title: A novel acute HIV infection staging system based on 4th generation immunoassay.
abstract: BACKGROUND
  Fourth generation (4thG) immunoassay (IA) is becoming the standard HIV screening method but was not available when the Fiebig acute HIV infection (AHI) staging system was proposed. Here we evaluated AHI staging based on a 4thG IA (4thG staging).
  
  
  RESULTS
  Screening for AHI was performed in real-time by pooled nucleic acid testing (NAT, n=48,828 samples) and sequential enzyme immunoassay (EIA, n=3,939 samples) identifying 63 subjects with non-reactive 2nd generation EIA (Fiebig stages I (n=25), II (n=7), III (n=29), IV (n=2)). The majority of samples tested (n=53) were subtype CRF_01AE (77%). NAT+ subjects were re-staged into three 4thG stages: stage 1 (n=20; 4th gen EIA-, 3rd gen EIA-), stage 2 (n=12; 4th gen EIA+, 3rd gen EIA-), stage 3 (n=31; 4th gen EIA+, 3rd gen EIA+, Western blot-/indeterminate). 4thG staging distinguishes groups of AHI subjects by time since presumed HIV exposure, pattern of CD8+ T, B and natural killer cell absolute numbers, and HIV RNA and DNA levels. This staging system further stratified Fiebig I subjects: 18 subjects in 4thG stage 1 had lower HIV RNA and DNA levels than 7 subjects in 4thG stage 2.
  
  
  CONCLUSIONS
  Using 4th generation IA as part of AHI staging distinguishes groups of patients by time since exposure to HIV, lymphocyte numbers and HIV viral burden. It identifies two groups of Fiebig stage I subjects who display different levels of HIV RNA and DNA, which may have implication for HIV cure. 4th generation IA should be incorporated into AHI staging systems.
authors.affiliation: SEARCH, Pathumwan, Bangkok, Thailand. Jintanat.A@searchThailand.org
authors.forename: Jintanat
authors.initials: J
authors.lastname: Ananworanich
authors.forename: James L K
authors.initials: JL
authors.lastname: Fletcher
authors.forename: Suteeraporn
authors.initials: S
authors.lastname: Pinyakorn
authors.forename: Frits
authors.initials: F
authors.lastname: van Griensven
authors.forename: Claire
authors.initials: C
authors.lastname: Vandergeeten
authors.forename: Alexandra
authors.initials: A
authors.lastname: Schuetz
authors.forename: Tippawan
authors.initials: T
authors.lastname: Pankam
authors.forename: Rapee
authors.initials: R
authors.lastname: Trichavaroj
authors.forename: Siriwat
authors.initials: S
authors.lastname: Akapirat
authors.forename: Nitiya
authors.initials: N
authors.lastname: Chomchey
authors.forename: Praphan
authors.initials: P
authors.lastname: Phanuphak
authors.forename: Nicolas
authors.initials: N
authors.lastname: Chomont
authors.forename: Nelson L
authors.initials: NL
authors.lastname: Michael
authors.forename: Jerome H
authors.initials: JH
authors.lastname: Kim
authors.forename: Mark
authors.initials: M
authors.lastname: de Souza
mesh_terms: D000328:Adult; D001402:B-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D004279:DNA, Viral / Q000097:blood; D005260:Female; D015658:HIV Infections / Q000175:diagnosis* / Q000276:immunology / Q000473:pathology*; D006801:Humans; D007118:Immunoassay / Q000379:methods; D007694:Killer Cells, Natural / Q000276:immunology; D008297:Male; D008403:Mass Screening / Q000379:methods*; D012367:RNA, Viral / Q000097:blood; D012720:Severity of Illness Index; D013997:Time Factors; D019562:Viral Load
chemical_list: D004279:DNA, Viral; D012367:RNA, Viral