The Ability of Antibody against Truncated Matrix Metalloproteinase 9 Peptide to Evaluate the Native Protein on Tear Drops of Dry Eye Disease Patients by a Point‑of‑Care Diagnostic System

To obtain a reactive and specific antibody against truncated matrix metalloproteinase 9 (MMP‑9), that has reactivity toward the native protein. Precision, accuracy, specificity, and sensitivity were evaluated using a point‑of‑care test.

An in silico study was used to confirm the anti peptide truncated MMP‑9 is against native MMP‑9. After an antibody titer assessment, purification, and characterization, the anti MMP‑9 was assessed. The cut-off value was determined using the purified gelatinases of the supernatant HCT 116 cell line. The supernatant was purified by preparative native‑polyacrylamide gel electrophoresis based on charge and size of the proteins. Furthermore, quality control (QC) of the results were performed following standard densitometry methods.

A truncated MMP‑9 is the major epitope peptide that can trigger the immune system to scavenge for a specific and reactive antibody against the native MMP‑9. The MMP‑9 native protein is purified from the supernatant of the HCT 116 cell line and the commercially available, full‑length MMP‑9. The cut-off value was estimated at 30 µg/mL. QC results indicated that the specificity was 80%, sensitivity was 96.7%, accuracy was 91%, and precision was 91.66%. The area under curve was 0.827 (P < 0.001). The positive predictive value was 83%, and the negative predictive value was 96%.

The antibody against the synthetic epitope peptide can detect the native MMP‑9. Native MMP‑9 is considered the main biomarker in an immunoassay POCT and is used to diagnose dry eye disease (DED). In accordance with QC results, MMP‑9 point of care test can be utilized for screening patients suffering from DED.