Ertugrul Cagri BOLEK, Ibrahim KARADUMAN, Ibrahim VASI, Burak KARAKAYA, Hamit KUCUK, Abdulsamet ERDEN
Rheumatology Quarterly - 2026;4(3):172-182
Objective: To evaluate longitudinal changes in the prognostic nutritional index (PNI) and their association with pulmonary function in systemic sclerosis-associated interstitial lung disease (SSc-ILD). Methods: This retrospective longitudinal subcohort included 43 patients with high-resolution computed tomography (HRCT)-confirmed SSc-ILD. Prognestic nutritional index was calculated from laboratory values obtained at systemic sclerosis (SSc) diagnosis and the last follow-up visit. Pulmonary function trajectories were assessed using the first and last available forced vital capacity (FVC, % predicted) measurements. Associations were evaluated using Spearman correlation analysis; survival comparisons were exploratory. Results: The cohort comprised 43 patients, 93.0% female, with a mean age at SSc diagnosis of 52.2 +/- 12.2 years and mean follow-up of 90.7 +/- 46.4 months; 6 patients died. Median PNI increased from 51.7 (IQR, 9.1) at SSc diagnosis to 54.2 (IQR, 6.0) at the last visit (p = 0.074). DeltaPNI correlated positively with annualized FVC change (rho = 0.335, p = 0.049; n = 35), but not with DeltaFVC. Last-visit PNI correlated with annualized FVC change (rho = 0.383, p = 0.023) and last available DLCO (rho = 0.374, p = 0.038). Prognestic nutritional index at SSc diagnosis was not associated with DeltaFVC. Prognestic nutritional index values at SSc diagnosis and the last visit were lower among non-survivors. Conclusion: Longitudinal changes in PNI showed a modest exploratory association with pulmonary functional trajectory in SSc-ILD. Given the small sample size, temporal misalignment of assessments, and absence of multiplicity adjustment, these findings should be considered hypothesis-generating and require validation in larger prospective cohorts.
