Inclusion-body myositis associated with Sjögren's disease: clinical characteristics and comparison with other Sjögren-associated myositis.

OBJECTIVES: To describe the characteristics of patients with Sjögren's disease (SjD) and inclusion-body myositis (IBM), and how they compare to SjD patients with other inflammatory myopathies (IM). METHODS: Patients were retrospectively recruited from 13 French centers and included if they met the ACR/EULAR criteria for SjD and for IM. They were categorized as SjD-IBM if sub-criteria for IBM were met, or as SjD-other IM if not. RESULTS: SjD-IBM patients (n = 22) were mostly females (86%), with a median [Q1; Q3] age of 54 [38.5; 64] years at SjD diagnosis, and 62 [46.5; 70] years at first IBM symptoms. Although most patients displayed glandular and immunological abnormalities, additional extra-glandular manifestations were uncommon, resulting in moderate disease activity at SjD diagnosis (ESSDAI 5.5 [1; 7.8]). Classic IBM features were frequent, such as progressive symptom onset (59%), asymmetrical (27%) and distal (32%) involvements, dysphagia (41%), low CPK (386.5 [221.8; 670.5] UI/l) and CRP (3.0 [3; 8.5] mg/l) levels. Immunosuppressants were reported as efficient in 55% of cases.Compared with SjD-IBM patients, SjD patients with other IM (n = 50) were significantly younger, displayed more frequent additional extra-glandular disease, higher ESSDAI score (11 [3; 30]), shorter delay between SjD diagnosis and myositis onset (0 [-0.5; 26]), more frequent CPK values over 1000 UI/l (36%), and less frequent classic IBM features. CONCLUSION: IBM can occur in SjD patients, with muscle features reminiscent of classic sporadic IBM characteristics, but mostly affecting women. In SjD patients with muscle involvement, extra-glandular manifestations, high ESSDAI score, elevated CPK values, and shorter delay after SjD diagnosis plead against IBM.

Fluorodeoxyglucose positron emission tomography-computed tomography findings in a first series of 10 patients with polyarteritis nodosa.

OBJECTIVE: 18F-fluorodeoxyglucose PET/CT (FDG-PET/CT) is widely used in patients with large vessel vasculitis. The benefits of FDG-PET/CT in PAN has only ever been assessed in three case reports. Our aim was to describe FDG-PET/CT findings in 10 patients with newly diagnosed PAN. METHODS: This was a retrospective study of patients with PAN who underwent FDG-PET/CT at diagnosis between 2017 and 2020. The FDG-PET/CT data were analysed retrospectively. RESULTS: Ten patients were included: nine men and one woman with a median age of 67 years (range 43-78). PAN was diagnosed according to ACR criteria in nine patients and histologically in one. All patients had high CRP levels (median 223 mg/l). The main FDG-PET/CT abnormality was increased tracer uptake in the muscles, particularly in the connective tissue (perimysium, epimysium) (n = 7), and in linear (n = 5) or focal (n = 2) patterns. Increased FDG uptake in large-diameter vessels was observed in four patients, in the humeral (n = 4), femoral (n = 1) and common interosseous arteries (n = 1). Nine patients had bone marrow FDG uptake and six had splenic FDG uptake. Three had synovitis and three had lymph node uptake. One patient had subcutaneous FDG uptake with a 'leopard skin' appearance. CONCLUSIONS: FDG-PET/CT seems to be a useful non-invasive imaging technique for diagnosing PAN, particularly in patients with non-specific systemic features. Tracer uptake in muscular connective tissue seems to be a recurrent sign in patients with PAN and may be pathognomonic.

Rituximab resistance at 3months of induction therapy in newly diagnosed or relapsing ANCA-associated vasculitis: A French multicentre retrospective study in 116 patients.

OBJECTIVE: To evaluate rituximab (RTX) resistance at 3months (M3) of induction therapy in antineutrophil cytoplasmic antibody (ANCA) associated vasculitis (AAV). METHODS: Multicentre French retrospective study conducted between 2010 and 2020 including patients with newly diagnosed or relapsing AAV (granulomatosis with polyangiitis or microscopic polyangiitis) having received induction therapy with RTX. Primary endpoint was the presence of RTX resistance at 3months (M3) defined as uncontrolled disease (worsening feature on the BVAS/WG 1month after RTX induction) or disease flare (increase in BVAS/WG of≥1 point before M3). RESULTS: Out of 121 patients included, we analysed 116 patients. Fourteen patients (12%) had RTX resistance at M3 with no difference in baseline demographics, vasculitis type, ANCA type, disease status or organ involvement. Patients with RTX resistance at M3 had a greater proportion of localized disease (43% vs. 18%, P<0.05) and were less often treated by initial methylprednisolone (MP) pulse (21% vs. 58%, P<0.01). Out of the 14 patients with RTX resistance, seven received additional immunosuppressive therapy. All patients were in remission at 6months. Compared to responders, patients with RTX resistance at M3 were less often treated with prophylactic trimethoprim-sulfamethoxazole (57% vs. 85%, P<0.05). Twenty-four patients died during follow-up, one-third of them from infections and half of them from SARS-CoV-2. CONCLUSION: Twelve percent of patients had RTX resistance at M3. These patients more often had localized form of the disease and were less treated by initial MP pulse and by prophylactic trimethoprim-sulfamethoxazole.