Comparison of Immunohistochemistry and DNA Sequencing for BRAF V600E Mutation Detection in Mandibular Ameloblastomas.

This study aimed to investigate the presence of BRAF V600E mutation in mandibular ameloblastoma by comparing the results of molecular detection and immunohistochemical analysis. A 128 cases of mandibular ameloblastoma and 30 cases of dentigerous cyst (control group) were selected for analysis. Detection of BRAF V600E mutation was performed with immunohistochemistry (IHC) and polymerase chain reaction techniques. Clinico-pathologic data were collected in order to investigate possible associations with the mutation. Of the 128 cases submitted to IHC, 81.2% (108 cases) showed positivity for anti-BRAF V600E antibody, whereas 24 were negative (18.8%). Molecular analysis of the BRAF V600E mutation by polymerase chain reaction was possible in 116 cases due to DNA quality. Of these cases, 96 were positive (82.8%) and 20 negative (17.2%). All cases of dentigerous cyst were negative for BRAF V600E mutation in both techniques. Considering the sequencing as a gold standard method, the receiver operating characteristics curve analysis showed sensitivity of 0.99 and specificity of 1 (area under the curve=0.995, standard error=0.006; P<0.001; 95% confidence interval=0.983 to 1). We also tested the agreement between the techniques by using the Cohen's κ coefficient, with κ being 0.97 (P<0.001). IHC is a reliable test for identifying the BRAF V600E mutation in ameloblastomas, presenting advantages such as being more frequently used in surgical pathology laboratories and requiring fewer critical steps for paraffin-embedded tissue compared with molecular biology techniques.

No detectable human herpesvirus-8 oral shedding in seronegative-healthy, immunocompetent individuals from non-endemic regions for Kaposi's sarcoma: A pilot study.

AIM: Saliva can play an important role in human herpesvirus-8 (HHV-8) transmission in endemic regions for Kaposi's sarcoma (KS). Little is known about HHV-8 oral shedding in immunocompetent individuals from non-endemic regions for KS. METHODS: We conducted a prospective study of HHV-8 salivary excretion among 59 healthy, immunocompetent individuals from São Paulo, Brazil, followed up weekly for 4 months, resulting in 16 saliva samples from each participant. Antibodies to HHV-8 latency-associated nuclear antigen (LANA) and lytic-phase antigens were investigated with immunofluorescence assays (IFA). HHV-8 DNA detection was performed using real-time polymerase chain reaction (PCR). RESULTS: All 59 individuals were seronegative to LANA and lytic antibodies. HHV-8 DNA was undetectable in saliva samples in 100% of the participants, totaling 944 samples and being consistently negative during the different periods of sampling, which lasted approximately 120 days. No sequences of HHV-8 DNA were detected in the saliva samples of healthy, immunocompetent adults by using real-time PCR, with the resulting data being consistent with IFA-based serological tests. CONCLUSIONS: Unlike other herpesviruses, HHV-8 is not excreted in the saliva of healthy individuals from non-endemic regions for KS.

Prospective study of human herpesvirus 8 oral shedding, viremia, and serological status among human immunodeficiency virus seropositive and seronegative individuals in Sao Paulo, Brazil.

Human herpesvirus 8 (HHV-8) is a gamma-herpesvirus and etiological agent of all forms of Kaposi sarcoma (KS). Saliva may play an important role in HHV-8 transmission in specific populations. Little is known about HHV-8 oral shedding pattern and the possible correlation with the HHV-8 serological profile and viremia. A prospective study was conducted of HHV-8 salivary excretion among human immunodeficiency virus HIV-seronegative (n = 47) and -seropositive (n = 44) homosexual men and HIV-seropositive women (n = 32) over a 6-month period with monthly HHV-8 serologies (immunofluorescence assays to identify antibodies to latent and lytic HHV-8 viral proteins, and a whole-virus HHV-8 enzyme-linked immunosorbent assay [ELISA]), monthly HHV-8 DNA serum/plasma detection, and daily self-collected oral rinses for HHV-8-DNA detection using real-time polymerase chain reaction. HHV-8 seropositivity was 51.1%, 63.6%, and 37.5%, in the three studied groups. There was no case of HHV-8 DNA detection in serum/plasma. Intermittent detection of oral HHV-8 DNA was observed during 5.1% (110/2,160) of visits among 28% (18/64) of HHV-8-seropositive individuals, all of whom were males and HHV-8 ELISA seropositive. In immunologically controlled populations of Brazil, HHV-8 oral shedding was limited to HHV-8-seropositive men, occurred infrequently and intermittently, and was not linked to HHV-8 viremia, suggesting a limited potential for oral or blood transmission.