Last data update: Dec 02, 2024. (Total: 48272 publications since 2009)
Records 1-12 (of 12 Records) |
Query Trace: Lin CY[original query] |
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Comparison of demographic characteristics and social determinants of health between adults with diagnosed HIV and all adults in the US
Dasgupta S , McManus T , Tie Y , Lin CY , Yuan X , Sharpe JD , Fletcher KM , Beer L . AJPM Focus 2023 2 (3) 100115 INTRODUCTION: Quantifying disparities in social determinants of health between people with HIV and the total population could help address health inequities, and ensure health and well-being among people with HIV in the U.S., but estimates are lacking. METHODS: Several representative data sources were used to assess differences in social determinants of health between adults with diagnosed HIV (Centers for Disease Control and Prevention Medical Monitoring Project) and the total adult population (U.S. Census Bureau's decennial census, American Community Survey, Household Pulse Survey, the Current Population Survey Annual Social and Economic Supplements; the Department of Housing and Urban Development's point-in-time estimates of homelessness; and the Bureau of Justice Statistics). The differences were quantified using standardized prevalence differences and standardized prevalence ratios, adjusting for differences in age, race/ethnicity, and birth sex between people with HIV and the total U.S. population. RESULTS: Overall, 35.6% of people with HIV were living in a household with an income at or below the federal poverty level, and 8.1% recently experienced homelessness. Additionally, 42.9% had Medicaid and 27.6% had Medicare; 39.7% were living with a disability. Over half (52.3%) lived in large central metropolitan counties and 20.6% spoke English less than very well based on survey responses. After adjustment, poverty (standardized prevalence difference=25.1%, standardized prevalence ratio=3.5), homelessness (standardized prevalence difference=8.5%, standardized prevalence ratio=43.5), coverage through Medicaid (standardized prevalence difference=29.5%, standardized prevalence ratio=3.0) or Medicare (standardized prevalence difference=7.8%), and disability (standardized prevalence difference=30.3%, standardized prevalence ratio=3.0) were higher among people with HIV than the total U.S. population. The percentage of people with HIV living in large central metropolitan counties (standardized prevalence difference=13.4%) or who were recently incarcerated (standardized prevalence ratio=5.9) was higher than the total U.S. population. CONCLUSIONS: These findings provide a baseline for assessing national-level disparities in social determinants of health between people with HIV and the total U.S. population, and it can be used as a model to assess local disparities. Addressing social determinants of health is essential for achieving health equity, requiring a multipronged approach with interventions at the provider, facility, and policy levels. |
Lifetime risk, life expectancy, and years of life lost to type 2 diabetes in 23 high-income jurisdictions: a multinational, population-based study
Tomic D , Morton JI , Chen L , Salim A , Gregg EW , Pavkov ME , Arffman M , Balicer R , Baviera M , Boersma-van Dam E , Brinks R , Carstensen B , Chan JCN , Cheng YJ , Fosse-Edorh S , Fuentes S , Gardiner H , Gulseth HL , Gurevicius R , Ha KH , Hoyer A , Jermendy G , Kautzky-Willer A , Keskimäki I , Kim DJ , Kiss Z , Klimek P , Leventer-Roberts M , Lin CY , Lopez-Doriga Ruiz P , Luk AOY , Ma S , Mata-Cases M , Mauricio D , McGurnaghan S , Imamura T , Paul SK , Peeters A , Pildava S , Porath A , Robitaille C , Roncaglioni MC , Sugiyama T , Wang KL , Wild SH , Yekutiel N , Shaw JE , Magliano DJ . Lancet Diabetes Endocrinol 2022 10 (11) 795-803 BACKGROUND: Diabetes is a major public health issue. Because lifetime risk, life expectancy, and years of life lost are meaningful metrics for clinical decision making, we aimed to estimate these measures for type 2 diabetes in the high-income setting. METHODS: For this multinational, population-based study, we sourced data from 24 databases for 23 jurisdictions (either whole countries or regions of a country): Australia; Austria; Canada; Denmark; Finland; France; Germany; Hong Kong; Hungary; Israel; Italy; Japan; Latvia; Lithuania; the Netherlands; Norway; Scotland; Singapore; South Korea; Spain; Taiwan; the UK; and the USA. Our main outcomes were lifetime risk of type 2 diabetes, life expectancy in people with and without type 2 diabetes, and years of life lost to type 2 diabetes. We modelled the incidence and mortality of type 2 diabetes in people with and without type 2 diabetes in sex-stratified, age-adjusted, and calendar year-adjusted Poisson models for each jurisdiction. Using incidence and mortality, we constructed life tables for people of both sexes aged 20-100 years for each jurisdiction and at two timepoints 5 years apart in the period 2005-19 where possible. Life expectancy from a given age was computed as the area under the survival curves and lifetime lost was calculated as the difference between the expected lifetime of people with versus without type 2 diabetes at a given age. Lifetime risk was calculated as the proportion of each cohort who developed type 2 diabetes between the ages of 20 years and 100 years. We estimated 95% CIs using parametric bootstrapping. FINDINGS: Across all study cohorts from the 23 jurisdictions (total person-years 1 577 234 194), there were 5 119 585 incident cases of type 2 diabetes, 4 007 064 deaths in those with type 2 diabetes, and 11 854 043 deaths in those without type 2 diabetes. The lifetime risk of type 2 diabetes ranged from 16·3% (95% CI 15·6-17·0) for Scottish women to 59·6% (58·5-60·8) for Singaporean men. Lifetime risk declined with time in 11 of the 15 jurisdictions for which two timepoints were studied. Among people with type 2 diabetes, the highest life expectancies were found for both sexes in Japan in 2017-18, where life expectancy at age 20 years was 59·2 years (95% CI 59·2-59·3) for men and 64·1 years (64·0-64·2) for women. The lowest life expectancy at age 20 years with type 2 diabetes was observed in 2013-14 in Lithuania (43·7 years [42·7-44·6]) for men and in 2010-11 in Latvia (54·2 years [53·4-54·9]) for women. Life expectancy in people with type 2 diabetes increased with time for both sexes in all jurisdictions, except for Spain and Scotland. The life expectancy gap between those with and without type 2 diabetes declined substantially in Latvia from 2010-11 to 2015-16 and in the USA from 2009-10 to 2014-15. Years of life lost to type 2 diabetes ranged from 2·5 years (Latvia; 2015-16) to 12·9 years (Israel Clalit Health Services; 2015-16) for 20-year-old men and from 3·1 years (Finland; 2011-12) to 11·2 years (Israel Clalit Health Services; 2010-11 and 2015-16) for 20-year-old women. With time, the expected number of years of life lost to type 2 diabetes decreased in some jurisdictions and increased in others. The greatest decrease in years of life lost to type 2 diabetes occurred in the USA between 2009-10 and 2014-15 for 20-year-old men (a decrease of 2·7 years). INTERPRETATION: Despite declining lifetime risk and improvements in life expectancy for those with type 2 diabetes in many high-income jurisdictions, the burden of type 2 diabetes remains substantial. Public health strategies might benefit from tailored approaches to continue to improve health outcomes for people with diabetes. FUNDING: US Centers for Disease Control and Prevention and Diabetes Australia. |
Trends in all-cause mortality among people with diagnosed diabetes in high-income settings: a multicountry analysis of aggregate data
Magliano DJ , Chen L , Carstensen B , Gregg EW , Pavkov ME , Salim A , Andes LJ , Balicer R , Baviera M , Chan JCN , Cheng YJ , Gardiner H , Gulseth HL , Gurevicius R , Ha KH , Jermendy G , Kim DJ , Kiss Z , Leventer-Roberts M , Lin CY , Luk AOY , Ma S , Mata-Cases M , Mauricio D , Nichols GA , Pildava S , Porath A , Read SH , Robitaille C , Roncaglioni MC , Lopez-Doriga Ruiz P , Wang KL , Wild SH , Yekutiel N , Shaw JE . Lancet Diabetes Endocrinol 2022 10 (2) 112-119 BACKGROUND: Population-level trends in mortality among people with diabetes are inadequately described. We aimed to examine the magnitude and trends in excess all-cause mortality in people with diabetes. METHODS: In this retrospective, multicountry analysis, we collected aggregate data from 19 data sources in 16 high-income countries or jurisdictions (in six data sources in Asia, eight in Europe, one from Australia, and four from North America) for the period from Jan 1, 1995, to Dec 31, 2016, (or a subset of this period) on all-cause mortality in people with diagnosed total or type 2 diabetes. We collected data from administrative sources, health insurance records, registries, and a health survey. We estimated excess mortality using the standardised mortality ratio (SMR). FINDINGS: In our dataset, there were approximately 21 million deaths during 0·5 billion person-years of follow-up among people with diagnosed diabetes. 17 of 19 data sources showed decreases in the age-standardised and sex-standardised mortality in people with diabetes, among which the annual percentage change in mortality ranged from -0·5% (95% CI -0·7 to -0·3) in Hungary to -4·2% (-4·3 to -4·1) in Hong Kong. The largest decreases in mortality were observed in east and southeast Asia, with a change of -4·2% (95% CI -4·3 to -4·1) in Hong Kong, -4·0% (-4·8 to -3·2) in South Korea, -3·5% (-4·0 to -3·0) in Taiwan, and -3·6% (-4·2 to -2·9) in Singapore. The annual estimated change in SMR between people with and without diabetes ranged from -3·0% (95% CI -3·0 to -2·9; US Medicare) to 1·6% (1·4 to 1·7; Lombardy, Italy). Among the 17 data sources with decreasing mortality among people with diabetes, we found a significant SMR increase in five data sources, no significant SMR change in four data sources, and a significant SMR decrease in eight data sources. INTERPRETATION: All-cause mortality in diabetes has decreased in most of the high-income countries we assessed. In eight of 19 data sources analysed, mortality decreased more rapidly in people with diabetes than in those without diabetes. Further longevity gains will require continued improvement in prevention and management of diabetes. FUNDING: US Centers for Disease Control and Prevention, Diabetes Australia Research Program, and Victoria State Government Operational Infrastructure Support Program. |
In-person vs electronic directly observed therapy for tuberculosis treatment adherence: A randomized noninferiority trial
Burzynski J , Mangan JM , Lam CK , Macaraig M , Salerno MM , deCastro BR , Goswami ND , Lin CY , Schluger NW , Vernon A . JAMA Netw Open 2022 5 (1) e2144210 IMPORTANCE: Electronic directly observed therapy (DOT) is used increasingly as an alternative to in-person DOT for monitoring tuberculosis treatment. Evidence supporting its efficacy is limited. OBJECTIVE: To determine whether electronic DOT can attain a level of treatment observation as favorable as in-person DOT. DESIGN, SETTING, AND PARTICIPANTS: This was a 2-period crossover, noninferiority trial with initial randomization to electronic or in-person DOT at the time outpatient tuberculosis treatment began. The trial enrolled 216 participants with physician-suspected or bacteriologically confirmed tuberculosis from July 2017 to October 2019 in 4 clinics operated by the New York City Health Department. Data analysis was conducted between March 2020 and April 2021. INTERVENTIONS: Participants were asked to complete 20 medication doses using 1 DOT method, then switched methods for another 20 doses. With in-person therapy, participants chose clinic or community-based DOT; with electronic DOT, participants chose live video-conferencing or recorded videos. MAIN OUTCOMES AND MEASURES: Difference between the percentage of medication doses participants were observed to completely ingest with in-person DOT and with electronic DOT. Noninferiority was demonstrated if the upper 95% confidence limit of the difference was 10% or less. We estimated the percentage of completed doses using a logistic mixed effects model, run in 4 modes: modified intention-to-treat, per-protocol, per-protocol with 85% or more of doses conforming to the randomization assignment, and empirical. Confidence intervals were estimated by bootstrapping (with 1000 replicates). RESULTS: There were 173 participants in each crossover period (median age, 40 years [range, 16-86 years]; 140 [66%] men; 80 [37%] Asian and Pacific Islander, 43 [20%] Black, and 71 [33%] Hispanic individuals) evaluated with the model in the modified intention-to-treat analytic mode. The percentage of completed doses with in-person DOT was 87.2% (95% CI, 84.6%-89.9%) vs 89.8% (95% CI, 87.5%-92.1%) with electronic DOT. The percentage difference was -2.6% (95% CI, -4.8% to -0.3%), consistent with a conclusion of noninferiority. The 3 other analytic modes yielded equivalent conclusions, with percentage differences ranging from -4.9% to -1.9%. CONCLUSIONS AND RELEVANCE: In this trial, the percentage of completed doses under electronic DOT was noninferior to that under in-person DOT. This trial provides evidence supporting the efficacy of this digital adherence technology, and for the inclusion of electronic DOT in the standard of care. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03266003. |
Trends in the incidence of diagnosed diabetes: a multicountry analysis of aggregate data from 22 million diagnoses in high-income and middle-income settings
Magliano DJ , Chen L , Islam RM , Carstensen B , Gregg EW , Pavkov ME , Andes LJ , Balicer R , Baviera M , Boersma-van Dam E , Booth GL , Chan JCN , Chua YX , Fosse-Edorh S , Fuentes S , Gulseth HL , Gurevicius R , Ha KH , Hird TR , Jermendy G , Khalangot MD , Kim DJ , Kiss Z , Kravchenko VI , Leventer-Roberts M , Lin CY , Luk AOY , Mata-Cases M , Mauricio D , Nichols GA , Nielen MM , Pang D , Paul SK , Pelletier C , Pildava S , Porath A , Read SH , Roncaglioni MC , Lopez-Doriga Ruiz P , Shestakova M , Vikulova O , Wang KL , Wild SH , Yekutiel N , Shaw JE . Lancet Diabetes Endocrinol 2021 9 (4) 203-211 BACKGROUND: Diabetes prevalence is increasing in most places in the world, but prevalence is affected by both risk of developing diabetes and survival of those with diabetes. Diabetes incidence is a better metric to understand the trends in population risk of diabetes. Using a multicountry analysis, we aimed to ascertain whether the incidence of clinically diagnosed diabetes has changed over time. METHODS: In this multicountry data analysis, we assembled aggregated data describing trends in diagnosed total or type 2 diabetes incidence from 24 population-based data sources in 21 countries or jurisdictions. Data were from administrative sources, health insurance records, registries, and a health survey. We modelled incidence rates with Poisson regression, using age and calendar time (1995-2018) as variables, describing the effects with restricted cubic splines with six knots for age and calendar time. FINDINGS: Our data included about 22 million diabetes diagnoses from 5 billion person-years of follow-up. Data were from 19 high-income and two middle-income countries or jurisdictions. 23 data sources had data from 2010 onwards, among which 19 had a downward or stable trend, with an annual estimated change in incidence ranging from -1·1% to -10·8%. Among the four data sources with an increasing trend from 2010 onwards, the annual estimated change ranged from 0·9% to 5·6%. The findings were robust to sensitivity analyses excluding data sources in which the data quality was lower and were consistent in analyses stratified by different diabetes definitions. INTERPRETATION: The incidence of diagnosed diabetes is stabilising or declining in many high-income countries. The reasons for the declines in the incidence of diagnosed diabetes warrant further investigation with appropriate data sources. FUNDING: US Centers for Disease Control and Prevention, Diabetes Australia Research Program, and Victoria State Government Operational Infrastructure Support Program. |
Comparison of DNA testing strategies in monitoring human papillomavirus infection prevalence through simulation.
Lin CY , Li L . BMC Infect Dis 2016 16 (1) 642 BACKGROUND: HPV DNA diagnostic tests for epidemiology monitoring (research purpose) or cervical cancer screening (clinical purpose) have often been considered separately. Women with positive Linear Array (LA) polymerase chain reaction (PCR) research test results typically are neither informed nor referred for colposcopy. Recently, a sequential testing by using Hybrid Capture 2 (HC2) HPV clinical test as a triage before genotype by LA has been adopted for monitoring HPV infections. Also, HC2 has been reported as a more feasible screening approach for cervical cancer in low-resource countries. Thus, knowing the performance of testing strategies incorporating HPV clinical test (i.e., HC2-only or using HC2 as a triage before genotype by LA) compared with LA-only testing in measuring HPV prevalence will be informative for public health practice. METHOD: We conducted a Monte Carlo simulation study. Data were generated using mathematical algorithms. We designated the reported HPV infection prevalence in the U.S. and Latin America as the "true" underlying type-specific HPV prevalence. Analytical sensitivity of HC2 for detecting 14 high-risk (oncogenic) types was considered to be less than LA. Estimated-to-true prevalence ratios and percentage reductions were calculated. RESULTS: When the "true" HPV prevalence was designated as the reported prevalence in the U.S., with LA genotyping sensitivity and specificity of (0.95, 0.95), estimated-to-true prevalence ratios of 14 high-risk types were 2.132, 1.056, 0.958 for LA-only, HC2-only, and sequential testing, respectively. Estimated-to-true prevalence ratios of two vaccine-associated high-risk types were 2.359 and 1.063 for LA-only and sequential testing, respectively. When designated type-specific prevalence of HPV16 and 18 were reduced by 50 %, using either LA-only or sequential testing, prevalence estimates were reduced by 18 %. CONCLUSION: Estimated-to-true HPV infection prevalence ratios using LA-only testing strategy are generally higher than using HC2-only or using HC2 as a triage before genotype by LA. HPV clinical testing can be incorporated to monitor HPV prevalence or vaccine effectiveness. Caution is needed when comparing apparent prevalence from different testing strategies. |
Evaluation of using composite HPV genotyping assay results to monitor human papillomavirus infection burden through simulation.
Lin CY . BMC Infect Dis 2015 15 (1) 123 BACKGROUND: Researchers often group various HPV types into composite measures based on vaccine subtypes, oncogenic potential, or phylogenetic position. Composite prevalence estimates based on PCR genotyping assay results have been calculated to assess HPV infection burden and to monitor HPV vaccine effectiveness. While prevention and intervention strategies can be made based on these prevalence estimates, the discussion on how well these prevalence estimates measure the true underlying infection burdens is limited. METHODS: A simulation study was conducted to evaluate accuracy of using composite genotyping assay results to monitor HPV infection burden. Data were generated based on mathematical algorithms with prespecified type-specific infection burdens, assay sensitivity, specificity, and correlations between various HPV types. Estimated-to-true prevalence rate ratios and percent reduction of vaccine types were calculated. RESULTS: When "true" underlying type-specific infection burdens were prespecified as the reported prevalence in U.S. and genotyping assay with sensitivity and specificity (0.95, 0.95) was used, estimated-to-true infection prevalence ratios were 2.35, 2.29, 2.18, and 1.46, for the composite measures with 2 high-risk vaccine, 4 vaccine, 14 high-risk and 37 HPV types, respectively. Estimated-to-true prevalence ratios increased when prespecified "true" underlying infection burdens or assay specificity declined. When prespecified "true" type-specific infections of HPV 6, 11, 16 and 18 were reduced by 50%, the composite prevalence estimate of 4 vaccine types only decreased by 17% which is much lower than 48% reduction in the prespecified "true" composite prevalence. CONCLUSIONS: Composite prevalence estimates calculated based on panels of genotyping assay results generally over-estimate the "true" underlying infection burdens and could under-estimate vaccine effectiveness. Analytical specificity of genotyping assay is as or more important than analytical sensitivity and should be considered in selecting assay to monitor HPV. |
Ready, set, go: African American preadolescents' sexual thoughts, intentions, and behaviors
Miller KS , Fasula AM , Lin CY , Levin ML , Wyckoff SC , Forehand R . J Early Adolesc 2012 32 (2) 293-307 Understanding of preadolescent sexuality is limited. To help fill this gap, we calculated frequencies, percentages, and confidence intervals for 1,096 preadolescents' reports of sexual thoughts, intentions, and sexual behavior. Cochran-Armitage trend tests accounted for age effects. Findings show that 9-year-olds are readying for sexual activity, with sexual readiness increasing between ages of 9 and 12. Sexual thoughts increased with age (p < .001): 46% of 9-year-olds and 70% of 12-year-olds were ready to learn about sex, and 14% of 9-year-olds and 41% of 12-year-olds thought about having sex. Few 9-year-olds anticipated sexual debut, but this increased with age (p < .05): 25% of 12-year-olds were ready for sex, and 20% anticipated initiating sex within a year. Our results indicate that preadolescents are initiating dating relationships and anticipating intercourse, and some have engaged in risk behaviors. Thus preadolescence is a critical time to implement prevention programs. (PsycINFO Database Record (c) 2012 APA, all rights reserved) (journal abstract). |
High and persistent HIV seroincidence in men who have sex with men across 47 U.S. cities
Ackers ML , Greenberg AE , Lin CY , Bartholow BN , Goodman AH , Longhi M , Gurwith M . PLoS One 2012 7 (4) e34972 OBJECTIVE: To provide HIV seroincidence data among men who have sex with men (MSM) in the United States and to identify predictive factors for seroconversion. METHODS: From 1998-2002, 4684 high-risk MSM, age 18-60 years, participated in a randomized, placebo-controlled HIV vaccine efficacy trial at 56 U.S. clinical trial sites. Demographics, behavioral data, and HIV status were assessed at baseline and 6 month intervals. Since no overall vaccine efficacy was detected, data were combined from both trial arms to calculate HIV incidence based on person-years (py) of follow-up. Predictors of seroconversion, adjusted hazards ratio (aHR), were evaluated using a Cox proportional hazard model with time-varying covariates. RESULTS: Overall, HIV incidence was 2.7/100 py and was relatively uniform across study sites and study years. HIV incidence was highest among young men and men reporting unprotected sex, recreational drug use, and a history of a sexually transmitted infection. Independent predictors of HIV seroconversion included: age 18-30 years (aHR = 2.4; 95% CI 1.4,4.0), having >10 partners (aHR = 2.4; 95% CI 1.7,3.3), having a known HIV-positive male sex partner (aHR = 1.6; 95% CI 1.2, 2.0), unprotected anal intercourse with HIV positive/unknown male partners (aHR = 1.7; 95% CI 1.3, 2.3), and amphetamine (aHR = 1.6; 95% CI 1.1, 2.1) and popper (aHR = 1.7; 95% CI 1.3, 2.2) use. CONCLUSIONS: HIV seroincidence was high among MSM despite repeated HIV counseling and reported declines in sexual risk behaviors. Continuing development of new HIV prevention strategies and intensification of existing efforts will be necessary to reduce the rate of new HIV infections, especially among young men. |
Enhancing HIV communication between parents and children: efficacy of the Parents Matter! Program
Miller KS , Lin CY , Poulsen MN , Fasula A , Wyckoff SC , Forehand R , Long N , Armistead L . AIDS Educ Prev 2011 23 (6) 550-63 We examine efficacy of the Parents Matter! Program (PMP), a program to teach African-American parents of preadolescents sexual communication and HIV-prevention skills, through a multicenter, randomized control trial. A total of 1115 parent-child participants were randomized to one of three intervention arms (enhanced, brief, control). Percentages and 95% confidence intervals compare parents' perception of child readiness to learn about sexual issues, communication effectiveness, and dyad concordance from baseline to 12 months postintervention. Wilcoxon rank sum tests compare the changes in scores measuring communication content in HIV/AIDS, abstinence, and condom use. Compared to control, parents in the enhanced arm increased perception of child readiness to learn about sex (16% vs. 29%; p < .001), and a greater proportion of parent-child dyads reported concordant responses on communication topics: HIV/AIDS (15%, 95% CI = 8-21%; p < .001), abstinence (13%, 95% CI = 7-20%; p < .001), condoms (15%, 95% CI = 9-22%; p < .001). Increases in communication scores in HIV/AIDS, abstinence, and condom use were greater in the enhanced arm than control (p < 0.01). We conclude that the enhanced PMP can help parents educate children about HIV and prepare children to avoid sexual risk. |
Natural substrate concentrations can modulate the prophylactic efficacy of nucleotide HIV reverse transcriptase inhibitors
Garcia-Lerma JG , Aung W , Cong ME , Zheng Q , Youngpairoj AS , Mitchell J , Holder A , Martin A , Kuklenyik S , Luo W , Lin CY , Hanson DL , Kersh E , Pau CP , Ray AS , Rooney JF , Lee WA , Heneine W . J Virol 2011 85 (13) 6610-7 Preexposure prophylaxis (PrEP) with antiretroviral drugs is a novel human immunodeficiency virus (HIV) prevention strategy. It is generally thought that high systemic and mucosal drug levels are sufficient for protection. We investigated whether GS7340, a next-generation tenofovir (TFV) prodrug that effectively delivers tenofovir diphosphate (TFV-DP) to lymphoid cells and tissues, could protect macaques against repeated weekly rectal simian-human immunodeficiency virus (SHIV) exposures. Macaques received prophylactic GS7340 treatment 3 days prior to each virus exposure. At 3 days postdosing, TFV-DP concentrations in peripheral blood mononuclear cells (PBMCs) were about 50-fold higher than those seen with TFV disoproxil fumarate (TDF), and they remained above 1,000 fmol/10(6) cells for as long as 7 days. TFV-DP accumulated in lymphoid and rectal tissues, with concentrations at 3 days exceeding 500 fmol/10(6) mononuclear cells. Despite high mucosal and systemic TFV levels, GS7340 was not protective. Since TFV-DP blocks reverse transcription by competing with the natural dATP substrate, we measured dATP contents in peripheral lymphocytes, lymphoid tissue, and rectal mononuclear cells. Compared to those in circulating lymphocytes and lymphoid tissue, rectal lymphocytes had 100-fold higher dATP concentrations and dATP/TFV-DP ratios, likely reflecting the activated status of the cells and suggesting that TFV-DP may be less active at the rectal mucosa. Our results identify dATP/TFV-DP ratios as a possible correlate of protection by TFV and suggest that natural substrate concentrations at the mucosa will likely modulate the prophylactic efficacy of nucleotide reverse transcriptase inhibitors. |
High susceptibility to repeated, low-dose, vaginal SHIV exposure late in the luteal phase of the menstrual cycle of pigtail macaques
Vishwanathan SA , Guenthner PC , Lin CY , Dobard C , Sharma S , Adams DR , Otten RA , Heneine W , Hendry RM , McNicholl JM , Kersh EN . J Acquir Immune Defic Syndr 2011 57 (4) 261-4 Fluctuations in susceptibility to HIV or SHIV during the menstrual cycle are currently not fully documented. To address this, time point of infection was determined in 19 adult female pigtail macaques vaginally challenged during their undisturbed menstrual cycles with repeated, low-dose SHIVSF162P3 exposures. Eighteen macaques (95%) first displayed viremia in the follicular phase, as compared to 1 macaque (5%) in the luteal phase (p<0.0001). Due to a viral eclipse phase, we estimated a window of most frequent virus transmission between days 24-31 of the menstrual cycle, in the late luteal phase. Thus, susceptibility to vaginal SHIV infection is significantly elevated in the second half of the menstrual cycle when progesterone levels are high, and when local immunity may be low. Such susceptibility windows have been postulated before but not definitively documented. Our data support findings of higher susceptibility to HIV in women during progesterone-dominated periods including pregnancy and contraceptive use. |
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