АHNAK2 ELISA-based urinary test for bladder cancer detection and monitoring: a pilot study

Abstract

Background & objectives: Non-invasive bladder cancer (BC) detection markers are urgently needed. Recent studies demonstrated that AHNAK nucleoprotein2, (AHNAK2) differentiates between cystitis and BC. We aimed to perform an ELISA urine test to compare AHNAK2 levels in BC patients with the control’s levels. Methods: Voided urine specimens were collected from 27 patients with histologically proven BC and 28 healthy controls. AHNAK2 concentrations were measured using a quantitative sandwich ELISA test, according to the manufacturer’s protocol. Associations between groups and the diagnostic performance of the assay were evaluated with the Student t-test, Spearman’s Rank correlation, MannWhitney U Test, and Receiver Operating Curve (ROC) curve analysis. Results: Mean AHNAK2 urine levels were higher in BC patients (80.7pg/ml; Median 13.87), compared to the controls (5.19pg/ml; Median 2.25) (p<0.05). In the BC group, we found a statistically significant difference in AHNAK2 urine values between non-invasive and invasive BC patients (p<0.01). We noted a moderate positive correlation between AHNAK2 urine levels and pT status (r=0.69; p<0.05), but no correlations were found with gender, age, and histologic grade. With a cut-off value of 11.84pg/ml (Mean+SD of the control group), the sensitivity and specificity of the assay were 51.85% and 85.71%, respectively. Alternatively, in a proposed cut–off value of 5.19pg/ml, the sensitivity increased to 62.96%, but the specificity declined to 67.86%. Conclusion: The measurement of AHNAK2 urine concentrations could represent an inexpensive, adjunct tool in the diagnostic evaluation of patients suspected of having BC. Future research should refine and validate these findings, which might ultimately reduce the number of unnecessary cystoscopies.