Clinical significance of preexisting microcalcification in the iliac artery in renal transplant recipients.

BACKGROUND: The clinical significance of preexisting microcalcification in the iliac artery is undetermined in renal transplant recipients.

METHODS: We obtained iliac artery segments from 90 transplant recipients at the time of renal transplantation and performed von Kossa staining for microcalcification. The clinical significance of intimal microcalcification was evaluated with allograft survival rate, rate of graft function decline, and composite of any cardiovascular event or patient death. Expression of fetuin-A and C-reactive protein, key regulators of calcification, was also investigated in the iliac artery.

RESULTS: Intimal microcalcification was positive in 48 (53.3%) patients, and its intensity was correlated positively with intimal C-reactive protein intensity (P = 0.019). Allograft survival in patients positive for intimal microcalcification was lower than patients who were negative (P = 0.017). The patients with positivity for both intimal microcalcification and fetuin-A showed lower allograft survival rate than patients with intimal microcalcification positivity alone (P = 0.012). The rate of renal graft function decline was significantly steeper in patients positive for intimal microcalcification than in patients who were negative (P = 0.036). In multivariate analysis, positivity for both intimal microcalcification and fetuin-A was an independent predictor for renal graft function decline (β = -10.21; P = 0.011). The intimal microcalcification was not associated with composite-event free survival.

CONCLUSION: Preexisting intimal microcalcification in the iliac artery predicts a lower allograft survival rate and rapid decline of allograft function. Positivity of fetuin-A with intimal microcalcification further reduces allograft survival rate and an independent predictor for renal graft function decline.