title: Viral dynamics in primary HIV-1 infection. Karolinska Institutet Primary HIV Infection Study Group.
abstract: OBJECTIVE
  To study the natural course of viremia during primary HIV infection (PHI).
  
  
  METHODS
  Eight patients were followed from a median of 5 days from the onset of PHI illness. Plasma HIV-1 RNA levels were measured frequently and the results were fitted to mathematical models. HIV-1 RNA levels were also monitored in nine patients given two reverse transcriptase inhibitors and a protease inhibitor after a median of 7 days from the onset of PHI illness.
  
  
  RESULTS
  HIV-1 RNA appeared in the blood during the week preceding onset of PHI illness and increased rapidly during the first viremic phase, reaching a peak at a mean of 7 days after onset of illness. This was followed by a phase of rapidly decreasing levels of HIV-1 RNA to an average of 21 days after onset. Viral density continued to decline thereafter but at a 5- to 50-fold lower rate; a steady-state level was reached at a median of 2 months after onset of PHI. Peak viral density levels correlated significantly with levels measured between days 50 and 600. Initiation of antiretroviral treatment during PHI resulted in rapidly declining levels to below 50 copies/mL.
  
  
  CONCLUSIONS
  This study demonstrates the kinetic phases of viremia during PHI and indicates two new contributions to the natural history of HIV-1 infection: PHI peak levels correlate with steady-state levels and HIV-1 RNA declines biphasically; an initial rapid decay is usually followed by a slow decay, which is similar to the initial changes seen with antiviral treatment.
authors.affiliation: Swedish Institute for Infectious Disease Control, Solna, Sweden.
authors.forename: S
authors.initials: S
authors.lastname: Lindbäck
authors.forename: A C
authors.initials: AC
authors.lastname: Karlsson
authors.forename: J
authors.initials: J
authors.lastname: Mittler
authors.forename: A
authors.initials: A
authors.lastname: Blaxhult
authors.forename: M
authors.initials: M
authors.lastname: Carlsson
authors.forename: G
authors.initials: G
authors.lastname: Briheim
authors.forename: A
authors.initials: A
authors.lastname: Sönnerborg
authors.forename: H
authors.initials: H
authors.lastname: Gaines
mesh_terms: D023241:Antiretroviral Therapy, Highly Active; D018791:CD4 Lymphocyte Count; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology; D005260:Female; D015658:HIV Infections / Q000188:drug therapy / Q000453:epidemiology / Q000821:virology*; D017320:HIV Protease Inhibitors / Q000627:therapeutic use; D015497:HIV-1; D020010:Heterosexuality; D006716:Homosexuality; D006801:Humans; D008297:Male; D012367:RNA, Viral / Q000097:blood; D012044:Regression Analysis; D018894:Reverse Transcriptase Inhibitors / Q000627:therapeutic use; D013548:Sweden / Q000453:epidemiology; D013997:Time Factors; D014766:Viremia
chemical_list: D017320:HIV Protease Inhibitors; D012367:RNA, Viral; D018894:Reverse Transcriptase Inhibitors