Background: Kidney injury represents a major clinical problem in OHT patients, which seriously raises their mortality rate. The aim of this work was evaluation of the usefulness of a new marker of kidney damage - NGAL, and correlations of serum NGAL with cystatin C, creatinine and GFR in patients  after heart and lung transplantation.
Material/Methods: The serum samples from 71 patients after heart transplantation, 7 patients after lung transplantation and 20 healthy controls were examined. Serum NGAL was measured using ELISA method, cystatin C - using latex immunonefelometry (Siemens), creatinine - with the use of alkaline-picrate method (Cobas Integra, Roche).
Results: Serum NGAL level was significantly elevated in transplant patients, but we did not find a significant correlation between serum NGAL and cystatin C (R=0.1315; p=0.1162 in transplant group; R=0.2627; p=0.2629 in control group), GFR and NGAL (R=-0.0964; p=0.2505 in transplant group and R=0.2176; p=0.3567 in controls). Serum NGAL significantly and positively correlated with serum creatinine (R=0.2670 p=0.0013) in transplant group.
Conclusions: In our group of patients plasma NGAL is not a good biomarker for monitoring of chronic renal disorders.

Keywords: Heart Transplantation, Lung Transplantation