Heat production rate in blood lymphocytes as a prognostic factor in non-Hodgkin's lymphoma

The heat production rate in peripheral blood lymphocytes was evaluated by direct calorimetry in 76 untreated adults with non-Hodgkin's lymphoma (NHL). Elevated values were recorded for 20 out of 54 patients with lymphomas of high or intermediate malignancy grade (37%) and for 1 out of 22 patients (5%) with low grade lymphomas (p = 0.01). Median survival was 39 months for patients with normal values and 8.5 months for those with elevated values (p = 0.005). In a subgroup of 38 patients with high or intermediate grade NHL stage III-IV, 17 patients with abnormally high lymphocyte heat production rates had a significantly shorter survival than 21 patients with normal values (p = 0.01). In a multivariate analysis the prognostic impact of lymphocyte heat production was superior to histologic malignancy grade, clinical stage and age.