2024-11-0920200954-691X10.1097/MEG.00000000000018042-s2.0-85089127035https://hdl.handle.net/20.500.14288/3643Immunocompromised patients may be at increased risk to develop COVID-19 during the 2019 β-coronavirus infection. We present the unique opportunity we had to monitor the liver, IL-6 and immune cell course before, during and after COVID-19 in a boy with autoimmune hepatitis (AIH) and type 1 diabetes (T1D). CD4+and CD8+T cells frequencies decreased because of prednisolone, followed by a plateauing increase whereas CD19+CD20+B cell increased strongly and was unaffected by COVID-19 infection. Moreover, the percentage of activated CD8+T cells expressing HLA-DR (CD8+HLA-DR+) increased during COVID-19 and subsided after its clearance. Total regulatory T cells (Tregs: CD4+CD25+CD127lowFOXP3+) remained stable. Although activated Tregs (CD4+CD45RA-FOXP3high) strongly increased upon prednisolone, it decreased afterwards. Furthermore, regulatory B cells (Bregs: CD19+CD20+CD24highCD38high) declined sharply owing to prednisolone. Serum IL-6 remained undetectable at all times. We demonstrated for the first time immune monitoring in a child with AIH and T1D before, during and after COVID-19. We hypothesize that continuing with low level of prednisolone without azathioprine may have abrogated activated Tregs, Bregs and IL-6 production and therefore permitting the activation of CD8+T cells, clearing the virus.pdfMedicineGastroenterology and hepatologyJournal Article1473-5687https://doi.org/10.1097/MEG.0000000000001804562738600025Q4NOIR02374