(1C4) and Parry et al. 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. SPECIMEN OF CHOICE Whole saliva, glandular-duct saliva, or mucosal transudates are specimens that can be collected for tests to detect antibody to HIV in oral secretions. A basic understanding of these different types of oral fluids, however, is necessary in choosing which 2,4-Diamino-6-hydroxypyrimidine oral fluid is the most appropriate and which method of recovery is best suited for the testing system employed. Detailed information on the nomenclature, specimen collection, and immunobiology of oral fluids can be found in references 5, 46, 58, 59, and 66. Best results are obtained with oral fluids that are rich in IgG, since the primary humoral immune response to HIV infection involves mainly 2,4-Diamino-6-hydroxypyrimidine this class of antibodies. Whole saliva. Whole saliva is the fluid obtained from the mouth by expectoration and includes secretions from the 2,4-Diamino-6-hydroxypyrimidine parotid, submandibular, sublingual, and minor salivary glands as well as transudates of the oral mucosa. It contains mostly secretory IgA and low levels of IgG (58). Whole saliva also contains bacteria, leukocytes, mucin, desquamated epithelial cells, and food debris, which may lead to degradation of IgG by bacterial and salivary proteases and makes the specimen difficult to process due 2,4-Diamino-6-hydroxypyrimidine to the viscosity. Either unstimulated saliva or saliva secreted in response to exogenous stimulation can be collected. Unstimulated saliva is obtained by tilting the Srebf1 head forward and dribbling saliva from the lower lip into a graduated test tube fitted with a funnel. After 5 min, the subject expectorates any remaining saliva from the mouth. To stimulate saliva, Parafilm, paraffin wax, neutral gum base, or rubber bands can be employed as mechanical stimuli. Dribbled saliva has a stability of 5 days at room temperature but can be stored 2,4-Diamino-6-hydroxypyrimidine for longer times at 4 to ?20C (63). Glandular-duct saliva. Saliva from the parotid, submandibular, and sublingual glands is obtained directly from the glandular ducts with specially designed collectors. Absorbent filter paper or suction aspiration with a micropipette can be used for the collection of secretions from the minor salivary glands. Glandular-duct saliva contains predominantly secretory IgA and should be stored as described for whole saliva. Oral mucosal transudates. Oral mucosal transudates are fluids from the capillaries beneath the buccal mucosa and at the base of the crevice between the teeth and gums. These fluids not only contain secretory IgA but are rich in IgG and IgM that originate in the plasma and are passively transferred to.