Fate of recurrent acute interstitial cellular rejection in an HLA identical kidney transplant recipient: impact of donor microchimerism.

We and others have shown that the incidence of acute interstitial rejection in HLA identical and non-identical kidney transplantation is similar. Chronic vascular rejection is, however, rare in full matched recipients. In light of the known correlation between previous acute cellular and chronic vascular rejections, lack of chronic rejection in full matched kidney allografts suggest that the immunological basis of acute and chronic rejections are different and/or only high-grade acute cellular rejection leads to chronic vascular rejection. Herein, we present the case of an HLA identical kidney transplant from a male donor to a female recipient who, because of poor compliance, had frequent acute interstitial cellular rejection culminating into chronic interstitial fibrosis with no evidence of vasculopathy or glomerulopathy characteristic of chronic vascular rejection. Donor cells, as examined by the presence of the Y chromosome DNA, were present in the peripheral blood during the most recent acute rejection but not thereafter. These findings support the notion that acute interstitial cellular rejection can lead to interstitial fibrosis but not chronic vasculopathy/glomerulopathy, and that microchimerism did not confer protection against acute cellular rejection.