Efficacy and tolerability of probenecid as urate-lowering therapy in gout; clinical experience in high-prevalence population.

OBJECTIVE: Probenecid is recommended as urate-lowering therapy (ULT) in patients with gout where xanthine oxidase inhibitors are ineffective, not tolerated, or contraindicated. The aim of our study was to determine the efficacy of probenecid to achieve serum urate (SU) targets (< 0.36 mmol/l) in clinical practice. METHODS: We identified 57 patients prescribed with probenecid from a database of 521 rheumatology clinic attenders with gout. Demographic characteristics, indications for probenecid, probenecid doses, side effects, and laboratory data including estimated glomerular filtration rate (eGFR) and SU were recorded. RESULTS: There were 30/57 (53%) patients treated with probenecid as monotherapy and 27/57 (47%) patients treated with probenecid in combination with allopurinol. Target SU concentrations (< 0.36 mmol/l) were achieved in 10/30 (33%) of the probenecid monotherapy group and 10/27 (37%) of the combination treatment group. Baseline SU concentrations, but not eGFR or probenecid dose, independently predicted achievement of target SU. Target SU was achieved in 5/15 (33%) patients with eGFR < 50 ml/min/1.73 m(2). There was no difference in the percentage of patients achieving SU target in those with eGFR < 50 ml/min/1.73 m(2) compared with those with eGFR ≥ 50 ml/min/1.73 m(2). Adverse events attributed to probenecid were observed in 8/42 (19%) patients with eGFR ≥ 50 ml/min/1.73 m(2) and in 2/15 (13%) patients with eGFR < 50 ml/min/1.73 m(2). CONCLUSION: Probenecid has moderate efficacy as ULT in clinical management of patients with complex gout who have a lack of efficacy or intolerance to allopurinol. Patients with chronic kidney disease may respond to probenecid with similar rates of adverse events.

Nail disease in psoriatic arthritis: distal phalangeal bone edema detected by magnetic resonance imaging predicts development of onycholysis and hyperkeratosis.

OBJECTIVE: To examine the association between magnetic resonance imaging (MRI) features of distal phalanx (DP) disease and the progression of nail pathology in psoriatic arthritis (PsA). METHODS: Clinical nail assessment and hand MRI scans were done on 34 patients with PsA. Twenty patients had repeat nail assessments after 1 year. RESULTS: Nails with onycholysis and hyperkeratosis at baseline were more likely to have corresponding DP bone erosion and proliferation on MRI. DP bone edema on baseline MRI was associated with development of onycholysis and hyperkeratosis in corresponding nails. CONCLUSION: Our data suggest that DP inflammation is central in the development of psoriatic nail disease.

Prevalence of airway and parenchymal abnormalities in newly diagnosed rheumatoid arthritis.

BACKGROUND: Pulmonary disease is a well recognised and important extra-articular manifestation of rheumatoid arthritis (RA). The objective of this study was to determine the prevalence of airway and parenchymal abnormalities in newly diagnosed patients with RA and to correlate these with clinical measures of RA severity and laboratory tests. METHODS: 60 patients with a new (symptom duration <12 months) diagnosis of RA (43 females, 42 European, mean age 54, 33 ever smoker, (17 current) underwent lung function testing and high resolution computed tomography (HRCT) scored by two independent radiologists. RESULTS: Eighteen (30%) patients reported respiratory symptoms: dyspnoea (11), cough (11), and wheeze (8). Twelve (20%) patients had physiologic evidence of airflow obstruction and 24 (40%) had reduced gas transfer. The prevalence of HRCT abnormalities (in any lobe) was as follows: decreased attenuation 67%, bronchiectasis 35%, bronchial wall thickening 50%, ground glass opacification 18%, reticular changes 12%. All abnormalities were more common in the lower lobes. With the exception of reduced DLCO, there were no significant differences in the prevalence of HRCT patterns or lung function parameters between smokers and non smokers. Anti-CCP antibodies and rheumatoid factor (RF) correlated strongly with DLCO and variably with other physiologic measures but poorly with radiologic abnormalities. CONCLUSION: Patients with newly diagnosed RA have a moderate prevalence of airway and parenchymal abnormalities on HRCT and lower than predicted lung function parameters which cannot entirely be explained by smoking. These data suggest that pulmonary involvement is present early in the disease course in RA.

MRI bone oedema scores are higher in the arthritis mutilans form of psoriatic arthritis and correlate with high radiographic scores for joint damage.

INTRODUCTION: The aim of this study was to investigate the magnetic resonance imaging (MRI) features of bone disease in the arthritis mutilans (AM) form of psoriatic arthritis (PsA). METHODS: Twenty-eight patients with erosive PsA were enrolled (median disease duration of 14 years). Using x-rays of both hands and feet, 11 patients were classified as AM and 17 as non-AM (erosive psoriatic arthritis without bone lysis)by two observers. MRI scans (1.5T) of the dominant hand (wrist and fingers scanned separately) were obtained using standard contrast-enhanced T1-weighted and fat-saturated T2-weighted sequences. Scans were scored separately by two readers for bone erosion, oedema and proliferation using a PsA MRI scoring system. X-rays were scored for erosions and joint space narrowing. RESULTS: On MRI, 1013 bones were scored by both readers. Reliability for scoring erosions and bone oedema was high (intraclass correlation coefficients = 0.80 and 0.77 respectively) but only fair for bone proliferation (intraclass correlation coefficient = 0.42). MRI erosion scores were higher in AM patients (53.0 versus 15.0, p = 0.004) as were bone oedema and proliferation scores (14.7 versus 10.0, p = 0.056 and 3.6 versus 0.7, p = 0.003 respectively). MRI bone oedema scores correlated with MRI erosion scores and X-ray erosion and joint space narrowing scores (r = 0.65, p = 0.0002 for all) but not the disease activity score 28-C reactive protein (DAS28CRP) or pain scores. CONCLUSIONS: In this patient group with PsA, MRI bone oedema, erosion and proliferation were all more severe in the AM-form. Bone oedema scores did not correlate with disease activity measures but were closely associated with X-ray joint damage scores. These results suggest that MRI bone oedema may be a pre-erosive feature and that bone damage may not be coupled with joint inflammation in PsA.