Provisional new classification criteria for Sjögren’s syndrome take into account the availability of new biologic treatment agents, rely solely on objective measures, and improve classification performance when compared with existing alternatives, according to the American College of Rheumatology.
The new criteria, which are the first to be endorsed by the ACR, target individuals with signs and symptoms suggestive of Sjögren’s syndrome and are based on expert opinion derived by analysis of data from the more than 1,300 patients in the SICCA (Sjögren’s International Collaborative Clinical Alliance) registry. They also differ from previous criteria in that only objective tests related to oral, ocular, and systemic manifestations of the syndrome are included.
This brings together three medical specialties – rheumatology, ophthalmology, and oral medicine – for the purpose of determining a patient’s disease status, and reinforces the importance of collaboration among these specialties when it comes to assessment and management of patients with Sjögren’s syndrome. It also protects patients by reducing the likelihood of misclassification, which could lead to unnecessary exposure to investigational drugs, according to Stephen C. Shiboski, Ph.D., of the University of California, San Francisco, and colleagues from the SICCA Research Groups, which authored the classification criteria.
Under the provisional guidelines, a classification as having Sjögren’s syndrome requires that a patient meet at least two of these three conditions:
• A blood test indicating the presence of anti–Sjögren’s syndrome antigen A and/or anti–Sjögren’s syndrome antigen B, or positive rheumatoid factor and antinuclear antibody titer of at least 1:320.
• An impaired ability to produce tears, as determined by an eye examination with an ocular staining score of 3 or greater.
• The presence of autoimmune impairment of salivary function, as determined by a focus score of 1 or more focus/4 mm2 in labial salivary gland biopsy samples, the investigators said (Arthritis Care Res. 2012;64:475-87).
A high level of consensus was reached by the 20 members of the expert panel with respect to the use of the these objective measures, with 86% agreeing or strongly agreeing that meeting two of these three criteria should be required to classify Sjögren’s syndrome.
Preliminary validation of the classification criteria was based on comparison with the American-European Consensus Group criteria, which are likely the most frequently used criteria, and with cases and controls from external sources to the population used for criteria development. These comparisons showed high levels of sensitivity (96.3%) and specificity (83%) for the new criteria, which exceeded those of the alternative criteria, the investigators noted.
The findings are important, given the availability and development of new biologic agents for the treatment of Sjögren’s syndrome.
"Until recently, since few therapeutic agents were being considered in the systemic management of [Sjögren’s syndrome], the development of classification criteria was mainly for the purpose of epidemiologic studies to estimate the prevalence of the disease. However, the development of new biologic immunomodulating agents that are being considered in the treatment of [Sjögren’s syndrome] increases the need and importance of developing stringent classification criteria that can be used in the context of clinical trials," the investigators wrote, explaining that the consequences of misclassifying someone as having Sjögren’s syndrome would be serious, given the potentially toxic side effects of the biologic agents.
The results of the validation analyses performed in the development of these criteria indicate that they constitute a set of criteria that are stringent enough to be used for allowing entry into clinical trials, they said.
These new classification criteria have been quantitatively validated using patient data, and have been approved by the ACR board of directors, but have not yet undergone validation based on an external data set.
This work was supported by the National Institutes of Health, including the National Institute for Dental and Craniofacial Research, the National Eye Institute, and the Office of Research on Women’s Health. Three authors made disclosures, including Dr. F. Vivino, who has received consultant fees and/or honoraria from Daiichi-Sankyo and Parion Sciences; Dr. A. Wu, who owns stock and/or stock options in Isis Pharmaceuticals and Schering-Plough; and Dr. J. S. Greenspan, who has received consultant fees from GlaxoSmithKline.