title: The prevalence of antiretroviral multidrug resistance in highly active antiretroviral therapy-treated patients with HIV/AIDS between 2004 and 2009 in South Korea.
abstract: 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.
  
  
  OBJECTIVE
  To investigate and estimate the annual antiretroviral drug resistance and prevalence of antiretroviral multi-class drug resistance in Korean patients with experience of treatment.
  
  
  METHODS
  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.
authors.affiliation: Division of AIDS, Department of Immunology and Pathology, National Institute of Health South Korea, The Korea Centers for Disease Control and Prevention, Republic of Korea.
authors.forename: Ju-yeon
authors.initials: JY
authors.lastname: Choi
authors.affiliation: Division of AIDS, Department of Immunology and Pathology, National Institute of Health South Korea, The Korea Centers for Disease Control and Prevention, Republic of Korea.
authors.forename: Oh-Kyung
authors.initials: OK
authors.lastname: Kwon
authors.affiliation: Division of AIDS, Department of Immunology and Pathology, National Institute of Health South Korea, The Korea Centers for Disease Control and Prevention, Republic of Korea.
authors.forename: Byeong-Sun
authors.initials: BS
authors.lastname: Choi
authors.affiliation: Division of AIDS, Department of Immunology and Pathology, National Institute of Health South Korea, The Korea Centers for Disease Control and Prevention, Republic of Korea.
authors.forename: Mee-Kyung
authors.initials: MK
authors.lastname: Kee
authors.affiliation: Division of AIDS, Department of Immunology and Pathology, National Institute of Health South Korea, The Korea Centers for Disease Control and Prevention, Republic of Korea.
authors.forename: Mina
authors.initials: M
authors.lastname: Park
authors.affiliation: Division of AIDS, Department of Immunology and Pathology, National Institute of Health South Korea, The Korea Centers for Disease Control and Prevention, Republic of Korea. Electronic address: sungskim63@gmail.com.
authors.forename: Sung Soon
authors.initials: SS
authors.lastname: Kim
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019380:Anti-HIV Agents / Q000494:pharmacology*; D023241:Antiretroviral Therapy, Highly Active / Q000379:methods*; D024921:Drug Resistance, Multiple, Viral; D005260:Female; D015658:HIV Infections / Q000188:drug therapy* / Q000453:epidemiology / Q000821:virology*; D015497:HIV-1 / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D056910:Republic of Korea / Q000453:epidemiology; D017422:Sequence Analysis, DNA; D055815:Young Adult; D054302:pol Gene Products, Human Immunodeficiency Virus
chemical_list: D019380:Anti-HIV Agents; D054302:pol Gene Products, Human Immunodeficiency Virus
keywords: Genotypic drug resistance assay; HAART-experienced; Multidrug resistance; South Korea