperative diagnosis of benign colonic tumors, treated laparoscopically at our institution from 1/2010 to 2/2020 were reviewed. Patients with polyps (1) affecting ileocecal valve, (2) occupying > 50% of the circumference, (3) ≥ 3 endoscopically unresectable polyps, (4) inflammatory bowel disease, (5) polyps within diverticular area post diverticulitis, (6) rectal polyps (7) foreseen impossibility of laparoscopy (8) preoperatively biopsy proven invasive adenocarcinoma were excluded. Group I consists of all patients potentially treatable by CELS but operated by laparoscopic colonic resection as CELS was not yet institutionally established. Group II includes all patients treated with CELS (since 11/2017). RESULTS: One hundred-fifteen consecutive patients were reviewed. Applying exclusion criteria, twenty-three patients form group I and twenty-three group II (female 30.4%, median age 68 years). Groups distributed homogenously for age, BMI (body mass index) and polyps´ localization with most polyps (60.4%) localized in right colon; group II patients had significantly higher American Society of Anesthesiologists (ASA) score. Median operating time, hospital stay and morbidity were significantly less in group II. Postoperative morbidity occurred overall in 14 patients (30.4%), mostly Clavien-Dindo class I-II (26.1%) and significantly less in group II (p = 0.017), Clavien-Dindo III-IV distributed equally (one patient each group) without postoperative mortality. Definitive histopathology showed invasive adenocarcinoma in 8.3% without differences between groups. Two patients with invasive adenocarcinoma after CELS were advised for oncological resection. CONCLUSION: CELS is safe and efficient to treat complex, benign colonic polyps by a complete minimal invasive laparoscopic approach. CELS showed better surgical outcomes with less morbidity, no mortality and appropriate pathological results avoiding unnecessary laparoscopic surgery with intestinal anastomosis.

Elevated intracranial pressure requiring decompressive craniectomy in a child with progressive primary angiitis of the central nervous system: a case report.

BACKGROUND: Elevated intracranial pressure is a potentially catastrophic complication of neurologic injury in children. Successful management of elevated intracranial pressure requires prompt recognition and therapy directed at both reducing intracranial pressure and reversing its underlying cause. A rare condition that causes elevated intracranial pressure is childhood primary angiitis of the central nervous system, which is a rare inflammatory central nervous system disease that poses diagnostic and therapeutic challenges. To our knowledge, this is the first reported case of angiography-positive progressive childhood primary angiitis of the central nervous system requiring decompressive hemicraniectomy for refractory elevated intracranial pressure in children. CASE PRESENTATION: We report the case of a 5-year-old Saudi girl who presented to the pediatric emergency department with fever and new-onset status epilepticus. She had elevated inflammatory markers with radiological and histopathological evidence of angiography-positive progressive childhood primary angiitis of the central nervous system, complicated by elevated intracranial pressure. Despite medical management for both childhood primary angiitis of the central nervous system and elevated intracranial pressure, her neurological status continued to deteriorate and the elevated intracranial pressure became refractory. She developed right uncal, right subfalcine, and tonsillar herniation requiring decompressive hemicraniectomy with a favorable neurological outcome. CONCLUSION: Decompressive craniectomy might be considered in cases of angiography-positive progressive childhood primary angiitis of the central nervous system with elevated intracranial pressure refractory to medication. A multidisciplinary approach for the decision of decompressive craniectomy is advised to ensure patient safety and avoid possible morbidities and mortality.

A simple and sensitive HILIC-based UHPLC-MS/MS method for quantifying of rivaroxaban in dried blood spots: Application in comparison with the plasma sample method.

Rivaroxaban, indicated for the treatment of atrial fibrillation, deep vein thrombosis, pulmonary embolism, and coronary or peripheral artery disease, is one of the most frequently used direct oral anticoagulants. Therapeutic drug monitoring [TDM] is essential to minimize bleeding and thrombosis during personalized rivaroxaban treatment. An efficient and reliable analytical technique is required to quatify the rivaroxaban during its therapeutic indication. Dried blood spots (DBSs) sampling is a convenient bioanalytical method with minimal invasive blood drawing, long-term stability, and low shipment and storage costs. Therfore, DBS sampling technique is growing rapidly for TDM of drugs in medical care. This study developed an ultra high performance liquid chromatography-tandem mass spectrometry method of quantitating rivaroxaban in DBSs samples using the isotopic labeled analog (rivaroxaban-d4) as an internal standard (IS). Rivaroxaban and IS were separated on an Acquity HILIC column and eluted with a mobile-phase composition of acetonitrile and 20 mM ammonium acetate in the ratio of 95:5 at a flow rate of 0.3 mL/min. The precursor-to-product ion transitions of 436.03 ˃ 144.9 for rivaroxaban and 440.04 ˃ 144.9 for IS were used to quantify in multiple reaction monitoring mode. The method was accurate and precise in the 2.06-1000 ng/mL calibration range without hematocrit and blood spot volume effects. Rivaroxaban was stable in DBSs samples under different anticipated storage and temperature conditions. We observed good correlation between the plasma concentration and the DBSs concentration, indicating that the proposed DBSs method is suitable for monitoring the rivaroxaban concentration using a simple and convenient sample collection procedure.