Background: Leukopenia due to immunosuppressive drugs represents a well-known complication in graft recipients, which might put patients at an increased risk for infections. In this study, recombinant human granulocyte colony-stimulating factor (rhG-CSF), a hematopoietic growth factor that selectively stimulates neutrophil colony formation and neutrophil cell differentiation, was tested for safety and efficacy.
Methods: We evaluated 30 episodes of leukopenia (<2000/mm3) in 19 kidney graft recipients treated with rhG-CSF. This cohort was compared with an age- and sex-matched historical control group without therapy. Peripheral and differential blood cell counts were analyzed, and the duration of leukopenia was estimated. Furthermore, the occurrence of infections associated with leukopenia was investigated.
Results: All patients responded to rhG-CSF therapy. Peripheral leukocyte counts increased from 1756+/-582 to a peak of 8723+/-3038/mm3 (P<0.0001). On the average, the peak was reached after 2.7 days (range 1 to 8). Furthermore, the effect was fairly persistent, because in 22 of 30 episodes leukocyte counts were within the normal range after 7 days. The elevation of total leukocytes was mainly due to a specific increase in neutrophil granulocytes from 1143+/-514 to 6895+/-1950/mm3 on the peak day (P<0.0001). Patients in the G-CSF group were leukopenic for a mean of 1.29+/-0.59 days, whereas in the control group leukopenia persisted for at least 7 days. Consequently, the rate of infections was significantly higher (P<0.045) in nontreated patients.
Conclusion: rhG-CSF was safe and effective in leukopenic kidney graft recipients. Leukopenic episodes in treated patients were significantly shorter, and infections occurred at a significantly lower rate. No evidence was found that rhG-CSF therapy might trigger rejection episodes, and no side effects were observed.