Pregnancy-Associated Plasma Protein-A: Evaluation of a New Biomarker in Renal Transplant Patients

ObjectiveTrophoblasts produce high concentrations of pregnancy-associated plasma protein-A (PAPP-A) during pregnancy. PAPP-A has been described as a new inflammatory marker and an independent risk factor for posttransplant cardiovascular risk. This study evaluated the clinical significance of PAPP-A in renal transplant patients.MethodsThe study included 78 adult renal transplant patients (56 men and 22 women) and 37 control subjects (27 men and 10 women). We determined serum PAPP-A, urea, creatinine, uric acid, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglyceride, 24-hour proteinuria, and C-reactive protein (CRP) levels.ResultsThe PAPP-A level was significantly higher among renal transplant patients [median (interquartile range), 10.5 (6.4 to 15.4) mU/L] than the control group [3.9 (3.1 to 5.2) mU/L; P < .001]. There were significant positive correlations between serum PAPP-A levels and urea (r = .547, P = .001), creatinine (r = .497, P = .001), uric acid (r = .452, P = .001), and CRP values (r = .387, P = .001). The drugs used for immunosuppression in transplant patients (cyclosporine, tacrolimus, and others) did not significantly affect serum PAPP-A levels (P > .05).ConclusionWe concluded that PAPP-A level was elevated in renal transplant patients and that high levels of PAPP-A might be a prognostic marker owing to their close association with high serum levels of urea, creatinine, uric acid, and CRP.