Aama. Baqui et al., Enhanced secretory leukocyte protease inhibitor in human immunodeficiency virus type 1-infected patients, CL DIAG LAB, 6(6), 1999, pp. 808-811
Secretory leukocyte protease inhibitor (SLPI) has been found to possess act
ivity against the human immunodeficiency virus type 1 (HIV-I) in vitro at p
hysiological concentrations. A study was undertaken to evaluate SLPI levels
in human saliva and plasma among HIV-positive (HIV+) patients with various
HIV-1 viral loads in comparison to uninfected controls. Whole blood in EDT
A and unstimulated saliva samples were collected from 37 HIV+ patients, of
whom 20 had a history of intravenous drug abuse (IVDA). Control samples wer
e collected from 20 appropriate age- and sex-matched HIV-1-negative individ
uals. SLPI was estimated from both saliva and serum samples by an enzyme-li
nked immunosorbent assay. EW viral load was determined using a quantitative
reverse transcription-PCR. SLPI levels were increased 16.7% in plasma and
10.3% in saliva among HIV+ patients in comparison to uninfected controls. S
LPI levels were increased 5.9% in saliva and 3.9% in plasma among HIV+ pati
ents with a high viral load (>10,000 copies/ml) as compared to patients wit
h a low viral load (<400 copies/ml). Only 23% of patients with a high viral
load used combination therapy with protease inhibitor drugs, whereas 92.9%
of HIV+ patients with a low viral load used protease inhibitors. SLPI leve
ls did not differ significantly among the IVDA patients, patients with diff
erent,viral loads, or patients using protease inhibitor drugs. There was a
statistically significant increase in SLPI levels in saliva among HIV patie
nts in comparison to non-HIV-infected controls. An increase in SLPI levels
among HIV+ patients may be a natural consequence of HIV pathogenesis and an
important factor in preventing oral transmission of HIV, but this increase
may not be evident during plasma viremia in patients with a high viral loa
d.