Vol 14, No 2 (2015)

Nodular lymphocyte-predominant Hodgkin's lymphoma (NLPHL) is a rare variant, diagnosed in 5% of all patients with Hodgkin's lymphoma. Tumor cells in NLPHL express CD20, CD79a, BCL-6, B-cell transcription factors (BSAP, BOB-1, Oct-2), can express PU.1 (transcription factor necessary for B-cell development). The profile of NLPHL tumor cell expression is similar to that of Berezovsky-Sternberg-Reed cells in classical Hodgkin's lymphoma. An important biological characteristic of NLPHL is probability of its transformation into aggressive B-cell non-Hodgkin's lymphoma. Patients with NLPHL receive various treatments: from surgery to combined chemoradiotherapy and rituximab target therapy.

The development of monoclonal antibodies (mAbs) for the treatment of hematological malignancies is in the focus of modern research. Several antibodies (Abs) effective in the treatment of acute lymphoblastic leukemia (ALL) in children are used at present. Nonconjugated humanized Abs are well tolerated and can be combined with chemotherapy, while immunoconjugats (with a second molecule - toxin, radioisotope, or label), delivering toxic compounds directly to the target cells, are fraught with serious side effects. Antigens with high selective expression on pathological cells are the ideal targets for Abs, their clinical trials (phases I/II and III) in children with ALL are now in progress. Antigens with stable expression on cell membrane (CD19, CD52) serve as substrates for bi-specific T-cell engagers (BiTEs) or for nonconjugated Abs realizing their mechanism of action through antibody-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC). Antigens subjected to rapid internalization (CD22, CD5, CD7) are suitable targets for immunoconjugates delivering toxic substances directly to target cells by specific binding. Effective compounds, corresponding to various antigens expressed in only certain ALL subgroups (CD20, CD33, CD2, CD3, CD4), can be used for therapy of patients with refractory leukemias. The mechanism of antileukemic activity of mAbs is quite different in comparison with chemotherapy; this approach is expected to modify significantly the therapeutic strategy in childhood ALL.

Patients with lymphoblastic lymphomas are effectively treated according to protocols developed by the BFM (Berlin-Frankfurt-Münster) group. Venous sinus thrombosis is a rare complication of therapy for lymphoblastic lymphomas. A clinical case is presented: development of combined thrombohemorrhagic complication in a boy aged 12 years with lymphoblastic lymphoma. The patient received replacement therapy with prothrombin complex factor, antithrombin III, and anticoagulant therapy with high-molecular-weight heparin gradually replaced by low-molecular-weight heparin. Five months of anticoagulant therapy led to complete recanalization of the involved sinuses.