Prognostic value of expression of ZAP-70, CD38, Fas and Fas ligand in chronic lymphocytic leukemia/ small lymphocytic lymphoma and relationship with bone marrow infiltration patterns

This study is planned to evaluate the possible relationship between zeta associated protein-70 (ZAP-70) and CD38 proteins, those which are concerned with rapid progression and agressive clinical course in chronic lymphocytic leukemia / small lymphocytic lymphoma (CLL/SLL); and Fas and its ligand Fas ligand (FasL), which induct apoptosis and are suspected to be poor prognostic indicators in that tumor.By avidine-biotin peroxidase method, ZAP-70, CD38, Fas and FasL antibodies were applied to sections obtained from paraffin blocks of bone marrow biopsy materials of 50 patients, who were diagnosed as CLL/SLL in 8-years time period and whose diagnoses were confirmed by flow cytometry. The ratio of stained tumor cells with each antibody were calculated by using a double-blind semi-quantitative method and compared with each other; and each antibody was evaluated according to bone marrow infiltration patterns of the tumor, i. e., diffuse, İnterstisiyel and nodular.A statisticaly significant positive correlation (P=0.002) was found between expressions of ZAP-70 and CD38, which are generally considered to be poor prognostic predictors and a similar correlation was obtained between these two markers and FasL (P=0.023 and P=0.021, respectively). No statistically significant results were established between Fas expression and the other three markers. In bone marrow infiltration aspect, statistically significant more ZAP-70 expression is found in diffuse infiltration pattern in comparison to İnterstisiyel and nodular patterns (P=0.029 and P=0.037, respectively), confirming the negatif prognostic effect of diffuse infiltration. With other markers, no remarkable results were obtained between infiltration patterns and staining ratio.Since ZAP-70 and CD38 overexpressions are accepted as poor prognostic predictors in CLL/SLL, it is concluded that increased FasL expression can be used as an additional negative prognostic parameter. New studies with larger series are needed to confirm this conclusion.