Cystatin C and Neutrophil Gelatinase-associated Lipocalin As Markers of Renal Function in Pediatric Heart Transplant Recipients

We hypothesized that use of Schwartz formula underestimates the prevalence of CKD in PHT recipients. This study determined the prevalence and risk factors for CKD in PHT using novel methods-serum cystatin C, CKiD formula, Revised Schwartz formula, s- and u-NGAL. Serum BUN, creatinine, cystatin C and s- and u-NGAL were measured after prospective enrollment. Schwartz formula GFR was compared with novel methods. CKD was defined as CKiD GFR < 90 mL/min/1.73 m(2) . The s- and u-NGAL were compared between those with and without CKD. Potential risk factors for CKD were analyzed. Seventy-nine patients (46 male children or boys), mean age 9.9 ± 5.8 yr formed the study cohort. The prevalence of mild and moderate CKD was 2- to 3-fold higher using novel methods compared to Schwartz formula. u-NGAL and u-NGAL/Cr were significantly higher in patients with CKD. u- and s-NGAL had negative correlation with estimates of GFR. Women were at a higher risk for CKD (odds ratio 8.7) as was longer duration since transplant (p = 0.009). In conclusion, use of novel methods of GFR estimation unmasked 2- to 3-fold increased prevalence of CKD in PHT. Women and those with longer duration since transplant are at higher risk for CKD.