Lymphocyte responses to herpes simplex virus isolates from patients with primary and recurrent herpes simplex genitalis.

The ability of herpes simplex (HSV) isolates from patients with herpes simplex genitalis (HSG) to induce lymphocyte transformation in cells from unrelated, healthy, seropositive donors was examined in a standard lymphocyte transformation assay. All HSV isolates were obtained, before the initiation of therapy, from patients who were enrolled in a placebo-controlled trial of acyclovir in the treatment of HSG. Isolates from patients with primary infections were used, as well as those from patients with frequent (eight or more episodes per year) or infrequent (two or fewer per year) recurrent disease. Blastogenic responses to isolates from patients with infrequent HSG recurrences were significantly less than those to isolates from patients either primary infections or frequent recurrences. No differences between the latter two groups of isolates were seen. These observations demonstrate that differences among naturally occurring HSV isolates exist as determined by this in vitro assay of host-virus interactions. Differences among strains may be important in the pathogenesis of HSV infections, particularly with respect to latency.