POS0565 IS ACTIVE SYNOVITIS OF METACARPOPHALANGEAL JOINTS A NEUROPATHIC CONDITION IN RHEUMATOID ARTHRITIS PATIENTS? RESULTS FROM A ULTRASOUND STUDY AT LEVEL OF THE PALMAR DIGITAL NERVES

Background:Rheumatoid arthritis (RA) is a chronic inflammatory arthritis that primarily affects the joints of hands, wrists, and feet. Anatomical damage (at bone, cartilage and tendon level) occurs as a consequence of a persistent synovial inflammation (1). In RA, periarticular soft tissues, including nerves, may also be involved. In particular, there is a high prevalence of neuropathic conditions such as carpal tunnel syndrome (CTS) in RA patients. In fact, the presence of inflammatory changes can frequently be documented by ultrasound (US) at the level of median nerve (2). Currently available very-high frequency US transducers allow high spatial resolution of small anatomical structures, including the palmar digital nerves.Objectives:The objectives of this study were: to document the presence of dimensional alterations of the palmar digital nerves, particularly in terms of increased cross-sectional area (CSA), and to determine the variables associated with increased CSA, in RA patients.Methods:From September 2020 to December 2020, adult RA patients from a tertiary outpatient clinic were consecutively included regardless of disease activity status. Patients underwent a clinical assessment to determine disease activity using the Clinical Disease Activity Index (CDAI), functional capacity using the QuickDASH, and the presence of neuropathic pain features using the PainDetect Questionnaire (PDQ). In the same visit, patients underwent a US examination of the 2nd to 5th metacarpophalangeal joints (MCPj) of the clinically more involved hand by an operator blinded to the clinical assessment. The presence/absence and US grading of synovitis was recorded for each joint. A third operator, blinded to the clinical and joint US assessment, measured the CSA of each pair of palmar digital nerves from 2nd to 5th finger scanned for assessment joint involvement. The CSA of the palmar digital nerves was measured at the MCPj. The US examinations were conducted with a MyLab Class C (Esaote, Genoa, Italy), with a 6-18 MHz probe for the articular examination, and with an 10-22 MHz probe for the examination of the palmar digital nerves. The serological status, respectively rheumatoid factor (RF) and anti-citrullinated peptide antibodies (ACPA), and the presence of radiographic erosive disease were also recorded for each patient. Statistical analysis was conducted by considering the sum of the CSA for each nerve pair of each finger. CSA was compared with respect to body mass index (BMI), disease duration, disease activity, US synovitis grading, functional capacity, neuropathic pain features, serological characteristics, and erosive status.Results:Sixty-three patients with RA were included, 48 women, 15 men, with a mean age of 62.2 (11.8, standard deviation [SD]) years, a mean disease duration of 10.9 (8.2) years, for a total of 252 MCPj and 504 palmar digital nerves. The CSA of the palmar digital nerves taken individually was 2.3 (0.9) mm2, ranging from 1 mm2 to 8 mm2, and 4.2 (1.5) mm2 as a pair for finger. There was a statistically significant association with disease activity as assessed by the CDAI (p <0.001), and with the grading of US synovitis (p <0.001), while there were no significant associations with any of the other variables.Conclusion:The presence of active RA, both in terms of clinical and ultrasonographic indices, correlates with an increased CSA of the palmar digital nerves. This alteration is probably due to inflammatory mechanisms of the perineural tissues at the level of the MCPj. Active synovitis during RA can somehow be framed as a condition capable of causing neuropathic damage to the palmar digital nerves.References:[1]Filippucci E, Cipolletta E, Mashadi Mirza R, et al. Ultrasound imaging in rheumatoid arthritis. Radiol Med 2019;124(11):1087-1100.[2]Smerilli G, Di Matteo A, Cipolletta E, et al. Ultrasound assessment of carpal tunnel in rheumatoid arthritis and idiopathic carpal tunnel syndrome. Clin Rheumatol 2020; doi: 10.1007/s10067-020-05293-z.Disclosure of Interests:None declared

The role of PET in a clinically silent and ultrasound negative synovitis in the course of rheumatoid arthritis - a case report

We present a case report of a rheumatoid arthritis patient, who underwent a PET scan, which revealed inflammation of multiple joints, which was missed by both physical and ultrasound examinations. A 55-year old woman with a long-term rheumatoid arthritis, who had undergone arthroplasty of the left knee in the past, consulted with the rheumatologist for pain in the left knee. The physical examination revealed signs of inflammation in the left knee and right elbow. The inflammatory parameters were high. Ultrasound showed intraarticular effusion without signs of active synovitis in the left knee. The ultrasound assessment of the other joints (hands, wrists and feet) was also negative for active synovitis, while positron-emission tomography (PET) revealed increased glucose metabolism at the level of the medial side of the left knee, left radio-ulno-carpal joint, I-II-III metacarpo-phalangeal joints bilaterally, right II metatarso-phalangeal joint, and left II-III metatarso-phalangeal joints. This case report demonstrates that PET might be more sensitive than ultrasound in detecting subclinical joint inflammation.

P022 Audit of musculoskeletal ultrasound to optimise DMARD therapy among patients in a district general hospital

Background/Aims Musculoskeletal ultrasound (MSUS) has utility in optimising the use of conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) and biologic DMARDs (bDMARDs) in patients with inflammatory arthritis. However, it is unclear whether this is useful among patients with concomitant chronic pain and/or fibromyalgia, who often have elevated disease activity scores. We aimed to evaluate the impact of MSUS on inflammatory arthritis patients with concomitant chronic pain and/or fibromyalgia who met criteria for treatment escalation in a district general rheumatology service. Methods We conducted a retrospective audit of inflammatory arthritis patients with concomitant chronic pain and/or fibromyalgia who were eligible for DMARD escalation and underwent a MSUS since 2017. Scanning was performed by either a trained rheumatologist or musculoskeletal ultrasonographer. Synovitis was assessed following OMERACT guidelines. Results 43 patients with inflammatory arthritis and concomitant chronic pain and/or fibromyalgia who underwent MSUS were identified. The mean age was 57.0 years (SD 15.6), and 34 patients (79%) were female. Rheumatoid arthritis was the most frequent diagnosis with 32 patients (74%), with psoriatic arthritis in 5 (12%), undifferentiated inflammatory arthritis in 4 (9%) and axial spondylarthritis (axSpA) in 2 (5%). 20 patients (47%) had a concurrent diagnosis of fibromyalgia. The median tender joint count among non-axSpA patients was 10 (IQR 4-15) and 2 (IQR 0-4) for swollen joints. MSUS was requested for consideration of a bDMARD switch in 21 patients (49%), a new bDMARD in 15 (35%), and starting an adjunctive csDMARD among 7 (16%). 34 patients (79%) were already established on csDMARDs, with 15 patients (35%) being on one or more, and methotrexate being the most prescribed csDMARD in 26 (76%). 14 patients (33%) were already established on bDMARDs, 9 (21%) had been on them previously and 20 (47%) were bDMARD naïve. Among those on bDMARDs, anti-TNFs agents were the most prescribed (71%). Active synovitis was identified in 17 patients (40%). Greyscale synovitis, tenosynovitis and enthesitis were seen in 30 (70%), 10 (23%) and 2 patients (5%), respectively. Erosions were identified in 12 patients (28%), with 2 (17%) having new erosions. 27 patients (63%) had either a csDMARD started (n = 7, 33%), or a bDMARD started (n = 11, 31%) or switched (n = 9, 25%) after MSUS. Those with fibromyalgia were less likely to start or switch DMARDs (8/20 patients, 40%) than those without (19/23 patients, 82.6%), Pchi-squared = 0.004. Furthermore, active synovitis on MSUS was associated with DMARD escalation (14/17 patients [82.4%] with synovitis versus 13/26 patients [50%] without; Pchi-squared = 0.03). Conclusion MSUS avoided unnecessary DMARD escalation in a significant proportion of patients with inflammatory arthritis and features of concomitant chronic pain and/or fibromyalgia (n = 26, 37%), potentially resulting in reduced patient exposure to harmful DMARD side effects, and cost savings for the service. Disclosure M. Chen-Xu: None. D. Hyseni: None. K. Achilleos: None.

Rheumatoid arthritis in a patient with cystic fibrosis: challenging treatment options

A 26-year-old Caucasian male patient with a history of cystic fibrosis presented with a 6-month history of diffuse joint pain and swelling. He was found to have active synovitis in bilateral wrists and proximal interphalangeal joints of the hands on physical examination. He was diagnosed with seropositive rheumatoid arthritis since he had positive anti-cyclic citrullinated peptide antibodies and erosions on hand and foot X-rays. The patient has responded well to abatacept which may have less infection risk compared with other biological therapies.

THU0587 TB OR NOT TB? THIS IS THE QUESTION. CASE REPORT OF AN EXTRAPULMONARY TUBERCULOUS ARTHRITIS.

Background:Tuberculous (TB) arthritis consists of 1-3% of all TB cases, whereas TB tenosynovitis & bursitis account for 1%. Primarily it involves large joints but occasionally smaller non-weight-bearing joints. Diagnosis is usually delayed due to lack of awareness, radiographic findings & constitutional or pulmonary involvement.Objectives:We aim to increase rheumatologists awareness to detect possible TB etiology for arthritis & tenosynovitis.Methods:Our case is a 32 years old male complaining of polyarthritis of wrists, MCPs, ankle joints 4 months prior to presentation. Patient was referred as diagnosed rheumatoid patient resistant to treatment based on clinical presentation & laboratory investigation. His lab. was as follows; ESR 76 mm/hr, CRP 56.6 mg/L, RF 181.8 IU/ml, Serum creat 0.8 mg/dL, SGOT 20 SGPT 22, FBS 94, Uric acid 5.4, Hepatitis & HIV negative. CBC showing Hb 14.1 g/dL, TLC 7030/ml & platelets 289000/ml. There was no history of genitourinary, gastrointestinal manifestations, oral/genital ulcers, ophthalmological, mucocutaneous, cardiac, pulmonary, hepatic nor renal manifestations. The treatment at time of presentation was Methotrexare 25mg/week IM injection, Leflunamide 20mg/d & low dose steroids, prednisolone 5mg/d. Patient was referred to our department to assess activity, perform musculoskeletal ultrasound to the various involved joints. Hence, expected by referring physician to shift from DMARDs to biologic treatment.Results:MSUS study following eular guidlines showed active synovitis in both radiocarpal & midcarpal joints bilaterally grade II by doppler signal (figure 1). Other active synovitis in multiple MCPs as well as tenosynovitis of Peroneus longus and brevis bilaterally was detected (figure 1). The swelling aound the ankle was alarming though the other swollen joints seemed to be consistent with a case of RA in activity. This swelling revealed a well-defined hypoechoic heterogeneous cystic fluid collection with posterior through-transmission (figure 2) & hyperechoic hyperemic wall on PD imaging opposite medial malleolous of right fibula. The laboratory investigations prior to shifting patient had to included TB tests, tuberculin test and PCR following the positive result that we found in the skin test. Aspiration was performed from the cystic swelling and sent for clinical pathology analysis. Thick yellowish fluid aspirate on cytology revealed moderately cellular mainly of PMN cells, neutrophils, nuclear debris in proteinaceous background no atypical or malignant cells were found. As regards bacteriology no pus with no growth (both aerobic & anerobic). These results warranted us to perform a culture for atypical bacteria and revealed growth of mycobacterium tuberculosis. AntiTB therapy was started for 9 months in the form of 2 months of isoniazid (INH) and rifampicin (RIF), pyrazinamide (PZA) and ethambutol (EMB) followed by 7 months of INH and RIF. Excision of the synovial cyst was done on the spot.Figure 1.Figure 2.Conclusion:Extrapulmonary TB is usually diagnosed late due to a reduced diagnostic suspicion. A variant of 8 - 60% of TB cases are +ve for RF & 7–39% +ve for ACPA. Musculoskeletal manifestations occur in approximately 1-3% of TB cases. Of these, spondylitis and arthritis are the most frequent, whereas bursitis and tenosynovitis are exceptional. Extraarticular cystic masses occur in tuberculous arthritis. Mixture of septic tuberculous arthritis and Poncet’s disease is rare but documented.References:[1]Varshney et al. Isolated tuberculosis of Achilles tendon. Joint Bone Spine, 74 (2007): 103-106.[2]Lee et al.Tuberculous Tenosynovitis and Ulnar Bursitis of the Wrist.Ann Rehabil Med. 2013 Aug; 37(4): 572–576.[3]Rekha et al. Tuberculous Olecranon Bursitis. Case Reports in Clinical Medicine, 2014, 3, 281-285.[4]Kim et al. Tuberculosis of the trochanteric bursa: a case report. Journal of Orthopaedic Surgery 2014;22(1):126-9.Disclosure of Interests:None declared

AB0746 EVALUATING TENDER AND SWOLLEN JOINTS FOR THE ASSESSMENT OF INFLAMMATORY PAIN IN PSORIATIC ARTHRITIS USING ULTRASOUND

Background:Tender and Swollen Joint Counts (TJC, SJC) are items of disease activity scores in rheumatoid arthritis (RA) and psoriatic arthritis (PsA). Recent studies suggest that TJC do not adequately reflect ongoing inflammation in RA when using Ultrasound (US) as a reference standard, and that pain might be due to other, non-inflammatory causes.1, 2In PsA, the role of tenderness and swelling of joints for reflecting active inflammation has not been well studied so far.Objectives:To evaluate tender (TJ) and swollen joints (SJ) for the assessment of inflammation in PsA.Methods:We performed a prospective study on 83 PsA patients undergoing clinical and ultrasound examinations at two study visits scheduled 12 months apart. Tenderness and swelling were assessed for 68 and 66 joints respectively and US examinations, including grey scale (GS) and power doppler (PD) were conducted at all 68 joints. GS- (range 0-204) und PD sum scores (0-204) were calculated. At patient level, correlations were performed between TJC, SJC and clinical or US values. At joint level a GS value≥1 and/or PD value≥1 was defined as active synovitis, which was compared to whether a joint was tender, swollen or both. A generalized linear mixed model was created to assess the predictive value of TJ and SJ for active synovitis after 12 months, taking into consideration the joint site.Results:At baseline the median TJC and SJC for 83 patients was 4 (range 0-59) and 1 (0-20), respectively and the median GSS- and PD sum score was 16 (3-56) and 3 (0-31) respectively. SJC correlated with the GSS sum score (r= 0.37, p=0.004) and PD sum score (r =0.47, p<0.001), while TJC only correlated with PD sum score (r=0.33, p=0.01). TJC correlated better than SJC with patient reported outcomes like patient global assessment (TJC: r=0.57, p<0.001; SJC r=0.39, p=0.002) and health assessment questionnaire (TJC: r=0.50, p<0.001, SJC no significant correlation). Swollen joints (with or without tenderness) showed active synovitis (GSS≥1 and/or PD≥1) in 67.6% of cases, while tender joints (with or without swelling) showed signs of US activation in only 34.5%. A joint that was considered swollen at baseline was more likely to express active synovitis after 12 months (OR: 4.3, 97.5 CI: 2.9-6.2), compared to a joint that was either tender or swollen at baseline (OR: 2.8, 97.5 CI: 2.1-3.5).Conclusion:SJC are more closely linked with US signs of inflammation as compared to TJC in PsA. While swelling of a joint predicts US inflammation after a year, the information whether the joint is additionally tender or not, gives no additional predictive information.References:[1]Hammer HB, Michelsen B, Sexton J, et al. Swollen, but not tender joints, are independently associated with ultrasound synovitis: results from a longitudinal observational study of patients with established rheumatoid arthritis.Ann Rheum Dis2019;78:1179-85.[2]Hammer HB, Michelsen B, Provan SA, et al. Tender joint count may not reflect inflammatory activity in established rheumatoid arthritis patients - results from a longitudinal study.Arthritis Care Res (Hoboken) 2018Disclosure of Interests:None declared

A comparison of thermographic characteristics of the hands and wrists of rheumatoid arthritis patients and healthy controls

Thermal imaging has been applied to detect possible temperature variations in various rheumatic disorders. This study sought to determine whether rheumatoid arthritis (RA) patients without active synovitis in their hands exhibit different baseline thermographic patterns of the fingers and palms when compared to healthy individuals. Data from 31 RA patients were compared to that of 51 healthy controls. The RA patients were recruited upon confirmed absence of synovitis by clinical examination and musculoskeletal ultrasound. Participants underwent medical infrared imaging of the regions of interest (ROIs). Significant differences were found between the mean temperatures of the palm regions (29.37 °C (SD2.2); n = 306) and fingers (27.16 °C (SD3.2); n = 510) of the healthy participants when compared to the palm regions (31.4(SD1.84)°C; n = 186) and fingers (30.22 °C (SD2.4); n = 299) of their RA counterparts (p = 0.001), with the latter group exhibiting higher temperatures in all ROIs. Logistic regression models confirm that both palm and finger temperature increase significantly in RA without active inflammation. These innovative findings provide evidence that baseline thermal data in RA differs significantly from healthy individuals. Thermal imaging may have the potential to become an adjunct assessment method of disease activity in patients with RA.

24. Chronic inflammatory arthritis in the context of cystic fibrosis

Introduction Cystic fibrosis (CF) is a genetic disease resulting in changes to the functioning of a transmembrane sodium transporter at mucosal surfaces and subsequent multisystem disease. Roughly 10,500 people in the UK live with CF, and life expectancy has improved markedly in the last few decades. Lung disease with bronchiectasis, chronic infection and progressive respiratory failure is accompanied by gastrointestinal, hepatic, pancreatic, and metabolic bone complications. An inflammatory arthritis known as cystic fibrosis associated arthritis (CFA), has been described in episodic and chronic forms for nearly 40 years now but remains without formal definition or an evidence base for treatment. Case description A 21-year-old woman with cystic fibrosis presented with a 4-year history of joint swelling and pain, initially affecting her fingers and then moving to knees and wrists and progressing from intermittent to chronic disease. Examination revealed active polyarthritis. Investigations included an ultrasound confirming active synovitis and blood tests showing negative rheumatoid factor, anti-CCP and HLA-B27. Her past medical history included cystic fibrosis and vitiligo. She had a Ph508del homozygous genotype and her CF was characterised by severe bronchiectasis with Pseudomonas aeruginosa and Pandorea apista colonisation, severe airflow obstruction (FEV1 30% predicted), CF related diabetes requiring insulin therapy, exocrine pancreatic insufficiency, CF related liver disease, and low body mass. She was diagnosed with an inflammatory arthritis felt likely to be a chronic form of cystic fibrosis associated arthritis. Hydroxychloroquine was commenced in November 2017 along with intramuscular corticosteroid which she had good but short lived response to. By December she had 14 tender and 5 swollen joints and had an acute exacerbation of her chest disease associated with a drop in FEV1 to 21% predicted and required IV antibiotics. Radiographs obtained at this point resulted in conflicting reports from radiologists about whether there was evidence of underlying periostitis in her distal radius and ulna, but it was decided that even if this represented hypertrophic periostitis secondary to CF lung disease then ongoing synovitis still required treatment with DMARDs. A multidisciplinary decision was taken to commence sulfasalazine after admission for IV antibiotics. A portacath was present for IV access and, as such, bloods monitoring was carried out within the CF unit. Sulfasalazine was escalated to 1.5g daily alongside hydroxychloroquine. Whilst this has not completely eliminated all flares it has significantly improved day to day symptoms and has markedly limited number and severity of flares. Discussion The top differential diagnoses here include seronegative rheumatoid, chronic cystic fibrosis associated arthritis (CFA), and secondary hypertrophic osteoarthropathy (HOA). CFA still has no formal definition and as such remains a diagnosis of exclusion in cases of inflammatory arthritis in the context of CF. It is unclear whether the more commonly seen episodic arthritis more frequently seen in CFA is part of a spectrum of disease that also includes chronic disease. Secondary HOA is reported in CF but the treatment evidence for this is also poor; X-rays are a poorly sensitive imaging modality for this; associated active synovitis still requires treatment. Evidence for treatment of inflammatory arthritis in the context of CF is poor and concerns include risks associated with immunosuppression (especially in cases with severe bronchiectasis), polypharmacy, comorbid diabetes and liver disease. Some information may be extrapolated from case series of patients who have received a liver transplant for CF related liver disease but still have their native CF lungs suggesting that post-transplant levels of immunosuppression is relatively safe. A number of cases have reported safe use of biologics in CF for inflammatory arthritis or inflammatory bowel disease but there may be reporting bias. RA-bronchiectasis and RA-ILD cohorts provide some additional information but have a very different pathogenesis that may affect outcomes. Inflammation pathways are known to be impacted by CF but the differences are not yet informed enough to impact clinical decision making. Sulfasalazine has provided a significant improvement in symptoms and in examination and ultrasound findings. We generally have not stopped it when courses of IV antibiotics have been required for exacerbations of chest disease, but would do so if systemic upset was present. Key learning points CF is a multisystem disease, in which life expectancy is increasing. Adult rheumatologists are likely to see more people with CF in their clinics over the coming decades with both CF related and non-CF related disease. They often have multiple associated comorbidities and a large burden of disease and treatment. They often attend their CF department with problems instead of the general practitioner and referrals may therefore come via respiratory consultants. Delays to treatment include a delay to presentation and delay whilst complex treatment decisions are taken. Supporting people with CF and inflammatory arthritis may include specific considerations regarding the need to carry out other treatments and an exercise regimen. Multidisciplinary and cross-specialty working is vital. Making a formal diagnosis of a specific inflammatory arthritis in the context of CF can be difficult, but the definitive presence of inflammatory joint disease should prompt consideration of disease modifying drug therapy. Definite inflammatory arthritis may be easier to assess and image in a case such as this where the disease is chronic rather than episodic. Both clinical examination and ultrasound have a role in distinguishing it from non-inflammatory causes of musculoskeletal pain. Immunosuppression in the context of CF is concerning. However, a growing but small body of evidence exists regarding safety. Pulling information from immunosuppression used for any indication in people with CF allows for better safety information to help teams and patients decide on the right treatment for them. Conflicts of interest The authors have declared no conflicts of interest.