Quantitation of human immunodeficiency virus type 1 in the blood of infected persons

N Engl J Med. 1989 Dec 14;321(24):1621-5. doi: 10.1056/NEJM198912143212401.


We used end-point-dilution cultures to measure the level of infectious human immunodeficiency virus type 1 (HIV-1) in peripheral-blood mononuclear cells (PBMC) and plasma of 54 infected patients who were not receiving antiviral chemotherapy. HIV-1 was recovered from the plasma and PBMC of every seropositive patient, but from none of 22 seronegative control subjects. The mean titers in plasma were 30, 3500, and 3200 tissue-culture-infective doses (TCID) per milliliter for patients with asymptomatic infection, the acquired immunodeficiency syndrome (AIDS), and the AIDS-related complex, respectively. In PBMC, the mean titers were significantly higher for symptomatic patients (AIDS, 2200, and AIDS-related complex, 2700 TCID per 10(6) PBMC) than asymptomatic patients (20 TCID per 10(6) PBMC). The values for the symptomatic patients were considered to indicate that at least 1 in 400 circulating mononuclear cells harbored HIV-1. The HIV-1 titers of seven patients with AIDS or AIDS-related complex treated with zidovudine for four weeks decreased significantly in plasma but not in PBMC. In addition, the mean titer in the plasma of 20 patients receiving long-term zidovudine treatment (130 TCID per milliliter) was 25-fold lower than the mean for comparable untreated patients with AIDS or AIDS-related complex. We conclude that the levels of HIV-1 in plasma and PBMC are much higher than previous estimates. This high degree of HIV-1 viremia raises the possibility that the direct cytopathic effect of this retrovirus alone may be sufficient to explain much of the pathogenesis of AIDS.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • AIDS-Related Complex / drug therapy
  • AIDS-Related Complex / microbiology
  • Acquired Immunodeficiency Syndrome / drug therapy
  • Acquired Immunodeficiency Syndrome / microbiology*
  • Blood / microbiology*
  • Cytopathogenic Effect, Viral
  • Female
  • HIV-1 / isolation & purification*
  • Humans
  • Leukocytes, Mononuclear / microbiology
  • Male
  • Viremia / microbiology
  • Zidovudine / therapeutic use


  • Zidovudine