Saliva flow rate and composition in lysinuric protein intolerance

Abstract

The aim of this study was to measure saliva flow rate and analyse microbiological, chemical and biochemical features of saliva in patients with lysinuric protein intolerance (LPI). The study comprised 20 patients with LPI (age 11 to 44 years) and 20 controls. Fourteen of the patients showed growth retardation. The LPI patients' diet consisted predominantly of fats and carbohydrates and contained small amounts of proteins. At the appointments, paraffin-stimulated saliva was collected. Buffer effect, mutans streptococci, lactobacilli and yeasts were measured using semiquantitative assays. Calcium, phosphate, ammonia, urea, protein, lysozyme, amylase and amino acids were o determined from saliva stored at -20 C. The mean saliva flow rates of the patients with LPI were lower than those of the controls (p < 0.05). Salivary pH and buffer effect did not differ significantly between the groups. Of the analysed microbiological, chemical and biochemical features of saliva, only the amylase activity was lower in the LPI patients than their controls (p < 0.05). Growth retardation associated with low saliva flow rates. No other differences in the analysed variables of the salivas between the growth-retarded and normal-sized patients were detected. Our data indicate that the LPI patients should not be particularly predisposed to caries despite their low-protein, highcarbohydrate, high-fat diet.