Objectives: To clarify the virological state of human immunodeficiency virus (HIV)-1-infected patients, we compared the plasma HIV-1 RNA copy number (plasma viral load (VL)), viral DNA and mRNA burdens in peripheral blood mononuclear cells (PBMCs), and the other clinical predictors.

Methods: One hundred and thirty-one samples of PBMCs and plasma from 26 patients infected with HIV-1 were obtained during 20 consecutive months for the measurement of VL, viral DNA and mRNA burdens, and CD4 positive (CD4+) cells count. The quantitative polymerase chain reaction (PCR) method with detection by solid phase DNA was utilized for the assay of VL, viral DNA and mRNA burdens.

Results: Eighty-six VL, 101 viral mRNA and 129 viral DNA out of 131 samples were detected. There was a significant positive correlation between VL and the viral mRNA burden (r= 0.600, P≤ 0.001), and between VL and the viral DNA burden (r= 0.368,P ≤ 0.001). Focused on individuals, the viral mRNA burdens varied in a manner relatively dependent on VL when both values were detectable. However, viral DNA burdens varied relatively independently of VL and the viral mRNA burdens. In six patients the viral mRNA burden was detectable and changed even if the VL was undetectable throughout the observation period.

Conclusions: Both viral DNA and viral mRNA burdens still showed detectable changes even when the VLs became undetectable in most patients. The measurement of viral mRNA or DNA burdens may be clinically available to identify viral replication when VL is undetectable.