Seroprevalence of Anti-Chikungunya IgG Antibodies among Rheumatoid Arthritis (RA) Patients

Abstract

Introduction: Chikungunya infection is an acute disabling illness characterised by high fever and severe arthralgia. Most of the patients recover completely; however few may develop postChikungunya Chronic Inflammatory Rheumatism (CHIK-CIR). Aim: To detect the seroprevalence of chikungunya among Rheumatoid Arthritis (RA) patients and to demonstrate association between them. Materials and Methods: This was a prospective study conducted from July 2018 to November 2018 at the Department of Microbiology, in a tertiary care hospital. Patients attending rheumatology clinic with complaints of arthritis and clinically suspected to have RA were included in the study. Samples were tested for Anti-Citrullinated Peptide Antibodies (ACPA), Anti-Chikungunya IgM and IgG antibodies by Enzyme Linked Immunosorbent Assay (ELISA) as per manufacturer’s instructions. Results: A total of 373 patients were included in the study. Of these serum samples 90 (24.12%) samples were positive for ACPA, with female predominance (n=66, 73.33%) and 29 (7.77%) patients’ serum samples tested positive for chikungunya IgM. Highest positivity for APCA was observed in the age group 40-60 years (n=47, 52.22%). IgG ELISA for chikungunya was positive in 58.89% (n=53), 60% (n=27) and 46.67% (n=21) of clinically suspected and ACPA positive, 45 clinically suspected but ACPA negative and 45 healthy individuals respectively. The difference was not statistically significant across the different groups. However, seroprevalence was higher among patients suffering with arthralgia as compared to that of healthy population group. Conclusion: Rheumatologist should always consider Chikungunya infection as one of the causes for arthralgia. In endemic countries like India it is difficult to ascertain whether chikungunya infection progresses to RA or not.

Keywords

• arthralgia
• chikungunya fever
• post-chikungunya chronic inflammatory rheumatism