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p21WAF1 (wild-type p53-activated fragment 1) is involved in the control of mammalian cell cycle through the binding and inhibition of cyclin-dependent kinases (Cdk). Because the product of WAF1 gene is a potent downstream effector of the p53 tumor-suppressor gene function, its pattern of cellular expression might correlate with nuclear accumulation of p53-encoded protein and/or p53 gene mutations occurring in malignant lymphomas. To investigate this issue, we analyzed immunohistochemically the expression of p53 and p21WAF1 proteins in tissue involved by non-Hodgkin's lymphomas (NHLs;253 cases) of various histologic types. In a proportion of them (80 cases), we also investigated the possible presence of p53 gene mutations using single- strand conformation polymorphism analysis and direct DNA sequencing. The absence of both p21WAF1 and p53 proteins was observed in 147 of 217 cases (67.7%) among CD30-NHL and in only 8 of 36 (22.2%) CD30+cases, which were mostly anaplastic large-cell lymphomas. A consistent number (> 10%) of p21WAF1-expressing cells was shown in 48 of 253 (18.9%) NHL cases, with a higher incidence in CD30+cases (25/36 [69.4%]), which mostly (21/36) coexpressed p53. These latter cases were characterized by a germline configuration of the p53 gene. In 50 of 253 NHL samples (19.7%), 47 of which (21.6%) belong to the CD30-group, neoplastic cells were p53+/p21-. In all of these cases, the p53+cells accounted for more than 50% of neoplastic cells, up to 100%. Point mutations of p53 gene were solely observed in all investigated cases with this latter phenotype. Our findings strongly suggest that the combined immunohistochemical evaluation of p53 and p21WAF1 is a valuable means of assessing the functional status of the p53 tumor-suppressor gene product in NHL with potential application in the monitorage and prognostication of individual cases.

Summary: One hundred and twenty-four sera, from patients with various leukemic B-cell chronic lymphoproliferative diseases were investigated at diagnosis by ELISA for their soluble CD23 content. Immunophenotyping was carried out in all patients, and in a selected subset the mean number of membrane-bound CD23 molecules per cell was also investigated. Seventy-three patients had typical B chronic lymphocytic leukenia, 41 leukemic B-cell disorders with atypical morphological and/or immunophenotypic features, 5 had low-grade follicular cell lymphoma in the leukemic phase, and 5 had splenic lymphoma with villous lymphocytes Soluble CD23 levels were significantly higher than in normal sera (meanSD: typical B chronic lymphocytic leukemia 3,6504,654 U/ml, atypical B chronic lymphocytic leukemia 3,4404,671 U/ml, follicular cell lymphoma 3,2001,511 U/ml, splenic lymphoma with villous lymphocytes 8,2367,294 U/ml, controls 137128 U/ml;P<0.001). More advanced Rai's stages were related to higher soluble CD23 levels (P<0.01), both in typical and atypical B chronic lymphocytic leukemias, the highest levels and the best correlation with the absolute number of circulating CD19+ cells (r=0.50) being observed in the typical form. The number of membrane-bound CD23 molecules per cell was significantly higher in typical than in atypical B chronic lymphocytic leukemias (mean number 156,72794,668 vs. 12,01010,643,P<0.001). Our data suggest that soluble CD23 levels correlate with the clinical and biological features of leukemic B-cell lymphoproliferative disorders.

Summary: Advances in the immunological identification of primitive haematopoietic cells have led to the development of various techniques for their characterisation and purification. The expression of the CD34 antigen by the stem cell compartment has been exploited for these purposes. Separation systems capable of isolating CD34+ cells on a large scale are finding use in the clinic. Areas of interest overlap for both researchers and clinicians, and efforts to mobilise, characterise, purify and transplant these cells continue. Different CD34 purification systems are reviewed, focusing on their possible applications in different research fields. Clinical results of CD34+ selection and the possible future applications of this technology in the clinic are also reported.

Summary: Previous reports have suggested soluble intercellular adhesion molecule-1 as a marker of disease activity in Hodgkin's disease. In the present study we investigated serum levels of intercellular adhesion molecule-1 at diagnosis in 104 patients with Hodgkin's disease and in 77 of these patients following the achievement of complete remission (within 12 months of diagnosis). Mean serum levels at diagnosis were significantly higher in patients than in controls (P<0.0001) and were related to advanced stages of disease (P=<0.0001) presence of “B” symptoms (P<0.0001), abnormality of laboratory indexes (P<0.0001), erythrocyte, sedimentation rate values (r=0.41,P<0.0001) and serum levels of soluble interleukin-2 receptor α chain (r=0.51,P<0.0001). Mean values in complete remission were significantly lower than at diagnosis (P=0.003). Lower mean values at diagnosis were detected in 30 patients with advanced disease who attained complete remission, compared with 6 patients who failed to attain complete remission with standard treatment. We conclude that in Hodgkin's disease, high serum levels of soluble intercellular adhesion molecule-1 are detectable at presentation and strictly correlate with some clinical features. Response to treatment is paralleled by reduced serum levels. Larger prospective studies are needed to evaluate the possible prognostic significance of serum levels of soluble intercellular adhesion molecule-1 at diagnosis.