Plasma Brain Natriuretic Peptide, Serum Troponin T and Echocardiographic Evaluation in Children Treated with Doxorubicin^*.

Background: Doxorubicin (DOX) is one of the most effective agents in treatment of acute lymphoblastic leukaemia (ALL). However, a potential heart damage caused by DOX in patients who have been cured of ALL may lessen the success of their cure. Plasma brain natriuretic peptide levels and cardiac Troponin T are highly sensitive biochemical markers for myocardial damage.

Objectives of the study: We aimed to measure N-terminal proBNP (8–29) (Nt-proBNP) and serum Troponin T(cTnT) levels in 125 children (98 with ALL after completion of treatment with DOX and 27 healthy children). Median age at diagnosis was 5.5 years.

Methods used: Concentration of plasma N-terminal proBNP was measured in children by enzyme immunoassay (Biomedica). cTnT levels were measured by an electrochemiluminescence immunoassay process (Third generation) on the Elecsys 1010 System (Roche Diagnostic). Echocardiograms were performed by paediatric cardiologists. Using two-dimensional M-mode echocardiography shortening fraction (%SF) and ejection fraction (%EF) were determined as systolic function.

Results: The cumulative DOX doses were 240mg/m². None of the patients had clinical signs or symptoms of cardiotoxicity. All of the patients had normal systolic function parameters. Mean Nt-proBNP plasma levels were normal − 64 fmol/ml (10.3–597.3 fmol/ml) in all examined children. Mean Nt-proBNP both in ALL patients (63.8 fmol/ml) and in healthy (58.4 fmol/ml) were within the normal range. Out of the 98 patients 45 (46%) had slightly elevated Nt-proBNP levels in comparison with healthy subjects. Nt-proBNP plasma levels were not significantly different in boys (55.8 fmol/mL) in comparison with girls (56.3 fmol/mL. In all patients the serum levels of cTnT were below the detection limit (<0.010 ng/ml).

Conclusion: Our preliminary results suggest that measurement of Nt-proBNP plasma levels is useful in the detection of subclinical left ventricular dysfunction in children with ALL receiving DOX therapy.