Classification criteria for primary Sjögren’s syndrome (SS) have been approved by the American College of Rheumatology (ACR) and European League Against Rheumatism (EULAR), validating an international set of classification criteria for SS using standards set by both organizations. Those criteria can now be found in the 2016 ACR/EULAR Classification Criteria for Primary Sjögren’s Syndrome: A Consensus and Data-Driven Methodology Involving Three International Patient Cohorts, which was published in the Oct. 27 online edition of Arthritis & Rheumatology, as well as Annals of the Rheumatic Diseases.
The new classification criteria are based on the weighted sum of five items, which reflect the higher importance of the immunologic abnormalities granted by the majority of clinician experts:
- Anti-SSA(Ro) antibody positivity and focal lymphocytic sialadenitis with a focus score of ≥1 foci/mm2, each scoring 3;
- An abnormal ocular staining score of ≥5 (or a van Bijsterveld score ≥4);
- A Schirmer test of ≤5 mm/5 minutes; and
- An unstimulated salivary flow rate of ≤0.1 mL/minute, each scoring 1.
Individuals who meet eligibility criteria and who have a total score of ≥4 for the items above meet the criteria for SS.
Caroline Shiboski, DDS, MPH, PhD, at the University of California, San Francisco, and lead author on the paper, says these classification criteria “provide more flexibility than the 2012 ACR criteria and more rigor than the 2002 American-European Consensus Group (AECG) criteria, which included symptoms as criteria items; the new criteria consider symptoms as determinants of eligibility. Further, the new criteria consider systemic signs and B-cell activation biomarkers through the EULAR Sjögren’s Syndrome Disease Activity Index (ESSDAI) as inclusion criteria, which will allow diagnosis of systemic and earlier forms of the disease when sicca features are not already present.”
The new criteria use improved methods that have been outlined by ACR and EULAR and have been applied successfully in the development and validation of the recently revised criteria for systemic sclerosis and rheumatoid arthritis, Dr. Shiboski says. In addition, the criteria eliminate the confusion of having two sets of criteria in active use, one with recognized limitations that is not approved by either ACR or EULAR, and the other recently proposed and only provisionally approved by the ACR.
Further, the new criteria do not include outdated, painful or expensive examinations, such as sialography and salivary scintigraphy, which were part of the AECG criteria. Preexisting lymphoma, which was included in the exclusion criteria list in the AECG criteria, has been deleted from that list, because diagnosis of SS is sometimes made after a prior lymphoma occurrence. Finally, the criteria include another important exclusion criterion, which is IgG4-related disease, and limit HCV infection as an exclusion criterion to active HCV infection with positive PCR, she says.