[Monitoring of renal grafts. Value of the determination of serum neopterin and neopterin versus creatinine ratio].

In a longitudinal study, 53 renal allograft recipients were investigated for changes in serum creatinine and neopterin levels and in the neopterin/creatinine (N/C) ratio which makes it possible to disregard the glomerular filtration level. The patients were divided into 5 groups according to their clinical situation: stability, acute renal failure due to acute tubular necrosis, acute graft rejection, bacterial or viral infection and cyclosporin overdosage. Only N/C discriminated between these situations, being normal (less than 200.10(-6) in groups 1 and 2, significantly elevated in groups 3 and 4 and low in group 5. The highest N/C value was observed in patients with primary cytomegalovirus infection. It is concluded that the N/C ratio is a good biochemical parameter to be used in the follow-up of renal allograft recipients.