Prognostic role of natural killer cells in pediatric mixed cellularity and nodular sclerosing Hodgkin's disease

OBJECTIVE: To study natural killer cells' spontaneous cytotoxic capacity against tumor cells and their prognostic significance in classical Hodgkin's disease. STUDY DESIGN: Thirty-eight pediatric mixed cellularity and nodular sclerosing Hodgkin's disease patients were included in the study. Immunohistochemical staining was performed for natural killer cells in the background using the monoclonal antibody CD57 in serial sections of B5-formalin-fixed, paraffin-embedded tissue blocks. CD57-positive cells were counted with an immersion objective among 5,000 cells on representative areas of the tumors. The degree of natural killer cells was classified as low (<150 cells) or high (> or = 150 cells). Multivariate regression analysis was performed to determine the differences between patients with and without relapse. RESULT: The mean of CD57-positive cell numberfor all the cases was 173.42 +/- 117.34 (range, 20-500). CD57-positive cells were high in 21 cases and low in 17. The mean of CD57-positive cell numbers was 191.85 +/- 115.33 in the disease-free group and 84.44 +/- 57.90 in the relapsing group. Log rank analysis showed statistical significance between event-free survival and number of CD57-positive cells (P = .0207). CONCLUSION: In multivariate analysis, CD57 expression proved to be a prognostic factor independent from otherfactors. As a result, CD57 expression by background natural killer cells may be used as a prognostic parameter in mixed cellularity and nodular sclerosing Hodgkin's disease.