Objective: To examine the demographic and clinical characteristics of systemic sclerosis (SSc) patients without antinuclear antibodies (ANA) compared to ANA-positive patients. Methods: SSc patients enrolled in the Scleroderma Family Registry and DNA Repository were included. Relevant demographic and clinical data were entered by participating sites or obtained by chart review. ANA and SSc-related antibodies were determined in all investigated patients using commercially available kits at our laboratories. Results: This study included 3249 patients, of whom 208 (6.4%) were ANA negative. The proportion of male patients was higher in the ANA-negative group (OR = 1.65; p = 0.008). ANA-negative patients experienced less vasculopathic manifestations of SSc. The percent predicted diffusing capacity of carbon monoxide (DLCO) was higher in ANA-negative patients (p = 0.03). Pulmonary arterial hypertension (PAH) per right heart catheterization was less common in the ANA-negative group (OR = 0.28; p = 0.03). Furthermore, patients with negative ANA had a lower prevalence of telangiectasias and digital ulcers/pits (OR = 0.59, p = 0.03 and OR = 0.38, p = 0.01, respectively). Although diffuse cutaneous involvement was more common, the modified Rodnan Skin Score (mRSS) was lower in the ANA-negative group (2.4 points lower, p = 0.05). Furthermore, they experienced more malabsorption (p = 0.05). There was no difference in the frequency of pulmonary fibrosis or scleroderma renal crisis. All-cause mortality was not different between the 2 groups (p = 0.28). Conclusions: In conclusion, the results of this study suggest that SSc patients who are ANA negative constitute a distinct subset of SSc with less vasculopathy (less PAH, digital ulcers, and fewer telangiectasias), a greater proportion of males, and possibly, more frequent lower gastrointestinal involvement.
Bibliographical noteFunding Information:
We would like to thank Tony Mattar for his assistance in the database management; Julio Charles for performing the IIF laboratory studies; and all the participating sites, including the Canadian Scleroderma Research Group, University of California Los Angeles, University of Michigan, Georgetown University, Boston University, Medical University of South Carolina, Johns Hopkins University, University of Utah, Northwestern University, University of Alabama Birmingham, and University of Minnesota. We would also like to thank and acknowledge the Scleroderma Research Foundation, the National Institute of Arthritis and Musculoskeletal and Skin Diseases of the National Institutes of Health, and the Department of Defense for their support of our centers to accomplish this study. Finally, we would like to extend a special acknowledgement to the late Dr. Janet Markland who contributed to this project. We would like to recognize her not only for her participation in this study but also for being a part of the effort to advance scleroderma research.
Grant support: NIH/NIAMS , USA K23 AR061436 (Assassi); N01-AR-0-2251 (Mayes); K24 AR063120-02 (Khanna); RO1-AR055258 , P50-AR05414 , U01AI09090-01 (Mayes) and the Department of Defense Congressionally Directed Medical Research Programs , USA W81XWH-07-01-0111 (Mayes).
© 2015 Elsevier Inc.
Copyright 2016 Elsevier B.V., All rights reserved.
- Antinuclear antibody
- Systemic sclerosis