The usefulness of scintigraphy with 99m Tc−Anti−Granulocyte antibody for diagnosis and follow−up in children with myocarditis

Abstract

Background and aim: The aim of this study was to investigate whether scintigraphy with ^99mTc-Anti-Granulocyte antibody is useful for diagnosis and follow-up in children with myocarditis, and to determine its correlation with endomyocardial biopsy (EMB) and clinical features.
Methods: A total of 11 children, mean age 13 years and presenting with symptoms of myocarditis, were evaluated at the time of initial presentation and 6, 12 and 24 months after the first study. In all patients, myocardial scintigraphy was performed with estimation of antigranulocyte antibody uptake. EMB was done in 10 patients at the time of initial presentation and in 8 patients after 6 months.
Results: In 10 (91%) patients, positive antigranulocyte uptake was observed, with EMB confirming myocarditis in 8 children. In scintigraphy after 6 months, positive uptake was found in 9 (82%) patients, with EMB performed in 8 patients showing persistent myocarditis; after 12 months, scintigraphy indicated positive uptake in 7 (64%), and after 24 months only in 4 (36%) patients.
Conclusions: 1. In 80% of patients with positive scintigraphy results, biopsy-proven myocarditis was observed. 2. The positive antigranulocyte uptake correlated with clinical features at diagnosis and in follow-up. 3. The control scintigraphy performed in follow-up after 6, 12, and 24 months allowed the evaluation of resolved or persistent myocarditis. 4. Myocardial scintigraphy results indicate that the inflammatory process in the myocardium decreases significantly after 12 months from the onset of the disease. 5. Scintigraphy with ^99mTc-Anti-Granulocyte antibody seems to be a useful diagnostic method in myocarditis, but further studies are needed to establish its sensitivity and specificity.