Salivary lysozyme and related parameters of a predominantly Chinese, HIV-infected cohort in Hong Kong

Abstract

OBJECTIVES: To evaluate the salivary lysozyme concentration, flow rate and pH of a predominantly Chinese, HIV-infected group in Hong Kong, and to compare with an equal number of age and gender-matched HIV-free individuals. STUDY DESIGN: A prospective longitudinal study over a 12-month period of 32 predominantly Chinese, male, HIV-infected group in a hospital setting in Hong Kong. Whole saliva collection by expectoration, lysozyme evaluation by 'lysoplate method'; pH and flow rate evaluation using standard methods and correlation with other clinical parameters using regression analysis. RESULTS: The flow rate and the pH of saliva were lower compared with HIV- free, healthy individuals (both P < 0.0001) and salivary lysozyme concentration of the HIV-infected group was 23% higher compared with the HIV- free group (P < 0.001), though there was no significant difference between the lysozyme output (P > 0.05) expressed as μg min-1. On multiple regression analysis, intravenous drug users had a higher salivary lysozyme concentration compared with the homosexual group (P = 0.0015) though other variables investigated were not significantly related to the salivary lysozyme concentrations. CONCLUSIONS: The significant changes in the flow rate, pH value and lysozyme concentration of whole saliva of the HIV-infected individuals as compared with the HIV-free, healthy individuals, may be due to the disease itself or a combination of factors including the medications used in the disease management.