4 Things You Need to Know About Calprotectin

Calprotectin is a common marker included in stool tests, but there’s significant misinformation surrounding what it indicates about your digestive health. Here’s a clear breakdown of what calprotectin can—and cannot—tell you about your colon, based on years of clinical experience testing calprotectin levels in thousands of patients.

What Is Calprotectin?

Calprotectin is a protein expressed by various cells in the body, particularly those involved in the immune system. As such, it’s considered an inflammatory marker since it’s associated with immune responses and inflammation.

You may have heard that calprotectin is primarily used to differentiate between Inflammatory Bowel Disease (IBD) and Irritable Bowel Syndrome (IBS), but the reality is far more nuanced.

Does Calprotectin Differentiate Between IBD and IBS?

The short answer: not reliably.

• While elevated calprotectin levels are more commonly associated with IBD, I’ve seen plenty of IBS patients with elevated calprotectin levels who don’t have IBD.
• Many of these IBS patients had undergone colonoscopies that definitively ruled out IBD, showing that calprotectin alone isn’t a definitive diagnostic tool.

Calprotectin may have some correlation with IBD, but it isn’t specific or sensitive enough to be a standalone marker for distinguishing between IBD and IBS.

Calprotectin Is One Inflammatory Marker, Not the Only One

Inflammation is incredibly complex, and calprotectin is just one of many markers that may indicate it.

• Not the Whole Picture: No single test can comprehensively measure inflammation in the body, including in the digestive tract. While calprotectin is a helpful tool, it doesn’t provide the full story.
• Variability in Inflammation: The presence of inflammation can be influenced by numerous factors, and other markers may be more relevant in specific cases.

Calprotectin Is Also Produced by Epithelial Cells

Another key fact about calprotectin is that it’s not solely produced by immune cells.

• Epithelial Cells: These cells line the digestive tract and other parts of the body, and they can also produce calprotectin.
• Misleading Associations: Elevated calprotectin levels might not always be tied to immune-related inflammation. Instead, the elevation could stem from epithelial cell activity, making the interpretation of results more complex.

What Does an Elevated Calprotectin Level Mean?

An elevated calprotectin level is not specific to any one condition. Here’s what you need to know:

1. It’s a Monitoring Tool, Not a Diagnostic Marker:
   • Calprotectin levels can be useful for tracking changes over time, especially to evaluate how well a treatment is working.
   • For example, a decrease in calprotectin levels might indicate that your treatment is reducing inflammation or addressing the issue effectively.
2. It Doesn’t Identify the Cause:
   • Elevated calprotectin levels don’t tell you why it’s elevated. The marker doesn’t point to a specific diagnosis or underlying condition.

The Bottom Line on Calprotectin

Calprotectin is a valuable tool, but it has limitations. Here’s a quick summary:

• What It Does: Helps monitor inflammatory activity and evaluate treatment effectiveness.
• What It Doesn’t Do: Diagnose specific conditions, reliably differentiate between IBD and IBS, or provide a complete picture of inflammation.
• If you’ve had calprotectin levels tested, it’s crucial to interpret the results within the broader context of your symptoms, other diagnostic tests, and clinical findings. Always consult with a knowledgeable healthcare provider to understand what your calprotectin levels mean for your unique situation.
• By understanding the nuances of calprotectin, you can approach your digestive health with clarity and informed decision-making.