3233 Von Willebrand Factor is Localized in the Extravascular tissue of Patients with Juvenile Scleroderma

Abstract

OBJECTIVES/SPECIFIC AIMS: To further explore the role of vWF in the pathogenesis of scleroderma by identifying its location within the tissue of sample biopsies obtained as part of routine diagnosis with the use of immuno-histochemical staining. METHODS/STUDY POPULATION: We examined 8 skin biopsies from 2 patients with systemic sclerosis (SSc), 2 with localized scleroderma (LS) and 4 with JDM. Double immunofluorescence staining was performed in each tissue with antibodies against vWF and collagens type I and III. DAPI (4′, 6-diamidino-2-phenylindole) was also used for counterstaining of inflammatory cells. Tissue staining patterns were compared between groups. RESULTS/ANTICIPATED RESULTS: Biopsies were obtained from the upper extremity of 7 females and the lower extremity of 1 male. Median age, symptom duration, and serum levels of vWF antigen around the time of biopsy was 8 years (IQR 4.5-11), 5.5 months (IQR 2.5-7), and 245% (IQR 203-302 for 7 patients), respectively. All but 1 biopsy was performed prior to initiation of immunosuppressive therapy. Immunofluorescence staining showed a superficial and deep perivascular inflammatory cell infiltrate that co-localized with vWF in all tissues. There was expression of vWF in the extravascular tissue of patients with JScl co-localizing with collagen III in the reticular dermis (Figures 1 and 2). In comparison, vWF expression was restricted to the endothelium and did not co-localize with collagen in the dermis of patients with JDM (Figure 3). Patients with SSc had higher expression of vWF as compared to patients with LS. DISCUSSION/SIGNIFICANCE OF IMPACT: vWF may participate in the pathogenesis of cutaneous inflammatory conditions. We have demonstrated that vWF co-localizes with cellular inflammatory infiltrates in the perivascular areas and in the dermis of patients with JScl and JDM. We additionally speculate that vWF may participate in the pathogenesis of fibrosing skin diseases based on evidence of increased extravascular expression in the tissue of patients with JScl (vs. JDM), and its co-localization with collagen. vWF expression intensity in the dermis of JScl patients may relate to disease extension (SSc vs. LS).