Cellular and plasma viral load in patients infected with HIV-2.
OBJECTIVE
To determine circulating viral load in HIV-2-infected individuals.


METHODS
Viral load was determined in 40 HIV-2-infected adults using standardized quantitative cell and qualitative plasma viraemia assays. We also tested for proviral HIV-2 DNA using single and nested polymerase chain reaction (PCR) in fresh lymphocytes from 27 subjects. The results were compared, on the basis of the CD4+ lymphocyte count, with our published data for HIV-1 infection.


RESULTS
HIV-2 was isolated from peripheral blood mononuclear cells (PBMC) from 19 individuals and plasma from four patients. The rate of cell and plasma viraemia positivity correlated with the CD4+ cell count and HIV-2 virus load increased as the CD4+ cell count fell. The cellular HIV-2 load in the patients with a CD4+ count < 200 x 10(6)/l was similar to reported values for HIV-1, but the HIV-2 isolation rate from the plasma of these individuals was significantly lower than for HIV-1. When the CD4+ count was between 200 and 500 x 10(6)/l, the rate of HIV-2 isolation from plasma and the cellular virus load were both significantly lower than for HIV-1. When the CD4+ count was > 500 x 10(6)/l, HIV-1 and HIV-2 were undetectable in plasma and HIV-1 was isolated from PBMC in significantly more cases than HIV-2. By single PCR, amplification were positive in 14 out of 27 subjects and there was a correlation between positivity and CD4+ cell count. By nested PCR, only four of the 27 subjects, all with a high CD4+ count, remained negative.


CONCLUSIONS
Differences in viral load between individuals infected with HIV-2 and those infected with HIV-1 could partly account for reported differences in the pathogenicity of the two viruses.
Simon
F
F
Laboratoire de Virologie, Hôpital Bichat-Claude Bernard, Paris, France.
Matheron
S
S
Tamalet
C
C
Loussert-Ajaka
I
I
Bartczak
S
S
Pépin
J M
JM
Dhiver
C
C
Gamba
E
E
Elbim
C
C
Gastaut
J A
JA
D000328:Adult; D015496:CD4-Positive T-Lymphocytes; D002452:Cell Count; D004279:DNA, Viral / Q000032:analysis; D005260:Female; D015726:Giant Cells / Q000382:microbiology; D015658:HIV Infections / Q000276:immunology / Q000382:microbiology*; D015498:HIV-2 / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D008297:Male; D016133:Polymerase Chain Reaction; D014766:Viremia / Q000276:immunology / Q000382:microbiology*; D014779:Virus Replication
D004279:DNA, Viral