Clinical and Laboratory Profile of Patients with Newly Diagnosed Juvenile Idiopathic Arthritis: An Observational Study from a Tertiary Care Centre, Karnataka, India

Introduction: Juvenile Idiopathic Arthritis (JIA) is the most common rheumatic condition of childhood. It represents a heterogeneous group of childhood arthritis.

Aim: To study the clinical profile and laboratory characteristics of all newly diagnosed JIA patients.

Materials and Methods: This hospital-based prospective observational study was conducted in the Department of Paediatric Rheumatology in Indira Gandhi Institute of Child Health, Bengaluru, Karnataka, India between December 2017 to April 2019. All children who fulfilled International League of Associations for Rheumatology (ILAR) criteria for the diagnosis of JIA were enrolled in the study, and their clinical and laboratory parameters were evaluated. The analysis between matched-pairs data like the comparison between age of onset and age of presentation in males and females were done by paired t-test.

Results: Fifty one children were included in the study with M:F of 1:1.12. Mean age at onset was 8.71±4.02 years and median duration of disease was 13 months (2-96 months). The most common subgroup was polyarticular JIA 18 (35.3%) followed by Systemic Onset Juvenile Idiopathic Arthritis (SOJIA) 14 (27.5%), enthesitis-related arthritis 13 (25.5%) and oligoarticular JIA 4 (7.8%). Knee (94%) was the most common joint involved followed by the ankle (70.5%). Fever was the most common extra-articular feature present in 73% of cases. Hepatomegaly, splenomegaly and lymphadenopathy was present in 33.3%, 9.8% and 21.6% children, respectively. Anaemia, leukocytosis, thrombocytosis and elevated Erythrocyte Sedimentation Rate (ESR) were more common in SOJIA. Macrophage Activation Syndrome (MAS) was diagnosed in 2 cases of SOJIA (14.3%) with no mortality.

Conclusion: Polyarticular JIA was the common subtype in the study, followed by SOJIA. Most common joint involved was knee, followed by ankle and fever is the most common extraarticular manifestation.