The use of thalidomide in chronic refractory graft versus host disease.

BACKGROUND: Chronic graft versus host disease (GvHD) is a serious complication of allogenic bone marrow transplantation. As prednisone and ciclosporine A are not always effective in its treatment, we investigated the value of thalidomide. METHODS: We describe the results of thalidomide in 12 patients with chronic prednison/ciclosporin A refractory GvHD seen in our clinic since 1991. A case history is given as illustration. RESULTS: Four patients had a complete remission of chronic GvHD on thalidomide; five patients showed a partial response. Of these five patients, three died eventually of respectively ongoing GvHD, pneumonia and recurrent leukemia. There were no serious side effects, except for one patient who had to stop thalidomide because of polyneuropathy. CONCLUSIONS: It is worthwhile to give thalidomide in prednison/ciclosporin A refractory chronic GvHD. Probably thalidomide should be given earlier in the course of GvHD, this needs further study.

Flow cytometric analysis of consecutive lymph node samples from patients with Hodgkin's disease: reproducible within one biopsy?

In Hodgkin's disease DNA aneuploidy is not a prognostic factor. However, the prognostic significance of DNA content in Hodgkin's disease may be missed by either intratumor DNA heterogeneity or DNA analysis of limited samples. For flow cytometry usually one section of 40-60 microns is used for the analysis. In breast cancer this proved to be insufficient. In Hodgkin's disease no data are available. Therefore, we examined if analysis of more sections does increase the yield of aneuploidy. Archival, formalin-fixed, parafin embedded tissues were used. From 13 patients four sections of 50 microns could be analysed for DNA content. In 12 of 13 patients the results were consistent in all four sections of one patient case; seven diploid, four aneuploid and one multiploid. In one case ploidy status changed: two sections were diploid and two were aneuploid. The DNA-index of the aneuploid samples ranged from 0.75 to 1.38 and varied from 0.02 to 0.14 within one case. The S-phase fraction remained constant within all evaluable cases (sd: 0.5-1.5%), except for one (sd: 4.7%). In conclusion, in Hodgkin's disease the ploidy status of the first section can be regarded to represent the whole tissue sample. Therefore, the absence of prognostic value of ploidy status is not explained by sampling errors in tissues analysed.

Inhibition of poly(ADP-ribose) polymerase increases (+/-)-anti-benzo [a]pyrene diolepoxide-induced micronuclei formation and p53 accumulation in isolated human peripheral blood lymphocytes.

In response to DNA damage, in particular DNA strand breaks, the proposed roles for normal tumour suppressor protein p53 are to increase the period of time available for DNA repair prior to replication, or to direct damaged cells into programmed cell-death. Since treatment of mammalian cells with (+/-)-anti-benzo[a]pyrene diolepoxide [(+/-)-anti-BPDE] --a mixture of metabolites comprising the most reactive (+)-anti-enantiomer of the full environmental carcinogen benzo[a]pyrene--has been shown to result in induction of DNA repair processes and consequently in DNA strand break formation, the aim of the present study was to investigate whether p53 accumulation is induced in (+/-)-anti-BPDE-treated phytohaemagglutinin-stimulated human peripheral blood lymphocytes (PBLs). Both immunocytochemical and immunoblot analysis indicated that treatment of PBLs with (+/-)-anti-BPDE results in p53 accumulation. Optimal accumulation was observed at 2.5 microM, while no increase of p53 levels was observed at concentrations < 2.5 microM and > 10 microM. Further, (+/-)-anti-BPDE-induced p53 accumulation in PBLs was found to be time-dependent with accumulation up to 24 h after the onset of treatment. Treatment of PBLs with 2.5 microM of (+/-)-anti-BPDE and 1 mM of 3-aminobenzamide, an inhibitor of the DNA strand break-dependent enzyme poly(ADP-ribose) polymerase, resulted in increased p53 levels, in comparison to cells treated with (+/-)-anti-BPDE alone. This combination also potentiated the frequency of (+/-)-anti-BPDE-induced micronuclei. These findings suggest that (+/-)-anti-BPDE-induced DNA strand break formation is responsible for the observed p53 accumulation. It is unlikely that poly(ADP-ribose) polymer formation is a prerequisite in the process of p53 accumulation, as triggered by DNA strand-break inducing agents like (+/-)-anti-BPDE. It is hypothesized that p53-dependent pathways may be activated in phytohaemagglutinin-stimulated human peripheral blood lymphocytes exposed ex vivo to (+/-)-anti-BPDE.

P53 as a marker of the malignant cell in Hodgkin's disease.

BACKGROUND: The p53 gene has a tumor-suppressor function. The mutated gene encodes for a protein which has a longer half-life than the normal p53 protein. This enables the detection of the mutated p53 protein by immunohistochemistry. MATERIALS AND METHODS: In this study we examined 53 lymph nodes of patients with Hodgkin's disease for the presence of p53. The lymph nodes were stained with DO-1 and CM-1, two antibodies directed against the p53 protein. RESULTS: DO-1 weakly stained 2/14 samples positively, and CM-1 10/25. When preincubated with Target Unmasking Fluid, CM-1 stained 51/53 samples positively. Although, only Hodgkin and Reed-Sternberg cells stained positively, p53-negative Hodgkin and Reed-Sternberg cells were also seen in the same sample. CONCLUSION: Based on these results, we conclude that the p53 mutated protein is present in a high number of cases with Hodgkin's disease, which is suggestive for an important event in the pathophysiology of the disease. In addition, because of the absence of positive staining in the surrounding lymphocytes, these cells are unlikely to be part of the malignant clone.

Multidrug resistance mediated by P-glycoprotein in haematological malignancies.

The phenomenon that a tumour, resistant to a cytotoxic drug, is also resistant to a large number of other drugs used in cancer chemotherapy, is called multidrug resistance. A transmembrane protein, known as P-glycoprotein (P-gp), is involved in this resistance pattern. P-gp is able to pump large, lipophilic molecules out of the cell. 'Naturally occurring' drugs such as the anthracyclines and the Vinca alkaloids meet these criteria. To study the future clinical implications of multidrug resistance, we have gathered data in the literature on the presence of P-gp in haematological malignancies. At diagnosis 14-62% of all patients showed P-gp expression. Of previously treated patients 29-62% was positive for P-gp. A slight tendency to find a higher frequency of P-gp positivity in these previously treated patients was observed (so-called 'acquired resistance'). Early mutation and selection by the cytotoxic drug could account for the higher levels in treated patients. Chemotherapy itself could induce the expression of the P-gp pump. With the use of in vitro work various pharmacological agents have been found that can antagonize P-gp's function. Using these agents in clinical trials, some refractory patients showed a response to chemotherapy. We conclude that P-gp is probably just one of many causes of drug resistance in patients with haematological malignancies. Clinical results in some studies look promising, but many problems have still to be solved before common use.