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We present the results of a cytogenetic and molecular cytogenetic analysis of a series of patients with bone and soft tissue tumors. PATIENTS ANDMETHODS: We analyzed a cohort of 26 patients with Ewing sarcoma/PNET, 15 patients with rhabdomyosarcoma, 5 with synovial sarcoma and one patient with an undifferentiated sarcoma using the cytogenetic and molecular cytogenetic techniques M-FISH and arrayCGH.We found nonrandom chromosomal structural and numerical changes with diagnostic and prognostic relevance in most patients. Eight patients with ES/PNET had only a t(11;22)(q24;q12), eight patients had secondary aberrations as well and six had only secondary aberrations. In the RMS patients we detected the t(1;13)(p36;q14) once and the t(2;13)(q35;q14) four times, both of them characteristic for the alveolar subtype with poor prognosis and numerical aberrations, characteristic for the embryonal subtype, in five patients. Four patients with synovial sarcoma had the diagnostic t(X;18)(p11.2;q11.2), one of them had a complex karyotype with a complex t(X;18;21) (p11.2;q11.2;q11.2) together with t(2;5)(q24-32;p13-14) and t(12;20)(p11;q13). We correlated the karyotype of cancer cells with histopathologic morphologic analysis, clinical outcome and foreign published results.Cytogenetic and molecular cytogenetic analysis is a valuable diagnostic tool in bone and soft tissue tumors, especially in less differentiated subtypes, and as such it should be an integral part of curative care.

Acute graft versus host disease (GvHD) remains a severe complication of allogeneic haematopoietic stem cell transplantation (HSCT). Our study summaries results of skin explant assay (SEA) as a pretransplant GvHD predictive test in a cohort of paediatric (n = 33) and adult (a = 8) patients receiving grafts from their HLA identical siblings (n = 28), haploidentical relatives (n = 3) and unrelated donors (n = 10). Results GvHD prediction are correlated with the occurrence and severity of acute GvHD posttransplant and effect of GvHD prophylaxis on GvHD clinical outcome is evaluated.SEA utilises responding lymphocytes of the donor, which are sensitized firstly in vitro by mononuclears cells of patient in allogeneic mixed lymphocyte culture (MLC) and subsequently co-cultured with recipient's skin. Histopathological changes found in patients' skin explants are evaluated according to standard Lerner classification for acute GvHD. In general, GvHD predictive results in SEA correlated with GvHd clinical outcome in 28 out of 41 tested patients (68%, p = 0.015). In a cohort of HLA identical sibling transplants GvHD predictive results correlated with clinical manifestation of acute GvHD only in 15 out of 28 patients on individual GvHD prophylaxis. GvHD prophylaxis in the form of cyclosporine A (CsA) combined with short-term methotrexate (MTX) reduced the risk of acute GvHD in 10 out of 14 transplanted patients (71%) meanwhile CsA alone prophylaxis only in 1 out of 5 patients (20%). In a cohort of unrelated pairs on CsA/MTX prophylaxis combined with horse anti-lymphocyte globuline (ALG) correlated the GvHD prediction with GvHD clinical outcome (100%, p = 0.003). In all patients transplanted with the grafts from their haploidentical relatives the occurrence of severe GvHD was predicted.Skin explant assay helps identify pretransplant patients at higher risk of severe acute GvHD. GvHD predictive results enable the transplantation team to individualise GvHD prophylaxis and to optimise selection of the donor.

sHLA molecules are the soluble forms of their membrane bound counterparts. sHLA class I. were recently reported to be a useful marker in the prediction of graft versus host reaction (GVHR) in adults. To confirm these presumptions in children we measured sHLA class I. serum levels in children after allogeneic bone marrow transplantation (BMT). We also investigated the levels of sHLA in the supernatants of mixed lymphocyte cultures (MLC) as possible predictors of GVHR prior to BMT.Group of 6 investigated children included 1 child with severe combined immunodeficiency, 3 children with acute lymphoblastic leukemia, 1 with severe combined immunodeficiency, 3 children with acute lymphoblastic leukemia, 1 with severe aplastic anemia and 1 with non Hodgkin lymphoma. The period of follow up varied from 15 days to 21 months according to the course of the disease. In the prediction of GVHR the levels of sHLA were measured in 5 children with acute leukemia in supernatants of MLC and the results were compared with the grade of GVHR classified according Seattle criteria. Soluble HLA class I. molecules were evaluated by ELISA. Rise of the levels of sHLA preceded 1-2 days the clinical signs of GVHR, however, it could not be distinguished from the occasional rise of a different cause. The levels of sHLA found in the supernatants of MLC showed individual results, which did not correspond to the level of cytokines in the same culture, or to the grade of GVHR observed. However, twice higher levels of sHLA in the culture of donor lymphocytes correlated with the lethal outcome of GVHR despite the fact that the donors were HLA identical siblings.The usefulness of sHLA levels as the predictors of GVHR has to be interpreted with great caution, but they can be used as a part of the mosaic composed of the clinical image and other laboratory results indicating GVHR. The predictive value of sHLA in supernatants of MLC is still to be evaluated.

The level of minimal residual disease is an important prognostic factor in childhood acute lymphoblastic leukaemia. The end of induction therapy is the most significant time-point for prediction of treatment outcome. Within a pilot study covered by the Paediatric Haematology Working Group in the Czech Republic 51 childhood patients were analysed at diagnosis of acute lymphoblastic leukaemia and at the end of induction using method based on detection of clonal rearrangements of immuno-receptor genes. The majority of tested patients (32/51, 63%) had a low or non-detectable levels of residual disease, a group of patients with the highest levels and thus the highest risk of relapse included 10% of patients (5/51). Within each of three risk groups one patient has relapsed so far. Therefore, the relapse rate in particular subgroups is 3% (1/32), 7% (1/14) and 20% (1/5) to date, respectively. The results are compared with these published by the BFM group (van Dongen et al., Lancet 1998). The pilot phase of a new BFM treatment protocols includes examination of residual disease for stratification of patients into the different risk groups.