Background Fibromyalgia (FM) exists in a substantial number of patients with rheumatoid arthritis (RA) (approx. 15%), who have higher disease activity as measured by DAS-28, than RA patients without concomitant FM. It is important to understand if there is an association between active inflammation on joint level and FM symptoms in RA patients
Objectives In this study, we examined the relation between joint inflammation and FM symptoms in RA patients. We hypothesized that there is no correlation between the severity of inflammation on joint level and FM symptoms.
Methods In a period of 8 months, RA patients (US-RA group) who were candidates to biological treatment underwent ultrasound (US) examination (Hitachi Preirus,14 or 18 MHz linear transducer) before initiation of biological treatment. The patients underwent screening for fibromyalgia (FM) using The Modified 2010 American College of Rheumatology (ACR) Diagnostic Criteria. Two experienced ultrasonographers (SC, AC) blinded to the DAS-28 and FM results performed the UL examination, while experienced nurses, blinded on US and FM results performed the DAS28 calculation.
In a study made at the same period of time in our department we found that 13 RA patients in established biological treatment were diagnosed as having concomitant FM (RAF group). These patients were in a stabile treatment during the examination time and there was calculate DAS-28 in the same way as above.
The comparisons between US-RA and RAF groups were performed by unpaired t-test after confirming normal distribution of data.
Results We included 13 patients in the US-RA group. They had at least two joints with high inflammation (Grey scale synovitis grade II and Colour Doppler grade II as minimum). They were screened for FM and only one of these patients fulfilled the Modified 2010 ACR diagnostic criteria. Three months later all patients were in DAS remission/low disease activity, except the patient with concomitant FM, who still had moderate high DAS because of many tender joints and high VAS-GH.
We also compared the US-RA group with RAF group and there was no significant difference in age, gender, disease duration & seropositivity. The rest of comparisons between the two groups are shown in Table 1.
Conclusions We did not find evidence that RA patients with high inflammation on joint level have higher rates of FM. Biological naïve RA patients (US-RA group) with high level of joints inflammation as confirmed by US had less severe subjective symptoms (VAS & HAQ) compared to RAF patients in a stabile biological treatment phase and without swollen joins.
Disclosure of Interest : None declared