Investigation And Study Of HIV Drug-resistant Strains Before And After Antiviral Treatment

BackgroundIt is efficient for people living with HIV to be regularly antiretroviral therapy,which could reduce the rate of morbidity and mortality.To prolong the survival time of people living with HIV,antiretroviral therapy can control the virus to a level that cannot be detected or below the test line,inhibiting secondary transmission.HIV belongs to RNA virus likely to vary.When antiretroviral therapy is carried out,drug-resistant strains can be produced under the pressure of selection of antiretroviral drugs.Drug-resistance strains can transmitted outward.Therefore,it is an effective way to end the HIV through inhibiting the emergence and prevalence of resistant strains.There are B subtype and many a circulating recombinant form in China,which mainly CRF01_AE,CRF07_BC,CRF08 BC,accompanying by various unique recombinant forms（URFs）.It introduces more DRMs（drug-resistance mutations）,which may lead to a failure of antiretroviral therapy.It has been implemented in China,a strategy of treatment as soon as discovery of people living with HIV,and then antiretroviral therapy has been one of the main preventive measures.In the current period of cumulative treatment and early antiretroviral treatment increasing year by year,it is necessary to strengthen the monitoring and influencing factors of pre-treatment HIV drug resistance and its therapeutic effect.Objective1.Understand the prevalence on the characteristics of pre-treatment HIV drug resistance（PDR）in China,and its influencing factors2.Acknowledge the changes of HIV resistant strains before and after one year of antiretroviral therapy.MethodsA cross-sectional PDR survey was performed from January 2018 to June 2018 across thirty-one provinces,autonomous regions and municipalities of mainland China.HIV PDR levels to NNRTIs,nucleoside reverse-transcriptase inhibitors（NRTIs）and protease inhibitors（PIs）were estimated by Sanger sequencing of plasma pol with the Stanford HIVdb version 8.9-1.It was carried out in a treatment point or several nearby treatment points in a city where the number of HIV positive people reported in the past 1-2 years was in the middle of the province.HIV pol region were amplified by RNA extracted from plasma in samples.More than two nodes carrying identical drug-resistant site in one molecular transmission network are defined as a drug-resistant transmission cluster.The patients with drug resistance before antiretroviral therapy in 2018 were followed up after treatment 12 months（9-15 months）as the case.At the same time,those who did not have drug resistance before antiretroviral therapy in 2018 were selected as the control,which was carried out according to the case ratio of 1:1.It is necessary to explore the changes of drug resistance before and after treatment.Before and after antiretroviral therapy,the methods applied into analysis of drug resistance were the same,version 8.9-1 in HIVdb database.The standard is one or more drugs of scores≥15 or level≥3.HIV drug resistance after antiretroviral therapy is defined the acquisition of sequences and the presence of drug-resistance mutation after antiretroviral therapy.ResultsThe first part is the distribution of subtypes,drug resistance and influencing factors about PDR in China before antiretroviral therapy.A total of 5151 participants were included in this study.Male accounted for 83.1%,Heterosexual transmission accounted for 52.4%.CD4 count<350cells/mm3 before therapy accounted for 59.8%.98.6%of the participants had never with any antiretroviral drug,and 82.1%were diagnosed and treated in one year.The prevalent forms of HIV in China were circulating recombinant forms（CRFs）,accounting for 95.2%（4902/5151）.CRF07_BC（40.8%,2102/5151）and CRF01_AE（36.2%,1869/5151）are the main subtypes in China.CRF55₀1B（3.7%,190/5151）appeared in 28 survey areas except Sichuan and Xinjiang.B/B’ accounted for 4.1%（209/5151）.The prevalence of PDR in China is 9.0%（465/5151）,6.3%（322/5151）,4.5%（231/5151）and 4.4%（227/5151）,respectively,according to NNRTIs/NRTIs/PIs drugs in the HIVdb database（all the three drugs are analyzed below）,13 drugs approved in China,12 first-line drugs commonly used in developing countries recommended by WHO,and 7 drugs in the national free antiretroviral treatment programme（NFATP）in China.Multivariate Logistic regression analysis showed that people aged 18-29 years,CRF55₀1B subtypes,injecting drug users and people with antiretroviral drug exposure had a higher risk of PDR（P<0.05）.There were significant differences in the frequency of M46,Q58,E138 and V179 mutations among CRF07_BC,CRF01_AE,CRF08_BC,B/B’,CRF55₀1B and other subtypes（P<0.01）.And there were significant differences（P<0.001）in the rate of antiretroviral drugs,such as EFV,NVP,ETR,RPV,TPV/r and NFV.Through molecular transmission network,at 0.5%distance threshold,Q58E appeared drug resistance transmission clusters in CRF07_BC,E138G+V179E in CRF55₀1B,E138A in CRF08_BC5 M46I/L and K103RR+V179D in CRF01_AE.The second part is the variation of HIV drug resistance after antiretroviral therapy.We planned 459 patients with PDR as cases and 663 without PDR as controls.352 cases and 603 controls were followed up in the final analysis.With the Stanford HIVdb database,46 patients with drug resistance after antiretroviral therapy in cases（13.1%,46/352）,while 18 patients with drug resistance after the therapy in controls（3.0%,18/603）.Furthermore,in patients with PDR,the adjusted odds ratio for rate of HIV drug resistance after antiretroviral therapy was 4.4（95%CI 2.44-7.91）compared with those without pretreatment drug resistance.It was significantly different（P<0.05）for the rate of DOR,EFV,ETR,NVP,RPV,ABC,FTC,3TC,TDF,D4T,DDI,NFV and TPV/r.between cases and controls.In addition,it was significant differences in the frequency of K103,V106,E138,V179,P225,K65,M184,M46 and Q58 between cases and controls（P<0.05）.After antiretroviral therapy,cases with single resistance of NNRTIs（2.8%,10/352）,NRTIs（0.6%,2/352）and PIs（0.9%,3/352）changed into multiple drug resistance.ConclusionsThe first part is the distribution of subtypes,drug resistance and influencing factors about PDR in China before antiretroviral therapy.There are 13 CRFs in China,and CRF07_BC,CRF01_AE,and CRF08_BC account for more than 85%.CRP55₀1B has been transmitting in 28 survey areas except Xinjiang and Sichuan.The prevalence of PDR in NNRTIs/NRTIs/PIs is close to 10%according to drugs in HIVdb,but the prevalence of PDR is still at a low level（<5%）as to drugs in NFATP.The rate of PDR to NNRTIs in CRF08_BC is 16.5%,and PDR to NNRTIs in CRF55₀1B was 15.8%.In molecular transmission network,Q58E exists drug resistance transmission clusters in CRF07_BC,E138G+V179E in CRF55₀1B,E138A in CRF08_BC,M46I/L and K103R+V179D in CRF01_AE.Multivariate Logistic regression analysis showed that people aged 18-29 years,CRF55₀1B subtypes,injecting drug users and people with antiretroviral drug exposure had a higher risk of PDR（P<0.05）.The second part is the variation of HIV drug resistance after antiretroviral therapy.Patients with PDR is higher frequency of K103,V106,E138,V179,P225,K65,M184,M46 and Q58 compared with those without PDR on HIV drug resistance after antiretroviral therapy（P<0.05）.After 12 months（9-15 months）antiretroviral therapy,8.0%cases increased drug-resistance mutations and 4.3%cases with PDR single resistance changed into multiple drug resistance.That can cause the increasing level of drug resistance,severe multiple drug resistance.In addition,in patients with PDR,the adjusted odds ratio for rate of HIV drug resistance after antiretroviral therapy was 4.4（95%CI 2.44-7.91）compared with those without pretreatment drug resistance.