Novel Case Report: A Previously Reported, but Pathophysiologically Unexplained, Association Between Collagenous Colitis and Protein-Losing Enteropathy May Be Explained by an Undetected Link with Collagenous Duodenitis

• Published in: Digestive diseases and sciences 2021-12, Vol.66 (12), p.4557-4564
• Main Authors: Gill, Inayat, Shaheen, Aciel Ahmed, Edhi, Ahmed Iqbal, Amin, Mitual, Rana, Ketan, Cappell, Mitchell S.
• Format: Article
• Language: English
• Subjects: Aged; Amino Acids - metabolism; Biochemistry; Case Report; Case reports; Colitis; Colitis, Collagenous - complications; Colitis, Collagenous - diagnosis; Colitis, Collagenous - physiopathology; Colitis, Collagenous - therapy; Collagen; Coronaviruses; COVID-19; COVID-19 - diagnosis; COVID-19 - etiology; COVID-19 - physiopathology; COVID-19 Drug Treatment; Diarrhea; Duodenitis - complications; Duodenitis - diagnosis; Duodenitis - physiopathology; Duodenitis - therapy; Duodenum - metabolism; Duodenum - physiopathology; Electrolytes; Female; Fluid Therapy; Gastroenterology; Glucocorticoids - therapeutic use; Health aspects; Hepatology; Humans; Infections; Inflammatory bowel disease; Internal medicine; Intestinal Absorption; Intestinal Mucosa - metabolism; Intestinal Mucosa - physiopathology; Malnutrition; Medicine; Medicine & Public Health; Nutritional Status; Oncology; Parenteral Nutrition, Total; Protein-Losing Enteropathies - diagnosis; Protein-Losing Enteropathies - etiology; Protein-Losing Enteropathies - physiopathology; Protein-Losing Enteropathies - therapy; Proteins; Risk Factors; Severe acute respiratory syndrome coronavirus 2; Transplant Surgery; Treatment Outcome
• ISSN: 0163-2116; 1573-2568
• DOI: 10.1007/s10620-020-06804-3

Collagenous colitis (CC) is associated with non-bloody, watery diarrhea, which is pathophysiologically reasonable because normal colonic absorption (or excretion) of water and electrolytes can be blocked by the abnormally thick collagen layer in CC. However, CC has also been associated with six previous cases of protein-losing enteropathy (PLE), with no pathophysiologic explanation. The colon does not normally absorb (or excrete) amino acids/proteins, which is primarily the function of the small bowel. Collagenous duodenitis (CD) has not been associated with PLE. This work reports a novel case of CD (and CC) associated with PLE; a pathophysiologically reasonable mechanism for CD causing PLE (by the thick collagen layer of CD blocking normal intestinal amino acid absorption); and a novel association of PLE with severe COVID-19 infection (attributed to relative immunosuppression from hypoproteinemia, hypoalbuminemia, hypogammaglobulinemia, and malnutrition from PLE).