IFN-gamma and IL-4 in saliva of patients with oral lichen planus: a study in an ethnic Chinese population.

Interferon-gamma (IFN-gamma) and interleukin-4 (IL-4) represent T helper 1 (Th1) and T helper 2 (Th2) cytokines involved in oral lichen planus (OLP), respectively. This study was to investigate the expression profile of IFN-gamma and IL-4 in saliva of OLP patients. Seventy-nine ethnic Chinese patients with OLP were recruited for this study, together with 41 age-sex-matched healthy volunteers served as control group. IFN-gamma and IL-4 levels in whole unstimulated saliva were screened by enzyme linked immunosorbent assay. OLP patient showed a low-level IFN-gamma but high-level IL-4 expression profile in saliva, with a lower ratio of salivary IFN-gamma/IL-4 compared to healthy controls. With regards to subtypes, salivary IL-4 level in erythematous/ulcerative group was significantly higher than that in reticular group. Imbalance of Th1/Th2 cytokines with Th2-predominant profile in saliva may be involved in OLP. Salivary IL-4 level may be a fine biomarker reflecting the severity of OLP.