Diagnostic prediction of urinary [TIMP-2] x [IGFBP7] for acute kidney injury among critically ill and postoperative patients: A systematic review and meta-analysis
Lin Ting， Qu Kai， Zhang Jingyao， Liu Sinan， Zhang Chun， Li Na， Di Ying
The First Affiliated Hospital of Xi'an Jiaotong University
Acute kidney injury (AKI) most commonly occurs in critically ill and postoperative patients. Tissue inhibitor of metalloproteinases-2 (TIMP-2) and insulin-like growth factor-binding protein 7 (IGFBP7) are two newly-identified urinary biomarkers that can help to detect early AKI, yet their predictive accuracies range widely. Here, we conduct a systematic meta-analysis to evaluate the diagnostic value of the product of TIMP-2 and IGFBP7 for AKI.
PubMed, EMBASE, Scopus and Web of Sciences databases were comprehensively searched on October 7, 2016. The diagnostic value of [TIMP-2] x [IGFBP7] for AKI in critically ill or postoperative patients was evaluated by pooled estimates of sensitivity, specificity, diagnostic odds ratio (DOR) and area under the receiver operating characteristic curves (AUROC).
Ten studies were meta-analyzed on 1606 patients. Overall, urinary [TIMP-2] x [IGFBP7] had a pooled sensitivity of 63% (95% confidence interval or CI, 49%-76%) and specificity of 76% (95% CI, 62%-86%). The AUROC of [TIMP-2] x [IGFBP7] to predict AKI was 0.75 (95% CI, 0.71-0.79). Subgroup analyses indicated that the AUROC of urinary [TIMP-2] x [IGFBP7] was 0.72 (95% CI, 0.68-0.76) in cardiac surgery patients and 0.55 (0.50-0.59) in critically ill patients at a cutoff value of 0.3. If the cutoff value was 2.0, the AUROC of urinary [TIMP-2] x [IGFBP7] was 0.84 (95% CI, 0.81-0.87) in critically ill patients. When 0.3 was chosen as the cutoff value, restricting analysis to patients who were tested within 4 hours postoperatively showed a sensitivity of 0.76 and specificity of 0.72, with the AUROC of 0.74 (95% CI, 0.70-0.78). When 2.0 was chosen as the cutoff value, the sensitivity and specificity were 0.49 and 0.93, respectively in patients who were tested within 24 hours postoperatively, with the AUROC of 0.70 (95% CI, 0.51-0.89).