Increased number of eosinophils reported in patients pretreated with thymoglobulin or alemtuzumab
Lymphocytic cryptitis is not specific for rejection
Acute neutrophilic cryptitis suggests infection
Specific viral infections must be ruled out
Cytomegalovirus
Inclusions may be too small to be diagnostic on H&E stain
Immunohistologic stain may demonstrate specific inclusions
Background may range from lack of infiltrate to typical features of infectious enteritis
Adenovirus
More common in pediatric patients
Features may overlap with rejection
Inflammation, crypt apoptosis and regenerative epitihelia changes may be seen
Viral inclusions in surface enterocytes (smudge cells)
Immunohistologic stain may specifically identify the inclusions
Herpes simplex virus
Histologic findings may overlap
Identification of inclusions useful
Ground glass nuclei
Margination of chromatin
Immunohistologic staining is useful
Post-transplant lymphoproliferative disorder
Infiltrate of atypical large lymphocytes
CD20+
May form a mass lesion
Clinical
Signs and symptoms
Abdominal pain
Fever, nausea, vomiting
Increased stomal output
Septic shock if severe
Endoscopic findings
Edema, hyperemia
Granularity
Loss of fine mucosal vascular pattern
Mucosal ulceration
Bibliography
Wu T, Abu-Elmagd K, Bond G, Nalesnik MA, Randhawa P, Demetris AJ. A schema for histologic grading of small intestine allograft acute rejection. Transplantation. 2003 Apr 27;75(8):1241-8.
Ruiz P, Bagni A, Brown R, Cortina G, Harpaz N, Magid MS, Reyes J. Histological criteria for the identification of acute cellular rejection in human small bowel allografts: results of the pathology workshop at the VIII International Small Bowel Transplant Symposium. Transplant Proc. 2004 Mar;36(2):335-7.
Wu T, Bond G, Martin D, Nalesnik MA, Demetris AJ, Abu-Elmagd K. Histopathologic characteristics of human intestine allograft acute rejection in patients pretreated with thymoglobulin or alemtuzumab. Am J Gastroenterol. 2006 Jul;101(7):1617-24.
