Monitoring of serum neopterin in renal transplant recipients.

Postoperative management of kidney allograft recipients requires a reliable and rapid diagnostic method so that proper therapy can be initiated. In this study, we tried to correlate serum neopterin levels with different conditions after transplantation. Serial serum neopterin levels were assessed after operation. Serum neopterin levels of uremic patients were significantly higher than those of healthy persons (239.9 +/- 177.7 nmole/L, n = 33 vs 6.14 +/- 2.78 nmole/L, n = 10, p < 0.001). In recipients with a stable post-transplant course, the serum neopterin level was low. On the contrary, acute rejection episodes were associated with a high level of serum neopterin which declined after successful treatment, although the difference was not significant (96.2 +/- 57.7 nmole/L vs 56 +/- 38.1 nmole/L, p > 0.05). The serum neopterin level was also high in post-transplant acute tubular necrosis (ATN, 256.6 nmole/L), which gradually declined parallel to the resolution of ATN. The neopterin level was low in patients with cyclosporine nephrotoxicity (17.8 +/- 7.6 nmole/L). In summary, the serum neopterin levels were persistently high in uremic and post-transplant ATN patients. Acute rejection episodes were correlated with an increased level of neopterin. It appears that daily measurement of the serum neopterin level may be useful for biochemical detection of immunologic complications in allograft recipients.