Recombinant interferon-alpha-2b treatment of hairy-cell leukaemia: experience with a low-dose schedule.

50 patients with hairy cell leukaemia (HCL) were treated with recombinant interferon (IFN) alpha-2b 2.0 x 10(6) IU/m2 subcutaneously three times weekly to evaluate the efficacy of low-dose IFN therapy in inducing and maintaining remission of the disease. At the time of this report 48 patients, of whom 22 were splenectomized, had been treated for at least 3 months and were considered evaluable for response. The median observation time on IFN-alpha-2b was 11 months (range 3 to 20). 4 cases with atypical disease (spongy lymphoid myelofibrosis) were also included. All patients responded to IFN. After 3 months 11/48 patients (23%) had achieved a partial remission (PR) with normalization of peripheral blood values. After 6 months 27/43 patients (63%) had achieved a favourable response; complete remission (CR) was recorded in 4 and PR in 23 patients. The proportion of patients with favourable responses (CR + PR) increased with the duration of therapy and after 12 months of therapy 23/28 (82%) patients showed CR or PR, 9 patients (32%) being in CR. Splenectomized patients disclosed a trend towards a more rapid response. It is concluded that IFN-alpha-2b is a highly effective first-line therapy for HCL.

Dissemination pattern of two immunologically induced transplanted malignant lymphomas in C57 B1/6J mice.

The need for syngenic tumors to elucidate factors in lymphoma dissemination prompted us to induce new lymphomas in a series of inbred C57B1/6J mice. The method of induction, immunosuppression and simultaneous immunostimulation, had a high mortality rate, but gave us 2 transplantable lymphomas. These tumors are described and compared in the present paper, with emphasis on their dissemination patterns. Both tumors disseminated rapidly from tail transplants to lymphoid organs, lungs and liver. They were characteristically dissimilar, however, in their s.c., i.p. and i.v. transplantabilities.

The effect of steroids on the circulating lymphocyte population--VI. Studies of the thoracic duct T- and B-lymphocyte populations after neonatal thymectomy and prednisolone treatment. An immunofluorescence study in the rat.

The corticosteroid effect on circulating lymphocytes in a steroid-sensitive species (rat) was studied by immunofluorescence. Both normal and neonatally thymectomized animals were injected with a high dose of prednisolone. T- and B-lymphocytes as well as T-lymphocyte subsets were analyzed in thoracic duct lymph during the involution phase (3 h after injection) and the restitution phase (17 h after injection) using conventional and monoclonal antisera. Neonatal thymectomy significantly reduced the number of circulating T-helper and T-non helper cells. In the involution phase, after a corticosteroid injection, there was a 64% reduction of lymph cell content in normal rats, affecting both T- and B-lymphocytes. Thymectomized animals showed an even more pronounced disappearance of cells. Counted in percentage, more B- than T-lymphocytes disappeared from the circulation. The T-non helper cells disappeared to a greater extent than the T-helper cells did. Cells with Ia-antigen showed about the same values as the B-lymphocytes. During the restitution phase all cells types were restored to normal levels. It seems that a high prednisolone dose has a more pronounced effect on the circulation of B- than of T-lymphocytes, and the T-non helper cells are probably more sensitive than the T-helper subpopulation. These data support the hypothesis that a major corticosteroid effect is a trapping and redistribution of circulating lymphocytes, more pronounced for certain cell types.