Virological characteristics of cervical cancers carrying pure episomal form of HPV16 genome.

OBJECTIVE: Many studies on integration have reported conflicting results regarding the role of HPV integration in cervical cancer. We hypothesized that high viral load and disruption of E2 gene associated with integration of HPV were not the only pathway leading to cancer development. METHODS: This study analysed the viral load and integration status of HPV16, measured the HPV16 E6/E7 mRNA transcript levels, delineated the E2 and LCR sequence variation, and determined the methylation status of two E2 binding sites. RESULTS: The results showed that viral load was not associated with the physical status of HPV genome. Levels of the three E6/E7 mRNA transcripts in invasive cervical cancers containing purely episomal viral genome were found to be similar to those containing integrated viral genome, suggesting that cancers containing episomal viral genome were also mediated by an up-regulated E6/E7 mRNA expression, and more importantly, did not depend on integration and disruption of the E2 gene. CONCLUSIONS: The alternative mechanism that up-regulated the expression of E6 and E7 in invasive cancers harbouring episomal viral genome was likely to be a consequence of methylation of the two E2 binding sites located at the promoter region of HPV16. These observations are in line with the hypothesis that HPV integration was not the only mechanism leading to the development of cervical cancer.

Influenza B lineage circulation and hospitalization rates in a subtropical city, Hong Kong, 2000-2010.

BACKGROUND: A need for quadrivalent vaccines to cover both lineages of influenza B has been raised. Information on the circulation status of influenza B lineages and the associated hospitalization rates is important to assist evidence-based decision making. This retrospective study revealed the situation in a subtropical city over a 10-year period. METHODS: Sequences of 268 influenza B isolates were analyzed to identify the circulating pool of virus lineages for each year. Hospital records and population census data were used to estimate annual age-specific hospitalization rates. RESULTS: Cocirculation with 2 influenza B lineages was found in 9 of the 10 years. Only in 6 of the 10 years had the vaccine strain successfully matched with the lineage that was found in >50% of the circulating pool. Six years were predominated by one lineage (occupying >80% of the circulating pool), and these years had higher (average, 1.4-fold) hospitalization rates. Matching between vaccine and circulating lineage was achieved only in 2 of the 6 "predominated years." The Yamagata lineage accounted for most (5/6) of the predominated years. Overall, 24% of influenza admissions were due to influenza B, and influenza B contributed to a higher proportion (41.9%) among children and young teenagers (5-14 years old). CONCLUSIONS: Cocirculation with 2 influenza B lineages is common in the subtropical region. To predict the next predominant lineage proves to be difficult. Influenza B accounts for a substantial fraction of influenza-associated hospitalizations, especially among children and young teenagers. Quadrivalent vaccines may improve the effectiveness of influenza vaccination programs.

Antagonist-mediated down-regulation of Toll-like receptors increases the prevalence of human papillomavirus infection in systemic lupus erythematosus.

INTRODUCTION: Prevalence of an abnormal Papanicolaou smear was significantly increased in lupus patients in cross-sectional studies, associated with a higher prevalence of high-risk human papillomavirus (HPV) infection. The nucleic acid-specific Toll-like receptors (TLRs) locate at the endolysosomal compartments and trigger the induction of cytokines for the innate immune response. This study evaluated whether abnormal host innate immune response in lupus patients may enhance HPV persistence. METHODS: Protein levels of TLRs 3, 7, 8 and 9 in cervical epithelial cells of lupus patients and controls with or without HPV infection were assessed using flow cytometry. Characteristics associated with the differential expression of TLRs in systemic lupus erythematosus (SLE) were elucidated. The effect and interferon-stimulated genes (ISGs) (ISG15 and Mx-1) gene expressions were then measured in oncogenic HeLa (HPV18), CaSki (HPV) and C33A (HPV negative) cell lines using flow cytometry and quantitative real-time PCR. Ex vivo productions of cytokines and interferon-gamma (IFN-γ) upon TLR ligands stimulations were subsequently measured using cytometric bead array and ELISA. RESULTS: For subjects with HPV infection, levels of TLR3 and TLR7 were significantly lower in lupus patients compared with controls. Significantly decreased TLRs 7, 8 and 9 levels were observed in HPV-negative SLE compared to healthy controls. For SLE with and without HPV infection, TLR7 and 9 levels were significantly lower in infected SLE than those in HPV-negative patients. Independent explanatory variables associated with down-regulation of TLR7 level included HPV infection and a higher cumulative dose of prednisolone; while a higher cumulative dose of hydroxychloroquine and HPV infection were associated with down-regulation of TLR9 level. In cervical cell lines, TLRs 3, 7, 8, 9 protein levels and antiviral ISG15 and Mx-1 gene expressions were inhibited in two oncogenic HPV types. Functional data showed that the induction of pro-inflammatory cytokines by TLR ligands (R837, ssRNA and ODN2395) was greatly impaired in CaSki and HeLa than C33A cells. CONCLUSIONS: In conclusion, prednisolone and TLR antagonist (hydroxychloroquine) may down-regulate protein levels of TLR7 and TLR9 in lupus patients, thereby decreasing the innate immune response against HPV infection. Upon infection, HPV further down-regulate TLR7 and 9 levels for viral persistence. Furthermore, reduction of nucleic acid-sensing TLRs 7, 8 and 9 in carcinogenic HPVs ensures that the expression of inducible pro-inflammatory cytokines is minimized to prevent the expression of antiviral ISGs (ISG15 and Mx-1) on a biologically relevant antiviral response.

Identification of human papillomavirus type 58 lineages and the distribution worldwide.

BACKGROUND: Human papillomavirus type 58 (HPV-58) accounts for a much higher proportion of cervical cancers in East Asia than other types. A classification system of HPV-58, which is essential for molecular epidemiological study, is lacking. METHODS AND RESULTS: This study analyzed the sequences of 401 isolates collected from 15 countries and cities. The 268 unique concatenated E6-E7-E2-E5-L1-LCR sequences that comprised 57% of the whole HPV-58 genome showed 4 distinct clusters. L1 and LCR produced tree topologies that best resembled the concatenated sequences and thus are the most appropriate surrogate regions for lineage classification. Moreover, short fragments from L1 (nucleotides 6014-6539) and LCR (nucleotides 7257-7429 and 7540-52) were found to contain sequence signatures informative for lineage identification. Lineage A was the most prevalent lineage across all regions. Lineage C was more frequent in Africa than elsewhere, whereas lineage D was more prevalent in Africa than in Asia. Among lineage A variants, sublineage A2 dominated in Africa, the Americas, and Europe, but not in Asia. Sublineage A1, which represents the prototype that originated from a patient with cancer, was rare worldwide except in Asia. CONCLUSIONS: HPV-58 can be classified into 4 lineages that show some degree of ethnogeographic predilection in distribution. The evolutionary, epidemiological, and pathological characteristics of these lineages warrant further study.

T-cell response to human papillomavirus type 52 L1, E6, and E7 peptides in women with transient infection, cervical intraepithelial neoplasia, and invasive cancer.

The E6 and E7 proteins encoded by human papillomaviruses (HPV) are prime targets for therapeutic vaccine development. Ninety-five women with HPV 52 infection (33 transient infections, 17 cervical intraepithelial neoplasia grade II, 15 cervical intraepithelial neoplasia grade III, and 30 invasive cervical cancers) were examined for T-cell responses using interferon-γ enzyme-linked immunospot (IFN-γ ELISPOT) assay. Of the 29 peptides (13 L1, 10 E6, and 6 E7) screened positive by an in vitro peptide-binding assay, 14 were positive by the IFN-γ ELISPOT assay. Positive epitopes for HLA A11 were located at amino acid positions 103-111, 332-340, 342-350, and 373-381 of the L1 protein; and at 27-35 and 86-94 of the E6 protein; and at 1-9 and 27-35 of the E7 protein. A24-specific epitopes included 60-68 and 98-106 of the L1 protein, 42-50 and 59-67 of the E6 protein, and 24-32 of the E7 protein. Only one epitope (99-107) of the E6 protein showed positive responses for HLA A2 subjects. Overall, T-cell responses against L1 were observed mainly in subjects who had cleared infection; whereas responses against E6 and E7 were confined mainly to subjects who had developed cervical neoplasia. The proportion of subjects showing detectable T-cell responses was low across all grades of cervical neoplasia suggesting that immune evasion mechanisms had set on early in the course of disease progression. This study provides the first set of T-cell epitopes mapped for HPV 52, which can be considered for further evaluation as targets for immunotherapy.

Clinical and virological course of infection with haemagglutinin D222G mutant strain of 2009 pandemic influenza A (H1N1) virus.

BACKGROUND: Aspartic acid to glycine substitution (D222G) of haemagglutinin subunit (HA1) was associated with adverse outcomes in 2009 pandemic influenza A (H1N1) infections. OBJECTIVES: To characterize the virological profile and antiviral response of patients infected with the HA1 D222G mutant. STUDY DESIGN: Sixty-three adults admitted for pandemic influenza in Hong Kong were tested for D222G mutation by direct sequencing. Nasopharyngeal viral concentration on presentation was measured by real-time PCR to evaluate shedding from the upper respiratory tract. Serial upper and lower respiratory tract specimens were monitored to determine preferential tropism and document virological response to treatment. RESULTS: The frequency of D222G infection was 17.4% among cases with severe pneumonia, and 26.7% among cases requiring intensive care. Altogether, four sporadic D222G cases spread across the first and second waves in Hong Kong were detected. A significant association between D222G infection with severe pneumonia (100% vs. 32.2%, P=0.015) and intensive care admission (100% vs. 18.6%, P=0.002) was observed. D222G was associated with lower concentrations of virus in the upper respiratory tract compared to wildtype, but persisted in the lower respiratory tract at high concentrations, despite clearance from the upper respiratory tract following antiviral treatment. CONCLUSIONS: These observations suggest that D222G can arise de novo, sheds less virus from the upper respiratory tract and may be less transmissible, but more pneumotropic and more resistant to antiviral treatment. D222G is associated with a higher chance of developing critical disease. Lower respiratory tract specimen is needed for a reliable detection of this mutant.

Risk factors for squamous intraepithelial lesions in systemic lupus erythematosus: a prospective cohort study.

OBJECTIVE: We undertook a prospective cohort study to ascertain the risk factors for the development of squamous intraepithelial lesions (SIL) in patients with systemic lupus erythematosus (SLE). METHODS: One hundred thirty-seven SLE patients with a normal Papanicolaou (Pap) smear at baseline were evaluated at 6-month intervals for up to 3 years. At each visit, a Pap smear, human papillomavirus (HPV) DNA test, and clinical assessment were performed. RESULTS: Among the 137 patients, there were 12 incident cases (8.8%) of SIL over a median followup duration of 30.7 months (interquartile range 25.5-31.7). Among the 30 patients with HPV infection detectable by DNA testing at baseline, 9 (30%) developed SIL. The independent risk factors for the incident SIL in this group of SLE patients included the use of cyclophosphamide (CYC) ever (odds ratio [OR] 5.6, 95% confidence interval [95% CI] 1.1-29.3; P=0.041) and persistent high-risk HPV infection (OR 26.9, 95% CI 3.2-222.3; P=0.002). The use of baseline HPV testing has a higher sensitivity than abnormal cytology (defined as atypical squamous cells of undetermined significance; 47.7% versus 33.3%) in predicting the development of SIL. CONCLUSION: Independent risk factors associated with the development of SIL in SLE patients included persistent high-risk HPV infection and the use of CYC. Low-risk patients who receive negative test results on both cervical cytology screening and HPV DNA testing may not need to be rescreened within 3 years.

T-cell response to human papillomavirus type 58 L1, E6, And E7 peptides in women with cleared infection, cervical intraepithelial neoplasia, or invasive cancer.

Human papillomavirus type 58 (HPV-58) exists in a relatively high prevalence in certain parts of the world, including East Asia. This study examined the T-cell response to HPV-58 L1, E6, and E7 peptides among women with cleared infection, cervical intraepithelial neoplasia grade 2 (CIN2) or CIN3, or invasive cervical cancer (ICC). Peptides found to be reactive in the in vitro peptide binding assay or mouse-stimulating study were tested with a gamma interferon (IFN-gamma) enzyme-linked immunospot (ELISPOT) assay to detect peptide-specific responses from the peripheral blood mononuclear cells (PBMC) collected from 91 HPV-58-infected women (32 with cleared infection, 16 CIN2, 15 CIN3, and 28 ICC). Four HLA-A11-restricted HPV-58 L1 peptides, located at amino acid positions 296 to 304, 327 to 335, 101 to 109, and 469 to 477, showed positive IFN-gamma ELISPOT results and were mainly from women with cleared infection. Two HLA-A11-restricted E6 peptides (amino acid positions 64 to 72 and 94 to 102) and three HLA-A11-restricted E7 peptides (amino acid positions 78 to 86, 74 to 82, and 88 to 96) showed a positive response. A response to E6 and E7 peptides was mainly observed from subjects with CIN2 or above. One HLA-A2-restricted E6 peptide, located at amino acid position 99 to 107, elicited a positive response in two CIN2 subjects. One HLA-A24-restricted L1 peptide, located at amino acid position 468 to 476, also elicited a positive response in two CIN2 subjects. In summary, this study has identified a few immunogenic epitopes for HPV-58 E6 and E7 proteins. It is worthwhile to further investigate whether responses to these epitopes have a role in clearing an established cervical lesion.

Development and comparison of molecular assays for the rapid detection of the pandemic influenza A (H1N1) 2009 virus.

Human infection with the novel pandemic influenza A (H1N1) virus was first identified in April 2009. Two months later, the World Health Organization (WHO) had raised the pandemic level to phase 6. Rapid case identification is essential for prompt patient management and public health actions. This study developed real-time and conventional reverse transcription-polymerase chain reaction (rRT-PCR and cRT-PCR) assays for pandemic H1N1 detection, and compared their sensitivities with protocols developed by WHO reference centres. Altogether, three rRT-PCR and one cRT-PCR targeting the matrix gene for universal detection of influenza A; three rRT-PCR, one cRT-PCR targeting the hemagglutinin (HA) gene for specific detection of pandemic H1N1; and one multiplex cRT-PCR for differentiating co-circulating seasonal H1N1, H3N2, and pandemic H1N1 were examined. The lower detection limit ranged from 1.252 to 125.2 copy equivalents. In general, rRT-PCR assays were more sensitive than cRT-PCR assays. All assays showed 100% sensitivity for "optimal" specimens (nasopharyngeal samples collected within 4 days after illness onset). For the other 36 samples, cRT-PCR assays were less sensitive except that the new Protocol I-cRT-pdmH1 still retained 100% sensitivity. The new Protocol F-rRT-PCR-pdmH1 was the only pandemic virus-specific rRT-PCR assay with 100% sensitivity across all specimen categories. In conclusion, rRT-PCR assays are 10-fold more sensitive than cRT-PCR assays. The newly developed cRT-PCR assay targeting the HA gene allows rapid, specific, and sensitive screening of this novel agent, which can serve as an alternative for laboratories where a real-time PCR machine is not available.

Distribution of human papillomavirus type 58 variants in progression of cervical dysplasia in Korean women.

This cross-sectional study examined the distribution of HPV 58 sequence variation in Korean women for the first time. Among 1,750 Korean women, 53 women were positive for HPV 58 single infection, of whom 26 were without disease, 20 were with cervical intraepithelial neoplasia (CIN) 1, and 7 with CIN 2 or 3. Altogether, 36 different nucleotide sequence variations were identified with the L1, 20 within E2, 5 within E6, and 10 within E7. Further studies on variants of oncogenic HPVs are necessary, particularly for the purpose of developing more predictive HPV detection methods.

Analysis of human papillomavirus type 18 load and integration status from low-grade cervical lesion to invasive cervical cancer.

The clinical value of viral load and integration testing for human papillomavirus (HPV) remains unclear. Data on HPV type 18 (HPV18) is limited. We examined the HPV18 viral load and integration status of 78 women with normal cervix or neoplasia. While the crude viral load appeared to increase with lesion severity, the association was not significant after normalization with sample cellularity. Unlike reports for HPV16, the amino-terminal 1 region of HPV18 E2 was most frequently (71.0%) disrupted, representing the best marker for integration. A substantial proportion (57.1%) of invasive cancers harbored only the episomal genome, thus jeopardizing the clinical value of integration testing. A large proportion (41.7%) of normal/low-grade lesions showed viral integration, suggesting that integration of HPV18 starts early and is unlikely to be a sole determinant for progression. Interpretation of viral load should take into account the form of HPV infection as single infections had significantly higher viral loads than coinfections (P = 0.046). More data generated from routinely collected samples are warranted to verify the clinical value of viral load and integration testing. Viral load quantitation for HPV18 is premature for clinical use at this stage.

Distribution of human papillomavirus types in anogenital warts of men.

BACKGROUND: A wide spectrum of human papillomavirus (HPV) types can infect the male genitalia. An HPV vaccine covering HPV6 and 11 is now available. Detailed data on the distribution of these two types in anogenital warts is needed to assess the potential benefits of the vaccine. STUDY DESIGN: Anogenital wart specimens collected from 130 Chinese men were examined for HPV-type distribution by a method that covers a broad spectrum of high- and low-risk HPVs, and able to reveal multiple types from a single specimen. RESULTS: Forty-four (33.8%) of the 130 specimens had a coinfection with multiple HPV types. In 63.1% of cases, only HPV6 and/or HPV11 were/was found. In 26.2% of cases, HPV6 and/or HPV11 were/was found together with one or more other HPV types. In 10.8% of specimens, only non-6/11 HPV types were found. HPV16 and/or 18 were/was found in 12 (9.2%) specimens, with majority (8/12, 66.7%) of which existed as coinfections with HPV6/11. Other HPV types found included HPV39, 51, 52, 55, 59, 61, 62, 68, 58, 72, 81, 83, 84 and CP6108. CONCLUSIONS: A substantial proportion of HPV6/11-positive male anogenital warts are coinfected with other HPV types. The efficacy of HPV6/11 vaccine for preventing these lesions needs to be defined before the benefits of vaccinating men can be precisely assessed.

Clearance of dengue virus in the plasma-derived therapeutic proteins.

BACKGROUND: Viral safety is of paramount importance for human plasma-derived therapeutic proteins. Recent reports of blood-associated transmission and continuous regional outbreaks of dengue fever have prompted a validation of clearance of dengue virus in the manufacture processes of the plasma-derived products. STUDY DESIGN AND METHODS: A high titer of cultured dengue virus serotype 2 was spiked into process samples before individual steps of albumin and immunoglobulin manufacture processes, including cold ethanol precipitation, cation-exchange chromatography, pasteurization, solvent/detergent treatment, and virus filtration. Clearance of dengue virus was quantified with TCID(50) assays in the culture of Vero E6 cells and, when appropriate, real-time polymerase chain reaction (RT-PCR) assays. RESULTS: The individual process steps were all effective in the inactivation and/or removal of dengue virus, and the data obtained clearly demonstrate that the risk of dengue virus transmission was reduced cumulatively by at least 10.12 and at least 14.24 log in the albumin and immunoglobulin manufacture processes, respectively. CONCLUSION: The dedicated viral inactivation and/or removal approaches currently implemented in the manufacture of plasma-derived products provide a good safety margin with regard to the transmission of dengue virus.

Increase of integration events and infection loads of human papillomavirus type 52 with lesion severity from low-grade cervical lesion to invasive cancer.

Infection load and the integration of human papillomaviruses (HPV) have been implicated as determinants for oncogenesis, but whether variation among different HPV types exists remains unclear. We investigated 91 women infected with HPV type 52 (HPV-52), a type that is rare worldwide but common in East Asia. The median viral load increased with the severity of the lesion (248 copies/cell equivalent for normal/cervical intraepithelial neoplasia [CIN] grade 1, 402 copies/cell equivalent for CIN 2, 523 copies/cell equivalent for CIN 3, and 1,435 copies/cell equivalent for invasive cancer). The proportion of specimens with integration increased significantly with the severity of the lesion (P < 0.001). The viral load was associated with the physical status of the viral genome, with higher levels for the pure episomal form (P = 0.001). Infection status should be considered when interpreting viral load data for HPV-52, as single infections with this HPV type were found to have marginally higher viral loads than coinfections (P = 0.051). All except one sample had E2 disruption restricted to only a part of the gene. Integration is a critical step in HPV-52-induced carcinogenesis. The profile of E2 disruption was different from that described for HPV-16, with the amino-terminal region being most frequently involved. Selecting the appropriate E2 region for amplification is critical in studying the integration of HPV-52. In summary, the HPV-52 viral load and the integrated proportion increased with the severity of the cervical lesions but had a different pattern than that of HPV-16.

Profile of viral load, integration, and E2 gene disruption of HPV58 in normal cervix and cervical neoplasia.

The clinical utility of viral-load and integration status of human papillomavirus (HPV) infection remains uncertain. We examined 75 women infected with HPV58, a worldwide rare type found to be prevalent in cervical cancers in eastern Asia. Viral load was significantly higher for cervical intraepithelial neoplasia (CIN) 1/2, but those for a normal control group and for CIN 3 or cancer overlapped substantially. A pure integrated genome was found for all lesion grades, giving a poor positive predictive value (23.1%) for cancer. The pure episomal form's negative predictive value for cancer was only 76.3%. Mixed patterns of E2 gene disruption were common and often involved the amino-terminal and hinge regions. Disruption of the whole E2 gene was rare and was restricted to high-grade lesions. The HPV58 variant E67-HK-2 was more likely to exist in the pure episomal form. Routinely collected cervical samples contain a heterogeneous population of viruses, hampering the application of viral load and integration testing in clinical settings.

Dose-by-dose virological and hematological responses to intravenous immunoglobulin in an immunocompromised patient with persistent parvovirus B19 infection.

A 42-year-old male with stage IV mantle cell lymphoma received chemotherapy and autologous peripheral blood stem cell transplantation. He developed pancytopaenia, and bone marrow examination indicated a parvovirus B19 (PVB 19)-induced red cell aplasia, confirmed by virological tests. Multiple doses of intravenous immunoglobulin (IVIG) were given over the following months, with blood samples being taken after each dose for quantitative PVB 19 DNA and hematological testing to assess the response. Each dose of IVIG produced a 1-3 log(10) drop in PVB 19 DNA levels. Eventually, after the fifth dose of IVIG, the PVB 19 DNA was reduced to <10 copies/ml serum, with a gradual improvement in his hematological parameters. This report demonstrates how close monitoring of the virological and hematological response to IVIG therapy for persistent PVB 19 infection in an immunocompromised patient can optimize the usage of this relatively expensive, and sometimes scarce intervention.

Association between HLA-DRB1 polymorphism, high-risk HPV infection and cervical neoplasia in southern Chinese.

Multiple determinants are involved in the progression of human papillomavirus (HPV)-infected cervical lesion to invasive cancer. Human leukocyte antigen (HLA) polymorphism seems to play a role. This study examined the association between HLA-DRB1 polymorphism, high-risk HPV infection, and the development of cervical neoplasia in southern Chinese. Three hundred and seventy women with cervical neoplasia (43 cervical intraepithelial neoplasia grade II, 154 grade III, and 173 invasive cancers) and 323 controls were recruited for HLA-DRB1 typing by a sequence-based approach. Cervical specimens were collected for HPV detection by a consensus primer-based polymerase chain reaction, and with the type of HPV identified by hybridization with type-specific oligonucleotide probes. A protective effect of HLA-DRB1*12 for cervical neoplasia was observed, and with stronger associations when subgroup analyses were carried out for patients infected with HPV16 and HPV58. The protective effect of HLA-DRB1*13 that had been reported from other populations was not observed. The data obtained in this study showed that HLA-DRB1*03 conferred a higher risk for HPV18-infected, but not for HPV16-, HPV52-, or HPV58-infected cervical lesions. Although, HPV52 was reported as uncommon worldwide, it was found to be the second most prevalent type in the southern Chinese population. However, no additional risk association was observed when subgroup analyses were performed for HPV52-infected patients. The current study shows that, among southern Chinese, the outcome of HPV-infected cervical lesions is associated with HLA-DRB1 polymorphism. These associations often vary with the type of HPV infection.

HLA-DQB1 polymorphisms and risk for cervical cancer: a case-control study in a southern Chinese population.

OBJECTIVES AND METHODS: HLA II DQB1 polymorphisms have been shown to associate with cervical cancer risk, but results varied among different populations. In this study, the HLA DQB1 alleles among 221 southern Chinese women with cervical intraepithelial neoplasia grade III (CIN III)/invasive cervical carcinoma (ICC) were compared to 191 controls. RESULTS: The frequency of DQB1*03 was significantly lower among ICC overall as compared to controls (65.4% vs. 79.1%, odds ratio [95% confidence interval]: 0.50 [0.28-0.88], corrected p-value: 0.04). The protective association of DQB1*03 remained significant for human papillomavirus (HPV) 16-positive ICC, but not for HPV16-negative cases. This is in contrast to studies on European populations where DQB1*03 was associated with an increased risk for ICC. In the current study, 70.1% of the HPV16 isolates were Asian variants, and 28.0% were European variants. However, no significant association between HPV16 variant and DQB1*03 distribution was observed. HPV52 and HPV58 were found respectively in 16.3% and 10.0% of CIN III/ICC, which were higher compared to that of Europe and North America. Further analyses revealed a positive risk association between DQB1*06 and HPV58-positive CIN III/ICC (3.68 [1.37-9.92], corrected p-value: 0.012). CONCLUSION: The host genetics and the distribution of HPV types/variants may account for the observed differences among southern Chinese and other populations.

Characterizing 56 complete SARS-CoV S-gene sequences from Hong Kong.

BACKGROUND: The spike glycoprotein (S) gene of the severe acute respiratory syndrome-associated coronavirus (SARS-CoV) has been useful in analyzing the molecular epidemiology of the 2003 SARS outbreaks. OBJECTIVES: To characterize complete SARS-CoV S-gene sequences from Hong Kong. STUDY DESIGN: Fifty-six SARS-CoV S-gene sequences, obtained from patients who presented with SARS to the Prince of Wales Hospital during March-May 2003, were analysed using a maximum likelihood (ML) approach, together with 138 other (both human and animal) S-gene sequences downloaded from GenBank. RESULTS: The maximum-likelihood (ML) trees showed little evolution occurring within these 56 sequences. Analysis with the other sequences, showed three distinct SARS clusters, closely correlated to previously defined early, middle and late phases of the 2003 international SARS outbreaks. In addition, two new single nucleotide variations (SNVs), T21615A and T21901A, were discovered, not previously reported elsewhere. CONCLUSIONS: The ML approach to the reconstruction of tree phylogenies is known to be superior to the more popular, less computationally and time-demanding neighbour-joining (NJ) approach. The ML analysis in this study confirms the previously reported SARS epidemiology analysed mostly using the NJ approach. The two new SNVs reported here are most likely due to the tissue-culture passaging of the clinical samples.

Viral load, E2 gene disruption status, and lineage of human papillomavirus type 16 infection in cervical neoplasia.

The clinical utility of human papillomavirus (HPV) load and integration status remains unclear. We applied refined methods to delineate the viral load, integration status, and lineage of 104 women with HPV-16 monotype infection, including 19 with normal cervices, 9 with histologically proven cervical intraepithelial neoplasia (CIN) 1, 24 with CIN 2, 27 with CIN 3, and 25 with squamous cell carcinoma (SCC). Higher crude viral load, as determined by real-time polymerase chain reaction (PCR) targeting the E7 gene, was observed for SCC but became insignificant after normalization for cell content. Integration was located and quantified by real-time PCRs targeting, respectively, the carboxyl, amino, and hinge domains of the E2 gene. Pure episomal, integrated, and mixed forms were observed in all disease groups. Most E2 gene disruptions involved the amino-terminal, but sparing the hinge region that has been frequently used as a surrogate marker of integration. Large-fragment disruption involving all 3 E2 regions was observed only in the CIN 3 and SCC groups. Altogether, 33.3% of the CIN 3 group and 28.0% of the SCC group harbored pure episomal genomes. The Asian lineage was associated with a higher risk for CIN 3/SCC than the European lineage, and 6 of the 7 large-fragment E2 disruptions were from Asian lineage. The link between viral lineage, integration pattern, and oncogenesis deserves further study.