DIRECT-DETECTION OF EPSTEIN-BARR VIRAL-ANTIGEN IN NASOPHARYNGEAL SWABS FROM PATIENTS WITH INFECTIOUS-MONONUCLEOSIS

Objective: To determine whether direct immunologic detection of Epstei n-Barr virus (EBV) early antigen diffuse component (EA-D) from nasopha ryngeal swabs is a feasible approach to the development of a rapid dia gnostic test for infections mononucleosis (IM). Methods: Nasopharyngea l swabs from 20 patients presenting with a presumptive diagnosis of IM (having the classic triad of symptoms-acute pharyngitis, fever, and l ymphadenopathy) and 5 controls were assayed for EA-D. EBV serologic te sting and a heterophil antibody titer (HAT) test also were performed. EA-D was assayed by polyacrylamide gel electrophoresis and subsequent transfer to a nylon membrane, followed by immunoblotting with a monocl onal antibody. Results: EA-D was detected in 17 of 20 patients (85%) w ith presumptive diagnoses of IM and in 1 of 5 normal subjects and was highly significant in predicting LM (p < 0.01), There was no significa nt difference in numbers of positive and negative results using either EA-D assay or HAT test in patients with IM (p < 0.35), Pharyngeal exu date in the 17 pharyngitis patients with this variable documented was significantly correlated with positive EA-D (p < 0.01), but not with t he HAT test (p < 1.00). Conclusions: Immunologic detection of EBV-deri ved antigens from nasopharyngeal swabs is a potential early diagnostic tool for clinically suspected IM, Sensitivity and specificity in pedi atric and adult populations, patients with other viral etiologies, and patients with streptoccocal pharyngitis should be determined in subse quent investigations.