Cellular immune alterations in fifty-two patients with oral lichen planus.

OBJECTIVES: Abnormal immune mechanisms appear to play an important role in the pathogenesis of lichen planus (LP). DESIGN: A prospective clinical study was made to investigate the differences in T cell subpopulations in 52 patients with oral lichen planus (OLP) and 54 healthy controls. RESULTS: Statistically significant differences were observed among the OLP patients versus the controls: the percentages of CD3+, CD8+, DR+, CD57+ and CD8CD45RA+ cells were depressed, while elevations were recorded in the subpopulations expressing CD4+, and in the ratios CD4/CD8+ and CD8CD45RO+/CD8CD45RA+. CONCLUSIONS: These results suggest the existence of differences in the lymphocyte subpopulations between healthy subjects and patients with OLP. These findings do not coincide with the previously published observations, however; the observed cellular immune alterations thus appear to relate more to lymphocyte reaction capacity than to the actual number of cells in each population subgroup.