| Sumario: | Systemic sclerosis (SSc) is an autoimmune disorder with high morbidity and mortality, is difficult to diagnose early, and has no curative treatment. PSGL-1 is a leukocyte receptor whose deficiency in mice promotes an SSc like disease. ADAM8, a metalloprotease that cleaves PSGL-1, is implicated in nflammatory processes. Our goal was to evaluate whether PSGL-1 and ADAM8 contribute to the pathogenesis of human SSc. We found that patients with SSc presented increased PSGL-1 expression on monocytes, dendritic cells, and T cells and decreased expression of PSGL-1 on B cells. PSGL-1 on monocytes from SSc patients failed to induce Syk phosphorylation or IL-10 production after interaction with P-selectin. Up to 60% of the IL-10eproducing B cells expressed PSGL-1, pointing to a regulatory role for PSGL-1 in B cells, and PSGL-1þ B cells from SSc patients had decreased IL-10 production. ADAM8 expression was increased on antigen-presenting cells and T lymphocytes of SSc patients. Patients treated with calcium antagonists had lower levels of ADAM8 on APCs and T lym phocytes. Multivariate analysis indicated that the high percentage of ADAM8-expressing plasmacytoid dendritic cells iscriminated patients from healthy donors. High PSGL-1 expression on dendritic cells was associated with the presence of interstitial lung disease.
|
|---|
