Methotrexate to treat hand osteoarthritis with synovitis (METHODS): an Australian, multisite, parallel-group, double-blind, randomised, placebo-controlled trial.

BACKGROUND: Hand osteoarthritis is a disabling condition with few effective therapies. Hand osteoarthritis with synovitis is a common inflammatory phenotype associated with pain. We aimed to examine the efficacy and safety of methotrexate at 6 months in participants with hand osteoarthritis and synovitis. METHODS: In this multisite, parallel-group, double-blind, randomised, placebo-controlled trial, participants (aged 40-75 years) with hand osteoarthritis (Kellgren and Lawrence grade ≥2 in at least one joint) and MRI-detected synovitis of grade 1 or more were recruited from the community in Melbourne, Hobart, Adelaide, and Perth, Australia. Participants were randomly assigned (1:1) using block randomisation, stratified by study site and self-reported sex, to receive methotrexate 20 mg or identical placebo orally once weekly for 6 months. The primary outcome was pain reduction (measured with a 100 mm visual analogue scale; VAS) in the study hand at 6 months assessed in the intention-to-treat population. Safety outcomes were assessed in all randomly assigned participants. This trial was registered with the Australian New Zealand Clinical Trials Registry (ACTRN12617000877381). FINDINGS: Between Nov 22, 2017, and Nov 8, 2021, of 202 participants who were assessed for eligibility, 97 (48%) were randomly assigned to receive methotrexate (n=50) or placebo (n=47). 68 (70%) of 97 participants were female and 29 (30%) were male. 42 (84%) of 50 participants in the methotrexate group and 40 (85%) of 47 in the placebo group provided primary outcome data. The mean change in VAS pain at 6 months was -15·2 mm (SD 24·0) in the methotrexate group and -7·7 mm (25·3) in the placebo group, with a mean between-group difference of -9·9 (95% CI -19·3 to -0·6; p=0·037) and an effect size (standardised mean difference) of 0·45 (0·03 to 0·87). Adverse events occurred in 31 (62%) of 50 participants in the methotrexate group and 28 (60%) of 47 participants in the placebo group. INTERPRETATION: Treatment of hand osteoarthritis and synovitis with 20 mg methotrexate for 6 months had a moderate but potentially clinically meaningful effect on reducing pain, providing proof of concept that methotrexate might have a role in the management of hand osteoarthritis with an inflammatory phenotype. FUNDING: National Health and Medical Research Council of Australia.

The longitudinal study of muscle changes with ultrasound: differential changes in idiopathic inflammatory myopathy subgroups.

OBJECTIVES: We investigated shear wave elastography (SWE), B mode US and power Doppler (PDUS) as imaging biomarkers for longitudinal follow-up in idiopathic inflammatory myopathy (IIM), with a particular focus on immune-mediated necrotizing myopathy (IMNM) and DM. METHODS: Participants had serial SWE, PDUS on the deltoid (D) and vastus lateralis (VL) muscles on four occasions at intervals of 3-6 months. Clinical assessments included manual muscle testing, and patient- and physician-reported outcome scales. RESULTS: Thirty-three participants were included: IMNM = 17, DM = 12, overlap myositis = 3, PM = 1. Twenty were in a prevalent clinic group, and 13 were recently treated cases in an incident group. Differential changes in SWS and US domains occurred with time in both the prevalent and incident groups. In the VL-prevalent subgroup, echogenicity increased over time (P = 0.040), while in the incident cases there was a trend for reduction to normal over time (P = 0.097) with treatment. Muscle bulk reduced in the D-prevalent subgroup over time (P = 0.096), suggesting atrophy. SWS also reduced in the VL-incident subgroup over time (P = 0.096), suggesting a trend towards improvement in muscle stiffness with treatment. CONCLUSION: SWE and US appear promising as imaging biomarkers for patient follow-up in IIM and indicate changes over time, especially with echogenicity, muscle bulk and SWS in the VL. Due to the limitations of the participant numbers, additional studies with a larger cohort are needed to help evaluate these US domains further and outline specific characteristics within the IIM subgroups.

A longitudinal study using B mode ultrasound and power Doppler as monitoring imaging tools in inclusion body myositis.

OBJECTIVES: There is growing interest in ultrasound (US) as an outcome measure in IBM. Our study aimed to determine the ability of B mode US and power Doppler (PD) to detect changes in affected muscles over time and if US domains correlate with disease progression. METHODS: Participants attended on four occasions over a median follow-up period of 26 months. All completed a patient self-reported health assessment questionnaire (HAQ), patient visual analogue scale (pVAS), manual muscle testing (MMT), and US (fascial thickness-FT, muscle bulk, echogenicity, and PD) on deltoid and vastus lateralis (VL) muscles at each visit. RESULTS: This longitudinal observational study had 35 participants: 21 (60%) males, median age 70 (IQR (64-76), and the majority (85.7%) not on immunosuppression. When analysed for sex differences at baseline, males had lower FT-VL (p=0.018) and higher muscle bulk (p=0.002) than females. Only FT-deltoid (p<0.001) increased significantly over time with follow-up. When participants were stratified into progressors and non-progressors, FT at baseline was lower in progressors (0.06 vs. 0.09, p=0.017), who were predominantly male. There were no significant differences in other US domains. CONCLUSIONS: Our study highlights previously unreported sex differences in US findings in IBM. Certain US domains, such as FT, showed measurable changes over time and correlated with disease progression. However, further studies with longer follow-up periods and larger patient cohorts will need to be performed to determine whether B mode US could be a useful disease outcome measure for therapeutic trials.

The temporal association between adverse drug reactions and antirheumatic drugs utilisation in Western Australia: a retrospective study from real-world data (1995-2015).

BACKGROUND/OBJECTIVES: Adverse drug reactions (ADRs) can result in morbidity, mortality, and higher healthcare costs. Given the limited information available on ADRs associated with antirheumatic medications, this study aims to analyse and compare ADR reporting for these drugs in the pharmacovigilance datasets of Western Australia (WA) and the United States (US). METHODS: Therapeutic Goods Administration provided WA pharmacovigilance data of selected antirheumatic drugs to from 1995 to 2015. The proportional reporting ratio (PRR) for WA case reports was compared to corresponding USA pharmacovigilance data by assessing the disproportionality of each ADR. clinically significant or true ADRs were determined using the Evans 2001 criteria (n > 2, chi-square > 4, PRR > 2). RESULTS: A total of 232 reports were found in WA, mostly on sixty-nine women aged 45 to 69. Methotrexate, leflunomide, azathioprine, sulfasalazine, and infliximab had the highest reported ADRs, related to gastrointestinal disorders. Patients who used biological agents in WA had 2.7 times the likelihood of reporting true ADRs compared to conventional antirheumatic drugs. The ADR rates in the two datasets were comparable over the study period. CONCLUSIONS: The PRR values of ADRs were consistent between WA and US databases. Methotrexate and infliximab use were commonly associated with ADR reports in WA females, with incidence rates comparable to the US; while patients using biological agents were more likely to report true ADRs than those on conventional antirheumatic drugs in WA.

Krill Oil for Knee Osteoarthritis: A Randomized Clinical Trial.

Importance: Knee osteoarthritis is disabling, with few effective treatments. Preliminary evidence suggested that krill oil supplementation improved knee pain, but effects on knee osteoarthritis remain unclear. Objective: To evaluate efficacy of krill oil supplementation, compared with placebo, on knee pain in people with knee osteoarthritis who have significant knee pain and effusion-synovitis. Design, Setting, and Participants: Multicenter, randomized, double-blind, placebo-controlled clinical trial in 5 Australian cities. Participants with clinical knee osteoarthritis, significant knee pain, and effusion-synovitis on magnetic resonance imaging were enrolled from December 2016 to June 2019; final follow-up occurred on February 7, 2020. Interventions: Participants were randomized to 2 g/d of krill oil (n = 130) or matching placebo (n = 132) for 24 weeks. Main Outcomes and Measures: The primary outcome was change in knee pain as assessed by visual analog scale (range, 0-100; 0 indicating least pain; minimum clinically important improvement = 15) over 24 weeks. Results: Of 262 participants randomized (mean age, 61.6 [SD, 9.6] years; 53% women), 222 (85%) completed the trial. Krill oil did not improve knee pain compared with placebo (mean change in VAS score, -19.9 [krill oil] vs -20.2 [placebo]; between-group mean difference, -0.3; 95% CI, -6.9 to 6.4) over 24 weeks. One or more adverse events was reported by 51% in the krill oil group (67/130) and by 54% in the placebo group (71/132). The most common adverse events were musculoskeletal and connective tissue disorders, which occurred 32 times in the krill oil group and 42 times in the placebo group, including knee pain (n = 10 with krill oil; n = 9 with placebo), lower extremity pain (n = 1 with krill oil; n = 5 with placebo), and hip pain (n = 3 with krill oil; n = 2 with placebo). Conclusions and Relevance: Among people with knee osteoarthritis who have significant knee pain and effusion-synovitis on magnetic resonance imaging, 2 g/d of daily krill oil supplementation did not improve knee pain over 24 weeks compared with placebo. These findings do not support krill oil for treating knee pain in this population. Trial Registration: Australian New Zealand Clinical Trials Registry Identifier: ACTRN12616000726459; Universal Trial Number: U1111-1181-7087.

An international survey of current management practices for polymyalgia rheumatica by general practitioners and rheumatologists.

OBJECTIVES: To explore current management practices for PMR by general practitioners (GPs) and rheumatologists including implications for clinical trial recruitment. METHODS: An English language questionnaire was constructed by a working group of rheumatologists and GPs from six countries. The questionnaire focused on: 1: Respondent characteristics; 2: Referral practices; 3: Treatment with glucocorticoids; 4: Diagnostics; 5: Comorbidities; and 6: Barriers to research. The questionnaire was distributed to rheumatologists and GPs worldwide via members of the International PMR/Giant Cell Arteritis Study Group. RESULTS: In total, 394 GPs and 937 rheumatologists responded to the survey. GPs referred a median of 25% of their suspected PMR patients for diagnosis and 50% of these were returned to their GP for management. In general, 39% of rheumatologists evaluated patients with suspected PMR >2 weeks after referral, and a median of 50% of patients had started prednisolone before rheumatologist evaluation. Direct comparison of initial treatment showed that the percentage prescribing >25 mg prednisolone daily for patients was 30% for GPs and 12% for rheumatologists. Diagnostic imaging was rarely used. More than half (56%) of rheumatologists experienced difficulties recruiting people with PMR to clinical trials. CONCLUSION: This large international survey indicates that a large proportion of people with PMR are not referred for diagnosis, and that the proportion of treatment-naive patients declined with increasing time from referral to assessment. Strategies are needed to change referral and management of people with PMR, to improve clinical practice and facilitate recruitment to clinical trials.

The relationship between clinical phenotype and kallikrein-kinin bioregulation in different forms of arthritis.

OBJECTIVE: Patients with rheumatoid arthritis (RA) have shown increased levels of neutrophils generating kallikrein-kinin peptides in blood which are potent mediators of inflammation. This study investigated the association between the bioregulation of kinin-mediated inflammation with the clinical, quality of life, and imaging characteristics (e.g. ultrasonography) of different arthritides. METHODS: Patients with osteoarthritis (OA, n = 29), gout (n = 10) and RA (n = 8) were recruited and screened for clinical symptoms, quality of life, and ultrasonographical assessment of arthritis. Blood neutrophils were assessed for the expression of bradykinin receptors (B1R and B2R), kininogens and kallikreins by immunocytochemistry with visualization by bright field microscopy. Levels of plasma biomarkers were measured by ELISA and cytometric bead array. RESULTS: Quality of life (SF-36 domains and summary scores; including pain; and, HAQ) was similar across OA, gout and RA patients; with the exception of worse physical functioning scores between OA and gout patients. Synovial hypertrophy (on ultrasound) differed between groups (p = 0.001), and the dichotomised Power Doppler (PD) score of greater than or equal to 2 (PD-GE2) was marginally significant (p = 0.09). Plasma IL-8 were highest in patients with gout followed by RA and OA (both, P < 0.05). Patients with RA had higher plasma levels of sTNFR1, IL-1ß, IL-12p70, TNF and IL-6, compared to OA and gout patients (all, P < 0.05). Patients with OA had higher expression of K1B and KLK1 on blood neutrophils followed by RA and gout patients (both, P < 0.05). Bodily pain correlated with B1R expression on blood neutrophils (r = 0.334, p = 0.05), and inversely with plasma levels of CRP (r = -0.55), sTNFR1 (r = -0.352) and IL-6 (r = -0.422), all P < 0.05. Expression of B1R on blood neutrophils also correlated with Knee PD (r = 0.403) and PD-GE2 (r = 0.480), both P < 0.05. CONCLUSIONS: Pain levels and quality of life were similar between patients with OA, RA and gout with knee arthritis. Plasma inflammatory biomarkers and B1R expression on blood neutrophils correlated with pain. Targeting B1R to modulate the kinin-kallikrein system may pose as a new therapeutic target in the treatment of arthritis.

Mortality and cause of death in patients with ANCA-associated vasculitis and polyarteritis nodosa in Australia-a population-based study.

OBJECTIVES: We compared survival and causes of death in Western Australian (WA) ANCA-associated vasculitis (AAV) and PAN patients with controls and the WA population. METHODS: In this data linkage study, we identified patients with incident AAV/PAN and age, sex and temporally matched controls 1980-2014 from the WA Rheumatic Disease Epidemiological Registry. Survival analyses and time-varying analyses were performed. RESULTS: Six hundred and fourteen patients with incident AAV/PAN were compared with 6672 controls; 229 AAV/PAN patients died over 5277 person-years of follow-up and 1009 controls died over 73835 person-years. Survival was reduced in patients with AAV/PAN compared with matched controls [hazard ratio (HR) 3.5 (95% CI: 3.1, 4.1)], and matched WA population rates [standardized mortality ratio 3.3 (95% CI: 2.9, 3.8)]. Greatest excess mortality in AAV/PAN patients was observed in the first year after diagnosis and remained higher than controls throughout follow-up. Greater excess mortality was observed in patients >60 years at diagnosis. In cause-specific analyses, mortality HR for vasculitis, infection and non-infective respiratory disease were greatest early after diagnosis and remained persistently elevated. The HRs for malignancy and cerebrovascular disease related deaths increased during follow-up, and were constant for ischaemic heart disease related deaths. CONCLUSION: Mortality was increased in AAV/PAN patients compared with controls, with patients older at diagnosis at greater risk. These findings provide mortality risk for AAV/PAN in an Australian population, highlighting key contributors to mortality at different time periods over follow-up and potential areas of focus for reducing mortality.

Development of a new ultrasound scoring system to evaluate glandular inflammation in Sjögren's syndrome: an OMERACT reliability exercise.

OBJECTIVE: The aim of this exercise from the OMERACT Ultrasound subgroup on Sjögren's syndrome was to develop and assess the reliability of a consensus-based semiquantitative colour Doppler US scoring system for pathologic salivary gland vascularization in patients with primary Sjögren's syndrome (pSS). METHODS: Using the Delphi method, a colour Doppler semiquantitative scoring system for vascularization of bilateral parotid and submandibular glands was developed and tested in static images and on patients (9 pSS patients and 9 sonographers). Intra-reader and inter-reader reliability of grading the salivary glands were computed by weighted Cohen and Light's kappa analysis, respectively. RESULTS: The consensus-based semiquantitative score was: grade 0, no visible vascular signals; grade 1, focal, dispersed vascular signals; grade 2, diffuse vascular signals detected in <50% of the gland; grade 3, diffuse vascular signals in >50% of the gland. In static images, the intra- and inter-reader reliability showed excellent kappa values (95% CI) of 0.90 (0.87, 0.93) and 0.80 (0.74, 0.84), respectively, for all four salivary glands together. In patients, the intra- and inter-reader reliability for all four salivary glands together was kappa = 0.84 (0.73, 0.92) and 0.70 (0.64, 0.76), respectively. CONCLUSION: The consensus-based colour Doppler US scoring for the evaluation of salivary gland vascularization in pSS showed a good inter-reader reliability and excellent intra-reader reliability in static images and in patients. The clinical application of the developed scoring system should be tested in clinical settings.

Assessment of liver fibrosis markers in people with rheumatoid arthritis on methotrexate.

BACKGROUND: Up to 3% of methotrexate (MTX)-treated rheumatoid arthritis (RA) patients might develop liver fibrosis or cirrhosis, requiring effective screening algorithms. AIMS: To assess the utility of non-invasive liver fibrosis assessment in RA patients on MTX. METHODS: Fifty-six patients were recruited from rheumatology outpatient clinics in a public tertiary centre from July 2017 to October 2018. Clinical data was collected. Screening for hepatic fibrosis was performed using transient elastography (TE), aminoaspartate transaminase to platelet ratio index (APRI), Hepascore and Fibrosis-4 index (FIB-4). Those with suspected significant liver fibrosis based on these screening tests were assessed by a hepatologist. RESULTS: Twenty-seven patients were suspected to have liver fibrosis on screening, including 10/56 (18%) by TE, 20/56 (36%) by Hepascore, 2/56 by APRI (4%) and 1/56 by FIB-4 (2%). Of these 27 patients, 11 were reviewed by a hepatologist and one diagnosed with significant liver fibrosis. TE, but not APRI, Hepascore or FIB-4, was found to have 100% sensitivity and 84% specificity (P = 0.029) for hepatologist-diagnosed liver fibrosis. CONCLUSION: Liver fibrosis develops in a minority of MTX-treated RA patients. The present study suggests that TE is a more sensitive screening test than APRI, FIB-4 or Hepascore in the identification of people with RA at risk of hepatic fibrosis.

METHODS - A randomised controlled trial of METhotrexate to treat Hand Osteoarthritis with Synovitis: study protocol for a randomised controlled trial.

BACKGROUND: Hand osteoarthritis is a common and disabling problem without effective therapies. Accumulating evidence suggests the role of local inflammation in causing pain and structural progression in hand osteoarthritis, and hand osteoarthritis with synovitis is a commonly encountered clinical phenotype. Methotrexate is a well-established, low-cost, and effective treatment for inflammatory arthritis with a well-described safety profile. The aim of this multicentre, randomised, double-blind, placebo-controlled trial is to determine whether methotrexate reduces pain over 6 months in patients with hand osteoarthritis and synovitis. METHODS: Ninety-six participants with hand osteoarthritis and synovitis will be recruited through the Osteoarthritis Clinical Trial Network (Melbourne, Hobart, Adelaide, and Perth), and randomly allocated in a 1:1 ratio to receive either methotrexate 20 mg or identical placebo once weekly for 6 months. The primary outcome is pain reduction (assessed by 100 mm visual analogue scale) at 6 months. The secondary outcomes include changes in physical function and quality of life assessed using Functional Index for Hand Osteoarthritis, Australian Canadian Osteoarthritis Hand Index, Health Assessment Questionnaire, Michigan Hand Outcomes Questionnaire, Short-Form-36, tender and swollen joint count, and grip strength, and structural progression assessed using progression of synovitis and bone marrow lesions from magnetic resonance imaging and radiographic progression at 6 months. Adverse events will be recorded. The primary analysis will be by intention to treat, including all participants in their randomised groups. DISCUSSION: This study will provide high-quality evidence to address whether methotrexate has an effect on reducing pain over 6 months in patients with hand osteoarthritis and synovitis, with major clinical and public health importance. While a positive trial will inform international clinical practice guidelines for the management of hand osteoarthritis, a negative trial would be highly topical and change current trends in clinical practice. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry (ANZCTR), ACTRN12617000877381. Registered 15 June 2017, https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=373124.

Ultrasound assessment of response to intra-articular therapy in osteoarthritis of the knee.

OBJECTIVE: Assessment of the synovium in patients with knee OA is of great potential value for clinical trials. Ultrasonography could provide this but few data exist on its ability to assess synovial response to therapies. The aim of this study was to examine whether US can detect synovial response to IA corticosteroid (IACS) therapy and to explore associations between synovial characteristics and symptoms. METHODS: A total of 35 people with ACR radiographic knee OA were included, including those who required an injection of 80 mg of IA methylprednisolone. All participants completed a visual analogue scale for pain and underwent US of the knee at baseline, 1 and 4 weeks. Minimum clinically important improvement (MCII) in pain was ≥20 mm. RESULTS: One week of data were available for 33 patients (19 received IACS and 14 others). Synovial thickness (ST) decreased in 16 IACS patients and 2 others [mean between-group difference 4.7 mm (95% CI 1.1, 8.2), P = 0.012]. Absolute reduction was not associated with absolute reduction in pain (r = 0.20, P = 0.289), but decreased ST was substantively associated with reduction in pain greater than or equal to the MCII (52.9% vs 23.1%, P = 0.098, φ = 0.30). The power Doppler score decreased in 13 IACS patients and 3 others {median change in IACS patients -1.0 [interquartile range (IQR) -5.0-0.0], others 0.0 [-0.3-1.3], P = 0.004}. Absolute changes in pain and power Doppler score were weakly associated (ρ = 0.36, P = 0.049) and a decreased power Doppler score was associated with reduction in pain greater than or equal to the MCII (64.3% vs 18.8%, P = 0.011, φ = 0.46). CONCLUSION: Ultrasonography can detect short-term synovial response in knee OA. In particular, power Doppler score may be both responsive to and associated with pain, warranting further investigation.

International Consensus for ultrasound lesions in gout: results of Delphi process and web-reliability exercise.

OBJECTIVE: To produce consensus-based definitions of the US elementary lesions in gout and to test their reliability in a web-based exercise. METHODS: The process consisted of two steps. In the first step a written Delphi questionnaire was developed from a systematic literature review and expert international consensus. This collated information resulted in four statements defining US elementary lesions: double contour (DC), tophus, aggregates and erosion. The Delphi questionnaire was sent to 35 rheumatology experts in US, asking them to rate their level of agreement or disagreement with each statement. The second step tested the reliability by a web-exercise. US images of both normal and gouty elementary lesions were collected by the participants. A facilitator then constructed an electronic database of 110 images. The database was sent to the participants, who evaluated the presence/absence of US elementary lesions. A group of 20 images was displayed twice to evaluate intra-reader reliability. RESULTS: A total of 32 participants responded to the questionnaires. Good agreement (>80%) was obtained for US definitions on DC, tophus, aggregates and erosion in the Delphi exercise after three rounds. The reliability on images showed inter-reader κ values for DC, tophus, aggregates, erosion findings of 0.98, 0.71, 0.54 and 0.85, respectively. The mean intra-reader κ values were also acceptable: 0.93, 0.78, 0.65 and 0.78, respectively. CONCLUSION: This, the first consensus-based US definition of elementary lesions in gout, demonstrated good reliability overall. It constitutes an essential step in developing a core outcome measurement that permits a higher degree of homogeneity and comparability between multicentre studies.

Population-wide long-term study of incidence, renal failure, and mortality rates for lupus nephritis.

OBJECTIVE: Given limited regional data, we investigate the state-wide epidemiology, renal and patient outcomes for lupus nephritis (LN) in Western Australia (WA). METHODS: Patients hospitalized with incident SLE (≥2 diagnostic codes in the state-wide WA Health Hospital Morbidity Data Collection) in the period 1985-2015 were included (n = 1480). LN was defined by the presence of glomerulonephritis and/or raised serum creatinine. Trends over three study decades for annual incidence rate (AIR)/100.000 population, mortality (MR), and end-stage renal disease (ESRD) rates/100 person years were analyzed by least square regression and compared with a matched control group (n = 12 840). RESULTS: Clinical evidence of LN developed in 366 SLE patients (25.9%) after a median disease duration of 10 months (IQR 0-101) with renal biopsy performed in 308 (84.2%). The AIR for LN (0.63/100.000) did not change significantly over time (R2 = .11, p = .85), while point prevalence reached 11.9/100.000 in 2015. ESRD developed in 14.1% (n = 54) of LN patients vs. 0.2% in non-LN SLE patients and 0.05% in controls (all p ≤ 0.01). ESRD rates increased over time in LN patients (0.4 to 0.7, R2 = .52, p = .26). The odds ratio for death was 8.81 (CI 3.78-22.9) for LN and 6.62 (CI 2.76-17.9) for non-LN SLE patients compared to controls and MR for LN patients increased over time (1.3 to 2.2, R2 = .84, p = .26). CONCLUSIONS: The incidence rate of LN in WA remained unchanged over 30 years. A lack of improvement in renal failure and mortality rates illustrates the pressing need for better long-term treatment options and/or strategies in LN.

Trends in Hospitalization for Tuberculosis and Other Opportunistic Infections in Australian Patients with Inflammatory Joint Diseases.

OBJECTIVE: As immune-modulating therapy has become the standard of care for idiopathic inflammatory joint diseases (IJD), we investigated whether this has changed the rates for hospitalization with opportunistic infections (OI). METHODS: Administrative longitudinal state-wide health data identified patients hospitalized at least twice with diagnostic codes for rheumatoid arthritis (RA, n = 7730), psoriatic arthritis (PsA, n = 529) or axial spondylarthritis (AS, n = 1126) in Western Australia in the period 1985-2015. Overall incidence rates/1000 person-years (IR with 95% CI) for microbiologically confirmed OI (mycobacterial, fungal, and viral infections) during 180,963 person-years were analyzed across 10-year periods with IR trend rates analyzed by least square regression (R2) for all IJD categories. RESULTS: A total of 2584 OI occurred with higher IR rates observed in RA (15.34, CI 14.71-15.99) than PsA (8.73, CI 7.14-10.56) and AS (10.88, CI 9.63-12.24) patients (p < 0.001). IR rates were highest for Candidiasis across all three IJD categories (IR 10.0 vs. 6.32 vs. 6.88, respectively), while Varicella-zoster (VZV) was most frequent non-candida OI (IR 2.83.0 vs. 1.50 vs. 1.49, respectively) followed by mycobacterial (IR 1.14 vs. 0.08 vs. 0.24, respectively) and other mycotic infections (IR 0.60 vs. 0.58 vs. 0.86, respectively). Over time, the IR for tuberculosis and pneumocystosis decreased and remained stable for VZV infections in RA patients, but IR for all other OI increased across all disease categories. OI admission associated with 6.5% (CI 5.6-7.5) in-hospital mortality. CONCLUSIONS: Despite decreasing admission rates for tuberculosis and pneumocystosis in RA patients, an overall increase in mycotic and viral infection rates over time was seen across all three IJD. Together with a significant case fatality rate, this indicates continued efforts are needed to improve OI prevention in the management of IJD patients.