Use of densitometric analysis for interpreting HSV serologies based on Western blot

Abstract

Western blot assays have been described for detecting antibodies to herpes simplex virus (HSV). A predominance of antibody binding to either the HSV-1 or the HSV-2-containing blot has been reported to indicate infection with HSV-1 or HSV-2, respectively. By densitometry, differential binding of total antibody on HSV-1 versus HSV-2 strips can be expressed as a ratio. To determine the clinical correlation of these ratios, sera from 81 patients with culture-proven oral or genital herpes were tested by Western blot (WB) and densitometry. Binding ratios accurately identified patients with primary HSV-2 infections. However, ratios on sera with HSV-1 antibody or dual antibody status showed considerable overlap. Densitometry was shown to amplify and clarify the band corresponding to the HSV-2 specific glycoprotein gG-2 and was useful, in this respect, for detecting HSV-2 antibody in the presence of HSV-1 antibody. Sera from 52 patients with asymptomatic HSV-1, HSV-2 or dual infection were also tested by WB. Typing results were confirmed by cross-adsorption of sera ("adsorption blot assay"). Ratios of HSV-2 to HSV-1 binding were higher in asymptomatic versus symptomatic patients with dual antibody (P less than 0.01). Ratios for those with HSV-1 or HSV-2 antibody types were not affected by disease expression.