SEVERE IMMUNODEFICIENCY IN PATIENTS TREATED WITH FLUDARABINE MONOPHOSPHATE

Fludarabine monophosphate (FAMP) has been shown to be highly effective against low-grade malignant B-cell lymphoproliferative diseases. Beca use some opportunistic infections were observed in patients treated wi th FAMP, we investigated the influence of this drug on several paramet ers of immunocompetence. For 17 consecutive patients treated with FAMP for CLL or low-grade malignant lymphoma we studied T-cell subpopulati ons during and after therapy by flow cytometry and our findings were c orrelated with the clinical course of their disease. A pronounced decr ease in the various T-cell subpopulations was seen in all cases, that for CD4+ cells was still present 11-13 months after the end of the the rapy. In 7 patients a severe opportunistic infection developed; the ou tcome was fatal in 2 cases. Only 5 patients did not experience any ser ious infection. These results show that FAMP therapy in a dose of 25 m g/m2/day for 5 d every 4 weeks might be too toxic for patients with ve ry advanced disease. However, in view of the efficacy of FAMP, the pos sibility of less intensive schedules for these advanced cases should b e explored.