A Study on Association between Common Haematological Parameters and Disease Activity in Rheumatoid Arthritis.

Introduction: Rheumatoid Arthritis (RA) is a chronic systemic inflammatory disease where assessment of disease activity is essential for management of patient. Currently, many composite scoring systems are used for evaluation of disease activity but they are mainly clinical-based. As several haematological parameters are altered due to systemic inflammatory process in RA, this study was intended to evaluate role of common haematological parameters to assess disease activity in RA.

Aim: To find out the association of disease activity of Rheumatoid Arthritis (RA) with platelet count, Mean Platelet Volume (MPV) and Haemoglobin (Hb) level so that these cost-effective haematological parameters can be used as additional factors to assess disease activity.

Materials And Methods: This hospital based cross-sectional study was done on newly diagnosed patients of RA along with age and sex matched healthy control population. Patients suffering from malignancies, renal failure, diabetes mellitus or RA patients on drug therapy were excluded. Clinically, disease activity of RA was measured using DAS 28-3 Score (Modified Disease Activity Score using three variables- tender joint count, swollen joint count and ESR). Haematological parameters were measured by automated cell counter.

Results: Total 80 cases were selected (60 female and 20 male). 48 patients with high disease activity (DAS 28-3>5.1) were labelled as Group-A and 32 with low to moderate disease activity (DAS 28-3 ≤5.1) as Group- B. Mean platelet count of patients of group A and group B were 4.53 lac/cmm and 2.17 lac/cmm respectively (p <0.001). MPV mean in group A and B were 11.86 fl and 10.19 fl respectively (p <0.001). Mean Hb (g/dl) was 10.05 and 12.25 for group A and B respectively (p=0.001) for male patients while in females it was 10.12 and 11.91 for group A and B, respectively (p=0.003). Mean platelet count and MPV in control population were 2.07 lac/cmm and 9.4 fl, respectively while mean Hb (g/dl) was 13.31 (male) and 12.01 (female).

Conclusion: In our study it was observed that Hb is significantly lower in patients with high disease activity whereas platelet count and MPV are significantly higher with high disease activity compared to patients with low to moderate disease activity.