Predictive Impact of Hematological and Biochemical Parameters on the Clinical Course of Sarcoidosis

Background: Sarcoidosis is a systemic granulomatous disease with a highly variable clinical course, and distinguishing it from other diseases and predicting its prognosis can be challenging. In recent years, hematological and biochemical parameters have been investigated as potential biomarkers for assessing inflammation and predicting disease prognosis. This study aimed to evaluate the prognostic value of the lactate dehydrogenase-to-albumin ratio (LAR), neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR) and lymphocyte-to-monocyte ratio (LMR). Methods: This retrospective, single-center study included 369 newly diagnosed patients with sarcoidosis who were admitted between January 2020 and October 2024. Sarcoidosis was diagnosed based on current ERS, ATS, and WASOG guidelines. At the 6-month follow-up, patients' clinical courses were classified as regression, stable, or progression based on clinical, radiological, and pulmonary function tests. The predictive values of various hematological and biochemical parameters were analyzed using statistical methods, including binary logistic regression analysis and ROC analysis. Results: A total of 369 patients were included in the study. At the 6-month follow-up, 63.4% of patients showed regression, 21.4% had a stable course, and 15.2% showed progression. The progression group had a significantly higher LAR (5.26 [4.21-7.76]) compared to the stable/regression group (4.59 [3.82-5.86]) (p = 0.033). Additionally, baseline FVC% (OR, 0.97; p = 0.036) and the presence of dyspnea (OR, 3.08; p = 0.03) were identified as independent risk factors for disease progression. No significant associations were found between NLR, PLR, LMR, and serum ACE levels and the clinical course. The cutoff value of LAR for predicting disease progression was 4.87 (AUC: 0.605), with a sensitivity of 58.8% and specificity of 59.7%. Conclusions: Our study, which is the first to evaluate the prognostic value of LAR in sarcoidosis, identified this parameter as a significant indicator for the clinical course. The finding of significantly higher LAR levels in patients with disease progression suggests its potential as a prognostic biomarker. These results may help guide treatment and follow-up strategies, although further large-scale prospective studies are needed for validation.