Blood cell kinetics after a 385 cGy total body irradiation given to a CML patient for bone marrow transplantation.

Fractionated total body irradiation was given to a patient with chronic myeloid leukemia as part of a conditioning regimen for bone marrow transplantation. The radiation treatment was discontinued after the third fraction (total dose: 385 cGy) and no bone marrow graft was given because of the patient's refusal. Peripheral blood lymphocyte levels were monitored for 3 months and lymphocyte subsets up to 50 days post-irradiation. Lymphocyte numbers reached the nadir 48 h after the last fraction and lymphopenia was still present 3 months later. All lymphocyte subsets (T, B, CD4 and CD8 cells) showed a similar decrease except for natural killer cells which exhibited a larger decline. The regenerative capacity of T cells, CD4 subset and natural killer cells was less than that of B cells and CD8 lymphocyte subsets.