No evidence of increased incidence of ANCA-associated vasculitis following the COVID-19 pandemic: a single-centre experience

We found no evidence of increased incidence of ANCA-associated vasculitis following COVID-19. Dear editor, Over the past few years, researchers have been intrigued by the potential link between coronavirus disease 2019 (COVID-19), COVID-19 vaccines and vasculitis [1–3]. Specifically, few studies have reported occurrences of ANCA-associated vasculitis (AAV) following vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) [4] or SARS-CoV-2 infection [5–7], prompting speculation about a causal relationship between COVID-19, or COVID-19 vaccinations, and AAV. In this context, a recent study from Japan has reported a statistically significant increase in the annual number of newly diagnosed cases of AAV in Nagasaki Prefecture (Southern Japan) since the initiation of the COVID-19 vaccination program [8]. Since the beginning of the COVID-19 pandemic, there has been a noted rise in newly identified cases of AAV in Israel, as informally reported by rheumatologists nationwide (N.Bisharat, unpublished data). Our objective was to determine the incidence of newly assigned cases of AAV since the beginning of the pandemic and compare it with the pre-pandemic period. To address this, we utilized nationally collected databases from Clalit Health Services to study the incidence of AAV from before the COVID-19 pandemic (2002–19) and throughout the pandemic to the end of 2022. Clalit Health Services is the largest healthcare provider in Israel, providing medical care for more than 5 million citizens. Newly diagnosed cases of AAV were extracted from the database spanning the years 2000–22, utilizing appropriate International Classification of Diseases, Ninth Revision codes. Additionally, all confirmed cases of SARS-CoV-2 infection, verified through positive PCR or certified rapid antigen tests, were retrieved, irrespective of the purpose of testing. Overall, the annual incidence of AAV during the past 22 years ranged from as low as 6.9 cases per million inhabitants (year 2001) to as high as 15.6 cases per million (year 2015) (Fig. 1). The mean annual rate of newly assigned diagnosis of AAV in the pre-pandemic period was 10.5 cases per million, while during the COVID-19 pandemic (2020–22) it averaged 12.8 cases per million (P = 0.9). Furthermore, there was no statistically significant linear trend identified in the dataset during the previous 22 years (R2 = 0.2002, Fig. 1). New cases of ANCA-associated vasculitis per million population during 2000–22 In conclusion, our analysis did not reveal any trend towards an increased incidence of AAV over the past 20 years or during the COVID-19 pandemic. It remains to be determined whether any potential delayed effects of SARS-CoV-2 or COVID vaccinations are associated with an increased incidence of AAV. Data generated or analysed during this study are available from the corresponding author upon reasonable request. Disclosure statement: The authors have declared no conflicts of interest. No specific funding was received from any bodies in the public, commercial or not-for-profit sectors to carry out the work described in this article. We wish to thank Sanit Ayalon for her help in data extraction.