beta 2-Microglobulin in saliva and its relation to flow rate in different glands in man

The concentration of beta 2-microglobulin (beta 2-m) in parotid saliva and sera from 13 adult hypogammaglobulinaemic subjects and in parotid saliva from 7 normal adults was determined by radioimmunoassay. Parotid and submandibular/sublingual saliva was collected from four normal and one hypogammaglobulinaemic subject in unstimulated and stimulated samples, and concentrations of IgA and beta 2-m were determined. The beta 2-m concentration in parotid saliva from hypogammaglobulinaemic subjects was 0.50 mg/l (0.2-1.1) and in normal adults 0.41 mg/l (0.2-0.9). In parotid saliva, the concentration of beta 2-m was negatively correlated with the flow rate, whereas in submandibular/sublingual a positive correlation was seen. Serum levels of beta 2-m in hypogammaglobulinaemic subjects were within the normal range of healthy adults. Gel filtration of saliva separated beta 2-m from IgA and from high molecular weight agglutinins. Beta 2-m was eluted as one single peak.