#5722 NEW ONSET OR RECURRENT GLOMERULONEPHRITIS FOLLOWING SARS-CoV2 VACCINATION: A MULTICENTER EXPERIENCE
Authors: Rimoldi Chiara , Gilberti Marica , Gesualdo Loreto , Sossai Giulia , Sinico Renato Alberto , Giglio Elisa , Calatroni Marta , Raimondo Davide , Gallelli Beniamina , Vecchio Lucia Del , Visca Sara 
Published: June 2023

Abstract

Background and Aims
In general, vaccination is a well-known trigger for the onset or recurrence of glomerulonephritis or more in general autoimmune disease. Starting from the beginning of 2021 millions of people worldwide have received a vaccination of SARS-CoV2. Over the months, several cases of glomerulonephritis with a clear temporal association with the vaccination have been described [1,2].

Method
To better understand the characteristics, pattern of presentation, temporal and qualitative association with SARS-CoV2 vaccination and outcome, we designed a retrospective, multicenter, nationwide study aimed at collecting information on new onset or recurrence of primary or secondary vaccination following SARS-CoV2 infection. We present the preliminary findings from the first seven participating centers that completed data collection. For inclusion patients needed to be ≥16 years, have either a biopsy-proven glomerulonephritis or gross haematuria without urological explanation in close relationship with the vaccine. For outcome definition, partial remission was proteinuria &gt;300 mg/day, complete remission proteinuria 300–3500 g/day.

Results
We report 57 cases (M/F 22/35, mean age 48.59±18.99 years, median follow-up of 11.8 months (min 1.1, max 22.5). Of these, 25 (44%) were new onset glomerulonephritis, the remaining 32 (56%) were recurrence of already known cases (1/3 in complete remission, 2/3 in partial remission). Table 1 summarises the diagnosis new-onset or recurrent glomerulonephritis. 37 (65%) were primary glomerulonephritis, the other 20 (35%) kidney involvement of systemic diseases. The most frequent diagnosis was IgA nephropathy (IgAN, n = 17, 30%), followed by lupus nephritis (n = 9, 16%) and membranous nephropathy (n = 7, 12%). Compared to recurrence, patients with new-onset glomerulonephritis had a higher prevalence of minimal change disease (4 vs 1 case), Henoch Shoenlein purpura (3 vs 0) and FSGS (2 vs 0). Conversely, in patients with recurrence, we observed a higher rate of IgAN (14 vs 3), microscopic polyangiitis (5 vs 1) and lupus nephritis (7 vs 2). Most of the cases occurred following an mRNA vaccine (n = 42, 90%). The median time of onset was of 18 days. The onset was related more to the second dose of vaccine (n = 27, 47.4%), followed by the first dose (n = 14, 25%) and then the third dose (n = 12, 21.1%), with an imbalance between new-onset vs recurrence (C2, 11.18; p = 0.011) Fig. 1). The information is missing in 4 cases. Most of the patients presented with nephrotic proteinuria (n = 24, 42%). Following treatment, 15 (26.3%) patients obtained partial remission, 18 (31.6%) had complete remission and the remaining 21 (36.8%) had no response. The information is missing for 3 patients.

Conclusion
Following SARS-CoV2 vaccine, de novo or recurrent glomerulonephritis can occur. The majority of the cases were related to mRNA vaccines. However, the vaccine policy in Italy could have influenced this finding.