The new ACR/EULAR 2013 classification criteria for scleroderma (systemic sclerosis) were debated by Dr. Sindhu Johnson and Dr. Marie Hudson.
Sindhu Johnson, who was instrumental in developing the new criteria, commented that the previous preliminary American Rheumatism Association criteria were weighted towards established disease (since there were clinical and chest X-ray features). The old criteria were one major (sufficient): skin thickening of the fingers and proximal to the MCPs, or if not present, 2 of 3 minor: sclerodactyly, digital pits or tuft resorption, pulmonary fibrosis.
The new criteria reflect the various components of the disease (vascular, fibrosis and autoantibodies). They are more sensitive and specific both in the validation of the criteria that was performed in the classification paper (published in Arthritis & Rheumatism and ARD simultaneously)1,2and they have been externally validated including using the Canadian Scleroderma Research Study Group (CSRG)3.
Patients with limited SSc and early SSc were less likely to be classified. The calculator for determining the score for the new SSc criteria is freely available on the RheumInfo website . The criteria can inform the constructs of the SSc disease.
Dr. Marie Hudson mentioned limitations, including the classification criteria are meant as a research tool. They are not diagnostic criteria. She demonstrated the false positive rate if applied in a Canadian population which could over-classify 35,000 Canadians. The gold standard for diagnosis of SSc remains the clinician. Making a very early diagnosis is being studied in “pre-SSc.” Not all patients will develop full SSc or have lead time bias if they are enrolled in a research study (since outcomes are better) if the patients do not progress to clinical disease. We do not yet know if early identification changes clinical outcomes. Dr. Hudson argued that the genetics and phenotypes are so varied that maybe we should concentrate on SSc subsets. These are the next steps in classification.
So, what is the take home message? It depends on what you want to use the criteria for. Good clinical judgment trumps all, but the criteria are an excellent teaching construct for SSc including what is not SSc (such as scleroderma renal crisis and tendon friction rubs) where some items are too rare or redundant and cluster with other included features. So, common sense trumps but the criteria do identify more patients with SSc who are early, mild or of the limited subset.
My bias needs to be declared: I am the co-PI of this project and spent a few years working on it.
1. van den Hoogen F, Khanna D, Fransen J, Johnson SR, Baron M, Tyndall A, et al. 2013 classification criteria for systemic sclerosis: an American College of Rheumatology/European League Against Rheumatism collaborative initiative. Arthritis Rheum. 2013;65:2737-47. doi: 10.1002/art.38098. Epub 2013 Oct 3.
2. van den Hoogen F, Khanna D, Fransen J, Johnson SR, Baron M, Tyndall A, et al. 2013 classification criteria for systemic sclerosis: an American College of Rheumatology/European League Against Rheumatism collaborative initiative. Ann Rheum Dis. 2013;72:1747-55. doi: 10.1136/annrheumdis-2013-204424.
3. Hudson M, Taillefer S, Steele R, Dunne J, Johnson SR, Jones N, et al. Improving the sensitivity of the American College of Rheumatology classification criteria for systemic sclerosis. Clin Exp Rheumatol. 2007;25(5):754-757.
Dr. Janet Pope is Professor of Medicine at Western University and Division Head of Rheumatology. Dr. Pope's research interests include epidemiologic studies in scleroderma, classification criteria in systemic sclerosis, systemic lupus erythematosus and rheumatoid arthritis.View Full Bio