Salivary secretory leukocyte protease inhibitor increases in HIV infection

BACKGROUND: Secretory leukocyte protease inhibitor (SLPI) is an antimicrobial protein found in saliva and having anti-HIV activity. The concentrations of SLPI in parotid and submandibular/sublingual (SMSL) saliva were determined in an HIV(+) population and compared with uninfected controls. The effect of highly active antiretroviral therapy (HAART) on the concentrations in saliva was determined. METHODS: Stimulated parotid and SMSL saliva was collected from 65 HIV(+) patients and 19 healthy controls. Flow rates, total protein and SLPI concentrations were determined as well as the effect of HAART on these measurements. RESULTS: Mean flow rates were reduced for parotid (64%) and SMSL (44%) saliva of HIV(+) patients. Flow rate reductions were unaffected by HAART. Total protein concentration in HIV(+) parotid saliva was increased 56%; patients on HAART had higher concentrations than control. For both groups, SLPI concentrations of SMSL saliva were twice that of parotid saliva. For HIV(+) patients SLPI concentrations of both saliva types were 70% greater than control; the increase in parotid saliva was greater for those taking HAART. For each saliva type, the secretory rate and specific SLPI protein concentration were not different between the groups. Patients with low CD4(+) counts had greater SLPI concentrations in parotid saliva than control. There was a negative correlation between CD4(+) counts and the SLPI concentration of parotid saliva. CONCLUSIONS: Salivary flow rate is decreased and the concentration of SLPI is increased in the presence of HIV infection. SLPI concentration in parotid and SMSL saliva is greater with HAART.