Impaired humoral immunity in treated Hodgkin's disease.

To define the contribution of aggressive lymphoma treatment to the risk of post-splenectomy septicemia, we investigated the humoral immunity of 44 patients with Hodgkin's disease. Specific antibody against Haemophilus influenzae Type b was significantly reduced (mean, 147 ng per milliliter, P less than 0.01) in patients receiving combined treatment (radiotherapy and chemotherapy), whereas single treatment reduced titers marginally (chemotherapy) or not at all (radiotherapy). Untreated patients had normal values (396 ng per milliliter), and splenectomy was without effect. In some patients who received combined treatment, titers were reduced to levels seen in infants. IgM levels were likewise normal in untreated patients. Chemotherapy, however, significantly reduced IgM levels (P less than 0.025), an effect potentiated by prior splenectomy. IgG, IgA, alternate-pathway activity, C3, C4 and CH50 were all normal or elevated. Aggressive treatment with chemotherapy and radiation impairs humoral defense against encapsulated micro-organisms, and thus magnifies the risk of post-splenectomy septicemia in patients with Hodgkin's disease.