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Immune checkpoint inhibitors (ICIs) constitute a class of drugs that stimulate the immune system to fight cancer cells. However, they can also induce immune-related adverse events (irAEs) in various organs, including the kidneys. One of the infrequent irAEs associated with ICIs is sarcoidosis, an inflammatory disease that can impact multiple organs, such as the lungs, skin, and lymph nodes. Sarcoidosis is characterized by the formation of granulomas, clusters of immune cells that can potentially harm tissues. In some cases, ICIs can trigger kidney sarcoidosis, leading to impaired renal function. The mechanism through which ICIs initiate sarcoidosis is believed to involve activating T cells and cytokines that foster inflammation.

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.

Kidney is one of the most predominantly organs affected by coronavirus disease 2019 (COVID-19) after the respiratory and immune systems. Among the renal parenchymal components, the tubulointerstitial compartment is presumed to be the prime target of injury in COVID-19. The main mechanism of renal tubular damage by COVID-19 is considered to be indirect, i.e., cytokine-mediated injury. A proportion of infected individuals mount a strong inflammatory response to the virus by an exaggerated immune response of the body, namely cytokine storm. Sudden and massive release of cytokines may lead to serious systemic hyper-inflammation and renal tubular injury and inflammation resulting in acute renal failure. In addition, a number of cases of glomerulopathies, particularly collapsing glomerulopathy (CG) have been reported, predominantly in people of African ancestry, as a rare form of kidney involvement by SARS-CoV-2 that may originate from the background genetic susceptibility in this population complicated by the second hit of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, either directly or indirectly. It is noteworthy that renal injury in COVID-19 could be severe in individuals of African origin due to the aforementioned genetic susceptibility, especially the presence of high-risk apolipoprotein L1 (APOL1) genotypes. Although the exact mechanism of kidney injury by SARS-CoV-2 is as yet unknown, multiple mechanisms are likely involved in renal damage caused by this virus. This review was aimed to summarize the salient points of pathogenesis of kidney injury, particularly glomerular injury in COVID-19 disease in the light of published data. A clear understanding of these is imperative for the proper management of these cases. For this review, a search was made of Google Scholar, Web of Science, Scopus, EBSCO and PubMed for finding English language articles related to COVID-19, kidney injury and glomerulopathy. From the information given in finally selected papers, the key aspects regarding glomerular involvement in COVID-19 were drawn out and are presented in this descriptive review.