Assessment of Disease Burden and Immunization Rates for Vaccine-Preventable Diseases in People Living with HIV: The Korea HIV/AIDS Cohort Study.

BACKGROUND: Prophylactic immunization is important for human immunodeficiency virus (HIV)-infected patients; however, there are insufficient data on the burden of vaccine-preventable diseases (VPDs), vaccination rates, and factors influencing vaccination. MATERIALS AND METHODS: The incidence and prevalence of VPDs in HIV-infected patients between 2006 and 2017 were estimated using the Korean HIV/acquired immune deficiency syndrome (AIDS) cohort database. In addition, we evaluated the vaccination rates and influencing factors for vaccination in HIV-infected patients through multilevel analysis of clinico-epidemiological factors, immune status, and psychological status. A questionnaire survey was conducted among experts to determine whether they recommend vaccination for HIV-infected patients. RESULTS: The incidence rates of hepatitis B virus (HBV) infection, herpes zoster, and anogenital warts were 1.74, 7.38, and 10.85 per 1,000 person-years, respectively. The prevalence of HBV infection and anogenital warts at enrollment was 4.8% and 8.6%, respectively, which increased to 5.3% and 12.0%, respectively, by 2017. In HIV-infected patients, HBV (21.7% in 2008, 56.3% in 2013, and 75.4% in 2017) and pneumococcal vaccination rates (3.0% in 2015, 7.6% in 2016, and 9.6% in 2017) increased annually, whereas the influenza vaccination rate remained similar by season (32.7 - 35.6%). In the multilevel analysis, peak HIV viral load (≥50 copies/mL: odds ratio [OR] = 0.64, 95% confidence interval [CI]: 0.44 - 0.93; reference, <50 copies/mL) was an influencing factor for pneumococcal vaccination, while nadir CD4 T-cell counts (200 - 350 cells/mm3: OR = 0.54, 95% CI: 0.38 - 0.76; <200 cells/mm3: OR = 0.89, 95% CI: 0.62 - 1.28; reference, ≥350 cells/mm3) was an influencing factor for HBV vaccination. Influenza vaccination was associated with male sex (OR = 1.94) and the number of antiretroviral therapy (ART) regimen change (OR = 1.16), but was not significantly associated with HIV viral load or CD4 T-cell counts. Most experts responded that they administer hepatitis A virus, HBV, pneumococcal, and influenza vaccines routinely, but not human papillomavirus (12.9%) or herpes zoster vaccines (27.1%). CONCLUSION: The burden of vaccine-preventable diseases was quite high in HIV-infected patients. Nadir CD4 T-cell counts, peak HIV viral loads, and the number of ART regimen change are significant factors related to vaccination. Considering the low vaccination rates for VPDs, there was a discordance between experts' opinions and real clinical practice in the medical field.

Characteristics of Adolescents and Young adults with HIV in the Republic of Korea from 2010 through 2015.

Although the number of newly diagnosed cases of HIV is decreasing worldwide, those in Korea have been steadily on the rise, especially among adolescents (ages 10-19 years) and young adults (ages 20-29 years). To identify the characteristics in the new diagnosis among these age groups, we analyzed HIV testing sizes and HIV prevalence under the national HIV surveillance system in Korea in the last six years. We collected data of HIV tests conducted at Blood Banks (BB), Public Health Centers (PHCs), and Military Manpower Administration (MMA) nationwide every year from 2010 to 2015, except for anonymous tests. HIV prevalence, calculated as the number of new HIV-diagnosed cases per 10,000 test-takers per year, was analyzed according to sex, age, institution, and reason for HIV testing. Data were analyzed using logistic regression. In the three testing institutes, there were new cases of HIV with 50% and 95% of cases diagnosed in young adults and adolescents, respectively. The total size of HIV tests at the three sites was approximately 3.5 million tests per year; 80% of these were conducted in BBs, 10% in PHCs, and 10% in MMA. HIV prevalence, according to age, increased across all age groups for the six years, especially prevalent in young adults doubled during that period (1.01 per 10,000 test-takers in 2010, 2.45 in 2015). HIV prevalence among the "suspected" young male adults who visited PHCs for tests, was highest during the six years, increasing 6.5 times in the last two years (315.79 per 10,000 test-takers in 2014, 335.55 in 2015) compared to before 2014. We identified the characteristics of growing HIV infection in Korea as the increase of HIV prevalence among the suspected of young male adults at PHCs. Further, we propose that HIV prevalence in MMA can be used as an essential index for national HIV surveillance of adolescent boys in Korea.

Status of HPV vaccination among HPV-infected women aged 20-60 years with abnormal cervical cytology in South Korea: a multicenter, retrospective study.

OBJECTIVES: Since 2007, human papillomavirus (HPV) vaccines have been administered for the prevention of cervical cancer in Korea. We investigated the status of HPV vaccination among HPV-infected adult women with abnormal cervical cytology before the introduction of National Immunization Program. METHODS: From 2010 to 2016, HPV-positive women (age, 20-60 years) with atypical squamous cells of undetermined significance or low-grade squamous intraepithelial lesion (LSIL) were enrolled from five hospitals across Korea. Their HPV genotype, epidemiologic, and clinical data, including HPV vaccination history, were obtained. We compared the epidemiological characteristics and prevalence of HPV-16/18 genotypes between vaccinated and unvaccinated women. RESULTS: Among the 1,300 women, approximately 26% had a history of vaccination. Vaccinated patients were significantly younger, unmarried, and had a higher education level than unvaccinated women. For HPV-vaccinated individuals by vaccine dose, there was a significant younger age at vaccination initiation (p=0.025), longer duration from HPV vaccination to Pap test date (p=0.001), and lower proportion of HPV-16/18 (p=0.028) in the women with three doses. There was a significantly lower prevalence of HPV-16/18 genotypes in women who were vaccinated at least 12 months prior than in unvaccinated women (adjusted prevalence ratio [aPR]=0.51; 95% confidence interval [CI]=0.29-0.88). For women with LSIL, the prevalence of the HPV-16/18 genotypes was significantly lower in women who were vaccinated more than 12 months prior than in unvaccinated women (aPR=0.35; 95% CI=0.13-0.96). CONCLUSION: This study highlighted the status of HPV vaccination and the prevalence of HPV-16/18 genotypes among HPV-infected women with abnormal cervical cytology according to HPV vaccination. It provides preliminary information regarding the status of HPV vaccination among Korean adult women.

Influence of anonymous HIV testing on national HIV surveillance in the Republic of Korea (2000 to 2015): a retrospective analysis.

BACKGROUND: Owing to the continuous increase in the number of new human immunodeficiency virus (HIV) infection in Korea, public health centers (PHCs) have performed anonymous tests since 1989. No study has examined the patterns of anonymous HIV testing performed at PHCs and the characteristics of HIV infection detected in those tests. We aimed to assess the influence of anonymous HIV testing on Korea's national HIV surveillance. METHODS: HIV screening test data from 253 PHCs over a 16-year period were classified into 13 groups based on reason for testing. For anonymous HIV test takers (Anonymous), the HIV positivity per 10,000 tests was calculated, as repetitions could not be distinguished. Those with suspected HIV infection voluntarily underwent HIV testing and revealed their identity (Suspected). HIV prevalence was calculated as the number of HIV-positive persons per 10,000 test takers. Analyses were performed using chi-square and Cochran-Armitage trend test with SAS 9.4. RESULTS: Approximately 400,000 HIV screening tests were performed at PHCs annually, which remained unchanged in the past 10 years. The proportion of anonymous testing increased from < 3.0% before 2014 to 4.8% in 2014 and 6.1% in 2015. While the number of HIV cases increased, the number of anonymous HIV-positive test results per 10,000 tests decreased from 68.8 in 2010 to 41.8 in 2015. The HIV prevalence among the suspected was approximately 20.0 per 10,000 test takers before 2014, which steeply increased to 71.6 in 2015. Those with suspected HIV were predominantly men, aged 20 years, foreigners, and metropolitan city dwellers in the last 6 years. The high prevalence of persons with suspected HIV resulted in a doubling of HIV prevalence at PHCs between 2014 and 2015. CONCLUSIONS: Anonymous and Suspected, which were driven by similar motives, impacted each other. Increase in HIV prevalence among the suspected led to a higher HIV prevalence among all test takers in PHCs and higher proportions of HIV infection nationwide, which could be attributed to the increase in the number of anonymous tests performed in PHCs. HIV positivity among the anonymous and HIV prevalence among the suspected are key indexes of the national HIV surveillance in Korea.

Significance of Increased Rapid Treatment from HIV Diagnosis to the First Antiretroviral Therapy in the Recent 20 Years and Its Implications: the Korea HIV/AIDS Cohort Study.

From December 2006 to December 2016, 1,429 patients enrolled in the Korea human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS) Cohort Study were investigated. Based on the year of diagnosis, the time interval between HIV diagnosis and initiation of antiretroviral therapy (ART) was analyzed by dividing it into 2 years. The more recent the diagnosis, the more likely rapid treatment was initiated (P < 0.001) and the proportion of patients starting ART on the same day of HIV diagnosis was increased in 2016 (6.5%) compared to that in 2006 (1.7%). No significant difference in the median values of CD4+ cell counts according to the diagnosis year was observed. In the past 20 years, the time from the HIV diagnosis to the initiation of ART was significantly reduced. Rapid treatment was being implemented at the HIV diagnosis, regardless of CD4+ cell count. Considering the perspective "treatment is prevention," access to more rapid treatment is necessary at the time of HIV diagnosis.

Risk of cervical dysplasia among human papillomavirus-infected women in Korea: a multicenter prospective study.

OBJECTIVE: Human papillomavirus (HPV) infection is the most important risk factor for cervical cancer, which progresses from precursor lesions with no symptom if left untreated. We compared the risk of cervical dysplasia among HPV-positive Korean women based on HPV types and infection patterns. METHODS: We observed participants of a 5-year multicenter prospective cohort study, comprising HPV-positive women with either atypical squamous cells of undetermined significance or low-grade squamous intraepithelial lesion of the cervix at their enrollment. Follow-ups, comprising cytology and HPV DNA testing results, were included in the final analysis. Incidence was calculated for each infection pattern (persistent infection, incidental infection, and clearance). To investigate cervical dysplasia risk, we used Cox proportional hazard models adjusted for variables that were significantly different among infection patterns. From April 2010 to September 2017, 71 of 1,027 subjects developed cervical dysplasia more severe than high-grade squamous intraepithelial lesion of the cervix. RESULTS: Of these 71 subjects, persistent infection, incidental infection, and clearance were noted in 30, 39, and 2 individuals, respectively. Based on changes in DNA results during follow-up, cumulative incidence was 27.2%, 10.4%, and 0.5% for persistent infection, incidental infection, and clearance, respectively. Compared to clearance, the adjusted hazard ratios for cervical dysplasia were 51.6 and 24.1 for persistent and incidental infections, respectively (p<0.001). CONCLUSION: Individuals persistently infected with the same HPV types during the follow-up period had the highest risk of severe cervical dysplasia. Hence, it is necessary to monitor HPV types and infection patterns to prevent severe cervical precancerous lesions.

Risk factors for cytological progression in HPV 16 infected women with ASC-US or LSIL: The Korean HPV cohort.

OBJECTIVE: This study was to identify the risk factors for cytological progression in women with atypical squamous cells of undetermined significance (ASC-US) or low-grade squamous intraepithelial lesions (LSIL). METHODS: We analyzed data from women infected with the human papillomavirus (HPV) who participated in the Korean HPV cohort study. The cohort recruited women aged 20-60 years with abnormal cervical cytology (ASC-US or LSIL) from April 2010. All women were followed-up at every 6-month intervals with cervical cytology and HPV DNA testing. RESULTS: Of the 1,158 women included, 654 (56.5%) and 504 (43.5%) women showed ASC-US and LSIL, respectively. At the time of enrollment, 143 women tested positive for HPV 16 (85 single and 58 multiple infections). Cervical cytology performed in the HPV 16-positive women showed progression in 27%, no change in 23%, and regression in 50% of the women at the six-month follow-up. The progression rate associated with HPV 16 infection was higher than that with infection caused by other HPV types (relative risk [RR], 1.75; 95% confidence interval [CI], 1.08-2.84; P=0.028). The cytological progression rate in women with persistent HPV 16 infection was higher than that in women with incidental or cleared infections (P<0.001). Logistic regression analysis showed a significant relationship between cigarette smoking and cytological progression (RR, 4.15; 95% CI, 1.01-17.00). CONCLUSION: The cytological progression rate in HPV 16-positive women with ASC-US or LSIL is higher than that in women infected with other HPV types. Additionally, cigarette smoking may play a role in cytological progression.

Opportunistic diseases among HIV-infected patients: a multicenter-nationwide Korean HIV/AIDS cohort study, 2006 to 2013.

BACKGROUND/AIMS: The frequencies of opportunistic diseases (ODs) vary across countries based on genetic, environmental, and social differences. The Korean HIV/AIDS cohort study was initiated in 2006 to promote research on human immunodeficiency virus (HIV) infection in Korea, and to provide a logistical network to support multicenter projects on epidemiological, clinical, and laboratory aspects of HIV infection. This study evaluated the prevalence of ODs among HIV-infected patients in the era of highly active antiretroviral therapy, and the risk factors associated with ODs. METHODS: The study enrolled 1,086 HIV-infected patients from 19 hospitals. This study examined the baseline data of the HIV/AIDS Korean cohort study at the time of enrollment from December 2006 to July 2013. RESULTS: Candidiasis was the most prevalent opportunistic infection (n = 176, 16.2%), followed by Mycobacterium tuberculosis infection (n = 120, 10.9%), Pneumocystis jirovecii pneumonia (n = 121, 11.0%), cytomegalovirus infection (n = 52, 4.7%), and herpes zoster (n = 44, 4.0%). The prevalence rates of Kaposi's sarcoma (n = 8, 0.7%) and toxoplasmosis (n = 4, 0.4%) were very low compared with other countries. The risk factors for ODs were a low CD4 T cell count at the time of HIV diagnosis (odds ratio [OR], 1.01; p < 0.01), current smoking (OR, 2.27; p = 0.01), current alcohol use (OR, 2.57; p = 0.04), and a history of tuberculosis (OR, 5.23; p < 0.01). CONCLUSIONS: Using recent Korean nationwide data, this study demonstrated that an important predictor of ODs was a low CD4 T cell count at the time of HIV diagnosis. Tuberculosis remains one of the most important ODs in HIV-infected patients in Korea.

The Impact of High-Risk HPV Genotypes Other Than HPV 16/18 on the Natural Course of Abnormal Cervical Cytology: A Korean HPV Cohort Study.

PURPOSE: The purpose of this study is to evaluate the impact of high-risk human papillomaviruses (HPVs) other than HPV 16/18 on the natural course of atypical squamous cells of undetermined significance (ASC-US) or low-grade squamous intraepithelial lesion (LSIL). MATERIALS AND METHODS: The study population was derived from the Korean HPV cohort (2010-2014). Women aged 20 to 60 who satisfied the criteria of having both HPV infection and abnormal cervical cytology of either ASC-US or LSIL were recruited from five institutions nationwide. Enrolled patients underwent cervical cytology and HPV DNA testing every 6 months. RESULTS: A total of 1,158 patients were enrolled. The 10 most common HPV types were HPV 16 (12.3%), 58 (10.0%), 56 (8.8%), 53 (8.4%), 52 (7.7%), 39 (6.2%), 18 (6.0%), 51 (5.7%), 68 (5.1%), and 66 (4.6%). Among these patients, 636 women were positive for high-risk HPVs other than HPV 16 or 18, and 429 women were followed for more than 6 months. Cytology evaluations showed progression in 15.3% of women, no change in 22.6%, and regression in 62.1% of women at 12 months. In cases of HPV 58 single infection, a more highly significant progression rate, compared to other high-risk types, was observed at 6 months (relative risk [RR], 3.3; 95% confidence interval [CI], 2.04 to 5.30; p < 0.001) and 12 months (RR, 5.03; 95% CI, 2.56 to 9.91; p < 0.001). CONCLUSION: HPV genotypes numbered in the 50s were frequent in Korean women with ASC-US and LSIL. HPV 58 was the second most common type, with a high progression rate of cervical cytology.

DNA methylation in human papillomavirus-infected cervical cells is elevated in high-grade squamous intraepithelial lesions and cancer.

OBJECTIVE: DNA methylation has been shown to be a potential biomarker for early cancer detection. The aim of this study was to evaluate DNA methylation profiles according to liquid-based Pap (LBP) test results and to assess their diagnostic value in a Korean population. METHODS: A total of 205 patients with various Papanicolaou test results were enrolled to this study (negative, 26; atypical squamous cells of undetermined significance, 39; low grade squamous intraepithelial lesion, 44; high grade squamous intraepithelial lesion (HSIL), 48; and cancer, 48). DNA methylation analysis of four genes, ADCYAP1, PAX1, MAL, and CADM1, was performed on residual cervical cells from LBP samples using a quantitative bisulfite pyrosequencing method. To evaluate the diagnostic performance of the four methylated genes for cancer detection, receiver operating characteristic (ROC) curves were drawn. Sensitivities and specificities were also tested at cutoffs determined from the ROC curves. RESULTS: Cervical cancer cells showed dramatically increased methylation levels for the four genes analyzed. ADCYAP1 and PAX1 also trended toward elevated methylation levels in HSIL samples, although the levels were much lower than those in cancer cells. The sensitivities of methylated ADCYAP1, PAX1, MAL, and CADM1 for the detection of cancer were 79.2%, 75.0%, 70.8%, and 52.1%, and the specificities were 92.0%, 94.0%, 94.7%, and 94.0%, respectively. Methylated ADCYAP1 and PAX1 demonstrated relatively better discriminatory ability than did methylated MAL and CADM1 (area under the curves 0.911 and 0.916 vs. 0.854 and 0.756, respectively). CONCLUSION: DNA methylation status, especially in the ADCYAP1 and PAX1 genes, showed relatively good specificity, ranging from 90% to 94%. The possible additive and complementary roles of DNA methylation testing with respect to conventional cervical cancer screening programs will need to be validated in prospective population-based studies.

Methylation of Cervical Neoplastic Cells Infected With Human Papillomavirus 16.

OBJECTIVE: This study was conducted to evaluate the role of methylation of adenylate cyclase activating peptide 1 (ADCYAP1), paired box gene 1 (PAX1), cell adhesion molecule 1 (CADM1), and T-lymphocyte maturation-associated protein (MAL) during carcinogenesis. METHODS: We evaluated the methylation of 4 genes by using the cervical carcinoma cell lines (CaSki, SiHa, HeLa, and C33A) and cervical neoplastic cells from 56 subjects with human papillomavirus 16 (HPV16)-infected low-grade squamous intraepithelial lesions (LSILs), 50 subjects with HPV16-infected high-grade squamous intraepithelial lesions (HSILs), and 24 subjects with HPV16-infected invasive cervical cancer who attended Seoul St. Mary's Hospital. Methylation of the 4 genes was evaluated using quantitative bisulfate pyrosequencing. RESULTS: The ADCYAP1 promoter was hypermethylated in the 4 cell lines (CaSki, 97.40 ± 1.39; SiHa, 82.04 ± 17.02; HeLa, 96.14 ± 2.08; and C33A, 78 ± 10.18). PAX1 and CADM1 were hypermethylated in the HPV16/18-infected cell lines CaSki (PAX1, 91.18 ± 9.91; CADM1, 93.5 ± 7.33), SiHa (PAX1, 96.14 ± 2.08; CADM1, 93.15 ± 8.81), and HeLa (PAX1, 82.04 ± 17.02; CADM1, 92.43 ± 9.95). MAL was hypermethylated in the CaSki cell line (96.04 ± 4.74). Among human cervical neoplastic cells, the methylation indices of ADCYAP1 were 7.8 (95% confidence interval [95% CI], 7.0-8.6) in subjects with LSILs and 39.8 (95% CI, 29.0-54.7) in those with cervical cancer (P < 0.001); for PAX1, 7.2 (95% CI, 6.1-8.5) and 37.8 (95% CI, 27.1-52.7), respectively; for CADM1, 3.5 (95% CI, 3.0-4.0) and 17.7 (95% CI, 10.8-29.1), respectively; for MAL, 2.7 (95% CI, 2.5-3.0) and 13.0 (95% CI, 7.6-22.0), respectively (P < 0.001 for each). Immunohistochemical staining results were positive in the cytoplasm of subjects with low methylation of the 4 gene promoters; however, they were negative in the cytoplasm of those with hypermethylation of the 4 gene promoters. CONCLUSIONS: The results of this study suggest that the methylation of ADCYAP1, PAX1, CADM1, and MAL may be highly associated with the development of cervical cancer, and that gene expression can be suppressed by gene promoter hypermethylation.

Anxiety and depressive symptoms among patients infected with human immunodeficiency virus in South Korea.

Patients infected with human immunodeficiency virus (HIV) may develop mental health problems such as anxiety and depression, which negatively impact of disease progression. We investigated factors associated with the prevalence of anxiety and depression symptoms among HIV-infected patients in Korea. A total of 840 HIV-infected patients who participated in the Korea HIV/AIDS Cohort Study from 2006 to 2012 were evaluated. Socio-demographic, epidemiologic, and clinical variables were obtained through standardized questionnaires. The State-Trait Anxiety Inventory and Beck Depression Inventory were used to assess the symptoms of anxiety and depression. Multiple logistic regression analyses were performed to identify factors associated with symptoms of anxiety and depression. The prevalence of anxiety and depressive symptoms among HIV-infected patients was 32% and 36%, respectively. Ex-smoker and persistent symptoms for more than one week within the past six months and diagnosis of HIV infection within one year were associated with increased anxiety symptoms (odds ratio [OR] 1.71, 95% confidence interval [CI] 1.09-2.69; OR 1.52, 95% CI 1.09-2.11; OR 1.49, 95% CI 1.02-2.20) and current smoking and persistent symptoms were also associated with increased depressive symptoms (OR 2.10, 95% CI 1.31-3.30; OR 1.87, 95% CI 1.25-2.79). Marital status, current smoking, current drinking, and persistent symptoms were associated with both increased anxiety and depressive symptoms (OR 1.75, 95% CI 1.07-2.88; OR 1.66, 95% CI 1.06-2.61; OR 1.88, 95% CI 1.18-2.99). The prevalence of anxiety and depressive symptoms among HIV-infected patients is higher than those estimated for the general population. This study shows the necessity to evaluate symptoms of anxiety and depression and suggest psychological support for HIV-infected patients who smoke or have persistent symptoms or have sexual partner or drink.

Prospective cohort study on the outcomes of hepatitis C virus-related cirrhosis in South Korea.

BACKGROUND AND AIMS: The outcomes of hepatitis C virus (HCV)-related liver cirrhosis was limitedly studied in a hepatitis B virus-endemic area. This multicenter, prospective cohort study was conducted to elucidate the incidence of hepatocellular carcinoma (HCC) and mortality in the Korean patients with HCV-related cirrhosis. METHODS: From January 2007 through June 2012, 196 patients with HCV-related cirrhosis were prospectively enrolled and regularly followed at six university hospitals to determine HCC occurrence and mortality. A multivariable analysis using Cox proportional hazards regression was performed to clarify the related factors to the outcomes. RESULTS: During a mean follow-up period of 39.2 months, 31 (15.8%) patients developed HCC, and 33 (16.8%) patients died or underwent liver transplantation. The estimated HCC incidence was 5.8 per 100 person-years, and the independent factors for HCC were absence of anti-HBV surface antibody (HBs hazard ratio [HR], 5.018; 95% confidence interval [CI], 1.710-14.726; P = 0.003) and serum albumin < 3.8 g/dL (HR, 3.051; 95% CI, 1.318-7.067; P = 0.009). The overall mortality rate was 5.1 per 100 person-years, and the related independent factors were the presence of ascites (HR, 2.448; 95% CI, 1.142-5.210; P = 0.022), serum albumin < 3.8 g/dL (HR, 3.067; 95% CI, 1.254-8.139, P = 0.014), and nonachievement of sustained virologic response (SVR) (HR, 0.066; 95% CI, 0.001-0.484, P = 0.002). CONCLUSION: The incidence of HCC in HCV-related cirrhosis seems to be high in Korea, and advanced liver disease and no achievement of SVR were associated with mortality. The absence of anti-HBs in hepatocarcinogenesis related to HCV warrants further study.

Geographic differences in the epidemiological features of HCV infection in Korea.

BACKGROUND/AIMS: The prevalence of hepatitis C virus (HCV) infection in Korea exhibits significant geographic variation, with it being higher in Busan and Jeonam than in other areas. The reason for this intranational geographic difference was investigated in this study by conducting a comparative analysis of the risk factors related to HCV infection among three geographic areas: the capital (Seoul), Busan, and the province of Jeolla. METHODS: In total, 990 patients with chronic HCV infection were prospectively enrolled at 5 university hospitals located in Seoul (n=374), Busan (n=264), and Jeolla (n=352). A standardized questionnaire survey on the risk factors for HCV infection was administered to these three groups of patients, and a comparative analysis of the findings was performed. RESULTS: The analysis revealed significant regional differences in exposure to the risk factors of HCV infection. By comparison with patients in Seoul as a control group in the multivariate analysis, patients in Busan had significantly more experience of invasive medical procedures, acupuncture, cosmetic procedures, and multiple sex partners. In contrast, patients in Jeolla were significantly older, and they had a higher prevalence of hepatocellular carcinoma, a lower prevalence of multiple sex partners, and had experienced fewer invasive procedures. CONCLUSIONS: There was a significant geographic difference in the exposure to potential risk factors of HCV infection between patients from the three studied regions. This may explain the regional variation of the prevalence of HCV infection in Korea, and should be taken into account when planning strategies for the prevention and management of HCV infection.

Development of reference materials to detect 15 different human papillomavirus genotypes.

Accurate human papillomavirus (HPV) typing is essential for evaluating and monitoring HPV vaccines in cervical cancer screening and in epidemiological surveys. In our country, different HPV DNA detection and genotyping methodologies have been established for diagnosing and monitoring HPV-related disease in clinical practice and for research. However, there is a lack of reference materials to standardize the methods for HPV detection and genotyping. In this study, we constructed candidate reference materials comprising 15 targets (13 types of high-risk HPV, two types of low-risk HPV). We evaluated whether the candidate reference materials could be used as the reference for HPV detection and genotyping using quantitative real-time polymerase chain reaction. Standard curves for the wide linear range (10(1)-10(6)copies/µL) produced high correlation regression coefficient R(2) of 0.99. The reaction efficiencies were 96.3% to 101.2% for the standard curves, indicating highly efficient reactions. Specific genotypes were detected in single or multiple mixed samples. Our results suggest that these reference materials may provide useful standards for standardizing quality assurance for different HPV-typing assays and for proficiency testing in diagnostic laboratories.

Establishment of a Korea HPV cohort study.

We have designed a five-year multicentre prospective cohort study in women who are both human papillomavirus (HPV)-positive with either atypical squamous cells of undetermined significance (ASCUS) or low-grade squamous intraepithelial lesion (LSIL) of cervix. This study aimed to analyze the risk of developing a high-grade squamous intraepithelial lesion (HSIL) from either ASCUS or LSIL in HPV-positive women, so called 'progression' rate, to investigate differences in the progression rates according to HPV type-specific infection, and to evaluate the various factors associated with the persistence or clearance of HPV infection in the Korean population. At present, the study protocol composed of cervical cytology, HPV DNA testing, and questionnaire have been conducted actively since the first participant was enrolled in 2010. This study is the first nationwide Korea HPV cohort study. Our data will provide valuable information about not only the ambiguous cytology results of ASCUS and LSIL but also the effect of the specific HPV type and other various factors on the progression to HSIL. Finally, the results of our study will be helpful and applicable to determine the primary cervical cancer prevention strategies.

Improvement in the performance of external quality assessment in Korean HIV clinical laboratories using unrecalcified human plasma.

BACKGROUND: The external quality assessment schemes (EQAS) organizer provides a suitable program to monitor and improve the quality of human immunodeficiency virus (HIV) testing laboratories with EQAS panels prepared under various conditions. The aim of the current study was to investigate the effects of human plasma samples on the EQAS results of HIV obtained from hospital-based clinical laboratories. METHODS: From 2007 to 2009, HIV EQAS panels consisted of four to six samples that consisted of undiluted positive and negative samples and were provided to laboratories twice per year. Up until the first half EQAS in 2008, EQAS panel materials were obtained by converting acid citrate dextrose treated plasma to serum via chemical treatment with CaCl2. Beginning with the second EQAS in 2008, all materials were prepared without the defibrination process. RESULTS: Approximately 300 HIV clinical laboratories participated in this program. The overall performance of clinical laboratories was shown to be improved when using unrecalcified plasma panels compared with recalcified panels. Significant differences were observed in EIA analyses of plasma for both positive (p<0.001) and negative (p<0.001) samples between the recalcified and unrecalcified groups. CONCLUSIONS: Our finding suggested that defibrination status of EQAS panels might affect the results of anti-HIV EQAS of Korean HIV testing laboratories.