Impact of varicella-zoster virus on dendritic cell subsets in human skin during natural infection.

Varicella-zoster virus (VZV) causes varicella and herpes zoster, diseases characterized by distinct cutaneous rashes. Dendritic cells (DC) are essential for inducing antiviral immune responses; however, the contribution of DC subsets to immune control during natural cutaneous VZV infection has not been investigated. Immunostaining showed that compared to normal skin, the proportion of cells expressing DC-SIGN (a dermal DC marker) or DC-LAMP and CD83 (mature DC markers) were not significantly altered in infected skin. In contrast, the frequency of Langerhans cells was significantly decreased in VZV-infected skin, whereas there was an influx of plasmacytoid DC, a potent secretor of type I interferon (IFN). Langerhans cells and plasmacytoid DC in infected skin were closely associated with VZV antigen-positive cells, and some Langerhans cells and plasmacytoid DC were VZV antigen positive. To extend these in vivo observations, both plasmacytoid DC (PDC) isolated from human blood and Langerhans cells derived from MUTZ-3 cells were shown to be permissive to VZV infection. In VZV-infected PDC cultures, significant induction of alpha IFN (IFN-alpha) did not occur, indicating the VZV inhibits the capacity of PDC to induce expression of this host defense cytokine. This study defines changes in the response of DC which occur during cutaneous VZV infection and implicates infection of DC subtypes in VZV pathogenesis.

Interobserver reproducibility of histopathologic prognostic variables in primary cutaneous melanomas.

BACKGROUND: The prognosis for patients with localized primary cutaneous melanoma is known to depend principally on tumor thickness, and to a lesser extent on ulcerative state and Clark level. We have recently found in an analysis of 3661 patients that tumor mitotic rate (TMR) is also an important prognostic parameter, ranking second only to tumor thickness. However, few studies have assessed the accuracy and reproducibility with which these features of a melanoma are recorded by histopathologists. AIM: To assess interobserver reproducibility of major pathologic prognostic parameters in cutaneous melanoma. METHODS: Single hematoxylin and eosin-stained slides of 69 dermally invasive primary cutaneous melanomas were circulated among six pathologists with differing experience in the assessment of melanocytic tumors. The observers independently determined the tumor thickness, Clark level of invasion, ulcerative state, and TMR for each lesion. Intraclass correlation coefficients and kappa scores for multiple ratings per subject were calculated. RESULTS: The intraclass correlation coefficients were 0.96 for tumor thickness and 0.76 for TMR. The kappa scores were 0.83 for ulcerative state and 0.60 for Clark level. These results indicated excellent agreement among the pathologists for measurements of tumor thickness, ulcerative state, and TMR and fair to good agreement for Clark level. CONCLUSIONS: Appropriately trained and experienced histopathologists can assess prognostically important features of melanomas accurately and reproducibly. Given our recent finding of the significance of TMR in determining prognosis, it is important that this feature be assessed by a standardized method and documented for all primary cutaneous melanomas.

Treatment of chronic leg ulcers with topical activated protein C.

BACKGROUND: The treatment of skin ulcers frequently presents a management challenge. Nonhealing wounds with poor response to conventional wound management therapy represent a significant cause of disability, affecting approximately 1% of the global population. Activated protein C is a serine protease with anticoagulant, angiogenic, and anti-inflammatory properties that has shown efficacy in patients for the treatment of severe sepsis. We report 4 cases of nonhealing lower limb skin ulcers that were treated with activated protein C. OBSERVATIONS: The study included 4 patients whose wounds were not improving despite standard wound treatment for 4 months or more. Activated protein C was applied topically to their wounds once weekly for 4 weeks. All 4 patients showed a rapid positive response to treatment that was maintained during a 4-month follow-up period. The treatment was well tolerated, with no remarkable adverse effects or complications. CONCLUSIONS: Activated protein C can stimulate wound healing in patients with skin ulcers that are refractory to conventional wound-healing therapies. The likely mechanism of action is its recognized ability to stimulate angiogenesis and reepithelialization and to inhibit inflammation. Activated protein C has potential as a therapeutic option for patients with chronic skin ulcers.