Estimating Glomerular Filtration Rate in Cirrhosis Using Creatinine-Based and Cystatin C-Based Equations: Systematic Review and Meta-Analysis.

Accurate estimation of kidney function in cirrhosis is crucial for prognosis and decisions regarding dual-organ transplantation. We performed a systematic review/meta-analysis to assess the performance of creatinine-based and cystatin C (CysC)-based eGFR equations compared with measured GFR (mGFR) in patients with cirrhosis. A total of 25 studies (n = 4565, 52.0 years, 37.0% women) comprising 18 equations met the inclusion criteria. In all GFR equations, the creatinine-based equations overestimated GFR (standardized mean difference, SMD, 0.51; 95% confidence interval [CI], 0.31-0.71) and CysC-based equations underestimated GFR (SMD, -0.3; 95% CI, -0.60 to -0.02). Equations based on both creatinine and CysC were the least biased (SMD, -0.14; 95% CI, -0.46 to 0.18). Chronic kidney disease-Epi-serum creatinine-CysC (CESC) was the least biased but had low precision and underestimated GFR by -3.6 mL/minute/1.73 m2 (95% CI, -17.4 to 10.3). All equations significantly overestimated GFR (+21.7 mL/minute/1.73 m2 ; 95% CI, 17.7-25.7) at GFR <60 mL/minute/1.73 m2 ; of these, chronic kidney disease-Epi-CysC (10.3 mL/minute/1.73 m2 ; 95% CI, 2.1-18.4) and GFR Assessment in Liver Disease (12.6 mL/minute/1.73 m2 ; 95% CI, 7.2-18.0) were the least biased followed by Royal Free Hospital (15 mL/minute/1.73 m2 ; 95% CI, 5.5-24.6) and Modification of Diet in Renal Disease 6 (15.7 mL/minute/1.73 m2 ; 95% CI, 10.6-20.8); however, there was an overlap in the precision of estimates, and the studies were limited. In ascites, overestimation of GFR was common (+8.3 mL/minute/1.73 m2 ; 95% CI, -3.1 to 19.7). However, overestimation of GFR by 10 to 20 mL/minute/1.73m2 is common in patients with cirrhosis with most equations in ascites and/or kidney dysfunction. A tailored approach is required especially for decisions regarding dual-organ transplantation.

Factors That Contribute to Indeterminate Results From the QuantiFERON-TB Gold In-Tube Test in Patients With Inflammatory Bowel Disease.

BACKGROUND & AIMS: The QuantiFERON-Tuberculosis Gold In-Tube (QFT-GIT) (QIAGEN Group, Hilden, Germany) test is widely used to screen for latent Mycobacterium tuberculosis infection in patients with inflammatory bowel diseases (IBD) before treatment with a tumor necrosis factor antagonist. The test frequently produces indeterminate results, prompting additional testing. We evaluated factors associated with indeterminate results from the QFT-GIT test among patients with IBD. METHODS: We conducted a case-control study among eligible adults with QFT-GIT test results and a concomitant diagnosis of IBD receiving care at a tertiary referral center from 2011 through 2013. We compared patients with IBD with indeterminate and determinate (positive or negative) results from the QFT-GIT test. We collected data on patient demographics, clinical features, laboratory parameters, and medication use from medical charts. We calculated odds ratios (OR) and 95% CIs using multivariate logistic regression models. RESULTS: A total of 400 patients with IBD (265 Crohn's disease and 135 ulcerative colitis) were included in the final analyses. Indeterminate results were noted in 11.5% of patients. At the time of testing, a higher proportion of patients with indeterminate results from the QFT-GIT test were on systemic corticosteroid therapy (60.9% vs 30.5% of patients with conclusive test results; P < .001), had levels of C-reactive protein above 0.8 mg (62.2% vs 39.9% of patients with clear test results; P = .005), had an erythrocyte sedimentation rate above 15 mm/h (55.6% vs 35.8% of patients with clear test results; P = .01), had serum levels of albumin below 3.5 g/dL (33.3% vs 6.3% of patients with clear test results; P < .001), and had low levels of hemoglobin (52.2% vs 28.3% of patients with clear test results; P = .001). In multivariable analysis, corticosteroid use (adjusted OR, 2.92; 95% CI, 1.44-5.88; P = .003) and serum levels of albumin below 3.5 g/dL (adjusted OR, 3.62; 95% CI, 1.36-9.60; P = .009) were independently associated with increased risk of indeterminate QFT-GIT test results. We did not identify a dose-related effect with corticosteroid therapy and the odds of indeterminate QFT-GIT test results. CONCLUSIONS: In a case-control study of patients with IBD, we associated systemic corticosteroid therapy and low levels of albumin with an increased likelihood of having indeterminate QFT-GIT test result.