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Inflammatory bowel disease (IBD) describes different illnesses characterized by chronic inflammation of the gastrointestinal tract. Although the pathogenic mechanisms leading to IBD are poorly understood, immune system disturbances likely underlie its development. Sphingolipids (SLs) have been identified as important players and promising therapeutic targets to control inflammation in IBD. Interestingly, it seems that microorganisms of the normal gut microbiota and probiotics are involved in sphingolipid function. However, there is a great need to investigate the role of SLs as intermediates in the crosstalk between intestinal immunity and microorganisms. This review focuses on recent investigations that describe some mechanisms involved in the regulation of cytokine profiles by SLs. We also describe the importance of gut microbiota in providing signaling molecules that favor the communication between resident bacteria and intestinal cells. This, in turn, modulates the immune response in the bowel and likely in other peripheral organs. The potential of SLs and gut microbiota as targets or therapeutic agents for IBD is also discussed.

The COVID-19 pandemic reached five waves in three years, with over 6.5 million deaths across the globe. Knowing the differential susceptibility to the novel betacoronavirus has allowed us to better understand the pathophysiology and inflammatory complications and dissect the response against the virus. As in other viral infections, CD8+ T lymphocytes and NK cells stand out as key players, together with viral sensors, type 1 interferons, an exaggerated inflammatory response by NLRP3, and a storm that includes cytokines IL-6 and IL-8. Whole-exome sequencing has identified several genes with pathogenic germline variants in patients with severe COVID-19; said genes would account for around 5% of all severe cases. In addition, up to 20% of hospitalized adults harbor autoantibodies against type-I and III interferons. These findings translate into novel genetic etiologies, whereas autoantibodies explain the worse prognosis of the elderly, linked to the inflammaging phenomenon. In general, patients with known primary immune deficiencies who acquired COVID-19 fared well, with global survival rates over 80% and a predominance of mild courses. The exceptions were patients with severe-combined immune deficiency, and with the autoimmune polyglandular syndrome 1, the latter because they develop autoantibodies against interferon. Neither have there been reports of greater severity in patients with autoimmune or autoinflammatory disorders. However, those receiving immunosuppressant treatments usually have a more protracted course. Patients with NLRP3 or STAT1 gain of function might be especially susceptible to systemic inflammatory complications. In this review, we summarize the global experience in the caretaking of patients with immune alterations who were infected by SARS-CoV-2. [ABSTRACT FROM AUTHOR]

Background and objectives: Glucose‐6‐phosphate catalytic subunit 3 (G6PC3) deficiency is characterized by severe congenital neutropenia with recurrent pyogenic infections, a prominent superficial venous pattern and cardiovascular and urogenital malformations caused by an alteration of glucose homeostasis, with increased endoplasmic reticulum stress and cell apoptosis. Methods: We reviewed our patients with G6PC3 deficiency diagnosed along the last decade in Mexico; we also searched the PubMed/Medline database for the terms ('G6PC3 deficiency' OR 'Dursun syndrome' OR 'Severe congenital neutropenia type 4'), and selected articles published in English from 2009 to 2020. Results: We found 89 patients reported from at least 14 countries in 4 continents. We describe five new cases from Mexico. Of the 94 patients, 56% are male, 48% from Middle East countries and none of them had adverse reactions to live vaccines; all presented with at least 1 severe infection prior to age 2. Seventy‐five per cent had syndromic features, mainly atrial septal defect in 55% and prominent superficial veins in 62%. Conclusions: With a total of 94 patients reported in the past decade, we delineate the most frequent laboratory and genetic features, their treatment and outcomes, and to expand the knowledge of syndromic and non‐syndromic phenotypes in these patients. [ABSTRACT FROM AUTHOR]

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G6PC3 deficiency is a monogenic immunometabolic disorder that causes syndromic congenital neutropenia. Patients display heterogeneous extra-hematological manifestations, contributing to delayed diagnosis. Here, we investigated the origin and functional consequence of the G6PC3 c.210delC variant found in patients of Mexican origin. Based on the shared haplotypes amongst carriers of the c.210delC mutation, we estimated that this variant originated from a founder effect in a common ancestor. Furthermore, by ancestry analysis, we concluded that it originated in the indigenous Mexican population. At the protein level, we showed that this frameshift mutation leads to an aberrant protein expression in overexpression and patient-derived cells. G6PC3 pathology is driven by the intracellular accumulation of the metabolite 1,5-anhydroglucitol-6-phosphate (1,5-AG6P) that inhibits glycolysis. We characterized how the variant c.210delC impacts glycolysis by performing extracellular flux assays on patient-derived cells. When treated with 1,5-anhydroglucitol (1,5-AG), the precursor to 1,5-AG6P, patient-derived cells exhibited markedly reduced engagement of glycolysis. Finally, we compared the clinical presentation of patients with the mutation c.210delC and all other G6PC3 deficient patients reported in the literature to date, and we found that c.210delC carriers display all prominent clinical features observed in prior G6PC3 deficient patients. In conclusion, G6PC3 c.210delC is a loss-of-function mutation that arose from a founder effect in the indigenous Mexican population. These findings may facilitate the diagnosis of additional patients in this geographical area. Moreover, the in vitro 1,5-AG-dependent functional assay used in our study could be employed to assess the pathogenicity of additional G6PC3 variants., Competing Interests: Competing Interests The authors declare that they have no relevant conflicts of interest. Additional Declarations: No competing interests reported.

Common variable immunodeficiency (CVID) is an heterogeneous group of disorders characterized by impaired antibody production. It shows a wide spectrum of manifestations including severe and recurrent respiratory infections (Streptococcus pneumoniae, Haemophilus) and gastrointestinal (Campylobacter jejuni, rotavirus and Giardia lamblia). Viral infections caused by herpes zoster, cytomegalovirus (CMV) and hepatitis C are rare. The opportunistic agents such as CMV, Pneumocystis jirovecii, cryptococcus and atypical mycobacteria have been reported as isolated cases. This paper reports the case of a 38-year-old female patient, who began six years before with weight loss of 7 kg in six months, fatigue, weakness, sweating, fever and abdominal pain. Furthermore, patient had intestinal obstruction and abdominal CT showed mesenteric lymph growth. The mesenteric lymph node biopsy revealed positives Mycobacterium PCR, Ziehl-Neelsen staining and culture for M. bovis. In the laparotomy postoperative period was complicated with nosocomial pneumonia, requiring mechanical ventilation and tracheostomy. Two years later, she developed right renal abscess that required surgical drainage, once again with a positive culture for Mycobacterium bovis. She was referred to highly specialized hospital and we documented panhypogammaglobulinemia and lymphopenia. Secondary causes of hypogammaglobulinemia were ruled out and common variable immunodeficiency (CVID) was confirmed, we started IVIG replacement. Four years later she developed mixed cellularity Hodgkin's lymphoma. Until today she continues with IVIG and chemotherapy. This report of a patient with CVID and Mycobacterium bovis infection, a unusual association, shows the cellular immunity susceptibility in this immunodeficiency, additional to the humoral defect.