Detection of human immunodeficiency virus antibodies in oral fluids.

Oral fluids, including saliva, gingival crevicular fluid, and mucosal transudates have been widely used for monitoring drugs, hormones, and a variety of other molecules and chemical substances for over 50 years (34, 35, 53, 54, 68). During the past decade, the use of oral fluids also has been advocated as a noninvasive alternative to the collection of blood for the detection of antibodies to a number of specific bacterial (32, 82), viral (1–4, 18, 40, 61–65, 75), fungal (41), and parasitic (17, 20) agents. Particular attention has been given to the value of oral fluids for the diagnosis of infection with human immunodeficiency virus (HIV) (58, 73). Oral-fluid testing for HIV antibodies was first reported by Archibald et al. (1–4) and Parry et al. (60, 61). As summarized by Malamud and Friedman (51), in studies with saliva conducted between 1986 and 1991, the concordance between positive serum tests and positive saliva tests for the detection of HIV antibodies ranged from 70 to 100%. The less-than-perfect agreement has led to considerable confusion regarding the efficacy of using oral fluids in screening for HIV antibody. This is due, in part, to variations in the type and volume of oral sample collected, how the sample is handled prior to testing, the concentration of immunoglobulin (Ig) G present, and if testing methods have been modified to accommodate the use of oral fluids. In early studies that reported poor sensitivity, whole saliva was used and there was little consideration for the volume and condition of the sample needed and the choice of screening assays employed. For this reason, investigators have developed specialized collection devices that enhance the level of antibodies, particularly IgG, in oral specimens, ensure sufficient specimen volume, and include reagents to prevent microbial growth and proteolytic breakdown of antibodies. In general, this has been accomplished by collecting oral fluids enriched in gingival crevicular fluid and mucosal transudate, which possess increased levels of IgG relative to saliva (46, 66). In addition, recent modifications to existing HIV antibody assays and the development of extremely sensitive assays specifically designed for oral fluids have greatly improved the accuracy of oral-based diagnostic tests for antibodies to HIV and have compensated for the low levels of antibodies present in oral secretions compared with serum (46, 66). In this review, we assess the usefulness of saliva and other oral fluids for the detection of HIV antibodies, discuss the devices employed for specimen collection, and analyze the current reliability and accuracy of performing HIV antibody tests on oral secretions compared to serum or plasma.