HLA-identical sibling bone marrow transplantation in younger patients with chronic lymphocytic leukemia. European Group for Blood and Marrow Transplantation and the International Bone Marrow Transplant Registry.

OBJECTIVE

To characterize in detail the outcomes of HLA-identical sibling bone marrow transplantation for chronic lymphocytic leukemia (CLL) in patients younger than 60 years of age.

DESIGN

Retrospective cohort study.

SETTING

30 centers for bone marrow transplantation worldwide, which reported data on outcome of HLA-identical sibling bone marrow transplantation for CLL to the European Group for Blood and Marrow Transplantation or the International Bone Marrow Transplant Registry between 1984 and 1992.

PATIENTS

54 patients diagnosed with CLL (median age, 41 years; range, 21 to 58 years). The median interval from diagnosis to transplantation was 37 months (range, 5 to 130 months). At the time of transplantation, 3 patients were at Rai stage 0; 10 were at stage 1; 10 were at stage 2; 7 were at stage 3; and 22 were at stage 4.

INTERVENTION

Transplant regimens varied. Most patients received high-dose cyclophosphamide and total body irradiation, followed by infusion of bone marrow from an HLA-identical sibling. After transplantation, immune suppression with cyclosporine or methotrexate or both was generally used to prevent graft-versus-host disease.

MEASUREMENTS

The primary outcome was survival. We also studied hematologic remission, defined as normalization of the leukocyte count, hemoglobin level, and platelet count, and absence of lymphadenopathy and splenomegaly.

RESULTS

38 patients (70%) achieved hematologic remission. Twenty-four (44%) remain alive a median of 27 months (range, 5 to 80 months) after transplantation. Three-year survival probability was 46% (95% CI, 32% to 60%). Three patients who received transplants at Rai stage 0 remain alive 21, 32, and 45 months after transplantation. Three-year survival probabilities were as follows: 68% (CI, 38% to 98%) in 10 patients who received transplants at Rai stage 1, 30% (CI, 2% to 58%) in 10 patients who received transplants at Rai stage 2, 57% (CI, 21% to 93%) in 7 patients who received transplants at Rai stage 3, and 34% (CI, 12% to 56%) in 22 patients who received transplants at Rai stage 4 CLL. Five patients (9%) died of progressive leukemia and 25 (46%) of treatment-related complications.

CONCLUSIONS

Bone marrow transplants from HLA-identical siblings can result in hematologic remission and survival in persons with CLL, but it is uncertain how these results compare with those of conventional therapies.