Amebic Colitis in a Post Liver Transplant Patient

Abstract

A 63-year-old Hispanic male, presented with two week history of blood tinged diarrhea, abdominal cramping, and decreased appetite. He had been discharged from the hospital one month prior for liver transplant for hepatocellular carcinoma. Prior to the transplant he had visited Mexico where he ate an unrestricted diet including seafood and pork. He also had contact with roosters, chicken, pigeon, cats, goats and horses. He was on immunosuppressive agents, Tacrolimus, with a normal level of 17.6 ng/mL and Prednisone with Valganciclovir, Clotrimazole and Trimethoprim Sulfamethoxazole. He was admitted and managed with intravenous fluid and electrolyte resuscitation. Stool studies were negative for Clostridium difficile, Shiga Toxin 1 and 2, Salmonella, Shigella, Campylobacter, E.coli 0157 and ova and parasites. He was referred for colonoscopy which demonstrated the presence of non-hemorrhagic ulcers throughout the colon starting from the rectum and ending in the cecum (Figure 1). There was no active bleeding and there were patchy areas of normal appearing mucosa. Multiple biopsies were taken from the bases and the edges of the ulcers and of normal mucosa.Figure 1Histological exam of biopsies (Figure 2) showed benign colonic mucosa with ulceration, and granulation tissue with accompanying necroinflammtory debris. Scattered among the mucosa, were amebic organisms consistent with Entamoeba histolytica showing foamy cytoplasm with ingested red blood cells and eccentric nucleus. Entamoeba antibody titer was found to be positive, and further work up including Toxoplasmosis IgG and IgM, Cysticercosis Trypanosoma Cruzi, Brucella and Bartonella antibody titer were negative. Patient was treated and subsequently discharged on Metronidazole, for the duration of six weeks. No changes were made to the immunosuppression therapy.Figure 2In 1875, Losch first described the trophozites of Ameba coli in the feces of a Russian woodcutter with fatal diarrhea. Acquired via the oral-fecal, oral-anal and oral-genital routes, this parasite was named E.Histolytica for its ability to lyse tissues. Though not seen in our patient, amebic liver abscess is the most common manifestation of invasive amebiasis. Other organs can also be involved, including pleuropulmonary, cardiac, cerebral, renal, genitourinary, peritoneal, and cutaneous sites. Intestinal amebic infections are relatively rare in the Unites States. For individuals infected with a single GI parasite, E. histolytica accounts for 1% of cases. This case confirms that prior travel to endemic areas is a significant risk factor for intestinal parasitic infections. This case also highlights the importance of a thorough dietary, travel and exposure history, prior to and after starting immunosuppression in an organ transplant recipient.