ARTHRITIS & RHEUMATISM Vol. 56, No. 10, October 2007, pp 3448–3458 DOI 10.1002/art.22861 © 2007, American College of Rheumatology Antiangiogenic Plasma Activity in Patients With Systemic Sclerosis Mary Jo Mulligan-Kehoe, 1 Mary C. Drinane, 1 Jessica Mollmark, 1 Livia Casciola-Rosen, 2 Laura K. Hummers, 2 Amy Hall, 1 Antony Rosen, 2 Fredrick M. Wigley, 2 and Michael Simons 1 Objective. Systemic sclerosis (SSc; scleroderma) is a systemic connective tissue disease with an extensive vascular component that includes aberrant microvascu- lature and impaired wound healing. The aim of this study was to investigate the presence of antiangiogenic factors in patients with SSc. Methods. Plasma samples were obtained from 30 patients with SSc and from 10 control patients without SSc. The samples were analyzed for the ability of plasma to affect endothelial cell migration and vascular structure formation and for the presence of antiangio- genic activity. Results. Exposure of normal human microvascu- lar dermal endothelial cells to plasma from patients with SSc resulted in decreased cell migration (mean  SEM 52  5%) and tube formation (34  6%) compared with that in plasma from control patients (P < 0.001 for both). SSc plasma contained 2.9-fold more plasminogen kringle 1–3 fragments (angiostatin) than that in control plasma. The addition of angiostatin to control plasma resulted in inhibition of endothelial cell migration and proliferation similar to that observed in SSc plasma. In vitro studies demonstrated that granzyme B and other proteases contained in T cell granule content cleave plasminogen and plasmin into angiostatin fragments. Conclusion. Plasminogen conformation in pa- tients with SSc enables granzyme B and granule content protease to limit the proangiogenic effects of plasmin and increase the levels of antiangiogenic angiostatin. This increase in angiostatin production may account for some of the vascular defects observed in patients with SSc. Systemic sclerosis (SSc; scleroderma) is a sys- temic connective tissue disease that affects the capillar- ies and small arteries, resulting in reduced blood flow, tissue ischemia, and defective wound healing (1). The spectrum of vascular abnormalities in SSc extends from Raynaud’s phenomenon, with reduced blood flow to the skin, finger ulcerations, and the potential for gangrene (2), progressive pulmonary hypertension, and coronary microvascular disease that can result in myocardial ischemia, contraction band necrosis, and fibrosis (3), to abnormal tissue healing leading to scarring and sclerosis (3). SSc vascular disease also affects other organs, including the kidneys and the gastrointestinal tract. Although the pathogenesis of SSc is not completely understood, the 3 main components of the disease process include autoimmunity, tissue fibrosis, and aber- rant microvascular function. Vascular homeostasis requires both proangio- genic and antiangiogenic factors. The proangiogenic factors are secreted molecules that promote endothelial cell proliferation, migration, and tubulogenesis (4,5). Cleavage products of several extracellular proteins, in- cluding matrix proteins such as type XVIII collagen and type IV collagen, and hemostatic proteins such as plas- minogen, among others, have been shown to possess antiangiogenic activity (6,7). The activity of these factors as well as other proteins controlling angiogenesis is tightly regulated in quiescent tissue. Its alteration under Dr. Mulligan-Kehoe’s work was supported by the NIH (grant HL-069948). Drs. Casciola-Rosen and Rosen’s work was supported by the NIH (grant HL-56091). Dr. Simons’ work was supported by the NIH (grants HL-53793 and HL-62289) and the Scleroderma Research Foundation. 1 Mary Jo Mulligan-Kehoe, PhD, Mary C. Drinane, MS, Jessica Mollmark, BS, Amy Hall, BS, Michael Simons, MD: Angio- genesis Research Center, Dartmouth Medical School, Lebanon, New Hampshire; 2 Livia Casciola-Rosen, PhD, Laura K. Hummers, MD, Antony Rosen, MD, Fredrick M. Wigley, MD: Johns Hopkins Uni- versity, Baltimore, Maryland. Address correspondence and reprint requests to Michael Simons, MD, Section of Cardiology, Dartmouth-Hitchcock Medical Center, Lebanon, NH 03756. E-mail: Michael.simons@ dartmouth.edu. Submitted for publication January 1, 2007; accepted in re- vised form June 1, 2007. 3448