Validation of Neutrophil gelatinase-associated lipocalin (NGAL) for Diabetes-associated Acute Kidney Injury

Abstract Introduction/Objective This study aimed to evaluate the analytical and clinical performance of the BioPorto NGAL Test on the Beckman Coulter AU480 to correlate plasma neutrophil gelatinase-associated lipocalin levels (pNGAL) with clinical progression and severity of diabetes-associated acute kidney injury (AKI) with hospitalized patients at an East Central Georgia Medical Center Methods/Case Report Analytical validation of the BioPorto NGAL Test was carried out on the AU480 and was based on imprecision, limit of blank, limit of detection, functional sensitivity, carryover, and specificity. Clinical validation studies included 45 patients hospitalized between January and November 2023 with and without diabetes at risk for developing AKI. All patients’ pNGAL levels were measured at admission until 96 hours post admission. Receiver operating characteristics and likelihood ratio methods were used to determine optimal sensitivity, specificity, cutoff value, and the discriminatory power of pNGAL. Results (if a Case Study enter NA) The intra-assay and inter-assay imprecision percent relative standard deviation was between 0.8 (2.7%) and 3.7 (4.2%). The limit of blank and limit of detection of Bioporto NGAL was 2.2 ng/mL and 15.4 ng/mL, respectively. An analytical coefficient of variation of 20% corresponded to a pNGAL value of 9.9 ng/mL. The optimal cutoff value for pNGAL to predict AKI for patients with DM was 293 ng/mL, with a sensitivity of 80% and specificity of 87%; AUC: 0.85, p < 0.001. In a multivariate logistic regression model, pNGAL levels at 48 hours post admission were a risk factor for diabetes-associated AKI (OR 1.012, 95% CI:1.000 – 1.023; p = 0.051). Conclusion These results show that pNGAL levels at 48h are an independent risk factor for diabetes-associated AKI, and the optimal cutoff for this condition is 293 ng/mL. The optimal cutoff values for AKI for early diagnosis and risk stratification, along with its association with comorbidities, are important to improve patient outcomes and diagnosis accuracy.