Detection of Type VII Collagen Autoantibodies Before the Onset of Bullous Systemic Lupus Erythematosus.

IMPORTANCE: Anti-type VII collagen autoantibodies are often detectable in patients with bullous systemic lupus erythematosus (BSLE). However, the timing of their appearance preceding the onset of disease is unknown to date. OBSERVATIONS: We report the case of a 50-year-old woman with a history of SLE who was seen with vesicles and bullae around her lips, trunk, axillae, arms, and thighs. Histologic analysis and immunofluorescence and immunoblot studies confirmed the diagnosis of BSLE. Immunoblotting and enzyme-linked immunosorbent assay studies of the patient's serum obtained 3 months before the onset of BSLE showed the presence of anti-type VII collagen autoantibodies. Levels of anti-type VII collagen IgG increased after bullous lesions appeared. Within 1 month after initiating dapsone therapy and increasing the dosage of prednisone, skin lesions promptly resolved. One year after the onset of BSLE, the anti-type VII collagen IgG decreased below levels observed before the inception of the bullous lesions. CONCLUSIONS AND RELEVANCE: Anti-type VII collagen autoantibodies can precede the clinical appearance of BSLE. The subsequent increase and decrease in levels of circulating anti-type VII collagen autoantibodies, which mirrored skin disease activity, support a potential role in their initiation of disease.

IgG, IgM, and IgA antinuclear antibodies in discoid and systemic lupus erythematosus patients.

IgG antinuclear antibodies (ANAs) are elevated in patients with systemic lupus erythematosus (SLE) compared with patients with discoid lupus erythematosus (DLE). To provide an expanded immunologic view of circulating ANAs in lupus patients, we compared the expressions of IgG, IgM, and IgA ANAs in DLE and SLE patients. In this cross-sectional study, sera from age-, gender-, and ethnic-matched SLE (N = 35), DLE (N = 23), and normal patients (N = 22) were tested for IgG, IgM, and IgA ANAs using enzyme-linked immunosorbent assays (ELISAs) and indirect immunofluorescence (IIF) with monkey esophagus as substrate. ELISAs showed elevated levels of IgG ANA, IgM ANA, and IgG/IgM ANA ratios in SLE patients compared with DLE and normal patients. IgA ANA expression was higher in SLE and DLE patients versus normal patients. IIF studies showed higher percentages of patients positive for IgG, IgM, and IgA ANAs in the SLE group. Higher IgG/IgM ANA ratios in SLE than DLE show enhanced class-switching and a more sustained humoral response in SLE. They also suggest a potential connection of IgM ANAs with disease containment.

Blockade of virus infection by human CD4+ T cells via a cytokine relay network.

CD4(+) T cells directly participate in bacterial clearance through secretion of proinflammatory cytokines. Although viral clearance relies heavily on CD8(+) T cell functions, we sought to determine whether human CD4(+) T cells could also directly influence viral clearance through cytokine secretion. We found that IFN-gamma and TNF-alpha, secreted by IL-12-polarized Th1 cells, displayed potent antiviral effects against a variety of viruses. IFN-gamma and TNF-alpha acted directly to inhibit hepatitis C virus replication in an in vitro replicon system, and neutralization of both cytokines was required to block the antiviral activity that was secreted by Th1 cells. IFN-gamma and TNF-alpha also exerted antiviral effects against vesicular stomatitis virus infection, but in this case, functional type I IFN receptor activity was required. Thus, in cases of vesicular stomatitis virus infection, the combination of IFN-gamma and TNF-alpha secreted by human Th1 cells acted indirectly through the IFN-alpha/beta receptor. These results highlight the importance of CD4(+) T cells in directly regulating antiviral responses through proinflammatory cytokines acting in both a direct and indirect manner.

Pre-assembly of STAT4 with the human IFN-alpha/beta receptor-2 subunit is mediated by the STAT4 N-domain.

CD4(+) T cells regulate adaptive responses to pathogens by secreting unique subsets of cytokines that mediate inflammatory processes. The innate cytokines IL-12 and IFN-alpha/beta regulate type I responses and promote acute IFN-gamma secretion through the activation of the STAT4 transcription factor. Although IL-12-induced STAT4 activation is a conserved pathway across species, IFN-alpha/beta-dependent STAT4 phosphorylation does not occur as efficiently in mice as it does in human T cells. In order to understand this species-specific pathway for IFN-alpha/beta-dependent STAT4 activation, we have examined the molecular basis of STAT4 recruitment by the human IFNAR. In this report, we demonstrate that the N-domain of STAT4 interacts with the cytoplasmic domain of the human, but not the murine IFNAR2 subunit. This interaction mapped to a membrane-proximal segment of the hIFNAR2 spanning amino acids 299-333. Deletion of this region within the hIFNAR2 completely abolishes IFN-alpha/beta-dependent STAT4 tyrosine phosphorylation when expressed in human IFNAR2-deficient fibroblasts. Thus, the human IFNAR2 cytoplasmic domain serves to link STAT4 to the IFNAR as a pre-assembled complex that facilitates cytokine-driven STAT4 activation.