Acute rejection episodes (ARE) are a major determinant of renal allograft survival. The incorporation of new immunosuppressive agents explains the improvement of the transplantation results in the last four decades. The objectives of this study are to analyse the incidence and severity of ARE, their risk factors and their influence on graft and patient survival. It's a retrospective study of 280 kidney transplants performed in adults during the period 1984, 2004. The diagnosis of ARE was based on the clinical and the analytical data, the intention to treat and the response to treatment. Renal biopsies were performed only in 10 cases. The treatment of ARE consisted of pulses Methylprednisolone and ATG or OKT3. Recipients were 186 males (66.4%) and 94 females (33.6%), their mean age was 31±8.9 years. The mean incidence of ARE was 40.4%. This incidence was > 45% between 1986 and 1997, decreased to 20.5% between 1998 and 2000 and to 9% between 2001 and 2003.

				ARE		P
Donors		Brain death		30.4%		NS
		Living		42.3%
Sensitized		YES		15.2%		<0.0001
Cross Match		NO		57.2%
MMF		YES		22.8%		<0.0001
		NO		52.4%

The late graft survival was better in patients without ARE. Graft survival rates at 1-3-5 and 10 years were 98%- 93%- 90%- 83% and 98%- 91%- 82%- 73% respectively in patients without ARE and patients with ARE. We found a decrease in the incidence of ARE in the last decade in adult renal transplants. This is related to the introduction of sensitized cross match and the new immunosuppressive agents particularly MMF. In the other hand, ARE had a deleterious impact in late graft survival in our population.