Annals of Internal MedicineLong-Term Autoimmune Inflammatory Rheumatic Outcomes of COVID-19: A Binational Cohort Study

Exploring the Aftermath: COVID-19’s Role in Triggering Autoimmune Reactions

A recent binational, longitudinal study offers new insights into the long-term impact of COVID-19 on the incidence of autoimmune inflammatory rheumatic diseases (AIRDs), leveraging extensive data from South Korea and Japan to provide a comprehensive analysis of the risks following infection.

Study Design:

• Population: 10,027,506 Korean and 12,218,680 Japanese patients aged 20 years or older.
• Period: January 1, 2020, to December 31, 2021.
• Comparison: COVID-19 patients matched with influenza patients and uninfected control patients.
• Data Source: Nationwide claims-based databases from South Korea (K-COV-N cohort) and Japan (JMDC cohort).
• Outcome Measures: Onset of AIRD within 1, 6, and 12 months post-COVID-19 or influenza infection.

Key Findings:

• Increased Risk: Post-30 days of infection, COVID-19 patients showed a higher risk of developing AIRD compared to uninfected and influenza-infected individuals.
• Hazard Ratios: Adjusted hazard ratio of 1.25 compared to uninfected controls and 1.30 compared to influenza patients.
• Severity Correlation: The severity of acute COVID-19 correlates with an increased risk of AIRD.
• Consistency Across Cohorts: Similar risk patterns observed in both Korean and Japanese cohorts.

HCN Medical Memo
This study highlights that patients recovering from COVID-19 face an elevated risk of developing autoimmune inflammatory rheumatic diseases (AIRD) for up to a year post-infection. Physicians should closely monitor for AIRD symptoms, especially in those who experienced severe COVID-19. Additionally, although COVID-19 vaccination generally lowers the risk of AIRD, this protective effect is less pronounced in patients who had severe COVID-19 despite being vaccinated.

More in Rheumatology