Introduction
Episodes of mild cellular rejection represent the majority of the acute rejection events in vascularized composite allotransplantation. Management of low grade rejection still represents a therapeutic challenge as an aggressive treatment can accelerate the occurrence of side effects of the systemic immunosuppressive therapy. In absence of clinical signs, the natural evolution of histologically diagnosed grade I rejection is not well understood.
Materials and Methods
A retrospective study was conducted on 8 patients who received 9 hand transplants between 1999 and 2012. Patients’ data concerning clinical course, immunosuppressive treatment, biopsy reports (Banff classification), high resolution ultrasound biomicroscopy were reviewed. The outcomes of the different treatments in the first year post-transplant were compared to the outcomes in the subsequent years with a Fisher's exact test.
Results
Three hundred and 10 biopsies were reviewed (147 grade 0, 118 grade I, 33 grade II and 12 grade III). When clinical and pathological criteria were combined a total of 141 rejection episodes were identified. Forty 8 episodes were considered grade I− and 24 episodes were grade I+ where (+) indicates presence and (−) indicates the absence of clinical signs of rejection. When treated conservatively (observation or topical immunosuppressants) 63% of grade I− episodes resolved in the first year as opposed to 100% in the subsequent years (p = 0.005). Eighty 4 percent of grade I+ episodes resolved in the first year with a conservative approach as opposed to 100% in the subsequent years (p = 1). All of I+ episodes presenting with less than 10% involvement resolved. There was no statistical difference between the outcome of the conservative management in I+ versus I−.
Conclusions
Grade I rejection events, when the through levels of the maintenance immunosuppressants are adequate, could be safely observed or treated with topical immunosuppressants, after the first year post-transplant. In the first year post transplantation, a conservative approach can be justified for grade I+ episodes if the rejection is clinically mild (<10 %).