Residual cancer lymphocytes in patients with chronic lymphocytic leukemia after therapy show increased expression of surface antigen CD52 detected using quantitative fluorescence cytometry.

Background: Rituximab and alemtuzumab, mAbs used in recent years to treat CLL, are directed against antigens CD20 and CD52. CD20 is not highly expressed by CLL tumor cells, and rituximab does not have significant effectiveness in CLL unless combined with chemotherapy. Alemtuzumab targets CD52, which is much more highly expressed, and is currently the most effective agent used alone for CLL.

[Toxoplasmosis of the central nervous systems after allogeneic stem cell transplantation].

Toxoplasmosis is a rare opportunistic protozoal infection, which may occur in patients after hematopoietic stem cell transplantation. This disease originates almost exclusively from reactivation of latent infection in seropositive recipients. We present a case report of one patient with diagnosis of acute myeloid leukemia undergoing two allogeneic stem cell transplantations at two years interval.

[Rare diagnosis of CD4+56+ leukemia from dendritic cells type DC2].

CD4+56+ hematodermic neoplasm or leukemia from early plasmocytoid dendritic cells type DC2 was recognized by WHO-EORTC classification of cutaneous lymphomas as a separate entity related to the plasmacytoid precursor dendritic cell (pDC). This diagnosis is based on expression of CD4 and CD56 antigens and absence of B, T or myeloid lineage markers. Immunohistochemistry and flow cytometry are the only methods, which allow identification of this disease, either in isolated skin lesions or in a leukemic form.