Immunohistological studies on valvular vegetations in nonbacterial thrombotic endocarditis (NBTE).

Thrombi and thrombus formation in nonbacterial thrombotic endocarditis (NBTE) were studied using light microscopy and immunohistology. Samples from vegetations on cardiac valves were taken at autopsy from five patients with NBTE and adenocarcinoma as an underlying disease. Morphological studies disclosed proliferative changes underneath the thrombi. In immunofluorescence microscopy, focal deposits of immunoglobulins and complement components Clq and C3 were found. The results suggest that immune complexes, elicited by the underlying malignant process, may play important role in the pathogenesis of the thrombus formation in NBTE.