Serum soluble Fas ligand levels and peripheral blood lymphocyte subsets in patients with drug-induced maculopapular rashes, dress, and viral exanthemas.

BACKGROUND: Fatty acid synthetase (Fas)/Fas ligand (FasL)-dependent apoptotic pathways have been reported as being involved in the pathogenesis of drug-induced maculopapular rashes. OBJECTIVE: We investigated serum soluble FasL (sFasL) levels and peripheral blood lymphocyte subtypes to discriminate maculopapular drug eruptions (MPDE) from viral exanthema (VE). PATIENTS/METHODS: Children with confirmed MPDE (group I), VE (group II), and drug rashes with eosinophilia and systemic symptoms (DRESS) or drug-induced hypersensitivity syndrome (DIHS) (group III) were included. Serum sFasL levels and peripheral blood lymphocyte subtypes were analyzed in groups I-III on admission, and repeated twice (only once for group IV - controls). RESULTS: There were no significant serum soluble FasL level differences among the groups for all the samples. In the initial samples, CD19+ cell numbers in group II were significantly higher than in group IV, and the CD4+/CD8+ ratio was higher than groups I and IV. In the second samples, CD4+ and CD19+ cell numbers were significantly higher in group II than group I. In the final samples, CD4+ cell numbers in group II were significantly higher than group I and group III. CD19+ cells numbers in group III were significantly lower than the other groups for all samples. CONCLUSION: Serum sFasL levels were not found to be useful in discriminating viral exanthemas from other drug rashes. The significant differences between MPDE, VE, and DRESS were high CD4+ and CD19+ cell-count numbers in VE but low B-cell numbers in DRESS. This might be important for discriminating VE from DRESS, and the low B-cell count in early symptoms might be a useful predictor of DRESS development.

Cross-sectional associations between cutaneous viral infections and regulatory T lymphocytes in circulation.

BACKGROUND: Cutaneous viral infections and immune suppression are risk factors for some forms of nonmelanoma skin cancer; however, their interrelationship is poorly understood. OBJECTIVES: To examine cross-sectional associations between cutaneous viral infections and circulating forkhead-box P3 (FOXP3)-expressing T-regulatory (Treg) cells, suppressive cells that dampen effective antitumour immunity. MATERIALS AND METHODS: Blood, eyebrow hair (EBH) and skin swab (SSW) samples were collected from 352 patients 60 years and older undergoing skin screening, without prevalent skin cancer, while participating in an ongoing prospective cohort study of cutaneous viral infections and skin cancer. DNA corresponding to 98 cutaneous human papillomavirus (HPV) types and five human polyomaviruses (HPyV) was assessed in EBH and SSW. Distinct classes of circulating Treg-cell subpopulations were defined by flow cytometry including cutaneous lymphocyte antigen (CLA) and CCR4high Treg cells, both previously associated with cutaneous diseases. Age- and sex-adjusted associations between circulating T-cell populations and infection were estimated using logistic regression. RESULTS: Total Treg-cell proportion in peripheral blood was not associated with ß HPV or HPyV infection. However, the proportion of circulating CLA+ Treg cells was inversely associated with γ HPV EBH infection [odds ratio (OR) 0·54, 95% confidence interval (CI) 0·35-0·84]. Interestingly, circulating Treg cells expressing markers indicative of antigen activation (CD27- CD45RA- FOXP3+ CD4+ ) were also inversely associated with γ HPV infection in SSW (OR 0·55, 95% CI 0·30-0·99) and EBH (OR 0·56, 95% CI 0·36-0·86). CONCLUSIONS: Inverse associations between circulating Treg cells and γ HPV infection suggest that localized viral infection may promote immunosuppressive cell migration into skin.

Parvovirus B19-associated purpuric-petechial eruption.

BACKGROUND: Papular-purpuric gloves-and-socks syndrome, characterized by focal acral purpuric eruptions with a symmetrical distribution, is a rare but representative purpuric dermatosis closely associated with parvovirus B19 (PVB19) infection. However, several atypical presentations such as involvement of other sites and generalized involvement have been recently reported in PVB19 infected patients. Such multifaceted features can cause considerable confusion when making a diagnosis of purpuric eruption associated with PVB19. OBJECTIVES: Describe two febrile patients with atypical presentation of papular-purpuric eruptions due to PVB19 infection and discuss the distinctive features of purpuric-petechial eruptions associated with PVB19 infection. STUDY DESIGN: Case reports and viral diagnosis by serologic tests and real-time PCR for PVB19 DNA in the serum. RESULTS: One presented with "asymmetrical gloves without socks" distribution of papular purpuric eruptions accompanied by asymmetrical intertriginous involvement, the other with generalized distribution characterized by prominent intertriginous and truncal involvement. Both cases were followed by erythema infectiosum. Paired serum antibody analysis and real-time PCR indicated the link between the development of papular purpuric eruption and the viremic phase of primary PVB19 infection. CONCLUSIONS: PVB19 infection should be considered in any patient presenting with a petechial or purpuric eruption of unclear origin, and not solely for PPGSS type presentations. Therefore, we propose a simple name "PVB19-associated purpuric-petechial eruption" to describe polymorphous purpuric-petechial eruptions due to PVB19 infection, coinciding with the viremic phase of primary infection and infectivity, characterized by a self-limiting course with a benign prognosis and common histological findings.

Tests for detecting herpes simplex virus and varicella-zoster virus infections.

Several laboratory diagnostic methods are available for the diagnosis, differentiation, and subtyping of HSV and VZV infections. In the office or at the bedside of a hospitalized patient, a positive Tzanck smear preparation is an inexpensive, rapid, and morphologic technique for confirming a suspected diagnosis of a herpesvirus infection. An expedient, slightly more expensive, reliable technique for establishing a HSV infection, yet not able to differentiate the subtype of that infection, is a recently marketed monoclonal antibody-based filtration type enzyme immunoassay (Kodak SureCell Herpes Test Kit). Serologic tests traditionally do not have a major role in the diagnosis of HSV infection; yet, new type-specific methods using Western blot assays may be useful for confirming the presence of unrecognized, subclinical HSV2 infections that are presently being underdiagnosed by current procedures. The gold standard for establishing the diagnosis of HSV infection has been the viral tissue culture. The fluorescent antibody to membrane antigen test and viral tissue culture have been the principal methods for diagnosing VZV infection. Immunomorphologic techniques have been useful adjuvant methods for both the diagnosis and the differentiation of HSV and VZV infections. Molecular virology techniques (particularly those using PCR) are likely to become the diagnostic methods of choice for both HSV infection and VZV infection once these tests become commercially available.