Differential Diagnosis for Elevated Lactoferrin in Stool

Elevated lactoferrin in stool is a marker of intestinal inflammation. After ruling out Inflammatory Bowel Disease (IBD), several other conditions can be considered. Here's a categorized differential diagnosis:

• Single Most Likely Diagnosis

  • Infectious Gastroenteritis: This is a common cause of elevated lactoferrin due to the inflammation caused by bacterial, viral, or parasitic infections in the gastrointestinal tract. The body's response to these pathogens can lead to increased lactoferrin levels as part of the innate immune response.

• Other Likely Diagnoses

  • Celiac Disease: An autoimmune reaction to gluten can cause inflammation in the small intestine, leading to elevated lactoferrin levels. This condition is less common than infectious gastroenteritis but should be considered, especially in patients with symptoms of malabsorption or those who have a family history of the disease.
  • Microscopic Colitis: This condition involves inflammation of the colon and can cause elevated lactoferrin. It's more common in older adults and can present with chronic diarrhea.
  • Small Intestine Bacterial Overgrowth (SIBO): While not always associated with inflammation, SIBO can lead to increased lactoferrin if there's an inflammatory component to the condition.

• Do Not Miss Diagnoses

  • Giardiasis: Caused by the Giardia lamblia parasite, this infection can lead to malabsorption and chronic diarrhea. It's crucial to diagnose and treat giardiasis promptly to prevent long-term complications.
  • Whipple's Disease: A rare, systemic bacterial infection caused by Tropheryma whipplei, which can lead to malabsorption, weight loss, and diarrhea. Early diagnosis is critical due to its potential for severe complications if left untreated.
  • Lymphoma: Although rare, gastrointestinal lymphoma can cause elevated lactoferrin due to intestinal inflammation and should be considered, especially in patients with systemic symptoms or those who do not respond to initial treatments.

• Rare Diagnoses

  • Eosinophilic Gastroenteritis: A condition characterized by eosinophilic infiltration of the gastrointestinal tract, leading to inflammation and potentially elevated lactoferrin.
  • Crohn's Disease Mimics: Such as sarcoidosis or Behçet's disease, which can cause gastrointestinal symptoms and inflammation similar to IBD but are distinct entities.
  • Autoimmune Enteropathy: A rare condition characterized by autoimmune-mediated damage to the small intestine, leading to severe diarrhea and malabsorption.