Utility of pan-immune-inflammation value as a predictor of the prognosis of childhood lupus.

Background: Systemic lupus erythematosus (SLE) is a chronic inflammatory multisystemic disease. Monitoring disease activity thoughtout the disease course is important for effective management and assessment of disease outcome.

Objective: To assess whether the pan-immune inflammation value (PIIV) at diagnosis could predict organ involvement and disease activity in childhood SLE (cSLE) patients after 12 months of disease onst.

Methods: This is an observational retrospective multicenter study that comprised cSLE patients seen and followed at the participating centers between January 2010 and December 2022. All patients met the EULAR/ACR-19 criteria, were immunosuppressive drug-naïve at the time of SLE diagnosis and had a minimal follow-up period of 12 months. The data included clinical and laboratory findings and disease activity using the SLEDAI-2K. Receiver operating characteristic (ROC) curves were employed to determine the optimal cut-off value of PIIV and assess its predictive potential for disease activity, and organ involvement.

Results: A total of 125 patients (104 female) with a median age of 16.0 (IQR 5.6) years, a median age at disease onset of 10.9 (IQR 3.0) years, and a median disease duration of 4.8 (IQR 5.3) years were included. The most frequent involved organs at diagnosis were hematological (89.6%), musculoskeletal (68.8%), mucocutaneous (63.2%), and renal (58.4%). However, at a 12-month follow-up visit, the most frequent involved organs were renal (40.0%), hematological (39.2%), musculoskeletal (15.2%), and mucocutaneous (10.4%). The median PIIV at diagnosis was 139 (IQR 229.6), while the median SLEDAI was 12 (IQR 6.5) and 3.5 (IQR 7.0) at diagnosis and 12 months, respectively. An optimal PIIV cut-off of 250 was found to be a predicative for disease activity, with a sensitivity of 45% and a specificity of 86%. The study revealed that the PIIV successfully predicted four systems in our cohort of patients.

Conclusion: Our work suggests the PIIV might be a reasonable predictor for organ involvement and disease activity in newly diagnosed cSLE, though further research, particularly larger studies, is required to validate these findings, especially regarding organ involvement.