"COVID-19 vaccines are effective against severity of SARS-COV-2 infection, but there has been a concern regarding their effect on the risk of flares in patients with gout, which are associated with health-related quality of life, healthcare resource utilization, and work productivity."
Patients with gout who received a COVID-19 vaccination, particularly the adenovirus vector ChAdOx1 nCov-19 (ChAd) vaccination, reported a slight increase in gout flares on the second day after vaccination. These findings emphasize the safety of the vaccination within this patient population, according to a study published in Seminars in Arthritis and Rheumatism.1
“The COVID-19 pandemic has had tremendous social and economic impacts, especially for people living with inflammatory disorders like gout,” investigators explained. “COVID-19 vaccines are effective against severity of SARS-COV-2 infection, such as hospitalization and death, but there has been a concern regarding their effect on the risk of flares in patients with gout, which are associated with health-related quality of life, healthcare resource utilization, and work productivity.”
A time-stratified case-crossover study included patients with gout who experienced flares between December 2020 (when public vaccination began) and September 2021. Data was pulled from The Health Improvement Network (THIN), which includes medical records from 17 million patients in the United Kingdom. Risk of gout flare was assessed for the first 7 days on and after the vaccination and compared with patients who did not receive vaccination during that time using conditional logistic regression. Subgroup analyses were performed based on different COVID-19 vaccines (ChAd and BNT162b2 [BNT]).
Of the 5904 patients with gout included in the study, 63.5% (n = 3748) experienced 1 flare, 19.1% (n = 1125) experienced 2 flares, and 17.4% (n = 1031) had 3 or more flares. The mean age was 63.1 years and more than 80% of those who had disease flare were men. Approximately 2/3 of patients received the ChAd vaccine.
The risk of gout flares slightly increased on the second day after the vaccination (odds ratio [OR]: 1·44; 95% CI: 1·02 to 2·07) and remained slightly increased, although not statistically significant, on the other remaining days as well (ORs ranged from 1·03 to 1·22). Those receiving the ChAd vaccine were more likely to experience a gout flare vaccine (OR: 1·44; 95% CI: 1·00 to 2·05).
Self-matching of patients on the same day of the week minimized confounding bias from the time constant risk factors for gout, like body mass index, as well as lifestyle factors, such as alcohol consumption. However, investigators were not able to adjust for short-term, time-varying confounding risk factors, such as medications taken during the past 7 days. Another limitation is the potential of misclassification of gout flares, which may have biased results towards the null. Lastly, the date of flare diagnosis may not have been on the same day that the flare occurred. However, patients are not likely to receive a COVID-19 vaccination during the time of flare.
“Previous study found that ChAd vaccines induce a more pronounced increase in several inflammatory markers than mRNA vaccine, which may explain why ChAd vaccine was a trigger of gout flares,” investigators concluded. “Moreover, both ChAd and BNT vaccines could generate interferon... Future studies are needed to understand the potential mechanisms.”
Li H, Dalbeth N, Wallace ZS, et al. Risk of gout flares after COVID-19 vaccination: A case-crossover study [published online ahead of print, 2022 Jun 28]. Semin Arthritis Rheum. 2022;56:152059. doi:10.1016/j.semarthrit.2022.152059