Expression of the CD11c antigen in B-cell chronic lymphoproliferative disorders.

This study analyzed the expression of the beta2 integrin CD11c in 155 patients with well-characterized B-cell chronic lymphoproliferative disorders: 106 B-cell chronic lymphocytic leukemias (B-CLL), 21 hairy cell leukemias (HCL), 9 B-cell prolymphocytic leukemias (PLL) and 19 low grade non-Hodgkin's lymphomas (NHL) in leukemic phase. CD11c was expressed in 100% of patients with HCL and B-PLL, while in B-CLL and NHL it was expressed in only 49 and 57%, respectively. Furthermore, in B-CLL the expression of CD11c was found mainly in patients with early stage of disease. In addition, when the fluorescence intensity of CD11c, calculated by MFI, was evaluated, it proved significantly higher in HCL and B-PLL compared to the values recorded in B-CLL and NHL (325 and 387 vs 34 and 56, respectively) (p < 0.05). Our results demonstrate that the evaluation of CD11c, both in terms of overall positivity and of fluorescence intensity, represents an additional useful parameter for a more precise differential diagnosis within the spectrum of B-cell chronic lymphoproliferative disorders.