From the Guidelines
The use of TIMP2*IGFBP7 biomarker test is recommended as a supplementary tool for predicting acute kidney injury (AKI) in acute heart failure patients, with a cutoff value of 0.3 (ng/ml)²/1000 indicating increased risk and values above 2.0 suggesting high risk. This recommendation is based on the most recent and highest quality study available, which demonstrated the predictive value of TIMP2*IGFBP7 in AKI development within 12 hours of testing 1. The biomarker works by detecting cellular stress and early damage in kidney tubular cells before functional decline occurs, potentially allowing for earlier intervention.
Key Points to Consider
- The clinical utility of TIMP2*IGFBP7 remains somewhat limited by variable cutoff values across different patient populations, the need for specialized laboratory equipment, and incomplete integration into AKI management protocols 1.
- Clinicians should consider using TIMP2*IGFBP7 alongside traditional markers like creatinine, urine output monitoring, and clinical assessment rather than as a standalone test for AKI prediction in heart failure patients 1.
- The ability to recognize the various pathophysiological processes mediating AKI will likely be critical in developing targeted therapies and designing pharmacological trials 1.
Implications for Clinical Practice
- The use of TIMP2*IGFBP7 can improve risk stratification in critically ill patients with AKI stage 1, and evaluation of longer-term outcomes demonstrated that the associated risks of TIMP-2 × IGFBP7 of greater than 2.0 (ng/mL)2/1000 were equivalent to AKI progression even in instances in which no progression from AKI stage 1 was seen based on sCr and urine output 1.
- Inclusion of biomarker data with clinical assessments can be used to identify patients who will need kidney replacement therapy (KRT) and facilitate optimal timing of KRT initiation 1.
From the Research
Current Use of TIMP2*IGFBP7 in Predicting AKI
- The use of TIMP2*IGFBP7 as a biomarker for predicting acute kidney injury (AKI) in acute heart failure patients has been studied in several research papers 2, 3, 4, 5, 6.
- Studies have shown that urinary TIMP2*IGFBP7 is associated with moderate to severe AKI and related to increased mortality in patients with acute decompensated heart failure 2.
- The biomarker has been found to discriminate for AKI stage 2-3 over the first day with an area under the ROC curve of 0.84 and over 7 days with an AUC of 0.77 2.
- A cut-off value of 0.3 for TIMP2*IGFBP7 has been suggested for predicting AKI, with a sensitivity of 86% and specificity of 95% for prediction of AKI stage 2-3 2.
- The use of TIMP2*IGFBP7 as an AKI risk screening tool has been found to result in differential application of various components of the KDIGO bundle for patient management in a real-world setting 5.
Application in Clinical Practice
- TIMP2*IGFBP7 has been confirmed to be superior in early detection of AKI, before the decrease of renal function is evident 6.
- The US Food and Drug Administration has permitted marketing of NephroCheck (measuring urinary TIMP2*IGFBP7) to determine if certain critically-ill patients are at risk of developing moderate to severe AKI 6.
- The biomarker has been applied to clinical work in many hospitals to improve the diagnostic accuracy and outcomes of AKI patients 6.
- Research is ongoing to evaluate the application value, meaning, and method of TIMP2*IGFBP7 in different clinical settings 6.
Predictive Value
- The predictive value of TIMP2*IGFBP7 for AKI has been found to be high, with an area under the ROC curve of 0.91 for predicting severe AKI in patients after cardiac arrest 4.
- A cut-off value of 0.39 for TIMP2*IGFBP7 has been suggested for predicting severe AKI, with a sensitivity of 97% and specificity of 72% 4.
- Combining TIMP2*IGFBP7 with other biomarkers, such as serum creatinine and urine output, has been found to improve predictive performance for AKI 4.