The kinetics of immunologic and hematologic recovery in mice after lethal total body irradiation and reconstitution with syngeneic bone marrow cells treated or untreated with mafosfamide (ASTA Z 7654).

The immunohematopoietic reconstitution of mice lethally irradiated (TBI) and reconstituted with syngeneic bone marrow cells untreated or treated with mafosfamide (ASTA Z 7654) [TBI + SBMT or TBI + SBMT-Maf mice, respectively] was examined. The number of CFU-S was greatly reduced in TBI + SBMT-Maf mice compared with those in TBI + SBMT mice. The recovery of blood parameters (hematocrit, reticulocytes, erythrocytes, white blood cells, granulocytes, platelets) and of bone marrow and spleen cells, but not of peritoneal exudate cells, was slightly delayed in TBI + SBMT-Maf mice compared with those in TBI + SBMT mice. The time for immune system regeneration was, however, considerably longer in TBI + SBMT-Maf than in TBI + SBMT mice, as measured by the incidence of Ig+, Thy-1.2+, L3T4+, Lyt-2+, and IL-2R+ cells in the spleens. The appearance of Mac-1+ and asialo-GM 1+ cells was only slightly prolonged or unchanged, respectively.