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A quantitative evaluation of p16 INK4A overexpression together with its topographical localization in the epithelium of cervical biopsies from non-neoplastic lesions and cervical intraepithelial neoplasias (CIN 1, 2, and 3) was obtained by the development of an objective and sensitive immunohistochemical assay with chemiluminescent detection (CL IHC assay). The cervical biopsy samples were also checked for the presence of human papillomavirus nucleic acids. The quantitative evaluation of p16 INK4A expression was performed by combining 2 parameters: (1) intensity of the chemiluminescent-positive signal in the epithelium and (2) percentage of epithelium interested by the overexpression of p16 INK4A, to obtain a p16 INK4A expression score. A cut-off value was determined by using the receiver-operator characteristic analysis to distinguish between low-grade and high-grade CIN. Quantitative data showed that both p16 INK4A expression parameters increased with worsening grades of CIN and, when combined to obtain the p16 INK4A expression score, they showed a sharp discrimination among different lesions. The differences between the average p16 score of CIN1 versus CIN2 (0.57 versus 1.05), of CIN1 versus CIN3 (0.57 versus 1.31) and of CIN1 versus CIN2/3 (0.57 versus 1.20) were statistically significant. The quantitative evaluation of p16 INK4A expression by CL IHC assay could be therefore an interesting adjuvant method to distinguish different CIN grades and to predict the risk of progression of early CIN lesions. more...

Parvovirus B19 is a frequent contaminant of human blood and plasma derivatives and iatrogenic transmission of B19 infection has been shown to occur through the administration of contaminated products. Manufacturing procedures, generally used for removal or inactivation of enveloped viruses (HIV, HCV and HBV) are not always effective in the elimination of B19 virus. A certain risk of contamination remains for some plasma derivatives due to the high-titer viral load in the starting blood donations and the extreme heat resistance and small size of the virus. This review provides an update on the different approaches currently available to detect, remove or inactivate B19 virus in order to enhance the safety margins of plasma products. Nucleic acid amplification techniques are the methods of choice for the detection of viruses, due to their high specificity and sensitivity. NAT assays are beneficial tools for the identification of contaminated mini-pools or plasma pools and the quantification of B19 contamination. They may also be valuable for testing the removal of B19 virus during manufacturing: since the virus may not be completely inactivated or removed by chemical or physical treatments, residual B19 contamination should always be checked. Solvent-detergent treatments fail to destroy B19 capsids because of the absence of a lipid-envelope, and heat treatments (pasteurization and dry-heat methods) cannot guarantee a complete viral inactivation because of the variable heat sensitivity of the virus. more...