LEVELS OF EXPRESSION OF CAF7 (CD98) HAVE PROGNOSTIC-SIGNIFICANCE IN ADULT ACUTE-LEUKEMIA

The levels of CD98 antigen expression were studied in 62 consecutive c ases of adult acute leukemia including 24 acute lymphoblastic leukemia (ALL) and 38 acute myeloid leukemia (AML) using the monoclonal antibo dy CAF7 and flow cytometry. The mean follow-up was 13.5 months. The me an relative fluorescence intensity (MIF) of CAF7 varied between 6 and 83 channels (256 channels resolution). No correlation was established between CAF7 cell surface density and most of the predictive parameter s such as age, sex, blood counts, immunophenotype, proliferative index (PI) or DNA index, Nevertheless expression of CAF7 correlated positiv ely with survival duration (mean 210 vs 391 days, P=0.048) and complet e remission (CR) duration (mean 132 vs 361, days P=0.032). The levels of CAF7 differed significantly between ALL and AML (P<0.001), the ALL cases being all CAF7(intermediate) or CAF7(high). In the AML group the low levels of CAF7 expression correlated with shorter CR duration (me an 132 vs 414 days, P=0.017). The lack of correlation with other clini cal and biological parameters suggested that CAF7 might have an indepe ndent prognostic significance in adult AML. Although PI was also posit ively related to survival duration (P=0.02), it did not correlate with CR duration or the expression of CAF7. We suppose that the prognostic impact of CD98 is related to the control of cell growth and survival in which the molecule normally participates. (C) 1998 Elsevier Science Ltd. All rights reserved.