[Complete remission during administration of rhG-CSF in acute myeloblastic leukemia with pneumonia]

A 54-year-old man was admitted with pneumonia and pancytopenia (WBC 400/microliters, RBC 297 x 10(4)/microliters, Hb 10.1g/dl, Plt 5.6 x 10(4)/microliter). Bone marrow aspiration revealed a proliferation of leukemic cells (61.6%) and led the diagnosis of AML (M2). Although no antileukemic agent had been administered previously, the combination therapy of antimicrobials and rhG-CSF for the infection not only improved pneumonia, but also induced a complete remission of AML. The short-term remission was followed by the first relapse of AML, in spite of the continuous administration of rhG-CSF. The abnormal karyotype (47, XY, +8) shown in the chromosomal analysis of the bone marrow cells at admission remained on the first remission. The second complete remission was induced by combination chemotherapy (BHAC-DMP), and the chromosomal analysis at this time showed a normal karyotype. These findings suggested that the first remission of AML in this case was caused mainly by the maturation induction effect of rhG-CSF on the leukemic cells, however, the possibility of the spontaneous remission in this case also remained.