ETIOLOGY AND OUTCOME OF DIARRHEA AFTER MARROW TRANSPLANTATION - A PROSPECTIVE-STUDY

Background/Aims: Acute diarrhea after marrow transplant is usually asc ribed to acute graft-vs.-host disease (GVHD) or infection, with a repo rted 40%-50% incidence of infection. The aim of this study was to dete rmine the incidence of acute diarrhea after transplantation, its cause s, and its outcome. Methods: Two hundred ninety-six patients were foll owed up; patients with diarrhea were studied using standard evaluation of stool plus immunoelectron microscopy; assays for astrovirus, picob irnavirus, and Norwalk virus; and gene-probe methods for toxin-produci ng Escherichia coli. In 38 patients with diarrhea, intestinal biopsy s pecimens and duodenal fluid were also analyzed. Results: One hundred f ifty acute diarrheal episodes developed in 126 patients (an incidence of 43%). Intestinal infection was found in 20 of 150 episodes: viruses (astrovirus, adenovirus, cytomegalovirus, and rotavirus) in 12 patien ts, nosocomially acquired bacteria (Clostridium difficile and Aeromona s) in 7 patients, and mixed infection in 1 patient. Acute GVHD was res ponsible for 72 of 150 episodes (48%). Clinical signs and symptoms of infection and GVHD were similar. In 58 of 150 episodes (39%), no clear etiology could be found for self-limited diarrhea. Conclusions: Intes tinal infection accounted for 13% and acute GVHD for 48% of diarrheal episodes. The most common infecting organisms were astrovirus, C. diff icile, and adenovirus. Most cases of diarrhea after marrow transplant are not caused by infection.