The newly proposed 2016 ACR-EULAR criteria can successfully diagnose primary Sjogren’s syndrome with 100% sensitivity, but the ethnicity of the study population influences its specificity, a Korean study reported.
The study, “Performance of the 2016 ACR-EULAR classification criteria for primary Sjogren’s syndrome in a Korean cohort,” was published in the journal Rheumatology International.
Sjogren’s syndrome is an autoimmune condition that can affect multiple organs. Primarily, the immune cells attack exocrine organs such as salivary and tear glands resulting in extremely dry mouth and eyes.
For the past decade, rheumatologists have used the 2002 American- European Consensus Group (AECG) criteria and the 2012 American College of Rheumatology (ACR) classification criteria for Sjogren’s syndrome to confirm the diagnosis in patients who have symptoms of the disease.
In 2016, a new Sjogen’s classification criteria — the 2016 ACR-EULAR — was proposed, taking into consideration different classification aspects of ACR and the European League Against Rheumatism (EULAR) criteria.
Here, investigators compared the three classification criteria and assessed the overall performance of the new 2016 ACR-EULAR criteria to confirm previously diagnosed cases of primary Sjogren’s in Korea.
A total of 328 patients (323 female) with a median age of 53 were included in the study. Patients were recruited from the Korean Initiative of Sjogren’s Syndrome (KISS), a nationwide Sjogren’s registry established in 2013, and from 12 other universities in South Korea. They were recruited from October 2013 to January 2017.
Baseline clinical and laboratory data, along with blood and salivary samples for each patient enrolled, are available on the KISS registry.
Researchers found that 93.6% of the patients met all three criteria of classification. The 2002 AECG and 2016 ACR-EULAR criteria were met by 99.1% (325) of the patients diagnosed with primary Sjogren’s, while 94.5% (310) fulfilled the 2012 ACR criteria.
A separate group of participants who showed signs of Sjogren’s syndrome and underwent a lower lip biopsy for confirmation were also included in this study as a validation group, to help determine the sensitivity and specificity of the three criteria. A total of 161 participants (95 Sjogren’s patients, 66 controls) were assessed in this section of the study.
The sensitivity of 2016 ACR-EULAR criteria was the highest (100%) — meaning there were no false negatives — compared with 2002 AECG (88.30%) and 2012 ACR criteria (91.10%).
However, the 2016 ACR-EULAR criteria had the lowest specificity (81.80%) compared with 2002 AECG (92.19%) and 2012 ACR criteria (90.60%) in this study population.
This means the newly proposed criteria led to a higher rate of false positives.
The low specificity of the 2016 criteria observed in this Korean group could be explained by previous studies that showed the influence of ethnicity and location in the diagnosis of primary Sjogren’s, the researchers wrote.
With a higher sensitivity and a lower specificity in the Asian population, “the newly proposed 2016 ACR-EULAR criteria performed well in Korean [primary Sjogren’s syndrome] patients, with most being met by [Sjogren’s] patients previously classified according to either the 2002 AECG criteria or 2012,” the team concluded.