Objective:

To develop a chemiluminescence-based stool assay for measuring granzyme A (GzmA) enzyme activity as a potential biomarker for monitoring inflammatory bowel disease (IBD).

Key Findings:

• Increased GzmA activity was found in inflamed intestinal tissue.
• CD8-positive T cells can release active GzmA.
• GzmA activity is linked to the induction of interleukin 8 (IL-8), indicating a role in pro-inflammatory signaling.
• Stool GzmA activity was higher in individuals with intestinal inflammation, aiding in distinguishing IBD from healthy controls.

Interpretation:

The assay may provide a noninvasive method to monitor T cell-associated inflammation in IBD, potentially complementing existing diagnostic tests.

Limitations:

• The assay is still in the research stage and cannot replace histologic evaluation.
• Further validation is required across different IBD phenotypes and real-world conditions.

Conclusion:

Activity-based stool biomarkers like GzmA could enhance monitoring of IBD, particularly when other assessments do not align.