Red Cell Distribution Width in Rheumatoid arthritis

BACKGROUND: Rheumatoid arthritis (RA) is a chronic systemic autoimmune inflammatory disease, which affects the joints and other body systems. Red cell distribution width (RDW) is a part of the complete blood count (CBC) test and estimates erythrocytic variability. OBJECTIVE: To evaluate RDW in RA and to assess the relationships of baseline demographic and clinical characteristics with RDW. PATIENTS AND METHODS: A total of 111 patients with RA diagnosed according to the 2010 American College of Rheumatology/European League Against Rheumatism (2010 ACR/EULAR) classification criteria for Rheumatoid arthritis) and compared with 97 healthy individuals matched in age and gender as controls. Age, gender, body mass index (BMI), clinical diseases activity index (CDAI) and diseases activity score 28 using erythrocyte sedimentation rate (ESR) (DAS28-ESR), and diseases durations were recorded. Rheumatoid Factor (RF), anti-citrullinated peptide antibody (ACPA), complete blood count (CBC) and ESR were all measured. RESULTS: The mean age for patients and controls were 46.53 ± 11.89 and 48.19 ± 12.06 years respectively (p=0.321). RDW was significantly higher in patients (14.5 ± 2.8%) compared with controls (12.4 ± 1.1 %) (p=>0.001). There was no significant correlation between various variables (age, Body Mass Index [BMI], disease duration, CDAI), DAS28-ESR, ESR, gender, RF, and ACPA) with RDW. The RDW had good ability to differentiate RA patients from controls (AUC=0.804, 95% CI=0.744 – 0.856. p=<0.001), while ESR had excellent ability to differentiate between RA patients and controls (AUC=0.926, 95% CI=0.882 – 0.958, p<0.001). CONCLUSIONS: RDW was significantly elevated in RA patients.