Urate lowering therapy to improve renal outcomes in patients with chronic kidney disease: systematic review and meta-analysis.

BACKGROUND: Hyperuricemia may contribute to renal injury. We do not know whether use of treatments that lower urate reduce the progression of chronic kidney disease (CKD) and cardiovascular disease. We performed a systematic review and meta-analysis of randomized controlled trials to assess the benefits and risks of treatments that lower urate in patients with stages 3-5 CKD. METHODS: We searched MEDLINE, EMBASE, CENTRAL, Web of Science and trial registers for randomized controlled trials (RCTs) without language restriction. Two authors independently screened articles, assessed risk of bias and extracted data. Data obtained included serum uric acid, serum creatinine or other estimates of glomerular filtration rate, incidence of end-stage renal disease (ESRD), systolic and diastolic blood pressure, proteinuria, cardiovascular disease and adverse events. RESULTS: From the 5497 citations screened, 19 RCTs enrolling 992 participants met our inclusion criteria. Given significant heterogeneity in duration of follow-up and study comparators, only trials greater than 3 months comparing allopurinol and inactive control were meta-analyzed using random effects models. Pooled estimate for eGFR was in favour of allopurinol with a mean difference (MD) of 3.2 ml/min/1.73 m(2), 95% CI 0.16-6.2 ml/min/1.73 m(2), p = 0.039 and this was consistent with results for serum creatinine. Statistically significant reductions in serum uric acid, systolic and diastolic blood pressure were found, favouring allopurinol. There were insufficient data on adverse events, incidence of ESRD and cardiovascular disease for analysis. CONCLUSIONS: Adequately powered RCTs are needed to establish whether treatments that lower urate have beneficial renal and cardiovascular effects.

Imaging modalities for the diagnosis and disease activity assessment of Takayasu's arteritis: A systematic review and meta-analysis.

BACKGROUND: Early diagnosis of Takayasu's Arteritis (TAK) and detection of disease activity may reduce the risk of vascular complications. The objective of this study was to determine the effectiveness of imaging modalities for the management of TAK. METHODS: MEDLINE and EMBASE were searched for studies of patients undergoing various imaging modalities for TAK diagnosis or to assess disease activity. We excluded case reports, reviews and case series with <10 patients. The methodologic quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2). Random effects meta-analyses with inverse-variance weighting were performed. RESULTS: From the 1126 citations screened, 57 studies met our inclusion criteria. Many of the studies were of small sample size (average N=27), cross-sectional design and low methodological quality. Ultrasound (US) had a lower pooled sensitivity (SN) of 81% (95% CI: 69-89%) than Magnetic Resonance Angiography (MRA) with SN=92% (95% CI: 88-95%) for TAK diagnosis (by clinical criteria and/or X-Ray angiography). Both had high specificities (SP) of >90% for TAK diagnosis. Fewer studies investigated computed tomography angiography (CTA), but SN and SP for TAK diagnosis was high (>90%). The utility of vessel wall thickening and enhancement by MRA and CTA to predict disease activity varied across studies. The pooled SN and SP of 18F-fluorodeoxyglucose-Positron Emission Tomography (FDG-PET) for disease activity was 81% (95% CI: 69-89%) and 74% (95% CI: 55-86%), respectively. CONCLUSION: US, CTA and/or MRA are effective for the diagnosis of TAK. The utility of these imaging modalities for assessing disease activity remains unclear.