**6. Histological tolerance of the intestinal allograft**

Finally, we reviewed a case of histological tolerance reported [25]. This case involves a transplant in a 4-year-old male patient who had short bowel syndrome

**95**

**7. Conclusion**

**Figure 5.**

**Appendices and nomenclature**

ACR acute cellular rejection CMV cytomegalovirus CRP C-reactive protein CTL cytotoxic T lymphocyte EBV Epstein–Barr virus

*Pathology of Intestinal Transplantation: Rejection and a Case of Tolerance*

and previously underwent a living small bowel transplant from his mother who was in her twenties. The patient underwent a small intestinal biopsy 2–3 times per week for one month. Immunological analysis was performed using CD3, CD4, CD8, CD20, CD56, CD79a, perforin, granzyme B, FasL, Fas, and TUNEL staining. No severe rejection with an increase in FasL-positive T cells was detected. The maximum level of CRP, an inflammation marker, was 1.0 (mg/10−1 L) at POD67. In situ hybridization was performed using a Y-chromosome probe to evaluate rejection or tolerance for evaluation of the immunologic stability of the graft and chimerization [36], which comprises multiplex staining with a CD3 fluorescent substance, for monitoring allografts. **Figure 5** shows photographs of the graft 5 years after transplantation. A part of native T lymphocytes were replaced with Y-chromosome positive T lymphocytes from a male patient. This patient has been living for longer than ten years without any clinical symptoms, such as rejection, and is likely one of

Early diagnosis of rejection of the transplanted small intestine is essential to facilitate the initiation of therapy that interferes with rejection progression. In addition to crypt apoptosis, apoptotic bodies in the lamina propria is considered useful for diagnosis. Furthermore, iNKT cell infiltration was another characteristic finding. Since histologic features of ACR have been studied extensively. Of note in

*Combined in situ hybridization of lymphocytes with the Y-chromosome probe (red: PE) and CD3-lymphocytic immunohistochemistry (green: FITC). The photos show the double-stained T cells carrying the Y-chromosomal investigation, indicating the male-donor derived lymphocytes in the female-derived intestinal allograft. Left* 

future diagnoses are the issues of humoral and chronic rejection.

*(100×) and right (400×). The nuclei were stained red, indicating Y-chromosome positivity.*

*DOI: http://dx.doi.org/10.5772/intechopen.94361*

the first cases of operational tolerance.
