Neutrophil-to-Lymphocyte Ratio and Platelet-to-Lymphocyte Ratio Predicts the Disease Activity in Patients with Paediatric Systemic Lupus Erythematosus: An Observational Cross-Sectional Study.

Background: To assess the association between Neutrophil-to-lymphocyte ratio (NLR) and Platelet-to-lymphocyte ratio (PLR) with a degree of activity of paediatric systemic lupus erythematosus (pSLE) in terms of Systemic Lupus Erythematosus Disease Activity Index (SLEDAI-2K) score.

Methods: This observational cross-sectional study was conducted in Paediatric Rheumatology Clinic, Medical College Kolkata. Systemic lupus erythematosus was diagnosed in children based on the 2019 EULAR/ACR criteria and/or SLICC 2012 criteria. A total of 31 children were included in the study whereas patients with chronic illnesses were excluded.

Results: The mean age of presentation was 6.87 years among 31 children with pSLE. The most common presenting feature is prolonged fever and pallor followed by renal involvement. Most of the children presented with active disease 24 (77.42%). The mean NLR and PLR ratios were 4.29 ± 2.45 (0.9 - 10.57) and 112.26 ± 45.08 (47.7 - 203.9) respectively. The average SLEDAI-2K score was 15.9 (± 7.33). The NLR ratio in children with active disease (SLEDAI-2K score > 6) was 4.68 ± 2.44 (1.54 - 10.57) and inactive disease (SLEDAI-2K score <6) was 2.94 ± 2.10 (0.9 - 5.7) with p 0.0002. The PLR ratio in children with the active and inactive disease was 125.91 ± 41.29 (54.2 - 203.9) and 65.45 ± 18.0 (47.7 - 91.2) respectively (p 0.008).

Conclusion: The NLR and PLR ratio might be utilised as a trusted and cost-effective tool in the evaluation and prediction of pSLE disease activity.