Autoimmunity of Gastrointestinal Tract

Gastrointestinal tract diseases are recognised as autoimmune based on typical histopathology, presence of autoantibodies in serum and clinical response to immunosuppressive therapy. Like in other autoimmune diseases, the inducing factor is unknown; however, accumulating data suggests an increasing role of microbiota homeostasis and relation between the immune system (mucous-associated lymphoid tissue) and microbiota in intestinal lumen. The inflammation process is now described as autoinflammation with inflammasome formation or autoimmune chronic inflammation with overproduction of pro-inflammatory cytokines. Diagnostic procedures include autoantibodies assay, histology of biopsy from intestinal mucous, genetic background (especially in celiac disease) and clinical symptoms. Therapy is adjusted to pathomechanism including regulation of microbiota homeostasis with pre-biotics and probiotics, inhibition of inflammatory process with steroids, classical immunosuppression and anti-cytokine monoclonal antibodies and haematopoietic stem cells transplantation in severe cases with therapy resistance, progression and life-threatening course. The aim of this chapter is to review mechanisms of autoinflammation and autoimmunity, diagnosis and therapy of gastrointestinal tract

Gene Signature of Regulatory T Cells Isolated from Children with Selective IgA Deficiency and Common Variable Immunodeficiency

Selective IgA deficiency (SIgAD) is the most common form and common variable immunodeficiency (CVID) is the most symptomatic form of predominant antibody deficiency. Despite differences in the clinical picture, a similar genetic background is suggested. A common feature of both disorders is the occurrence of autoimmune conditions. Regulatory T cells (Tregs) are the major immune cell type that maintains autoimmune tolerance. As the different types of abnormalities of Treg cells have been associated with autoimmune disorders in primary immunodeficiency (PID) patients, in our study we aimed to analyze the gene expression profiles of Treg cells in CVID and SIgAD patients compared to age-matched healthy controls. The transcriptome-wide gene profiling was performed by microarray technology. As a result, we analyzed and visualized gene expression patterns of isolated population of Treg cells. We showed the differences at the gene level between patients with and without autoimmunizations. Our findings suggest that the gene signatures of Treg cells isolated from SIgAD and CVID patients differ from age-matched healthy controls and from each other, presenting transcriptional profiles enriched in innate immune or Th response, respectively. The occurrence of autoimmunity in both types of PID is associated with down-regulation of class I IFNs signaling pathways. In summary, our findings improve our understanding of Treg dysfunctions in patients with common PIDs and associated autoimmunity

COVID-19 in unvaccinated patients with inborn errors of immunity - Polish experience

At the beginning of the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) pandemic, patients with inborn errors of immunity (IEI) appeared to be particularly vulnerable to a severe course of the disease. It quickly turned out that only some IEI groups are associated with a high risk of severe infection. However, data on the course of Coronavirus Disease 2019 (COVID-19) in patients with IEI are still insufficient, especially in children; hence, further analyses are required. The retrospective study included 155 unvaccinated people with IEI: 105 children and 50 adults (67.7% and 32.3%, respectively). Male patients dominated in the study group (94 people, 60.6%). At least two comorbidities were found in 50 patients (32.3%), significantly more often in adults (56% vs. 21%). Adult patients presented significantly more COVID-19 symptoms. Asymptomatic and mildly symptomatic course of COVID-19 was demonstrated in 74.8% of the entire group, significantly more often in children (88.6% vs. 46%). Moderate and severe courses dominated in adults (54% vs. 11.4%). Systemic antibiotic therapy was used the most frequently, especially in adults (60% vs. 14.3%). COVID-19-specific therapy was used almost exclusively in adults. In the whole group, complications occurred in 14.2% of patients, significantly more often in adults (30% vs. 6.7%). In the pediatric group, there were two cases (1.9%) of multisystem inflammatory syndrome in children. Deaths were reported only in the adult population and accounted for 3.9% of the entire study group. The death rate for all adults was 12%, 15.4% for adults diagnosed with common variable immunodeficiency, 12.5% for those with X-linked agammaglobulinemia, and 21.4% for patients with comorbidity. The results of our study imply that vaccinations against COVID-19 should be recommended both for children and adults with IEI. Postexposure prophylaxis and early antiviral and anti-SARS-CoV-2 antibody-based therapies should be considered in adults with IEI, especially in those with severe humoral immune deficiencies and comorbidity