Associations of Serum Long-Chain Fatty Acids with Multiple Organ Involvements in Patients with Sarcoidosis

Background: Fatty acids have diverse immunomodulatory functions and the potential to be associated with inflammatory responses in sarcoidosis. Methods The serum levels of multiple long-chain fatty acids (LCFAs) were compared between 63 patients with sarcoidosis and 38 healthy controls. The associations of LCFAs with clinical outcomes of sarcoidosis were also evaluated. Results The patients with sarcoidosis had significantly lower levels of n-3 poly-unsaturated fatty acids (PUFAs) ( p  < 0.001) and n-6 PUFAs ( p  < 0.001) than the healthy controls. However, there were no significant differences in the levels of saturated fatty acids (SFAs) and mono-unsaturated fatty acids (MUFAs) between the two groups. On multivariate logistic analysis, lower levels of n-3 PUFAs, n-6 PUFAs, and n-3/n-6 ratio were predictive of sarcoidosis. Among the patients with sarcoidosis, those with multiple organ involvement had significantly lower levels of n-3 PUFAs and n-3/n-6 ratio than those with single organ involvement. There were no significant differences in the levels of n-6 PUFAs, SFAs, and MUFAs between the patients with multiple and single organ involvement. On multivariate logistic analysis, lower levels of SFAs and n-3/n-6 ratio were predictive of multiple organ involvement. The levels of LCFAs had no significant association with radiographic stage or spontaneous remission. Conclusions Assessment of LCFA profiles may be useful for the diagnosis of sarcoidosis and evaluation of the disease activity.