Musculoskeletal Ultrasound Findings in First Degree Relatives of Rheumatoid Arthritis Patients

Abstract Background Rheumatoid arthritis (RA) is an autoimmune inflammatory disease that primarily targets synovial joints. Retrospective analysis of individuals who ultimately developed RA have shown RA autoantibodies such as rheumatoid factor (RF) and anticitrullinated protein antibodies (ACPA) develop months to years prior to the onset of clinically evident synovitis. So there has been increasing interest in identifying individuals at risk for future development of RA, with the hope of intervening to prevent the onset of disease. Aim of the Work To detect the presence of early synovitis (preclinical stage of RA) among healthy first degree relatives of RA patients by MSUS and its correlation to serological markers. Patients and Methods This was a cross sectional study which was conducted on 60 subjects with high risk of developing arthritis; healthy first degree relatives (FDR) of RA patients classified according to ACR/EULAR 2010 criteria. It was carried out at Ain Shams University Hospital. All patients were recruited from Rheumatology outpatient clinic and the inpatient department of Ain Shams University Hospital. Results The study included subjects aged 16 to 55 years, predominantly female, with a mean BMI of 26.44 kg/m². Rheumatoid arthritis (RA) duration ranged from 1 month to 30 years, averaging 6.96 years. Among familial disease relatives (FDRs), 78.3% were nonsmokers. Arthralgia was common (58.3%), with varied joint involvement. Laboratory findings showed elevated ESR and CRP levels. Wrist and MTP-II joints were most frequently affected on ultrasound. A 7-joint ultrasound score (US7) was developed for efficient rheumatological evaluation. Conclusion This cross-sectional study aimed to assess preclinical synovitis by musculoskeletal ultrasound (MSUS) in first-degree relatives (FDRs) of rheumatoid arthritis (RA) patients and its correlation with laboratory findings. We found a prevalence of 51.6% for MSUS positive findings, primarily synovitis. ESR was significantly higher in FDRs with positive MSUS findings. RF showed the highest positive predictive value (75%) for MSUS positivity. Clinical arthralgia exhibited the highest sensitivity (58%). Our study underscores the potential of combining RF, Anti-CCP, and clinical arthralgia in predicting preclinical synovitis in at-risk populations, facilitating early intervention strategies.