Cells infiltrating human periapical inflammatory lesions.

Cells infiltrating human periapical granulomas and cysts were analyzed using cell suspensions. Over 50% of the total cells studied were lymphocytes whilst neutrophils were the next most frequent cell type observed. Two percent of the cells were mast cells. Only a few monocytes/macrophages and natural killer cells were found. More than half of the lymphocytes infiltrating the lesions were T cells, and more than half of the T cells were of the suppressor/cytotoxic (OKT8) phenotype. The OKT4/OKT8 ratio was 0.5. The findings are compared to previous reports and the differences discussed.