A prospective study of the changes in immune status following radiotherapy for Hodgkin's disease.

In a prospective study, immune status was measured in 23 previously untreated patients with Hodgkin's disease Stage I-IIIA. Assessments of immunologic capacity were performed at diagnosis and repeated after staging laparotomy and after radiotherapy. The immune status was measured using delayed-type hypersensitivity tests to common recall antigens, the number of T- and B-lymphocytes in the peripheral blood, in vitro lymphocyte responsiveness to mitogens, antigens, and allogeneic lymphocytes, and serum levels of immunoglobulins. Skin reactivity was not significantly affected by either the staging laparotomy with splenectomy or the radiotherapy. Absolute T-lymphocyte count increased after splenectomy (P less than 0.025) and decreased after radiotherapy (P less than 0.005 compared to postsplenectomy values). In vitro lymphocyte responsiveness after splenectomy was comparable to the initial presenting level and diminished after radiotherapy (P less than 0.005). Serum levels of IgM were lowered after radiotherapy (P less than 0.05) while the fall was not significant after splenectomy. Three months after radiotherapy, lowest mean T-cells percentages were noted, but the responses to mitogens were significantly higher than those obtained immediately after treatment (P less than 0.01). While the reduction in the proportion of the T-lymphocytes persisted for 18 months, the mean lymphocyte responsiveness to mitogens, antigens, and allogeneic lymphocytes increased on follow-up. Apart from a severe impairment of the immune status following radiotherapy, this study also shows the existence of significant repair mechanisms during the follow-up period.