A cross-sectional study on the prevalence of HIV drug resistance in patients receiving antiretroviral treatment in Shenqiu county, Henan province / 中华流行病学杂志

Objective To understand the prevalence of drug resistance in AIDS patients who had been receiving HAART in a long run,in Shenqiu county,Henan province.Methods This crosssectional study included 120 HIV infected patients who began receiving ART (antiretroviral therapy) in 2003.Viral loads and CD4 +T cells counts were measured,and In-house drug resistance test was performed in VL ＞ 1000 copies/ml patients.Results 114 cases out of 120 patients had complete viral load data.Among them,33 cases having viral loads less than 50 copies/ml,and the remaining viral loads showed an average of lg (4.09 ± 1.10) copies/ml.The average of CD4+ T cell counts was (377 ±2 1 8) cells/ml,with 64 (53.3％) cases showing their CD4+ T cell counts higher than 350 cells/ml.In 67 patients,58 of them showed genotypic resistance,and 40 cases showed reverse transcriptase inhibitors (RTIs) resistance.The ratios of nucleoside reverse transcriptase inhibitors (NRTIs) and nonnucleoside reverse transcriptase inhibitors (NNRTIs) resistance were 53.4％ (31/58) and 67.2％ (39/58),respectively.There were no differences of drug resistance ratio in the three treatment programs.The highest drug resistance rates in NRTIs and NNRTIs were zidovudine,lamivudin,nevirapine.However,protease inhibitors (PIs) resistance variants were not found.Conclusion The prevalence of drug-resistant strains seemed to be high in Shenqiu country,Henan province.Long-term follow-up monitoring strategy should be developed to optimize the timely treatment programs.

Studying on the prevalence and mutation pattern of N348I which related to the resistance of HIV-1 / 中华流行病学杂志

Objective To elucidate the prevalence and the mutation pattern of N348I that related to the resistance seen in the AIDS patients, in China. Methods Partial pol gene of HIV-1 comprising of full protease (PR) and reverse transeriptase (RT) was obtained from plasma samples of therapy-failure individuals (n=614) and therapy-naive individuals (n=619) by using reverse transcription polymerase chain reaction(RT-PCR). 1233 sequences were then submitted to the HIV-1 drug resistance database of the Stanford University to analyze the prevalence and the emergence pattern of N348I. Results The prevalence of N348I was 6.5％ in the therapy-failure patients and 0.8％ in the naive individuals, respectively. The prevalence of N348I was more popular among those patients whose ART regimens containing zidovudine (AZT or ZDV) than those without AZT in regimens( 14.1％ vs. 4.7％, x2=10.21, P＜0.01 ). N3481 always emerged, and combined with others mutations among patients of ART, whose frequencies were: 85.0％ in combination with thymidine analog mutations (TAMs) and 52.5％ with M184V/I, respectively. Conclusion N348I was somehow prevalent in the therapy-failure patients when using the first-line antiretroviral drugs,and it emerged as unique patterns. This study laid the ground in improving the techaology of drug resistance genotypes detection and providing theoretical basis to study the mechanism of resistance and the law of molecular evolution.

Screening program on novel drug resistance mutations of subtype B' in human immunodeficiency virus type 1 in China / 中华流行病学杂志

Objective To screen the level of novel drug resistance mutations in subtype B' in China. Methods 451 pol sequences collected from the previous study, which including 354 AIDS patients who had received antiretroviral treatment(ART)and 97 the untreated patients. Entire protease gene(codous 1-99)and full-length reverse transcriptase gene(codons 1-560)were included.Variation of mutations between the treated and the untreated patients with consensus/ancestral sequences were compared and the mutations with higher frequencies in the treated patients than in the untreated patients were screened before submitting the mutations to the Stanford HIV Drug Resistance Database(SHDB)(http://hivdb.stanford.edu/). Relation between the mutations and resistance preliminarily was then analyzed, according to the information including SHDB. Results Frequencies of 7 mutations at 6 positions, DI23E, V292I, K366R, T369A, T369V, A371V and 1375V, 2 at DNA polymerase domain and 5 at connection domain of reverse transcriptase(RT)were higher in the treated patients than in the untreated patients. The information of 7 mutations including the SHDB showed that 7 mutations were major variants at corresponding positions, and theirs frequencies were higher in the treated patients using some drugs, than in the untreated patients. Conclusion 7mutations being screened from the China subtype B were possibly associated with the resistance,which called for the construction of mutated viruses by site-directed mutagenesis to identify their effects on the susceptivity of different drugs.

Allele-specific real-time PCR testing for minor HIV-1 drug resistance mutations: assay preparation and application to reveal dynamic of mutations in vivo / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>It is very important for the clinical management to test for minor HIV-1 resistance mutations accurately and sensitively. The conventional genotypic assays of HIV drug resistance detection based on sequencing can only discriminate the mutations which present in more than 20% - 30%. The aim of this study was to evaluate allele-specific real-time PCR (ASPCR) to detect the resistance-related mutations located at positions 103, 184 and 215.</p><p><b>METHODS</b>We developed the allele-specific PCR assay, using the most common drug resistance mutations in Chinese AIDS patients, K103N, M184V/I, T215F/Y as a model system. The standards were constructed by cloning the wild-type and mutant DNA fragments into the T-vector. We designed specific primers to discriminate mutant templates in the real-time PCR using SYBR green as a fluorescence reporter. And then we evaluated the ASPCR assay and tested 140 clinical samples using this method.</p><p><b>RESULTS</b>The sensitivities of ASPCR assay were 0.04% for K103N, 0.30% for M184I, 0.40% for M184V, 0.03% for T215F and 0.02% for T215Y. The intra-assay and inter-assay coefficients of variation were less than 0.42. One hundred and forty plasma samples were tested by ASPCR and dynamic resistance curves of ten patients were obtained.</p><p><b>CONCLUSIONS</b>Drug resistance emerged half a year after the start of antiretroviral therapy. The mutation of T215Y emerged 1 to 1.5 years after starting treatment and then increased rapidly. The ASPCR assay we developed was a sensitive, accurate and rapid method to detect the minor HIV-1 variants and it can provide earlier and more drug-resistance information for HIV research and AIDS antiretroviral therapy.</p>

Competitive capacity of HIV-1 strains carrying M184I or Y181I drug-resistant mutations / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Virus with nucleoside reverse transcriptase inhibitors (NRTIs) or nonnucleoside reverse transcriptase inhibitors (NNRTIs) resistant mutations show different evolution tendencies when the anti-viral therapies are interrupted. Understanding the replication fitness of drug-resistant virus is important for the study of the prevalence of drug-resistance. For this purpose, we characterized the replication capacity of HIV-1 virus carrying lamivudine (3TC) or nevirapine (NVP) resistant mutations.</p><p><b>METHODS</b>3TC and NVP resistant variants were induced in vitro by selecting wild type virus in the presence of drugs. For the competitive replication assay, drug-resistant variants were cocultured with wild-type virus in the presence or absence of drugs. The ratios of the viral species were determined over time by using a real-time RT-PCR-based assay.</p><p><b>RESULTS</b>3TC-resistant (M184I mutation) and NVP-resistant (Y181I mutation) virus should be selected in vitro in two different ways. The competitive replication assay showed that the ratio of virus carrying a M184I mutation increased from 98.8%, while the wild type virus decreased to 1.2% after 4 passages in the presence of 3TC; the percentage of virus carrying the Y181I mutation increased to 90.5%, while wild type virus decreased to 9.5% in the presence of NVP. In the absence of drugs, the ratio of virus carrying the M184I mutation decreased to 5.3%, while wild type virus increased to 94.7%; the ratio of virus carrying Y181I increased to 75%, while wild type virus decreased to 25% after 4 passages.</p><p><b>CONCLUSIONS</b>The NVP-resistant virus is fitter than wild type virus even in the absence of NVP that may be the reason that NNRTIs-resistant virus is spreading quickly.</p>

Subtype and characterization of gag gene of HIV-1 strains prevalent in some areas of China / 军事医学科学院院刊

Objective:To investigate the subtype distribution of HIV-1 strains prevalent in four areas of China,and to study the characteristics of gag gene variation and changes in antigen epitopes under the host immune pressures. Methods:The plasma of HIV-1 infected people from Henan, Guangdong, Sichuan and Beijing in China were collected. Virion RNA was extracted directly from plasma after the virion was condensed. The gag gene was amplified by RT-PCR and nested-PCR.Sequences were subtyped by Genotyping Tool software, and phylogenetic analysis of gag gene were performed using the MEGA 4.1 software.The gene distances intra each subtype were calculated by Distance program. The Ks/Ka ratios were calculated using SNAP program. The variation analysis of CTL antigen epitopes restricted by main HLA-Ⅰ specificities in China was performed.Results:Six subtypes or circulating recombinant forms(CRFs)of HIV-1,including B',CRF07_BC,CRF01_AE,B,CRF08_BC and CRF02_AG,were identified in four areas of China.The gene distances intra each subtype were CRF01_AE>B>CRF08_BC> CRF07_BC>B' listed in order of size, meanwhile the order of Ks/Ka ratios was CRF01_AE>B>CRF08_BC>B'>CRF07_BC. Far more diversity of antigen epitopes in P17 region was observed than that in P24.Epitope mutations intra subtypes were CRF01_AE>B>B'>CRF07_BC listed in order of size. Conclusion:Itseems that CRF01_AE is under the strongest immune pressures,and displays the most diversity of gene and variation of epitopes intra subtypes prevalent in China, followed by subtype B, B' and CRF07_BC. The discrepancy of epitope mutations intra the subtypes is significant.

Research on the selective kinetics of HIV-1 nucleoside reverse transcriptase inhibitor drug resistance-associated mutations among 4 AIDS patients receiving highly active antiretroviral therapy / 中华流行病学杂志

<p><b>OBJECTIVE</b>To elucidate the molecular evolutional characteristics of HIV-1 nucleoside reverse transcriptase inhibitor (NRTI) drug resistance-associated mutations in patients with AIDS receiving highly active antiretroviral therapy.</p><p><b>METHODS</b>We selected 4 AIDS patients receiving highly active antiretroviral therapy (HAART) with good adherence under a HIV-1 drug resistance cohort from a rural region in central China. Those people carried susceptible virus at the beginning of treatment and gradually came to produce virus resistant to NRTIs during the process of antiretroviral therapy (ART). Reverse transcriptase (RT) genes from each patient's peripheral blood samples (from 3 to 33 months after withdrawal) were cloned and sequenced in succession.</p><p><b>RESULTS</b>We sequenced a total number of 855 clones and obtained the HIV-1 NRTI drug resistance-associated mutations patterns of the 4 patients. Typical resistance mutations of thymidine analogue mutations (TAMs) pattern 1, such as L210W, T215Y and M41L, were generated in patient 'A'. TAMs pattern 2, including D67N, K70R and K219Q mutations, was discovered in patient 'B'. Interestingly, in patient 'C', some clones comprising not only TAMs pattern 1 mutations (T215Y) but also TAMs pattern 2 mutations (K70R, D67N).</p><p><b>CONCLUSION</b>The four patients show different pathways on HIV-1 NRTI drug resistance-associated mutations, including TAMs pattern 1, TAMs pattern 2 and the fusion pattern of TAMs-1 & TAMs-2. We also noticed that the tendency of gradual accumulation was obvious and those mutations detected earlier tended to be the predominant strains.</p>

Study on the difference of the APOBEC3G mRNA levels among HIV long-term nonprogressors, slow progressors, people at high risks and normal people / 中华流行病学杂志

Objective To examine the APOBEC3G(hA3G)mRNA levels of four different groups in the human immunodeficiency virus(HIV)prevalent areas in central China and to analyze the relationship between hA3G mRNA levels and HIV disease progression.Methods We collected peripheral blood and isolated the peripheral boold monouuclear cells(PBMCs),and then cryo-preserved the PBMCs in liquid nitrogen.Prior to the total extraction of RNA,PBMCs were resuscitated and mRNA were reverse Transcripted to cDNA in vitro.Real-time polymerase chain reaction(PCR)was used to test hA3G mRNA levels of different groups.Results There were 13 HIV long term non-progressors with the mean CD+4 T lymphocyte count as(716±169)per μl and the mean affection time as(12.5±2.3)years.There were 48HIV slow progressors with the mean CD+4 T lymphocyte count as(233±144)per μl and the mean affection time as(10.7±2.2)years.The hA3G mRNA level of HIV long term nonprogressors was higher than that of normal people while the hA3G mRNA level of HIV slow progressors was higher than that of normal people and high risk people.There were no correlations between CD+4 T lymphocyte count and hA3G mRNA levels of HIV long term nonprogressors as well as in HIV slow progressors.Conclusion There was difference found in the hA3G mRNA levels of four groups in the HIV popular area in central China while no correlation between CD+4 T lymphocyte count and hA3G mRNA levels of HIV long term nonprogressors as well as in HIV slow progressors were found.

Study on the antiviral therapy program among people with human immunodeficiency virus in Guangxi Zhuang Authority / 中华流行病学杂志

<p><b>OBJECTIVE</b>To explore the reconstitution of immune function and viral suppression condition and to analyze the occurrence of drug resistance HIV-1 variants and its prevalence after using HAART in Guangxi Autonomy Region.</p><p><b>METHODS</b>From July 2004 to October 2005, 133 HIV infected individuals who had received HAART for more than three months were recruited, and 58 infected persons with no antiviral therapy were selected as controls. Questionnaire was used to collect information about the adherence of HAART therapy. Immune reconstruction and viral suppress conditions were obtained by CD4+ counts and viral load and RT-PCR were used to amplify the PR and RT regions of HIV-1 genome while HIV-1 drug resistance rates were analyzed to show the occurrence and prevalence in both treated and naive patients.</p><p><b>RESULTS</b>In terms of CD4+ T cell counts: 70.69% of the treated patients showed obvious increase and 23.28% had no apparent change but 6.03% of them went down. 70.48% of the patients who had received antiviral therapy more than 3 months had their viral load lower than the low detectable limitation. When comparing the log of viral load between treated and untreated cohort, the mean value of the treated was obviously less than the untreated (P < 0.05). However,the result of drug resistance showed no obvious difference between the treated and untreated groups.</p><p><b>CONCLUSION</b>The antiviral therapy being used in Guangxi region, had achieved obvious effect on the reconstruction of immune system and the suppression of viral replication in vivo under good adherence while the occurrence of drug-resistant HIV strain did not show obvious difference between treated and naive patient groups.</p>

Study on the effect of treatment and the status of drug resistance among HIV/AIDS patients treated with highly active antiretroviral therapy in Shandong province / 中华流行病学杂志

<p><b>OBJECTIVE</b>To understand the effect of highly active antiretroviral therapy (HAART) on AIDS patients, and to explore the prevalence and the impact of HIV-1 drug resistance in Shandong province.</p><p><b>METHODS</b>2 cross-sectional studies were carried on in 2004 and 2005, to collect data on clinical symptoms and compliance of the AIDS patients with HAART through questionnaire. Informed-consent principle was followed to test on immunological, viral and laboratory index of them. HIV-1 drug genotype resistance by sequencing the gene of HIV-POL after RT-PCR was performed and analyzed.</p><p><b>RESULTS</b>31 AIDS cases with and. 27 AIDS cases without HAART, were studied. 83.3% and 64.5% of the AIDS patients with HAART showed that the CD4+ T cell count was rising to over 350/microl, in the first study (2004) and in the second (2005) study respectively but still 45.8% and 45.2% of AIDS patients under HAART in the 2 years showed a decreasing HIV load under the detected limit. However, these findings were showing remarkable difference when compared with the AIDS without HAART. 7 drug resistance gene sites were found in AIDS patients with HAART and in AIDS patients without HAART. The rate on high degree drug resistance mutation and total drug resistance rate of mutation of the former were higher remarkably than those of the latter.</p><p><b>CONCLUSION</b>Most of the AIDS patients with HAART met the purpose of rebuilding immunity and control of HIV,as well as alleviation of symptoms. Although the drug resistance stain appeared in Shandong,but had little effect on HAART. AIDS; Drug resistance; Highly active antiretroviral therapy</p>

Phenotypic resistance of resistant strains of HIV type-1 subtype B in China / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>This study was aim to explore the characteristics of phenotypic resistance of resistant strains of HIV type-1 (HIV-1) subtype B and to compare the concordance between the phenotypic resistance and genotypic resistance.</p><p><b>METHODS</b>The genotypic resistance assay for the HIV-1 clinical isolates was performed. One isolate without resistance mutation was chosen as a drug-sensitive reference strain and seven subtype B isolates with resistance mutations were phenotypically tested. Fifty percent inhibitory concentrations (IC50) between resistant and sensitive viruses were compared. The resistance extent was determined by the folds of the increased IC50. The concordance between the phenotypic resistance and genotypic resistance was also analyzed.</p><p><b>RESULTS</b>IC50 of resistant isolates were 0.0006 - 0.1300 micromol/L for zidovudine (AZT), 0.0016 - 0.0390 micromol/L for lamivudine (3TC), 0.0104 - 0.4234 micromol/L for nevirapine (NVP), and 0.0163 - 0.1142 micromol/L for indinavir (IDV), respectively. Genotypic and phenotypic resistance assays indicated that the resistant strains were intermediately and highly resistant to nucleotide analog reverse transcriptase inhibitors and non-nucleotide analog reverse transcriptase inhibitors. The phenotypic assay was consistent with the genotypic assay. For measuring the potential resistance, the genotypic assay was more sensitive than the phenotypic. In evaluating the resistance to protease inhibitors, these two assays were discrepant.</p><p><b>CONCLUSIONS</b>Both the phenotypic and genotypic assays indicate that the resistant viruses exist in HIV-infected patients in China who have received treatment. Phenotypic and genotypic assays have high concordance, and the genotypic assay could replace the phenotypic assay to predict the HIV-1 resistance.</p>

Cohort study on human immunodeficiency virus discordant couples in the countryside of central China / 中华流行病学杂志

<p><b>OBJECTIVE</b>To establish a cohort of human immunodeficiency virus (HIV) discordant couples for follow-up studies and to collect data on frequency of HIV heterosexual transmission and related factors.</p><p><b>METHODS</b>A total of 52 HIV discordant couples were identified by face to face interview and serological testing, in which the HIV negative individuals had no HIV infection behaviors including injecting drug use, blood transfusion or having sexual partners other than his/her own wife/husband. Three times of follows-up studies were carried out in 0.5 year, 1 year and 2.5 years to collect information on their sexual practices and condom use through face to face interview together with 20 ml whole blood collected to test HIV antibody, CD4+ T cell count and viral load.</p><p><b>RESULTS</b>(1) In the period of 2.5 years follow-up, no HIV seroconversion and HIV transmission was found. (2) The frequencies of sexual intercourse between once per month to once per week were 65.4%, 72.9%, 71.7% and 80.0% at the time of cohort setup: 0.5 year, 1 year and 2.5 years of follow-up respectively. The rates of "occasional use" to "never use" condoms were 76.9%, 66.6%, 69.1% and 60.0% at the time of cohort setup as: 0.5 year, 1 year and 2.5 years of follow-up, respectively. No significant difference between different times of follow-up for sexual intercourse or condom use. (3) 85.4%, 66.6% and 60.0% of the HIV positive individuals kept their CD4+ T cell count stabilized or raised during the 0.5 year, 1 year and 2.5 years follow-up period, respectively. However, 66.7% of them showed stable or declined viral load in the period of 2.5 years follow-up. It appeared that stable or raised CD4+ T cell and the stable/declined viral load happened simultaneously.</p><p><b>CONCLUSION</b>No transmission was identified in this study. The stabilized CD4+ T cell count and viral load might be account for the reason of no transmission while the biological factors from host and virus related with transmission need to be further studied.</p>

Genotypic antiretroviral resistance testing and phylogenetic analysis of protease and reverse transcriptase in antiretroviral drug-naïve AIDS patients in Henan province / 中华流行病学杂志

<p><b>OBJECTIVE</b>Frequency, type and clinical implications on protease and reverse transcriptase drug resistance mutations were investigated and phylogenetic analysis in antiretroviral drug-naïve AIDS patients was carried out in Henan province.</p><p><b>METHODS</b>45 plasma samples were separated from the anticoagulatory whole blood, from which reverse transcription-polymerase chain reaction technique was used to amplify the partial pol gene. The sequences were analysed for genotypic antiretroviral resistance and phylogenetic relation through landing the websites http://hivdb.stanford.edu and http://hiv-web.lanl.gov, under BioEdit and DNAClub software.</p><p><b>RESULTS</b>Partial pol sequences of 36 samples were successfully amplified. The major mutation rate of resistance to protease was 8.3% (3/36), including types D30A, V32A, G73C and V82A. Minor mutation rate of resistance was 100%, including types of L63PS (36/36), I93L (35/36), V77IL (34/36), A71IVT (10/36) and D60E (2/36). The mutation rate of resistance to reverse transcriptase was 38.9% (14/36). Mutation-scoring and clinical implication clewed drug resistance rates were 5.6% (2/36) and 22.2% (8/36) to protease inhibitors and reverse transcriptase inhibitors respectively, while 1 sample was potentially low-level resistant to all of the protease inhibitors and 3 samples to part of the reverse transcriptase inhibitors. Phylogenetic analysis revealed that the pol gene of 36 samples were highly homologous and having a near relative to B.US.83.RF ACC M17451. 36 samples seemed to have the same infection source while their resistance mutations were not due to drug-resistant virus infection but to the evolving of virus in vivo.</p><p><b>CONCLUSION</b>Most of the antiretroviral drug-naïve AIDS patients in Henan province were sensitive to the currently available antiviral medicine, but antiviral treatment must be in accordance with the strict procedure and to keep better adherence, to avoid the epidemics caused by drug-resistant virus.</p>