Overlapping fibromyalgia may be present in 30% or more of patients with primary Sjögren’s syndrome based on the American College of Rheumatology 2010 criteria, but only 19% of the same patients met 1990 criteria, according to the results of a study.
Researchers studied 100 patients with primary Sjögren’s syndrome (pSS) who were consecutively evaluated for fibromyalgia based on the American College of Rheumatology (ACR) 2010 criteria. All patients met American-European Consensus Group (AECG) criteria for pSS, and were excluded in the presence of thyroid dysfunction, infections or other chronic diseases.
Clinical evaluations included tender point counts, a 0-100 mm VAS for pain and fatigue, and the Hamilton depression rating scale 17-items (HAM-D) was used to identify depression, cognitive dysfunction and insomnia. The European League Against Rheumatism (EULAR) Sjögren’s Syndrome Patient Reported Index (ESSPRI) was administered to assess symptoms of pSS and disease activity was measured with the EULAR Sjögren’s Syndrome Disease Activity
Index (ESSDAI) and the Symptom Severity Scale (SSS). The Widespread Pain Index (WPI) was used to assess pain.
Serological evaluations included a complete blood count and measurement of the erythrocyte sediment rate and C-reactive protein (CRP). The presence of antinuclear antibodies, antiSSA/Ro, anti-SSB/La, rheumatoid factor, levels of total serum immunoglobulin G and complements (C3 and C4), serum 2-microglobulin, and vitamin D levels were assessed.
The revised Fibromyalgia Impact Questionnaire (FIQR) was administered to patients in whom fibromyalgia was identified, and tender points were assessed by two rheumatologists based on ACR 1990 criteria.
Fibromyalgia was identified in 31 of 100 patients based on the ACR 2010 diagnostic criteria and in 19 patients according to the ACR 1990 criteria. However, all patients who met ACR 1990 criteria also met ACR 2010 criteria, while 12 who met 2010 criteria also met 1990 criteria. All had similar FIQR and VAS scores for pain and fatigue; patients who met ACR 1990 criteria tended to be older and had more severe symptoms.
Among other correlations, patients with both pSS and fibromyalgia had significantly higher tender point counts than patients without fibromyalgia and tender point counts correlated with the WPI, VAS for pain and fatigue, ESSPRI, HAM-D and CRP. However, ESSDAI was not significantly associated with tender point counts, WPI or SSS.
Mild depression was identified in 36 patients and moderate-to-severe depression was identified in 21, and the prevalence was significantly higher in patients with fibromyalgia. The HAM-D score correlated with the FIQR score in patients with both pSS and fibromyalgia. – by Shirley Pulawski
Disclosure: The researchers report no relevant financial disclosures.