Transmitted HIV-1 drug resistance in a large international cohort using next-generation sequencing: results from the Strategic Timing of Antiretroviral Treatment (START) study.

OBJECTIVES: The aim of this analysis was to characterize transmitted drug resistance (TDR) in Strategic Timing of Antiretroviral Treatment (START) study participants by next-generation sequencing (NGS), a sensitive assay capable of detecting low-frequency variants. METHODS: Stored plasma from participants with entry HIV RNA > 1000 copies/mL were analysed by NGS (Illumina MiSeq). TDR was based on the WHO 2009 surveillance definition with the addition of reverse transcriptase (RT) mutations T215N and E138K, and integrase strand transfer inhibitor (INSTI) surveillance mutations (Stanford HIVdb). Drug resistance mutations (DRMs) detected at three thresholds are reported: > 2%, 5% and 20% of the viral population. RESULTS: Between 2009 and 2013, START enrolled 4684 antiretroviral therapy (ART)-naïve individuals in 35 countries. Baseline NGS data at study entry were available for 2902 participants. Overall prevalence rates of TDR using a detection threshold of 2%/5%/20% were 9.2%/5.6%/3.2% for nucleoside reverse transcriptase inhibitors (NRTIs), 9.2%/6.6%/4.9% for non-NRTIs, 11.4%/5.5%/2.4% for protease inhibitors (PIs) and 3.5%/1.6%/0.1% for INSTI DRMs and varied by geographic region. Using the 2% detection threshold, individual DRMs with the highest prevalence were: PI M46IL (5.5%), RT K103NS (3.5%), RT G190ASE (3.1%), T215ISCDVEN (2.5%), RT M41L (2.2%), RT K219QENR (1.7%) and PI D30N (1.6%). INSTI DRMs were detected almost exclusively below the 20% detection threshold, most commonly Y143H (0.4%), Q148R (0.4%) and T66I (0.4%). CONCLUSIONS: Use of NGS in this study population resulted in the detection of a large proportion of low-level variants which would not have been detected by traditional Sanger sequencing. Global surveillance studies utilizing NGS should provide a more comprehensive assessment of TDR prevalence in different regions of the world.

Sexual risk and HIV testing disconnect in men who have sex with men (MSM) recruited to an online HIV self-testing trial.

OBJECTIVES: We report the frequency of previous HIV testing at baseline in men who have sex with men (MSM) who enrolled in an HIV self-testing (HIVST) randomized controlled trial [an HIV self-testing public health intervention (SELPHI)]. METHODS: Criteria for enrolment were age ≥ 16 years, being a man (including trans men) who ever had anal intercourse (AI) with a man, not being known to be HIV positive and having consented to national HIV database linkage. Using online survey baseline data (2017-2018), we assessed associations with never having tested for HIV and not testing in the previous 6 months, among men who reported at least two recent condomless AI (CAI) partners. RESULTS: A total of 10 111 men were randomized; the median age was 33 years [interquartile range (IQR) 26-44 years], 89% were white, 20% were born outside the UK, 0.8% were trans men, 47% were degree educated, and 8% and 4% had ever used and were currently using pre-exposure prophylaxis (PrEP), respectively. In the previous 3 months, 89% reported AI and 72% reported CAI with at least one male partner. Overall, 17%, 33%, 54%, and 72% had tested for HIV in the last 3 months, 6 months, 12 months and 2 years, respectively; 13% had tested more than 2 years ago and 15% had never tested. Among 3972 men reporting at least two recent CAI partners, only 22% had tested in the previous 3 months. Region of residence and education level were independently associated with recent HIV testing. Among current PrEP users, 15% had not tested in the previous 6 months. CONCLUSIONS: Most men in SELPHI, particularly those reporting at least two CAI partners and current PrEP users, were not testing in line with current UK recommendations. The results of the trial will inform whether online promotion of HIVST addresses ongoing testing barriers.

Continuation of emtricitabine/lamivudine within combination antiretroviral therapy following detection of the M184V/I HIV-1 resistance mutation.

OBJECTIVES: The aim of the study was to investigate whether lamivudine (3TC) or emtricitabine (FTC) use following detection of M184V/I is associated with better virological outcomes. METHODS: We identified people with viruses harbouring the M184V/I mutation in UK multicentre data sets who had treatment change/initiation within 1 year. We analysed outcomes of viral suppression (< 200 HIV-1 RNA copies/mL) and appearance of new major drug resistance mutations (DRMs) using Cox and Poisson models, with stratification by new drug regimen (excluding 3TC/FTC) and Bayesian implementation, and estimated the effect of 3TC/FTC adjusted for individual and viral characteristics. RESULTS: We included 2597 people with the M184V/I resistance mutation, of whom 665 (25.6%) were on 3TC and 458 (17.6%) on FTC. We found a negative adjusted association between 3TC/FTC use and viral suppression [hazard ratio (HR) 0.84; 95% credibility interval (CrI) 0.71-0.98]. On subgroup analysis of individual drugs, there was no evidence of an association with viral suppression for 3TC (n = 184; HR 0.94; 95% CrI 0.73-1.15) or FTC (n = 454; HR 0.99; 95% CrI 0.80-1.19) amongst those on tenofovir-containing regimens, but we estimated a reduced rate of viral suppression for people on 3TC amongst those without tenofovir use (n = 481; HR 0.71; 95% CrI 0.54-0.90). We found no association between 3TC/FTC and detection of any new DRM (overall HR 0.92; 95% CrI 0.64-1.18), but found inconclusive evidence of a lower incidence rate of new DRMs (overall incidence rate ratio 0.69; 95% CrI 0.34-1.11). CONCLUSIONS: We did not find evidence that 3TC or FTC use is associated with an increase in viral suppression, but it may reduce the appearance of additional DRMs in people with M184V/I. 3TC was associated with reduced viral suppression amongst people on regimens without tenofovir.

Containing a measles outbreak in Minnesota, 2017: methods and challenges.

AIMS: We report on a measles outbreak largely occurring in Minnesota's under-vaccinated Somali community in the spring of 2017. The outbreak was already into its third generation when the first two cases were confirmed, and rapid public health actions were needed. The aim of our response was to quickly end transmission and contain the outbreak. METHODS: The state public health department performed laboratory testing on suspect cases and activated an Incident Command staffed by subject matter experts that was operational within 2 h of case confirmation. Epidemiologic interviews identified exposures in settings where risk of transmission was high, that is, healthcare, childcare, and school settings. Vaccination status of exposed persons was assessed, and postexposure prophylaxis (PEP) was offered, if applicable. Exposed persons who did not receive PEP were excluded from childcare centers or schools for 21 days. An accelerated statewide measles, mumps, and rubella (MMR) recommendation was made for Somali Minnesota children and children in affected outbreak counties. Partnerships with the Somali Minnesota community were deepened, building off outreach work done with the community since 2008. RESULTS: Public health identified 75 measles cases from 30 March to 25 August 2017: 43% were female, 81% Somali Minnesotan, 91% unvaccinated, and 28% hospitalized. The median age of cases was 2 years (range: 3 months-57 years). Most transmission (78%) occurred in childcare centers and households. A secondary attack rate of 91% was calculated for unvaccinated household contacts. Over 51,000 doses of MMR were administered during the outbreak above expected baseline. At least 8490 individuals were exposed to measles; 155 individuals received PEP; and over 500 persons were excluded from childcare and school. State and key public health partners spent an estimated $2.3 million on response. CONCLUSION: This outbreak demonstrates the necessity of immediate, targeted disease control actions and strong public health, healthcare, and community partnerships to end a measles outbreak.

HIV self-testing intervention experiences and kit usability: results from a qualitative study among men who have sex with men in the SELPHI (Self-Testing Public Health Intervention) randomized controlled trial in England and Wales.

OBJECTIVES: SELPHI (HIV Self-Testing Public Health Intervention) is the largest randomized controlled trial (RCT) of HIV self-testing (HIVST) in a high-income setting to date, and has recruited 10 000 men who have sex with men (cis- and transgender) and transgender women who have sex with men. This qualitative substudy aimed to explore how those utilizing self-tests experience HIVST and the implications for further intervention development and scale-up. This is the first qualitative study in Europe investigating experiences of HIVST among intervention users, and the first globally examining the experience of using blood-based HIVST. METHODS: Thirty-seven cisgender MSM SELPHI participants from across England and Wales were purposively recruited to the substudy, in which semi-structured interviews were used to explore testing history, HIVST experiences and intervention preferences. Interviews were audio-recorded, transcribed and analysed through a framework analysis. RESULTS: Men accessed the intervention because HIVST reduced barriers related to convenience, stigma and privacy concerns. Emotional responses had direct links to acceptability. Supportive intervention components increased engagement with testing and addressed supportive concerns. HIVST facilitated more frequent testing, with the potential to reduce sexually transmitted infection (STI) screening frequency. Substudy participants with an HIV-positive result (n = 2) linked to care promptly and reported very high acceptability. Minor adverse outcomes (n = 2; relationship discord and fainting) did not reduce acceptability. Ease of use difficulties were with the lancet and the test processing stage. CONCLUSIONS: Intervention components shaped acceptability, particularly in relation to overcoming a perceived lack of support. The intervention was broadly acceptable and usable; participants expressed an unexpected degree of enthusiasm for HIVST, including those with HIV-positive results and individuals with minor adverse outcomes.

Operative and survival outcomes in a series of 100 consecutive cases of robot-assisted transhiatal esophagectomies.

Robotic-assisted transhiatal esophagectomy (RATE) is a technically complex procedure with potential for improved postoperative outcomes. In this report, we describe our experience with RATE in a large case series. A retrospective review was conducted to collect clinical, outcomes, and survival data for 100 consecutive patients with esophageal cancer (n = 98) and benign (n = 2) conditions undergoing RATE between March 2007 and December 2014. Progression-free (PFS) and overall (OS) survival were estimated using the Kaplan-Meier curves with comparisons by log-rank tests. Median operative time and estimated blood loss were 264 minutes and 75 mL, respectively. Median intensive care unit stay was 1 day and median length of hospital stay was 8 days. Postoperative complications commonly observed were nonmalignant pleural effusion (38%) and recurrent laryngeal nerve injury (33%); 30 day mortality rate was 2%. Median number of lymph nodes removed during RATE was 17 and R0 resection was achieved in 97.8% patients. At the end of the median follow-up period of 27.7 months, median PFS was 41 months and median OS was 54 months. 1-year and 3-year PFS rates were 82% (95% CI, 75%-89%) and 53% (95% CI, 42%-62%), respectively, and OS rates were 95% (95% CI, 91%-99%) and 57% (95% CI, 46%-67%). In our experience, RATE is an effective and safe oncologic surgical procedure in a carefully selected group of patients with acceptable operative time, minimal blood loss, standard postoperative morbidity and adequate PFS and OS profiles.

Recent trends and patterns in HIV-1 transmitted drug resistance in the United Kingdom.

OBJECTIVES: Transmission of drug-resistant HIV-1 has decreased in the UK since the early 2000s. This analysis reports recent trends and characteristics of transmitted drug resistance (TDR) in the UK from 2010 to 2013. METHODS: Resistance tests conducted in antiretroviral treatment (ART)-naïve individuals between 2010 and 2013 were analysed for the presence of transmitted drug resistance mutations (TDRMs), defined as any mutations from a modified 2009 World Health Organization surveillance list, or a modified 2013 International Antiviral Society-USA list for integrase tests. Logistic regression was used to examine associations between demographics and the prevalence of TDRMs. RESULTS: TDRMs were observed in 1223 (7.5%) of 16 425 individuals; prevalence declined from 8.1% in 2010 to 6.6% in 2013 (P = 0.02). The prevalence of TDRMs was higher among men who have sex with men (MSM) compared with heterosexual men and women (8.7% versus 6.4%, respectively) with a trend for decreasing TDRMs among MSM (P = 0.008) driven by a reduction in nucleoside reverse transcriptase inhibitor (NRTI)-related mutations. The most frequently detected TDRMs were K103N (2.2%), T215 revertants (1.6%), M41L (0.9%) and L90M (0.7%). Predicted phenotypic resistance to first-line ART was highest to the nonnucleoside reverse transcriptase inhibitors (NNRTIs) rilpivirine and efavirenz (6.2% and 3.4%, respectively) but minimal to NRTIs, including tenofovir, and protease inhibitors (PIs). No major integrase TDRMs were detected among 101 individuals tested while ART-naïve. CONCLUSIONS: We observed a decrease in TDRMs in recent years. However, this was confined to the MSM population and rates remained stable in those with heterosexually acquired HIV infection. Resistance to currently recommended first-line ART, including integrase inhibitors, remained reassuringly low.

Antiretroviral resistance at virological failure in the NEAT 001/ANRS 143 trial: raltegravir plus darunavir/ritonavir or tenofovir/emtricitabine plus darunavir/ritonavir as first-line ART.

OBJECTIVES: To describe the pattern of drug resistance at virological failure in the NEAT001/ANRS143 trial (first-line treatment with ritonavir-boosted darunavir plus either tenofovir/emtricitabine or raltegravir). METHODS: Genotypic testing was performed at baseline for reverse transcriptase (RT) and protease genes and for RT, protease and integrase (IN) genes for patients with a confirmed viral load (VL) >50 copies/mL or any single VL >500 copies/mL during or after week 32. RESULTS: A resistance test was obtained for 110/805 (13.7%) randomized participants qualifying for resistance analysis (61/401 of participants in the raltegravir arm and 49/404 of participants in the tenofovir/emtricitabine arm). No resistance-associated mutation (RAM) was observed in the tenofovir/emtricitabine plus darunavir/ritonavir arm, and all further analyses were limited to the raltegravir plus darunavir arm. In this group, 15/55 (27.3%) participants had viruses with IN RAMs (12 N155H alone, 1 N155H + Q148R, 1 F121Y and 1 Y143C), 2/53 (3.8%) with nucleotide analogue RT inhibitor RAMs (K65R, M41L) and 1/57 (1.8%) with primary protease RAM (L76V). The frequency of IN mutations at failure was significantly associated with baseline VL: 7.1% for a VL of <100,000 copies/mL, 25.0% for a VL of ≥100,000 copies/mL and <500,000 copies/mL and 53.8% for a VL of ≥500,000 copies/mL (PTREND = 0.007). Of note, 4/15 participants with IN RAM had a VL < 200 copies/mL at time of testing. CONCLUSIONS: In the NEAT001/ANRS143 trial, there was no RAM at virological failure in the standard tenofovir/emtricitabine plus darunavir/ritonavir regimen, contrasting with a rate of 29.5% (mostly IN mutations) in the raltegravir plus darunavir/ritonavir NRTI-sparing regimen. The cumulative risk of IN RAM after 96 weeks of follow-up in participants initiating ART with raltegravir plus darunavir/ritonavir was 3.9%.

Virological failure and development of new resistance mutations according to CD4 count at combination antiretroviral therapy initiation.

OBJECTIVES: No randomized controlled trials have yet reported an individual patient benefit of initiating combination antiretroviral therapy (cART) at CD4 counts > 350 cells/µL. It is hypothesized that earlier initiation of cART in asymptomatic and otherwise healthy individuals may lead to poorer adherence and subsequently higher rates of resistance development. METHODS: In a large cohort of HIV-positive individuals, we investigated the emergence of new resistance mutations upon virological treatment failure according to the CD4 count at the initiation of cART. RESULTS: Of 7918 included individuals, 6514 (82.3%), 996 (12.6%) and 408 (5.2%) started cART with a CD4 count ≤ 350, 351-499 and ≥ 500 cells/µL, respectively. Virological rebound occurred while on cART in 488 (7.5%), 46 (4.6%) and 30 (7.4%) with a baseline CD4 count ≤ 350, 351-499 and ≥ 500 cells/µL, respectively. Only four (13.0%) individuals with a baseline CD4 count > 350 cells/µL in receipt of a resistance test at viral load rebound were found to have developed new resistance mutations. This compared to 107 (41.2%) of those with virological failure who had initiated cART with a CD4 count < 350 cells/µL. CONCLUSIONS: We found no evidence of increased rates of resistance development when cART was initiated at CD4 counts above 350 cells/µL.

HLA alleles and haplotypes in Burmese (Myanmarese) and Karen in Thailand.

This is the first report on human leukocyte antigen (HLA) allele and haplotype frequencies at three class I loci and two class II loci in unrelated healthy individuals from two ethnic groups, 170 Burmese and 200 Karen, originally from Burma (Myanmar), but sampled while residing in Thailand. Overall, the HLA allele and haplotype frequencies detected by polymerase chain reaction sequence-specific primer (PCR-SSP) at five loci (A, B, C, DRB1 and DRQB1) at low resolution showed distinct differences between the Burmese and Karen. In Burmese, five HLA-B*15 haplotypes with different HLA-A and HLA-DR/DQ combinations were detected with three of these not previously reported in other Asian populations. The data are important in the fields of anthropology, transplantation and disease-association studies.

Global HIV-1 transmitted drug resistance in the INSIGHT Strategic Timing of AntiRetroviral Treatment (START) trial.

OBJECTIVES: HIV-1 transmitted drug resistance (TDR) in treatment-naïve individuals is a well-described phenomenon. Baseline genotypic resistance testing is considered standard of care in most developed areas of the world. The aim of this analysis was to characterize HIV-1 TDR and the use of resistance testing in START trial participants. METHODS: In the Strategic Timing of AntiRetroviral Treatment (START) trial, baseline genotypic resistance testing results were collected at study entry and analysed centrally to determine the prevalence of TDR in the study population. Resistance was based on a modified 2009 World Health Organization definition to reflect newer resistance mutations. RESULTS: Baseline resistance testing was available in 1946 study participants. Higher rates of testing occurred in Europe (86.7%), the USA (81.3%) and Australia (89.9%) as compared with Asia (22.2%), South America (1.8%) and Africa (0.1%). The overall prevalence of TDR was 10.1%, more commonly to nonnucleoside reverse transcriptase inhibitors (4.5%) and nucleoside reverse transcriptase inhibitors (4%) compared with protease inhibitors (2.8%). The most frequent TDR mutations observed were M41L, D67N/G/E, T215F/Y/I/S/C/D/E/V/N, 219Q/E/N/R, K103N/S, and G190A/S/E in reverse transcriptase, and M46I/L and L90M in protease. By country, the prevalence of TDR was highest in Australia (17.5%), France (16.7%), the USA (12.6%) and Spain (12.6%). No participant characteristics were identified as predictors of the presence of TDR. CONCLUSIONS: START participants enrolled in resource-rich areas of the world were more likely to have baseline resistance testing. In Europe, the USA and Australia, TDR prevalence rates varied by country.

Phenotypic and genotypic analyses to guide selection of reverse transcriptase inhibitors in second-line HIV therapy following extended virological failure in Uganda.

OBJECTIVES: We investigated phenotypic and genotypic resistance after 2 years of first-line therapy with two HIV treatment regimens in the absence of virological monitoring. METHODS: NORA [Nevirapine OR Abacavir study, a sub-study of the Development of AntiRetroviral Therapy in Africa (DART) trial] randomized 600 symptomatic HIV-infected Ugandan adults (CD4 cell count <200 cells/mm(3)) to receive zidovudine/lamivudine plus abacavir (cABC arm) or nevirapine (cNVP arm). All virological tests were performed retrospectively, including resistance tests on week 96 plasma samples with HIV RNA levels ≥1000 copies/mL. Phenotypic resistance was expressed as fold-change in IC(50) (FC) relative to wild-type virus. RESULTS: HIV-1 RNA viral load ≥1000 copies/mL at week 96 was seen in 58/204 (28.4%) cABC participants and 21/159 (13.2%) cNVP participants. Resistance results were available in 35 cABC and 17 cNVP participants; 31 (89%) cABC and 16 (94%) cNVP isolates had a week 96 FC below the biological cut-off for tenofovir (2.2). In the cNVP arm, 16/17 participants had resistance mutations synonymous with high-level resistance to nevirapine and efavirenz; FC values for etravirine were above the biological cut-off in 9 (53%) isolates. In multivariate regression models, K65R, Y115F and the presence of thymidine analogue-associated mutations were associated with increased susceptibility to etravirine in the cABC arm. CONCLUSIONS: Our data support the use of tenofovir following failure of a first-line zidovudine-containing regimen and shed further light on non-nucleoside reverse transcriptase inhibitor hypersusceptibility.

Vitamin D represses dentin matrix protein 1 in cementoblasts and osteocytes.

Calcium and phosphorus homeostasis is achieved by interplay among hormones, including 1,25(OH)2D3 (1,25D), parathyroid hormone, and fibroblast growth factor 23 (FGF23), and their interactions with other proteins. For example, mutations in dentin matrix protein 1 (DMP-1) result in increased FGF23 and hypophosphatemic rickets. 1,25D is reported to modulate FGF23; thus, we hypothesized that 1,25D may be involved in modulating DMP-1 in an intermediary step. Murine cementoblasts (OCCM-30) and osteocyte-like cells (MLO-Y4 and MLO-A5), known to express DMP-1, were used to analyze effects of 1,25D on DMP-1 expression in vitro. DMP-1 mRNA levels decreased by 50% (p < .05) in the presence of 1,25D in all cell types, while use of a vitamin D receptor (VDR) agonist (EB1089) and antagonist (23S,25S)-DLAM-2P confirmed that VDR pathway activation was required for this response. Further analysis showed that histone deacetylase recruitment was necessary, but neither protein kinase A nor C pathways were required. In conclusion, our results support the hypothesis that 1,25D regulates DMP-1 expression through a VDR-dependent mechanism, possibly contributing to local changes in bone/tooth mineral homeostasis.

Combining HLA-DR risk alleles and anti-Epstein-Barr virus antibody profiles to stratify multiple sclerosis risk.

BACKGROUND: Risk factors for multiple sclerosis (MS) include human leukocyte antigen (HLA)-DR and Epstein-Barr virus (EBV)-specific antibody responses, including an epitope within EBV nuclear antigen 1 (EBNA-1) that is of recent interest. OBJECTIVE: The objective of this paper is to assess case-control associations between MS risk and anti-EBV antibody levels as well as HLA-DR profiles, gender and age in a population-based cohort. METHODS: Serological responses to EBV were measured in 426 MS patients and 186 healthy controls. HLA-DR typing was performed using sequence-based methods. RESULTS: MS patients had significantly higher levels of antibodies against epitope-specific and polyspecific EBNA-1 and viral capsid antigen (VCA), compared with controls (all p < 10(-15)). In regression analyses, anti-EBNA-1 and anti-VCA antibody levels, protective HLA-DR*04/07/09 alleles and gender (all p < 0.003) contributed independently to a model that classified cases and controls with an odds ratio > 20 (sensitivity 92%, specificity 64%). Notably, the strong influence of high-risk HLA-DR alleles was abrogated after inclusion of EBV serology results. CONCLUSIONS: The ability to discriminate MS cases and controls can be substantially enhanced by including anti-EBV serology as well as HLA-DR risk profiles. These findings support the relevance of EBV-specific immunity in MS pathogenesis, and implicate both HLA-dependent and HLA-independent immune responses against EBNA-1 as prominent disease risk factors.

Drug-resistance development differs between HIV-1-infected patients failing first-line antiretroviral therapy containing nonnucleoside reverse transcriptase inhibitors with and without thymidine analogues.

OBJECTIVES: We evaluated the emergence of drug resistance in patients failing first-line regimens containing one nonnucleoside reverse transcriptase inhibitor (NNRTI) administered with zidovudine (ZDV) + lamivudine (the ZDV group) or non-thymidine analogues (non-TAs) (tenofovir or abacavir, + lamivudine or emtricitabine; the non-TA group). METHODS: Three hundred HIV-1-infected patients failing a first-line NNRTI-containing regimen (nevirapine, n = 148; efavirenz, n = 152) were included in the analysis. Virological failure was defined as viraemia ≥ 400 HIV-1 RNA copies/mL for the first time at least 6 months after starting the NNRTI-based regimen. For each patient, a genotypic resistance test at failure was available. The presence of drug-resistance mutations in HIV-1 reverse transcriptase was evaluated by comparing patients treated with NNRTI + zidovudine + lamivudine vs. those treated with NNRTI + non-TA. RESULTS: A total of 208 patients were failing with NNRTI + zidovudine + lamivudine and 92 with NNRTI + non-TA. No significant differences were observed between the non-TA group and the ZDV group regarding the time of virological failure [median (interquartile range): 12 (8-25) vs. 13 (9-32) months, respectively; P = 0.119] and viraemia [median (interquartile range): 4.0 (3.2-4.9) vs. 4.0 (3.3-4.7) log10 copies/mL, respectively; P = 0.894]. Resistance to reverse transcriptase inhibitors (RTIs) occurred at a significant lower frequency in the non-TA group than in the ZDV group (54.3 vs. 75.5%, respectively; P = 0.001). This difference was mainly attributable to a significantly lower prevalence of NNRTI resistance (54.3 vs. 74.0%, respectively; P = 0.002) and of the nucleoside reverse transcriptase inhibitor (NRTI) mutation M184V (23.9 vs. 63.5%, respectively; P < 0.001) in the non-TA group compared with the ZDV group. As expected, the mutation K65R was found only in the non-TA group (18.5%; P < 0.001). CONCLUSIONS: At first-line regimen failure, a lower prevalence of RTI resistance was found in patients treated with NNRTI + non-TA compared with those treated with NNRTI + zidovudine + lamivudine. These results confirm that the choice of backbone may influence the prevalence of drug resistance at virological failure.

Subtype-specific differences in the development of accessory mutations associated with high-level resistance to HIV-1 nucleoside reverse transcriptase inhibitors.

OBJECTIVES: To identify accessory mutations associated with high-level resistance to reverse transcriptase (RT) inhibitors in HIV-1 subtypes B and C. METHODS: Changes relative to the wild-type for codons 1-400 of RT were analysed from treatment-experienced patients infected with subtypes B (5464 patients) and C (1920 patients). Positions associated with the accumulation of mutations conferring resistance to thymidine analogues and to non-nucleoside RT inhibitors (NNRTIs) were identified. A subtype-specific single-replication cycle drug susceptibility assay was used to determine whether some of the mutations affected drug susceptibility or viral infectivity. RESULTS: In subtype B, mutations at 31 and 26 positions were associated with the accumulation of thymidine analogue mutations (TAMs) and NNRTI mutations, respectively; in subtype C, 18 and 13 positions were identified, respectively. Amino acid changes at the following positions were differentially associated with (i) the accumulation of 0-4+ TAMs in subtypes B and C (away from consensus): 43 (27.0% B versus 2.5% C); 118 (36.4% B versus 16.2% C); 135 (12.5% B versus 28.0% C); and 326 (2.6% towards consensus in B versus 7.6% away in C) and (ii) the accumulation of 0-3+ NNRTI mutations (away from consensus): 43 (10.2% B versus 0.5% C); and 68 (5.2% B versus 10.3% C). Codon changes K43E, E44D and V118I were found to have no effect on susceptibility to three NRTIs with or without TAMs in either subtype; however, some accessory mutations had subtype-specific effects on viral infectivity. CONCLUSIONS: Differences between subtypes B and C were observed in the development and effect of accessory mutations associated with high-level resistance to RT inhibitors.

Robot-assisted transhiatal esophagectomy: a 3-year single-center experience.

Minimally invasive esophagectomy has emerged as an important procedure for disease management in esophageal cancer (EC) with clear margin status, less morbidity, and shorter hospital stays compared with open procedures. The experience with transhiatal approach robotic esophagectomy (RE) for dissection of thoracic esophagus and associated morbidity is described here. Between March 2007 and November 2010, 40 patients with resectable esophageal indications underwent transhiatal RE at the institute. Clinical data for all patients were collected prospectively. Of 40 patients undergoing RE, one patient had an extensive benign stricture, one had high-grade dysplasia, and 38 had EC. Five patients were converted from robotic to open. Median operative time and estimated blood loss were 311 minutes and 97.2 mL, respectively. Median intensive care unit stay was 1 day (range, 0-16), and median length of hospital stay was 9 days (range, 6-36). Postoperative complications frequently observed were anastomotic stricture (n= 27), recurrent laryngeal nerve paresis (n= 14), anastomotic leak (n= 10), pneumonia (n= 8), and pleural effusion (n= 18). Incidence rates of laryngeal nerve paresis (35%) and leak rate (25%) were somewhat higher in comparison with that reported in literature. However, all vocal cord injuries were temporary, and all leaks healed following opening of the cervical incision and drainage. None of the patients died in the hospital, and 30-day mortality was 2.5% (1/40). Median number of lymph nodes removed was 20 (range, 3-38). In 33 patients with known lymph node locations, median of four (range, 0-12) nodes was obtained from the mediastinum, and median of 15 (range, 1-26) was obtained from the abdomen. R0 resection was achieved in 94.7% of patients. At the end of the follow-up period, 25 patients were alive, 13 were deceased, and 2 patients were lost to follow-up. For patients with EC, median disease-free survival was 20 months (range, 3-45). Transhiatal RE, by experience, is a feasible albeit evolving oncologic operation with low hospital mortality. The benefits include minimally invasive mediastinal dissection without thoracotomy or thoracoscopy. A reasonable operative time with minimal blood loss and postoperative morbidity can be achieved, in spite of the technically demanding nature of the procedure. Broader use of this technology in a setting of high-volume comprehensive surgical programs will almost certainly reduce the complication rates. Robotic tanshiatal esophagectomy with the elimination of a thoracic approach should be considered an option for the appropriate patient population in a comprehensive esophageal program.

Non-uptake of highly active antiretroviral therapy among patients with a CD4 count < 350 cells/µL in the UK.

OBJECTIVES: Current British HIV Association (BHIVA) guidelines recommend that all patients with a CD4 count <350 cells/µL are offered highly active antiretroviral therapy (HAART). We identified risk factors for delayed initiation of HAART following a CD4 count <350 cells/µL. METHODS: All adults under follow-up in 2008 who had a first confirmed CD4 count <350 cells/µL from 2004 to 2008, who had not initiated treatment and who had >6 months of follow-up were included in the study. Characteristics at the time of the low CD4 cell count and over follow-up were compared to identify factors associated with delayed HAART uptake. Analyses used proportional hazards regression with fixed (sex/risk group, age, ethnicity, AIDS, baseline CD4 cell count and calendar year) and time-updated (frequency of CD4 cell count measurement, proportion of CD4 counts <350 cells/µL, latest CD4 cell count, CD4 percentage and viral load) covariates. RESULTS: Of 4871 patients with a confirmed low CD4 cell count, 436 (8.9%) remained untreated. In multivariable analyses, those starting HAART were older [adjusted relative hazard (aRH)/10 years 1.15], were more likely to be female heterosexual (aRH 1.13), were more likely to have had AIDS (aRH 1.14), had a greater number of CD4 measurements < 350 cells/µL (aRH/additional count 1.18), had a lower CD4 count over follow-up (aRH/50 cells/µL higher 0.57), had a lower CD4 percentage (aRH/5% higher 0.90) and had a higher viral load (aRH/log(10) HIV-1 RNA copies/ml higher 1.06). Injecting drug users (aRH 0.53), women infected with HIV via nonsexual or injecting drug use routes (aRH 0.75) and those of unknown ethnicity (aRH 0.69) were less likely to commence HAART. CONCLUSION: A substantial minority of patients with a CD4 count < 350 cells/µL remain untreated despite its indication.