Clinical and immunological evaluation of primary splenic irradiation in chronic lymphocytic leukemia: a study of 24 cases.

Little is known about the effects of primary splenic irradiation (SI) in B-cell chronic lymphocytic leukemia (B-CLL) on subpopulations of lymphocytes, immunoglobulins, and the induction of autoantibodies against erythrocytes and platelets. Twenty-four untreated patients with B-CLL were studied prospectively. One patient was excluded from analysis because of intercurrent death. Of the remaining 23 patients, 7 were female and 16 were male, with an average age of 68.4 and 61.2 years, respectively. Treatment consisted of a weekly dose of I Gy up to a total dose of 10 Gy to the spleen. Standardized evaluation was done 2 weeks before and 6 weeks after SI. Twenty patients completed the course of SI. In 14 patients there was a partial response and in 9 patients the disease remained stable. The number of leukocytes decreased rapidly and significantly, with a decrease in the fraction of lymphocytes and an increase in the neutrophil count (all P<0.0001). There was a significant increase in platelet count, but not in hemoglobin level. Nausea, slight diarrhea, pleuropneumonia, granulopenia with fever (all n=1), urinary tract infection and high fever (n=1), and thrombocytopenia occurred (n=2). One patient received transfusion of packed cells because of upper digestive tract bleeding for which cessation of SI was not necessary. The number of malignant cells showed a significant decrease (P<0.01). No significant changes in CD4/CD8 ratio were found. The number of CD4+ and CD8+-cells, however, decreased significantly (P<0.01 and 0.03, respectively). DAT remained unchanged in most (93%) and tests for antibodies to platelets in 83% of the patients. No significant changes in immunoglobin levels were observed.