Selective internalization of monoclonal antibodies by B-cell chronic lymphocytic leukaemia cells.

B-cell chronic lymphocytic leukaemia (B-CLL) cannot be cured by conventional chemotherapy, therefore, toxin-linked therapeutic monoclonal antibodies (mAbs) are increasingly examined for their potential to improve clinical outcome. The current study aimed to identify mAbs that were internalized by the B-CLL cells of 14 patients, using both flow cytometry and confocal laser scanning microscopy. Anti-CD5, CD22 and CD40 mAbs were effectively taken up by B-CLL cells, whereas mAbs against CD19, CD20, CD23 and CD45 were not. This study may form a basis for further research to identify antibodies that may serve as carriers for toxins to treat B-CLL.