Histological Evaluation of Myocarditis

Heart tissue sections were fixed in 10% buffered formalin, dehydrated in absolute ethanol, cleared in xylene, and embedded in paraffin. Five-micron tissue sections were subjected to staining with hematoxylin and eosin (H&E) o at the Research Histopathology Core at the UTMB, and evaluated by light microscopy using an Olympus BX-15 microscope (Center Valley, PA) equipped with a digital camera and Simple PCI software (v.6.0; Compix, Sewickley, PA). Myocarditis (presence of inflammatory cells) in H&E stained tissue sections was scored as 0 (absent), 1 (focal/mild, ≤1 foci), 2 (moderate, ≥2 inflammatory foci), 3 (extensive coalescing of inflammatory foci or disseminated inflammation), and 4 (diffused inflammation, tissue necrosis, interstitial edema, and loss of integrity). Inflammatory infiltrates was characterized as diffused or focal depending upon how closely the inflammatory cells were associated [21 (link)].