[Why should we revaccinate children after stem cell transplantations?]

Stem cell transplantation is a procedure often used in treatment of proliferative and non-prolifarative diseases. Recipient's immunological system has been damaged during pretransplant and conditioning therapy: deprived from B- and T-cell mediated immunological response and memory cells. One of the prophylactic procedures against post-transplant infections in recipients is efficient and safe revaccination. In Poland so far there is no uniform revaccination schedule for stem cell transplantation recipients.

Lymphocyte populations in lymph nodes in different histological types of Hodgkin's disease in children

Proliferating Reed-Sternberg and Hodgkin's cells within the lymph node in Hodgkin's disease (HD) affect the surrounding cells, which results in alterations of the proportion between T and B lymphocytes and the activation of these cells. The purpose of this study was to assay the changes within lymphocyte populations in lymph nodes in different types of HD. The lymph nodes of 10 children with nonmalignant, reactive changes, and 31 children with HD of the following types: mixed cellularity (MC; 11 cases), nodular sclerosis (NS; 17 cases) and lymphocyte depletion (LD; 3 cases) were included in the study. The percentage of T lymphocytes (CD3+), B lymphocytes (CD22+), T cell (CD4+ and CD8+) and B cell subsets (kappa+ and lambda+ light chain) were assayed with flow cytometry. The ratio of T:B lymphocytes in reactive lymph nodes and in NS type of HD was similar. An increase of the T cell percentage (resembling an increase of the CD4+ subset) and a decrease of B cells resulted in a high ratio of T:B and was noted in the MC and LD types of HD. These HD types were associated with marked changes in lymphocytes within the lymph node, which suggested a different effect of proliferating Reed-Sternberg and Hodgkin cells in HD on the surrounding cells.

Bone marrow morphology during haematopoietic stem cell mobilization with G-CSF in mice

The aim of the work was to examine the morphology of the bone marrow of mice during stimulation with G-CSF. Experimental Balb C mice were daily injected subcutaneously with 250 microg/kg b.w. G-CSF (Neupogen). After 2, 4 and 6 days of the experiment femurs were obtained for morphological study. On day 2 of the mobilization the amount of haematopoietic cells in the bone marrow increased and dilatation of the sinusoids was observed. Only single leukocytes were observed in the lumen of the vessels. There were numerous leukocytes in the lumen of the sinusoids on day 4 of the mobilization. The morphology of the bone marrow on day 6 was similar to that of the control. Mobilization of mice with G-CSF resulted in migration of haematopoietic cells from the bone marrow and the process is most pronounced on day 4.