Rabbit Anti-Human CD4 monoclonal antibody, clone TQ46

Objective We aimed to assess incidence and clearance of oral human papillomavirus (HPV) infection and the respective risk factors in HIV-infected and uninfected men who have sex with men (MSM). Methods Oral rinse and gargles were collected semiannually from 244 MSM (103, 42.2% HIV-infected). HPV-DNA testing was performed with the Linear Array HPV Genotyping test. A Markov model was used for estimation of incidence, clearance and risk factor analysis. Results Incidence rates for any HPV were 21.2 and 15.0x1000 person-months in HIV-infected and uninfected MSM, respectively. The respective figures for high-risk HPVs were 10.7 and 6.5x1000 person-months. The clearance rate was 4-12 times higher than the respective incidence rate. HIV-infected MSM with >95 lifetime oral sex partners showed increased incidence of any HPV (adjusted HR, aHR: 8.46, 95% CI 1.89 to 37.92). Condomless oral sex appeared the strongest predictor for incident infection by high-risk HPVs in this group (aHR: 13.40, 95% CI 2.55 to 70.53). Those aged >46 years (aHR: 0.30, 95% CI 0.12 to 0.74) and those with nadir CD4+ T count of <200 cells/mm(3) (aHR: 0.14, 95% CI 0.03 to 0.75) displayed a significantly reduced clearance of any and high-risk HPVs, respectively. HIV-uninfected MSM aged >46 years had increased risk of acquiring any HPV (aHR: 3.70, 95% CI 1.30 to 10.52) and high-risk HPV (aHR: 5.33, 95% CI 1.06 to 26.68). Any HPV clearance declined in those with more than six recent oral sex partners (aHR: 0.18, 95% CI 0.05 to 0.65). Conclusions Acquisition of oral HPV infection in MSM seems to occur rarely, whereas clearance seems to be a frequent event. Oral HPV natural history in these at-risk subjects is differently influenced by age and sex behaviour, depending on HIV status.

Regulation of melanogenesis by tyrosinase has now become an attractive approach for treatment of vitiligo but still the role of tyrosinase in the induction of depigmentation remains largely unexplored. This study was explored the role of tyrosinase in the induction of autoimmune depigmentation in C57BL/6 mice. Depigmentation was induced in C57BL/6 mice by tyrosinase immunization. Induced depigmentation was characterized by visual detection and was verified by histopathological analysis of lesional and non-lesinal skin biopsies. Moreover, induced depigmentation was re-validated by gene expression analysis of vitiligo-relevant genes by Taqman assays. Immunization of C57BL/6 mice by tyrosinase induces depigmentation on hairs as well as on skin. Immunoassays with Protein A-purified immune IgGs showed high titre antibodies against tyrosinase. Histopathological analysis showed that the total melanocytes were depleted from the basal layer of the epidermis and also from the dermis of depigmented lesions. The gene expression of vitiligo-relevant genes TYRP1, DCT, MLANA, MCIR, POMC, FOXJ2, CSNK1G3, SOX10, PMEL and KIT was significantly low in lesional skin as compared with non-lesional skin (p < .05). In contrast, the mRNA expression of CASP3 and NF kappa B1 was significantly high in lesional skin of depigmented mice as compared with non-lesional skin (p < .05). Furthermore, involvement of cellular immunity in depigmentation was confirmed by the reduction of CD4(+):CD8(+) lymphocytes ratio. In conclusion, this study shows that the autoimmune response against tyrosinase induces depigmentation in black C57BL/6 mice. The data obtained from the lesional and non-lesional skin biopsies showed the same features as were reported in human vitiligo patients.