Eosinophil Protein X (EPX), also known as eosinophil-derived neurotoxin (EDN), is a protein released by eosinophils, a type of white blood cell that plays a crucial role in the body’s immune responses to allergies, infections, and inflammatory conditions.(*) Elevated Eosinophil Protein X (EPX) in stool can offer valuable insights into gastrointestinal (GI) health. In today’s article I will explain What eosinophil protein X is, what it means when you have elevated eosinophil protein X (EPX) in stool, What causes elevated levels, different health problems seen when your levels are elevated, and some tips to help lower high levels.

Key Takeaways

• Elevated levels of EPX in stool samples is a diagnostic and predictive biomarker of eosinophil activity and disease activity in these conditions.
• Monitoring EPX levels can help in monitoring disease progression, predicting relapse and distinguishing eosinophilic inflammation from other causes of gut symptoms like irritable bowel syndrome or food allergies.
• Elevated histamine or mast cell activation in the gut can recruit eosinophils.
• H. pylori can trigger an immune response involving eosinophils in some individuals.
• Crohn’s disease and ulcerative colitis can cause elevated EPX due to immune dysregulation and gut inflammation.
• Parasites like Giardia, Entamoeba histolytica, Strongyloides, or Ascaris can stimulate eosinophil activity.

What is Eosinophil Protein X?

Eosinophil protein X (EPX) is a marker produced by eosinophils. These cells are vital for defending against parasitic infections, modulating immune responses, and participating in allergic inflammation. EPX is one of the potent proteins released by eosinophils, serving functions that include antimicrobial actions and inflammation mediation.

Assessing Eosinophil Protein X in Stool

Examining eosinophil protein X levels in a Function stool test is particularly useful for diagnosing and monitoring gastrointestinal disorders where eosinophils play a role. Understanding its levels can offer insights into diseases affecting the GI tract, often linked to inflammation and allergic reactions.(*)

Why Elevated Levels of Eosinophil Protein X in Stool Is A Problem

Elevated levels of eosinophil protein X in stool indicate increased eosinophil activity in the gastrointestinal tract. Lets review are a few conditions where high levels of EPX in stool might be found.

1. Allergic Gastrointestinal Disorders

Eosinophilic Gastroenteritis: elevated levels of eosinophil protein X in stool is often elevated in a condition known as Eosinophilic Gastroenteritis. This condition involves the infiltration of eosinophils into the gastrointestinal tract, leading to elevated EPX levels in the stool. It is often characterized by symptoms like abdominal pain, diarrhea, and weight loss.

Eosinophilic gastroenteritis (EGE) is an underestimated disorder characterized by the infiltration of eosinophils, a type of white blood cell, into various layers of the gastrointestinal (GI) tract. Understanding what causes eosinophilic gastroenteritis is crucial because timely diagnosis and appropriate treatment can help manage this condition effectively.

One of the most well-documented causes of eosinophilic gastroenteritis is food allergies (IgE). Foods such as dairy, eggs, soy, wheat, nuts, and seafood can trigger an immune response that leads to eosinophil accumulation in the GI tract. These allergic reactions can cause inflammation and result in symptoms ranging from Atopic Dermatitis, abdominal pain and nausea to severe gastrointestinal discomfort.(*)

In addition to food allergies, environmental allergens like pollen, dust mites, and mold spores can sometimes induce eosinophilic responses in susceptible individuals.

Mold spores are a type of allergen that can trigger an immune response in sensitive individuals, leading to allergic reactions and inflammation in various tissues, including the respiratory tract and the gastrointestinal system. This immune response often involves the activation of eosinophils, a type of white blood cell that plays a key role in combating allergens. When eosinophils are activated, they release proteins, including EPX, as part of the inflammatory process. Elevated levels of EPX can thus be an indicator of an allergic or inflammatory response to mold exposure

Research suggests that a genetic component may contribute to the development of eosinophilic gastroenteritis. Individuals with a family history of allergies, asthma, or other eosinophil-related disorders may be more prone to developing EGE. Genetic predisposition can influence the immune system’s response to various allergens, making certain individuals more susceptible.

Eosinophilic gastroenteritis can also arise from broader immune system dysregulation. For some individuals, the immune system might react inappropriately to benign stimuli, causing chronic inflammation and eosinophil infiltration in the GI tract. This process can occur even in the absence of clear allergic triggers, leading to symptoms typical of EGE.

Though less common, autoimmune diseases—where the body’s immune system mistakenly attacks its own tissues—can also play a role in triggering eosinophilic gastroenteritis. Conditions like systemic lupus erythematosus (SLE) or eosinophilic granulomatosis with polyangiitis (EGPA, formerly Churg-Strauss syndrome) can involve eosinophilic infiltration into the GI tract, contributing to symptoms of EGE.

2.Inflammatory Bowel Diseases (IBD)

Inflammatory Bowel Disease (IBD) is a term primarily used to describe two chronic conditions that involve inflammation of the digestive tract: Crohn’s disease and ulcerative colitis. These conditions are autoimmune diseases that lead to symptoms such as abdominal pain, severe diarrhea, fatigue, weight loss, and malnutrition.

Managing IBD typically involves medication, lifestyle changes, Dietary changes and sometimes surgery, aimed at reducing inflammation, controlling symptoms, and maintaining long-term remission.

Crohn’s Disease and Ulcerative Colitis can cause elevated eosinophil activity, resulting in higher levels of eosinophil protein X in the stool. Monitoring these levels helps gauge inflammation and disease activity.

Microscopic Colitis: This includes conditions like collagenous colitis and lymphocytic colitis, which can similarly elevate EPX levels due to underlying inflammation.

3. Parasitic Infections

Parasitic infections, particularly by helminths (parasitic worms), are well-known to induce eosinophil proliferation and activity. As the body attempts to combat these infections, eosinophils infiltrate infected tissues, including the gastrointestinal lining, leading to inflammation and other symptoms associated with eosinophilic gastroenteritis.

4. Bacterial and Viral Infections

Bacterial Infections caused by certain bacteria or viruses can also trigger eosinophil infiltration and lead to high levels of EPX in stool. While these instances are less common, localized infections in the GI tract can provoke an immune response that includes increased eosinophil activity, resulting in symptoms similar to those of EGE.

5. Drug-induced Gastrointestinal Reactions

Several medications can cause injury to the intestines, potentially leading to inflammation and increased levels of eosinophil protein X (EPX). Non-Steroidal Anti-Inflammatory Drugs (NSAIDs), commonly used for pain relief and to reduce inflammation, can cause gastrointestinal irritation, ulcers, and bleeding.

Certain antibiotics, such as clindamycin, amoxicillin, and erythromycin, can disrupt the normal gut flora, leading to inflammation and intestinal injury.

Chemotherapy agents are known to damage the gut lining as a side effect, while immunosuppressive agents like azathioprine and mycophenolate mofetil, used in organ transplantation and autoimmune diseases, can have gastrointestinal complications.

Some biologic agents used to treat autoimmune conditions, such as TNF alfa inhibitors can cause high levels of EPX in stool as well as inflammatory changes throughout the gut.

Tumor necrosis factor-alpha (TNF-α) inhibitors are a class of medications used to manage various inflammatory and autoimmune conditions such as rheumatoid arthritis, ankylosing spondylitis, psoriatic arthritis, and Crohn’s disease.

Heres a few Medications (TNF alfa inhibitors) that can cause elevated EPX.

1. Infliximab (Remicade): A monoclonal antibody that is usually administered via intravenous infusion.

2. Etanercept (Enbrel): A fusion protein that is administered via subcutaneous injection.

3. Adalimumab (Humira): A fully human monoclonal antibody given by subcutaneous injection.

4. Certolizumab pegol (Cimzia): A pegylated monoclonal antibody administered via subcutaneous injection.

5. Golimumab (Simponi): A human monoclonal antibody that can be administered either by subcutaneous injection or intravenous infusion (as Simponi Aria for the intravenous form).

These medications work by neutralizing TNF-α, a cytokine involved in systemic inflammation, thereby reducing inflammatory processes. It’s important to note that while effective, TNF-α inhibitors can have potential side effects and risks, such as increased susceptibility to infections, gut inflammation and other adverse effects. The use of these medications should be closely monitored by your healthcare provider.

Ironic how these medications can lead to intestinal inflammation, which triggers an immune response, including the activation of eosinophils and the release of proteins like EPX.(*) If you suspect medication-related intestinal injury, it is important to consult a healthcare provider for appropriate management and potential alternatives.

6. Food Intolerances IgA and IgG Food reactions

I have already mentioned how food allergies (IgE) can cause elevated eosinophil protein X to be elevated in gut, but food allergies (IgE) are not the only culprit when it comes to food. If you continue to struggle with reactions to food despite having been tested for food allergies and you have elevated eosinophil protein X levels, you may want to talk to your doctor about testing for foods sensitivities and food intolerances.

Food intolerance/foods sensitivities that cause and IgA or IgG reaction can also elevate your eosinophil protein X levels. These immune responses involve specific antibodies – IgG or IgA – that recognize antigens and can trigger eosinophils to be activated and recruited to the gut.

Eosinophils accumulate and get activated and release granule proteins such as eosinophil protein X (EPX), eosinophil cationic protein (ECP) and eosinophil derived neurotoxin which cause tissue damage and inflammation.

Eosinophilic inflammation is seen in many inflammatory conditions of the gut including eosinophilic gastroenteritis, ulcerative colitis, Crohns disease and microscopic colitis. Elevated levels of EPX in stool samples is a diagnostic and predictive biomarker of eosinophil activity and disease activity in these conditions.

Monitoring EPX levels can help in monitoring disease progression, predicting relapse and distinguishing eosinophilic inflammation from other causes of gut symptoms like irritable bowel syndrome or food allergies.

Heres What You Should Remember About Eosinophil Protein X in Stool

Eosinophil protein X in stool is a significant marker for diagnosing and monitoring various gastrointestinal conditions characterized by eosinophilic inflammation.

Elevated levels of eosinophil protein X in stool indicate increased eosinophil activity, often associated with allergic gastrointestinal disorders, inflammatory bowel diseases, parasitic infections, and drug-induced reactions. Understanding and monitoring these levels are crucial for accurate diagnosis, effective treatment, and early detection, ultimately contributing to improved gastrointestinal health and patient outcomes.

Monitoring eosinophil protein X levels in stool provides insights into gastrointestinal health and the extent of eosinophilic inflammation. Tracking EPX levels can offer information about the effectiveness of treatments, including diet modifications and medications, for GI conditions. Monitoring stool EPX levels can help detect early signs of gastrointestinal conditions, potentially leading to prompt and more effective interventions.

By staying informed about what eosinophil protein X in stool is and what elevated levels indicate, individuals and healthcare providers can make more informed decisions about managing and treating gastrointestinal health issues.