The role of lactate dehydrogenase‐to‐albumin ratio in clinical evaluation of adult‐onset Still’s disease

Objectives The aim of the study is to evaluate the importance of lactate dehydrogenase-to-albumin ratio (LAR) in patients with adult-onset Still's disease (AOSD) and to investigate the relationship between this ratio and clinical laboratory variables. Methods The study design was retrospective cross-sectional. The demographic and clinical data, laboratory results and imaging findings were documented. Univariate and multinomial logistic regression analyses were performed to find the predictors, which could be useful to define the ferritin level and organ involvement. Receiver-operating characteristic (ROC) analysis was used to clarify the diagnostic ability of the LAR for ferritin level and organ involvement. Results Fifty-eight patients with AOSD were evaluated. When patients were divided into two groups according to the serum ferritin level with a cut-off of 1500 ng/dL, lymphocyte count and albumin level were significantly less in patients who had higher ferritin levels (P = .015 and P = .005). In multinominal logistic regression analysis, AST, LDH and LAR were found as predictors for ferritin levels. When we compared LAR between patients with and without organ involvement, higher LAR was found in patients with HM, SM, serositis and MAS. Also, LAR was significantly higher in patients with higher ferritin levels (≥1500 ng/dL) than those without (P < .001). In ROC analysis, the cut-off point of LAR predicting the ferritin level was determined as 80.75 with 83.7% sensitivity and 80.0% specificity (AUC = 0.89, 95% CI 0.79-0.98, P < .001). Conclusion LAR can be a valuable inflammatory marker to determine AOSD patients with organ involvement and higher ferritin level.