An analysis of lymphocyte subsets in the regional lymph nodes of patients with papillary thyroid carcinoma.

Lymphocyte subsets in the lymph nodes regional to papillary thyroid carcinoma were determined using flow cytometry to ascertain the differences in local immunological responses between elderly and young patients. Lymph nodes from age-matched patients with benign thyroid tumors were used as controls. No significant alterations in lymphocyte subsets were observed in the lymph nodes from the young patients regardless of whether metastasis was present, whereas those from the elderly patients showed significant decreases in pan T cell (CD2+, CD3+) and cytotoxic T cell (CD8+, CD8+CD11b-) populations, and a significant increase in B cells (CD19+) compared with those from both the young patients and the age-matched controls. These results indicate that local immunological alterations occur in elderly patients with papillary thyroid carcinoma, and we believe that immunological changes are one of the clinical characteristics of this tumor.