Relapses or de-novo IgA nephropathy following COVID-19 vaccination; a narrative review

Immunoglobulin A (IgA) nephropathy is the most common type of glomerulonephritis worldwide characterized by excessive serum levels of glycosylated which triggers the generation of glycan-specific IgG and IgA autoantibodies. This pathological condition results in the formation of circulatory IgA immune complexes, which are essential for the development of glomerular inflammation, especially IgA nephropathy. The serum galactosylated IgA1, IgG, and IgA autoantibodies are suggested as the biomarkers of IgA nephropathy since IgA antibodies are early markers for disease activity too. Serum IgA antibodies emerged as the early COVID-19-specific antibody response about two days after initial symptoms of COVID-19 in comparison with IgG and IgM antibody concentrations, which appeared after five days. IgA nephropathy is frequently presented as microscopic or macroscopic hematuria and proteinuria with a male predominance. COVID-19 infection can include several organs aside from the lungs, such as kidneys through different mechanisms. It is demonstrated in most cases that short-lasting symptoms such as gross hematuria resolve either spontaneously or following a short course of steroids. This review summarized the reported cases of relapses or denovo reported cases of relapses or de-novo IgA nephropathy and IgA vasculitis following COVID-19 vaccination.