MO205IMPACT OF THE COVID-19 PANDEMIC ON KIDNEY DISEASES REQUIRING RENAL BIOPSY: A SINGLE-CENTER OBSERVATIONAL STUDY
Authors: Tampe Björn , Hakroush Samy 
Published: May 2021

Abstract

Background and Aims
The coronavirus disease-2019 (COVID-19) pandemic impacted healthcare services for kidney disease patients. Lockdown and social distancing were mandated worldwide, resulting in closure of medical services. The diagnosis of various kidney diseases may have been delayed during the COVID-19 pandemic because non-urgent tests and visits were postponed due to closure of medical services during the lockdown. Based on previous reports, this afftects especially kidney diseases requiring renal biopsy and histological analysis for diagnosis. We have previously reported that during the lockdown period in March and April 2020, an incidence-shift with a COVID-19 gap of no diagnosed antineutrophil cytoplasm antibodies (ANCA)-associated vasculitis (AAV) and ANCA glomerulonephritis (GN) based on renal biopsy was followed by a postlockdown phase in subsequent months with a compensatory increased incidence rate. This has been attributed to a decreased number of renal biopsies during the lockdown period and a compensatory increased number in the postlockdown phase. We here expanded our analysis to evaluate the effect of the COVID-19 pandemic on kidney diseases requiring renal biopsy. Furthermore, we aimed to identify effects of the COVID-19 pandemic on clinical outcomes in patients with kidney diseases, including ANCA GN. With multiple vaccines currently undergoing human trials to combat this pandemic, there is an urgent need for a clear sense for patient populations most susceptible to shutdown of medical services. We here report the impact of the COVID-19 pandemic on native kidney diseases requiring renal biopsy for diagnosis in a retrospective observational study from a tertiary hospital in Germany.

Method
A total number of 209 renal biopsies performed on native kidneys of patients hospitalized at the University Medical Center Göttingen in 2019 and 2020 were included. Variables were tested for normal distribution using Shapiro-Wilk test. Non-normally distributed continuous variables are expressed as median and interquartile range (IQR), categorical variables are presented as frequencies and percentages. Statistical comparisons were not formally powered or prespecified. For group comparisons, the Mann-Whitney U-test was used to determine differences in medians. Non-parametric between-group-comparisons were performed with Pearson’s Chi-square test. Data analyses were performed with GraphPad Prism (version 8.4.0 for MacOS, GraphPad Software, San Diego, California, USA).

Results
The lockdown period in March and April 2020 primarily affected patients admitted to the normal medical ward with a compensatory increased rate of renal biopsies in the postlockdown phase. In addition, there was a shift towards more patients admitted with hemoglobinuria during the COVID-19 pandemic. This phenomenon of an increased number of patients with hemoglobinuria during the COVID-19 pandemic was specifically observed in a subgroup with ANCA GN and hypertensive nephropathy requiring renal biopsy.

Conclusion
To our knowledge, this is the first report of identifying a subpopulation susceptible to closure of medical services during the COVID-19 pandemic and diagnostic delay of specific kidney diseases. Therefore, the COVID-19 pandemic should be regarded as a risk factor especially in patients with diseases other than COVID-19 primarily admitted to the normal medical ward.