CD11C EXPRESSION IN B-CELL CHRONIC LYMPHOCYTIC-LEUKEMIA - A COMPARISON OF RESULTS OBTAINED WITH DIFFERENT MONOCLONAL-ANTIBODIES

In order to obtain more information on the pattern of CD11c-positivity in otherwise typical B-cell chronic lymphocytic leukemia (CLL), we an alyzed immunological and clinico-pathological features of 99 such pati ents studied with two different monoclonal antibodies (MoAbs). fifty-t wo out of 70 (74.2%) patients stained with IOM-11C MoAb and 3 out of 2 9 (10.3%) patients stained with Leu-M5 MoAb had more than 30% CD11c po sitive cells (P < 0.0002). The two groups were similar with regard to the expression of B-cell CLL-related antigens (CD5, CD20, CD23), as we ll as clinico-pathological features (i.e. Binet clinical stage and pat tern of bone marrow involvement), thus suggesting that differences in CD11c expression were due to different reactivity patterns of the MoAb s utilized. In our experience, the use of different reagents may affec t immunophenotyping results, thus providing conflicting data at times.