Giovanna Flamini

Immunohistochemical analysis of p53 protein in transplant recipients with Kaposi's sarcoma

Purpose: Kaposis sarcoma (KS) is a proliferative process of suspected viral aetiology associated with immune deficiency. In transplanted patients, lesions regress on discontinuation of immunosuppressive therapy. The purpose of this work was to analyse the expression of thep53 oncosuppressor gene product, a proliferation regulator overexpressed in both malignant and non-malignant conditions, with the aim of better qualifying KS proliferation characteristics.Methods: We analysedp53 expression in a group of transplanted, cyclosporin A-treated, KS patients by immunohistochemistry, utilizing the DO-7 (with and without the antigen retrieval pretreatment), and the PAb 240 monoclonal anti-p53 antibodies, the latter of which is able to detect a mutated epitope, and evaluating staining intensity and localization, whether cytoplasmic or nuclear.Results: Seventy five percent of KS lesions from transplanted patients presented both nuclear and cytoplasmic positive p53 immunostaining with DO-7 antibody, thus demonstrating a presumably functional inactivation; one case also presented immunoreactivity with the PAb 240 antibody.Conclusions: On the basis of the results obtained and in the presence of lesion regression upon immunosuppression withdrawal, it may be concluded that KS in transplanted patients can be considered a non-malignant proliferative process, and that the cytoplasmic expression ofp53 may stand for a functional inactivation pattern.

Non-Hodgkin Lymphoma Associated with Double Monoclonal Immunoglobulin

We describe an unusual case displaying the features of double monoclonal gammapathy (IgM-kappa plus IgG-lambda) associated with non-Hodgkin lymphoma (NHL). In the last years monoclonal gammapathies have been sometimes found to be associated with NHLs; it is a very peculiar occurrence the association between a different class double monoclonal gammapathy and NHL, as the case reported in this paper.

P-170 Glycoprotein (MDR) and p53 Expression in Breast Cancer.

Abstract: An immunohistochemical comparative analysis of P‐170 glycoprotein and p53 was performed in 37 breast cancer patients who underwent curative resection without preoperative chemotherapy. The antibodies utilized were C‐219 and JSB‐1 for P‐gp and DO‐7 for p53. Positive cytoplasmic and membrance positivity for P‐gp was found in 22 (59.45%) of the 37 tumor specimens. In comparing tissue immunoreactivity by the specific antibodies, 15 (40.54%) samples showed immunostaining for C‐219, 12 (32.43%) for JSB‐1, and 5 (23%) for both. P‐gp expression was not statistically related with the clinicopathological variables analyzed, that is, age, TNM stage, histologic type, lymph node involvement, tumor diameter, and hormone receptor status. p53 overexpression was observed in 22 (59.45%) of the 37 tumor samples analyzed. There was a significant correlation between p53 overexpression and P‐gp positive immunostaining (p = .007). p53 was also significantly correlated with TNM stage (p < .05) and lymph node involvement (p < .02). Our results demonstrated that the three distinct patterns of reactivity with the two antibodies result from the combined expression of each of the three P‐gp isoforms. An immunohistochemical analysis with different antibodies may be used to determine and correlate the expression pattern of P‐gp isoforms with response to chemotherapy.