Examination of non-involved skin, previously involved skin, and peripheral blood for herpes simplex virus DNA in patients with recurrent herpes-associated erythema multiforme.

The association between infection with HSV and the subsequent development of erythema multiforme is well established, although the role that the virus plays in the pathogenesis of this disorder is not known. HSV DNA has been detected in cutaneous lesions of herpes-associated erythema multiforme (HAEM), and it has been suggested that the tissue damage seen in these lesions is virus-specific. In the current, prospective study, we examined biopsies of lesional, non-involved, and previously involved but healed skin, in addition to specimens of peripheral blood, from patients with HAEM, for HSV DNA by using the polymerase chain reaction. HSV DNA was detected in lesional skin of 10 of 11 patients compared to 2 of 11 non-involved skin biopsies obtained at the same time. HSV was present in 4 of 6 blood specimens obtained during the acute episode. Five patients returned 3 months after the acute episode resolved for biopsies of previously involved skin. HSV was detected in 4 of these 5 biopsies. Thus, the presence of HSV DNA in the skin of patients with HAEM appears to be predominantly in areas of clinical involvement; the virus remains in those cutaneous sites for up to 3 months without evidence of clinical disease; and HSV DNA may be detected in the peripheral blood cells during acute HAEM. Based on these findings, we suggest that the virus plays a role in lesion development, that the skin may function as a site of viral persistence, and that hematogenous spread of viral DNA may be an important factor in the development of HAEM.

Human herpesvirus 6 is present in lesions of Langerhans cell histiocytosis.

Langerhans cell histiocytosis (LCH) is a disease characterized by Langerhans cell infiltration of skin and bone, with its most severe form manifested by multifocal infiltration of many organs. The etiology is unknown, although viral infection has been proposed as a potential pathogenic factor. Human herpesvirus 6 (HHV-6), a recently described member of the human herpesvirus family, has been associated with atypical or malignant lymphocytic processes, and immune disorders. Based on these observations, we suspected that HHV-6 may play a role in the pathogenesis of LCH. Lesional tissue of 30 patients with LCH was retrospectively examined for the presence of HHV-6 by using the polymerase chain reaction. Tissue specimens from 63 patients with other benign and malignant histiocytic and lymphocytic diseases served as controls. In addition, all specimens were examined with control primers specific for herpes simplex virus (HSV). HHV-6 DNA was detected in lesions of 14 of 30 patients with LCH (47%). On clinical subgroup analysis, HHV-6 DNA was found in 10 of 16 patients with extraosseous disease (63%) and in four of 14 patients with disease limited to bone (29%). In each case, the prevalence of HHV-6 in LCH lesions was statistically significant, when compared to the control population. HSV DNA was not found in any of the LCH or control specimens. Although the presence of a virus alone does not establish a causal role in the disease, it supports the possibility of an etiologic relationship. From this study, we emphasize the need for further investigation of the potential HHV-6-mediated pathogenesis of LCH.

Examination of cutaneous T-cell lymphoma for human herpesviruses by using the polymerase chain reaction.

The etiology of cutaneous T-cell lymphoma remains unknown, although an association with viral infection, in particular certain retroviruses and human herpesviruses, has been suggested. The purpose of this study was to examine skin biopsies of cutaneous T-cell lymphoma for the presence of Epstein-Barr virus, herpes simplex virus type 1 and type 2, and human herpesvirus-6 by using the polymerase chain reaction. Lesional skin biopsies from 30 patients with cutaneous T-cell lymphoma were studied. Control specimens included biopsies from 9 patients with lymphomatoid papulosis and 10 patients with pityriasis lichenoides et varioliformis acuta. DNA extracted from each specimen, as well as from a known positive control for each virus, was examined by using the polymerase chain reaction with viral-specific primers. Each DNA specimen was also amplified with control primers for human beta globin. The specificity of the amplified products was confirmed by Southern analysis. Neither Epstein-Barr virus nor herpes simplex virus was detected in any of the patient specimens examined. Human herpesvirus-6 was detected in one specimen of cutaneous T-cell lymphoma and one specimen of lymphomatoid papulosis. These results do not support a role for any of these herpesviruses in the pathogenesis of cutaneous T-cell lymphoma.

The herpes-specific immune response of individuals with herpes-associated erythema multiforme compared with that of individuals with recurrent herpes labialis.

Infection with herpes simplex virus (HSV) is the most common precipitating factor in the development of erythema multiforme (EM). It is not known why only a few of the many individuals who experience recurrent HSV infection also develop herpes-associated EM (HAEM), although a difference in the HSV-specific immune response has been postulated. The purpose of this study was to compare the HSV-specific immune response of individuals with HSV infection alone with that of individuals with HAEM. There were 21 patients in each of the two groups. Four parameters of the HSV-specific immune response were examined: (1) anti-HSV IgG titers were measured by ELISA; (2) antibody neutralization was assessed using a plaque assay; and (3) antibody-dependent complement-mediated cytotoxicity, and (4) antibody-dependent cellular cytotoxicity were investigated using a previously described in vitro HSV-specific cytotoxicity assay. No statistically significant differences were detected between the two patient groups. Thus, a difference in these HSV-specific immune mechanisms does not explain the development of HAEM in some individuals with recurrent HSV infection.

Detection of herpes simplex virus DNA in the peripheral blood during acute recurrent herpes labialis.

BACKGROUND: Although herpes simplex virus (HSV) has been detected in the peripheral blood of immunocompromised patients and in neonates with disseminated disease, the extent to which this virus may be present in the blood during a localized infection in otherwise healthy adults is unknown. OBJECTIVE: The purpose of this study was to determine whether HSV may be detected in the peripheral blood during acute recurrent herpes labialis. METHODS: Peripheral blood mononuclear cells (PBMCs) were obtained from otherwise healthy adults with recurrent herpes labialis, both during an acute episode and several weeks after the lesions had healed. The PBMCs were examined for the presence of HSV with the polymerase chain reaction (PCR) and viral culture. RESULTS: By PCR, HSV DNA was detected in 7 of 34 specimens from an acute episode but in none of 24 specimens in the convalescent stage (p less than 0.004). PBMCs from seven donors, who were seronegative for HSV, were also negative for HSV by PCR. Viral cultures of 22 PBMC specimens were negative (including four specimens that were positive by PCR). CONCLUSION: The presence of HSV DNA in the blood is a transient phenomenon limited to the period of active infection in a minority of patients with herpes labialis, although it may be important in the development of disseminated disease as well as in the pathogenesis of herpes-associated cutaneous processes such as erythema multiforme.