Arthritis & Rheumatism, Volume 60,
October 2009 Abstract Supplement
The 2009 ACR/ARHP Annual Scientific Meeting
Philadelphia October 16-21, 2009.
Autoantibody Profiles in Systemic Sclerosis More Predictive of Clinical Outcomes Than Disease Subset Classification
Statkute1, Laisvyde, Carns1, Mary, Huang1, Spencer, Hinchcliff1, Monique E., Varga2, John
Systemic sclerosis (SSc) clinical subtypes, diffuse (dcSSc) and limited (lcSSc), have been associated with specific autoantibodies (autoAb): anticentromere (ACA) for lcSSc and topoisomerase 1 (topo-1) for dcSSc. Patients with lcSSc/topo-1 and patients with dcSSc/ACA could be referred as "atypical". Additionally, patients lacking ACA or topo-1 likely express 1 of less common SSc-specific autoAb (double negative, DN). We compared different subsets of patients (by clinical subtype and autoAb) to determine if specific autoAb or clinical subtype is more predictive of particular SSc manifestations.
254 consecutive patients with SSc seen at the Northwestern Scleroderma Program between 2005 and 2008 were evaluated retrospectively. Subjects were assigned into 1 of 6 groups based on clinical classification and autoAb (determined by ELISA). T and Chi square tests were utilized, p<0.005 was used for level of significance.
167 patients (66%) had lcSSc and 87 (34%) had dcSSc. 27% of lcSSc patients were ACA+ and 23% were Topo-1+. 5% of dcSSc patients were ACA+ and 35% were Topo-1+. 50% of lcSSc, 60% of dcSSc and 53% of total were DN.
Patients with lcSSc who had topo-1 were more likely to have pulmonary fibrosis (PF) and less likely to have pulmonary hypertention (PH) compared to other lcSSc patients with either ACA or DN. No patients with topo-1 or ACA developed scleroderma renal crisis (SRC). Within 1st group of comparison (dcSSc/topo-1 vs lcSSc/topo-1) presence PF was comparable (97 vs 83%, p=0.073). In group 2 (dcSSc/ACA vs lcSSc/ACA), PF was present in 50 vs 24%, isolated PH in 25 vs 28%, not statistically significant. For group 3 (dcSSc/topo-1 vs dcSSc/ACA), rate of PF (97 vs 50%) and isolated PH (0 vs 25%) differed significantly. Group 4 (dcSSc/DN vs dcSSc/ACA) showed no differences in PF, PH or isolated PH. dcSSc/DN had 4 SRC cases (8%); 23% had severe cardiac involvement and 9 patients (17%) died. Within group 5 (lcSSc/topo-1 vs lcSSc/ACA), PF (83% vs 24%, p<0.001) including severe (16 vs 4%) was more prevalent in patients with topo-1. Group 6 (lcSSc/topo-1 vs lcSSc/DN) showed similar significant differences in rates of PF (83 vs 54%) and isolated PH (0 vs 13%). lcSSc/DN demonstrated another 3 SRC cases (4%) and frequent (15%) severe cardiac involvement.
While ACA is rare in patients with dcSSc, topo-1 is frequent in patients with lcSSc.Topo-1 positive lcSSc patients are at higher risk for PF than other lcSSc patients. However, no patients with topo-1 developed SRC. These results indicate that while ACA is useful in delineating clinical subsets of SSc, topo-1 is less predictive. Furthermore, autoantibodies are more predictive of severity and disease outcomes than clinical subsets. In particular, disease manifestations and severity in lcSSc patients who are topo-1 positive are comparable to those in dcSSc patients.
To cite this abstract, please use the following information:
Statkute, Laisvyde, Carns, Mary, Huang, Spencer, Hinchcliff, Monique E., Varga, John; Autoantibody Profiles in Systemic Sclerosis More Predictive of Clinical Outcomes Than Disease Subset Classification [abstract]. Arthritis Rheum 2009;60 Suppl 10 :469