Short and long-term immune changes in different severity groups of COVID-19 disease.

BACKGROUND: There are limited data on short- versus long-term changes in adaptive immune response across different COVID-19 disease severity groups. METHODS: A multicenter prospective study of 140 adult patients with COVID-19 (a total of 325 samples) were analyzed for inflammatory markers and lymphocyte subsets at presentation, week 2, and week 24. RESULTS: Inflammatory markers at presentation were higher in the critical/severe than in moderate and mild groups. A predominance of memory B cell response in the mild and moderate group was noted by week 2. In contrast, the immune system in the severe/critical group was dysfunctional, with expansion of exhausted CD8+ T cells and atypical memory B cells. By 24 weeks, there was a possible trend of normalization. CONCLUSION: There was substantial difference in the degree of inflammation and distribution of different B and T cell subsets in the different disease severity groups. Despite the initial dysfunctional immune response in the severe/critical group, a comparable memory B and CD8+ T cell responses to the mild group was achieved at 24 weeks.

Fatal hepatitis A virus infection in an adolescent.

Acute hepatitis A infection is largely self-limiting illness, rarely resulting in fulminant course with consequent hepatic failure and death. We present a 13-year old previously healthy Omani with fatal hepatitis A virus infection. This case highlights the critical role of hepatitis A vaccination and argues for consideration of its inclusion in national vaccination programs in order to avert similar devastating consequences of yet another vaccine preventable disease.

Detection of human cytomegalovirus IgG antibody using automated immunoassay with recombinant antigens gives uniform results to established assays using whole virus antigens.

AIM: Serological testing for human cytomegalovirus (CMV) immunoglobulin G (IgG) continues to play a major role in the evaluation of tissue and organ transplant donors and recipients, screening blood donors and in estimating the risk of infection in pregnant women. In this study we evaluated the performance and technical characteristics of two semi-automated commercial CMV IgG immunoassays. METHODS: One hundred consecutive sera submitted to a referral serology laboratory for CMV IgG antibody testing were assayed using two automated CMV IgG immunoassays: the Architect (Abbott Diagnostics) and Elecsys (Roche Diagnostics) immunoassays. Because this patient population has a high rate (∼87%) of seropostivity, we took a further 50 sera that were CMV IgG negative on Architect and tested on the Elecsys assay, in order to assess the specificity of the assays. RESULTS: The assays showed an excellent qualitative agreement with two (2%) discrepant results in the 100 patients tested initially, with all of the 50 additional sera negative on Architect also negative on the Elecsys. However, there was no correlation between the optical density of results generated by the instruments for the set of samples. CONCLUSION: Both Elecsys and Architect immunoassays are convenient for detection of CMV IgG antibody, with near identical qualitative results.