en ارتقای سلامت، پیشگیری و کنترل بیماری‌ ها Health Promotion, Protection, and Disease Control مروری Review Article <span style="font-size:12px;"><span style="line-height:2;"><span style="font-family:Times New Roman;"><b>Background </b>The global outbreak of coronavirus (SARS-CoV-2), first reported in Wuhan, China, in December 2019, rapidly evolved into a worldwide health crisis. Various vaccines were developed to combat COVID-19; however, concerns have emerged regarding potential side effects, particularly renal complications. Nephrotic syndrome has been reported as a post-vaccination adverse effect, potentially triggered by immune system activation through an unknown mechanism. This study aimed to investigate the frequency of different types of nephrotic syndrome following COVID-19 vaccination.<b> </b><br> <b>Methods</b> In this cross-sectional study, all new cases of nephrotic syndrome admitted to Vali-Asr Hospital in Zanjan between 2020 and 2023 were reviewed. The study period covered up to three months following COVID‑19 vaccination. Collected data included age, gender, type of vaccine, vaccination dose, time interval between vaccination and symptom onset, and kidney biopsy findings. Due to the small sample size, no inferential statistical tests were performed, and data analysis was limited to descriptive statistics.<b><span style="font-family:"Times New Roman",serif"></span></b><br> <b>Results</b> A total of 11 patients met the inclusion criteria. The most common nephrotic syndrome observed was Membranous Nephropathy, reported in all cases following administration of the Sinopharm vaccine, mostly after the first dose. The average time interval to symptom onset after the first dose of vaccine was 26 days. Middle-aged individuals were most affected, and the distribution of nephrotic syndrome subtypes appeared similar across genders; however, the study was not powered to detect statistical associations.<br> <b>Conclusion </b>Membranous Nephropathy was the most commonly observed subtype of nephrotic syndrome among the studied cases (11 patients) following COVID-19 vaccination, particularly after administration of the Sinopharm vaccine. However, given the limited sample size, a causal relationship between vaccination and the onset of nephrotic syndromes cannot be confirmed. Therefore, larger retrospective studies are recommended to better elucidate this potential association.</span></span></span> <div data-manual-position="false" id="quick-actions-wrapper" style="position: fixed; z-index: 2147483646; pointer-events: auto; opacity: 1; transition: opacity 0.15s; left: 20px; top: -10.0469px;"> <div class="deepseek-quick-action-buttons light-mode" style="box-sizing: border-box !important; height: 40px !important; padding: 4px 10px !important; opacity: 1; position: static;"></div> </div> COVID-19, Membranous nephropathy, Nephrotic syndrome, Vaccination 32 39 http://hsm.umsu.ac.ir/browse.php?a_code=A-10-360-1&slc_lang=en&sid=1 Hanieh Davoodi hd1376med@yahoo.com 10031947532846004985 10031947532846004985 Yes Faculty of medicine, Zanjan University of Medical Sciences, Zanjan, Iran Nadia Agharafiei n.agharafiei.995@gmail.com 10031947532846004986 10031947532846004986 No Faculty of medicine, Zanjan University of Medical Sciences, Zanjan, Iran Bahareh Hajisalimi baharehajisalimi@yahoo.com 10031947532846004987 10031947532846004987 No Department of Internal Medicine, Vali-Asr Hospital, Zanjan University of Medical Sciences, Zanjan, Iran