National survey for drug-resistant variants in newly diagnosed antiretroviral drug-naive patients with HIV/AIDS in South Korea: 1999-2005

Short Communication: Trends in Transmitted Drug Resistance in Treatment-Naive HIV Patients in Korea

Transmitted drug resistance (TDR) in treatment-naive HIV patients can contribute to failure of initial antiretroviral therapy. In Korea, there has been a gradual increase in TDR, but the recent increase in the use of integrase strand transfer inhibitors (INSTIs) could affect TDR trends and INSTI resistance mutations. We evaluated the patterns of TDR in newly diagnosed HIV patients over time from 2011 to 2019. We analyzed the genotypic resistance of strains in 336 patients and sequenced the integrase gene in 71 among 336 subjects. The overall prevalence of TDR was 5.9% (20 of 336 patients), and it showed a tendency to increase over time (5.1% in 2011-2013, 6.1% in 2014-2016, and 7.2% in 2017-2019; p = .3018). Furthermore, non-nucleoside reverse transcriptase inhibitor resistance showed a marginally significant increase over time (1.45% in 2011-2013, 3.48% in 2014-2016, and 6.02% in 2017-2019; p = .0505). Regarding transmitted INSTI resistance mutation, there were no major INSTI resistance mutations but several accessory INSTI resistance mutations and predominant natural polymorphisms. This study shows several significant changes in TDR and suggests the importance of continuous surveillance of TDR and genetic variation in the integrase region.

Phylogenetic transmission clusters among newly diagnosed antiretroviral drug-naïve patients with human immunodeficiency virus-1 in Korea: A study from 1999 to 2012

Population-level phylogenetic patterns reflect both transmission dynamics and genetic changes, which accumulate because of selection or drift. In this study, we determined whether a longitudinally sampled dataset derived from human immunodeficiency virus (HIV)-1-infected individuals over a 14-year period (1999–2012) could shed light on the transmission processes involved in the initiation of the HIV-1 epidemic in Korea. In total, 927 sequences were acquired from 1999 to 2012; each sequence was acquired from an individual patient who had not received treatment. Sequences were used for drug resistance and phylogenetic analyses. Phylogenetic and other analyses were conducted using MEGA version 6.06 based on the GTR G+I parameter model and SAS. Of the 927 samples, 863 (93.1%) were classified as subtype B and 64 were classified as other subtypes. Phylogenetic analysis demonstrated that 104 of 927 patient samples (11.2%) were grouped into 37 clusters. Being part of a transmission cluster was significantly associated with subtype-B viruses, infection via sexual contact, and the infection of young males. Of all clusters, three (~8.1%) that comprised 10 individual samples (22.2% of 45 individuals) included at least one member with total transmitted drug resistance (TDR). In summary, HIV transmission cluster analyses can integrate laboratory data with behavioral data to enable the identification of key transmission patterns to develop tailored interventions aimed at interrupting transmission chains.

Molecular Epidemiology of Human Immunodeficiency Virus

During the evolution of human immunodeficiency virus (HIV), transmissions between humans and primates resulted in multiple HIV lineages in humans. This evolution has been rapid, giving rise to a complex classification and allowing for worldwide spread and intermixing of subtypes, which has consequently led to dozens of circulating recombinant forms. In the Republic of Korea, 12,522 cases of HIV infection have been reported between 1985, when AIDS was first identified, and 2015. This review focuses on the evolution of HIV infection worldwide and the molecular epidemiologic characteristics of HIV in Korea.

The trend of transmitted drug resistance in newly diagnosed antiretroviral-naive HIV/AIDS patients during 1999-2012 in South Korea

BACKGROUND

The use of antiretroviral drugs has reduced the mortality and morbidity of patients with HIV/AIDS. More than 20 antiretroviral drugs have been used in patients with HIV/AIDS since zidovudine was first introduced in 1991 in South Korea.

OBJECTIVES

To investigate and estimate the annual prevalence of transmitted drug resistance and drug-resistant variants of HIV-1 in newly diagnosed antiretroviral-naive patients in South Korea during 1999-2012.

STUDY DESIGN

Plasma specimens were collected from 928 antiretroviral-naive patients during 1999-2012. Mutations in the protease and reverse transcriptase sections of the HIV-1 pol gene were identified using the Stanford HIV Drug Resistance Database (Stanford DB).

RESULTS

Among 928 HIV-1 isolates from antiretroviral-naive patients, 45 (4.8%) showed 'intermediate' or 'resistant' drug resistance. The predicted prevalence of drug resistance among isolates was 2.2%, 2.7%, and 0.3% for resistance to nucleoside reverse transcriptase inhibitors, non-nucleoside reverse transcriptase inhibitors, and protease inhibitors, respectively.

CONCLUSIONS

There was no significant increase in the prevalence of drug resistance among antiretroviral-naive patients infected with HIV-1 during 1999-2012 in South Korea, although there was a slight increase during 2009-2012. The emergence of drug-resistant variants will continue to be monitored by national surveys.

Short Communication: Increase of HIV-1 K103N Transmitted Drug Resistance and Its Association with Efavirenz Use in South Korea

Previous studies reported a relatively low prevalence of transmitted drug resistance (TDR) in South Korea (<5%). A genotypic resistance test was performed on 131 treatment-naive HIV-1-infected individuals from February 2013 to February 2014. Eleven individuals (8.4%) presented TDR, of whom eight had K103N, revealing a significant increase in K103N TDR compared to previous studies (p<0.001). Using phylogenetic analysis, we identified three distinct clustering pairs with genetic relativeness and a total of five independent strains among the eight K103N cases. Our findings suggest that multiple sources of K103N occurred, most likely as a consequence of increased efavirenz use in South Korea.

The prevalence of antiretroviral multidrug resistance in highly active antiretroviral therapy-treated patients with HIV/AIDS between 2004 and 2009 in South Korea

BACKGROUND

Highly active antiretroviral therapy (HAART) including protease inhibitors (PIs) has been used in South Korea since 1997. Currently, more than 20 types of antiretroviral drugs are used in the treatment of human immunodeficiency virus-infected/acquired immune deficiency syndrome patients in South Korea. Despite the rapid development of various antiretroviral drugs, many drug-resistant variants have been reported after initiating HAART, and the efficiency of HAART is limited by these variants.

OBJECTIVES

To investigate and estimate the annual antiretroviral drug resistance and prevalence of antiretroviral multi-class drug resistance in Korean patients with experience of treatment.

STUDY DESIGN

The amplified HIV-1 pol gene in 535 patients requested for genotypic drug resistance testing from 2004 to 2009 by the Korea Centers for Disease Control and Prevention was sequenced and analyzed annually and totally. The prevalence of antiretroviral drug resistance was estimated based on "SIR" interpretation of the Stanford sequence database.

RESULTS

Of viruses derived from 787 specimens, 380 samples (48.3%) showed at least one drug class-related resistance. Predicted NRTI drug resistance was highest at 41.9%. NNRTI showed 27.2% resistance with 23.3% for PI. The percent of annual drug resistance showed similar pattern and slightly declined except 2004 and 2005. The prevalence of multi-class drug resistance against each drug class was: NRTI/NNRTI/PI, 9.8%; NRTI/PI, 21.9%; NNRTI/PI, 10.4%; and NRTI/NNRTI, 21.5%.

CONCLUSIONS

About 50% and less than 10% of patients infected with HIV-1 have multidrug and multiclass resistance linked to 16 antiretroviral drugs, respectively. The significance of this study lies in its larger-scale examination of the prevalence of drug-resistant variants and multidrug resistance in HAART-experienced patients in South Korea.

Evaluating immunologic response and clinical deterioration in treatment-naive patients initiating first-line therapies infected with HIV-1 CRF01_AE and subtype B

BACKGROUND

HIV-1 group M viruses diverge 25%-35% in envelope, important for viral attachment during infection, and 10%-15% in the pol region, under selection pressure from common antiretrovirals. In Asia, subtypes B and CRF01_AE are common genotypes. Our objectives were to determine whether clinical, immunological, or virological treatment responses differed by genotype in treatment-naive patients initiating first-line therapy.

METHODS

Prospectively collected longitudinal data from patients in Thailand, Hong Kong, Malaysia, Japan, Taiwan, and South Korea were provided for analysis. Covariates included demographics, hepatitis B and C coinfections, baseline CD4 T lymphocyte count, and plasma HIV-1 RNA levels. Clinical deterioration (a new diagnosis of Centers for Disease Control and Prevention category B/AIDS-defining illness or death) was assessed by proportional hazards models. Surrogate endpoints were 12-month change in CD4 cell count and virologic suppression post therapy, evaluated by linear and logistic regression, respectively.

RESULTS

Of 1105 patients, 1036 (93.8%) infected with CRF01_AE or subtype B were eligible for inclusion in clinical deterioration analyses and contributed 1546.7 person-years of follow-up (median: 413 days, interquartile range: 169-672 days). Patients >40 years demonstrated smaller immunological increases (P = 0.002) and higher risk of clinical deterioration (hazard ratio = 2.17; P = 0.008). Patients with baseline CD4 cell counts >200 cells per microliter had lower risk of clinical deterioration (hazard ratio = 0.373; P = 0.003). A total of 532 patients (48.1% of eligible) had CD4 counts available at baseline and 12 months post therapy for inclusion in immunolgic analyses. Patients infected with subtype B had larger increases in CD4 counts at 12 months (P = 0.024). A total of 530 patients (48.0% of eligible) were included in virological analyses with no differences in response found between genotypes.

CONCLUSIONS

Results suggest that patients infected with CRF01_AE have reduced immunologic response to therapy at 12 months, compared with subtype B-infected counterparts. Clinical deterioration was associated with low baseline CD4 counts and older age. The lack of differences in virologic outcomes suggests that all patients have opportunities for virological suppression.

Transmitted antiretroviral drug resistance and thumb subdomain polymorphisms among newly HIV type 1 diagnosed patients infected with CRF01_AE and CRF07_BC virus in Guangdong Province, China

The aim of this study was to elucidate the prevalence of transmitted drug-resistant (TDR) mutations and reverse transcriptase (RT) thumb subdomain polymorphisms in CRF01_AE and CRF07_BC virus among newly diagnosed, therapy-naive HIV-1 patients in Guangdong Province, China. One hundred and sixty-four samples were collected in the Guangzhou Eighth People's Hospital. The entire protease gene and 300 codons of the entry part of the reverse transcriptase were amplified and sequenced. Furthermore, genotypic drug resistance, polymorphisms, and their phylogeny were analyzed. According to eligibility criteria, seven samples were excluded, and 119 of 157 (75.8%) samples (84 CRF01_AE and 35 CRF07_BC) were amplified and sequenced successfully. The prevalence of TDR identified in the present study was 6.7% [8/119, 95% confidence interval (CI) 1.8-11.6%]. Three major resistance mutations, K103N, M184V, and Y188L, each of which caused more than one drug resistance, appeared in only two patients; the prevalence [1.7 % (2/119)] was relatively low. Until now, this is the first observation of the five newly identified accessory mutations, V35T, K43E, V60I, K122E, and E203D, and seven thumb subdomain polymorphisms, A272P, K277R, K281R, T286A, E291D, V292I, and I293V, in the RT gene in China. These findings provide useful information for guidance on the antiretroviral therapy (ART) policy in China where therapeutic options are still limited.

The prevalence of drug resistance mutations among treatment-naive HIV-infected individuals in Beijing, China

To investigate the prevalence of HIV-1 genotypic mutations for drug resistance among patients in Beijing, blood samples from 145 newly confirmed (2006-2007), treatment-naive HIV-1-infected individuals were analyzed. Seven subtypes or CRF were subsequently determined and scored by the Stanford HIV Drug Resistance algorithm: CRF01_AE HIV-1 (27.6%), subtype B' (24.1%), CRF07_BC (21.4%), subtype B (20.7%), CRF08_BC (3.4%), subtype C (2.1%), and CRF06_cpx (0.7%). Eleven of the 145 subjects studied were found to harbor the strains resistant to either protease inhibitors (PIs) (3.4%), or nucleoside reverse transcriptase inhibitors (NRTIs) (2.1%), or nonnucleoside reverse transcriptase inhibitors (NNRTIs) (3.4%). Although the prevalence of drug resistance was relatively low among the treatment-naive HIV-1 patients in Beijing in comparison to those in industrialized countries, we will continue monitoring newly infected subjects for any potential alteration of the prevalence pattern to ensure the success of the ongoing scale-up of antiretroviral treatment.

Infectivity of Homologous Recombinant HIV-1 Pseudo-virus with Reverse Transcriptase Inhibitor-related Mutations from Highly Active Antiretroviral Therapy Experienced Patients

Objectives

In this study, the viral fitness of pseudo-viruses with a drug-resistant site in the reverse transcriptase (RT) region of the genome was investigated. The pseudo-viruses were derived from highly active antiretroviral therapy (HAART)-experienced HIV/AIDS patients.

Methods

HIV-1 RNA was extracted from the plasma of HAART-experienced (KRB9149, KRB7021, KRC1097) and HAART-naïve (KRC5180, KRC5123) HIV-1 patients. The RT gene from the extracted viral RNA was amplified and the polymerase chain reaction product was cloned from the pHXB2Δ2-261 RT vector. C8166 and TZM-bl cell lines were used as the HIV-1 replication capacity measurement system. To quantify the infectivity of homologous recombinant HIV-1, the infectivity derived from each pseudo-virus was compared with the infectivity of the reference strain HXB2.

Results

Patient-derived HIV-1 was cotransfected into C8166 cells and the expression level of the p24 antigen was measured. The expression was high in the HIV-1 isolates from patients KRC5180 and KRB9149 and low in patients KRB7021, KRC5123, and KRC1097, when compared with the reference strain. The infectivity of the pseudo-virus measured in TZM-bl cells decreased in the order, reference strain HXB2 > KRC5180 > KRC5123 > KRB9149 > KRB7021 > KRC1097.

Conclusion

In this study, HIV-1 infectivity of the drug-resistant strain isolated from HAART-experienced patients with HIV/AIDS was found to be lower than the infectivity of the reference strain HXB2. This study provides useful data for the phenotypic susceptibility assay in HAART-experienced patients infected with HIV-1.

Genetic variation of the HIV-1 integrase region in newly diagnosed anti-retroviral drug-naïve patients with HIV/AIDS in Korea

The survival time of HIV/AIDS patients in Korea has increased since HAART (highly active anti-retroviral therapy) was introduced. However, the occurrence of drug-resistant strains requires new anti-retroviral drugs, one of which, an integrase inhibitor (INI), was approved by the US Food and Drug Administration (FDA) in 2007. INIs have been used for therapy in many countries and are about to be employed in Korea. Therefore, it is important to identify basic mutant variants prior to the introduction of INIs in order to estimate their efficacy. To monitor potential drug-resistant INI mutations in Korean HIV/AIDS patients, the polymorphism of the int gene was investigated together with the pol gene using a genotypic assay for 75 randomly selected Korean HIV-1 patients newly diagnosed in 2007. The drug-resistant mutation sequences were analysed using the Stanford HIV DB and the International AIDS Society resistance testing-USA panel (IAS-USA). Seventy strains of Korean subtype B were compared with foreign subtype-B strains, and there were no significantly different variants of the int gene region in the study population. Major mutation sites in the integrase (E92Q, F121Y, G140A/S, Y143C/R, Q148H/R/K and N155H) were not detected, and only a few minor mutation sites (L74M, V151I, E157Q, V165I, I203M, S230N and D232N) were identified in 21 strains (28%). Resistance due to mutations in the pol gene was observed in a single strain (1.3%) resistant to protease inhibitors (PIs) and in four strains (5.3%) resistant to reverse transcriptase inhibitors (RTIs). In summary, this demonstrates that INIs will be susceptible to drug naïve HIV/AIDS patients in Korea.

Stable and low prevalence of transmitted HIV type 1 drug resistance despite two decades of antiretroviral therapy in Hong Kong

Transmitted HIV resistance is of both clinical and public health importance. Baseline genotypic resistance testing was performed for HIV-1-infected treatment-naive patients who were newly diagnosed between 2003 and 2007 and attended the government HIV clinic in Hong Kong. International AIDS Society-USA mutation figures and the Stanford resistance interpretation algorithm were used to identify resistance mutations and drug susceptibility, respectively. The pattern and factors associated with resistance were examined. The presence of one or more IAS-USA resistance mutations was found in 26 (3.6%) of 731 patients over the 5-year study period. Overall, protease inhibitor (PI) resistance mutations were most common (16), followed by nucleoside reverse transcriptase inhibitors (NRTIs) (8) and nonnucleoside reverse transcriptase inhibitors (NNRTIs) (3). Resistance to drugs in one, two, and three classes was present in 25 (3.4%), 1 (0.1%), and 0, respectively. Seventy-eight (10.7%) had strains of reduced susceptibility, as predicted by the Stanford algorithm to display at least low-level resistance to one or more drugs of the three classes. Intermediate or high-level resistance was found in 1.6% overall, and in descending order for NRTIs, PIs, and NNRTIs. There was no temporal trend of increase in resistance. Sex between men, Chinese ethnicity, and lower baseline CD4 were associated with harboring resistant strains as elucidated by either method. We conclude that transmitted HIV-1 drug resistance is uncommon in up to two decades of antiretroviral therapy in Hong Kong. The situation has to be continually monitored for any change in significance.

Hidden drug resistant HIV to emerge in the era of universal treatment access in Southeast Asia

BACKGROUND

Universal access to first-line antiretroviral therapy (ART) for HIV infection is becoming more of a reality in most low and middle income countries in Asia. However, second-line therapies are relatively scarce.

METHODS AND FINDINGS

We developed a mathematical model of an HIV epidemic in a Southeast Asian setting and used it to forecast the impact of treatment plans, without second-line options, on the potential degree of acquisition and transmission of drug resistant HIV strains. We show that after 10 years of universal treatment access, up to 20% of treatment-naïve individuals with HIV may have drug-resistant strains but it depends on the relative fitness of viral strains.

CONCLUSIONS

If viral load testing of people on ART is carried out on a yearly basis and virological failure leads to effective second-line therapy, then transmitted drug resistance could be reduced by 80%. Greater efforts are required for minimizing first-line failure, to detect virological failure earlier, and to procure access to second-line therapies.

The prevalence of transmitted antiretroviral drug resistance in treatment-naive HIV-infected individuals in China

BACKGROUND

Transmission of HIV drug resistance (TDR) gives rise to reduced efficacy of initial antiretroviral treatment and has become a public health concern.

METHODS

A nationwide survey on TDR was conducted in antiretroviral therapy-naive HIV-1-infected individuals from September 2004 to October 2005 in China. Drug resistance genotyping was performed on subjects' plasma samples. Drug resistance mutations were determined and scored by Stanford HIV Drug Resistance algorithm.

RESULTS

Sequences were obtained from 676 individuals, of whom 61.2% were former plasma and blood donors, 17.3% were infected sexually, and 17.2% were intravenous drug users. Subtype B' HIV-1 strains were found in 73.5%, CRF01_AE in 13.9%, CRF07_BC in 6.2%, CRF08_BC in 2.7%, subtype C in 1.04%, subtype B in 0.9%, CRF02_AG in 0.4%, and B'/C intersubtype recombinant strains in 1.3% of the subjects. Twenty-six (3.8%) were found to harbor drug resistance strains. The rates of resistance to protease inhibitors, nucleoside reverse transcriptase inhibitors, and nonnucleoside reverse transcriptase inhibitors were 0.4%, 1.6%, and 2.1%, respectively. Though there was no significant difference in TDR rates between 2004 and 2005 (2.9% vs. 4.4%), an increased trend was observed in the rate of high-level drug resistance (0.8% in 2004 vs. 3.0% in 2005, P = 0.0634).

CONCLUSIONS

The rate of TDR was relatively low in China, as compared with those in developed countries. Surveys among recently HIV-infected subjects should be performed continually to ensure the success of the scale-up antiretroviral treatment.

Comparison of genotypic resistance mutations in treatment-naive HIV type 1-infected patients in Korea and China

Seventy-six treatment-naive human immunodeficiency virus (HIV)-1-infected patients were recruited from Korea and China to evaluate transmitted drug resistance (TDR). Although no major TDR was observed within the study population, some resistance-associated mutations in the reverse transcriptase region were observed (V118I 9.2%, V179D 7.9%). The frequencies of resistance-associated mutations in NNRTI (V179D) and PI minor mutations were higher in Korean patients compared with Chinese patients (13.6% vs. 0%, 45.5% vs. 12.5%, p < 0.05). Although unique clustering was observed in phylogenetic analyses according to geographic sources, cautious monitoring is recommended due to increasing TDR reports in this area where the population shares close geographic and cultural aspects.