Autoimmune rheumatologic diseases
Objective: To analyze the expression of co-inhibitory and costimulatory molecules in different cellular subpopulations in JIA patients stratified by age and treatment.
Methods: Exploratory cross-sectional study. 53 patients fulfilling Oligoarticular JIA (ILAR) criteria and 22 controls were included. All of them were children or young adults (2 to 35 years of age). JIA patients were either not treated (n=14) or treated with MTX (n=14), anti-TNF (n=8), or a combination of both (n=16). Four flow cytometry panels were designed for the analysis of co-stimulatory/co-inhibitory markers, some typical of "exhausted" cells (PD1, TIM 3, TIGIT, CD226, CD137, HVEM, LIGHT, BTLA), assessed in memory, effector and naïve CD4+ and CD8+ T lymphocytes, and also in B lymphocytes and NK cells. FDR correction was applied for p values.
Results: No correlation was found among the exhaustion/activation markers and age neither in JIA nor in controls. Interestingly, age-related differential trends were observed in the CD8+ compartment in controls, while in JIA patients were detected in the B cell compartment. We didn’t observe, after correcting for treatment, any significant difference in lymphocyte subpopulations defined by the above co-inhibitory and co-stimulatory markers in JIA patients in relation to indexes of disease activity. However, there was a tendency towards a higher expression of CD137 in several CD8+ subpopulations of active patients as compared to inactive.