C3a, TNF-α and interleukin myocardial expression in a case of fatal sudden cardiac failure during clinic reactivation of systemic lupus erythematosus

Isolated myocarditis, or dilated cardiomyopathy, is a rare and usually late clinical manifestation of systemic lupus erythematosus (SLE). Increased levels of complement split products are associated with disease activity. Injury of the vascular endothelium due to complement activation and immune complexes may contribute to the vasculopathy in SLE. We present a case of sudden cardiac failure and death in a 28-year-old Caucasian man, during reactivation of SLE. To explain the sudden cardiac failure, we looked for anti-tumour necrosis factor (TNF)- proportional, variant and anti-interleukin (IL) expression in cardiac cells, and anti-complement (anti-C)3a in small cardiac vessels. The immunohistochemical examination of heart specimens revealed a strong positive reaction in cardiac myocytes for antibodies anti-TNF- proportional, variant and IL-8, and a milder positive reaction for antibodies anti-IL-15 and IL-10. A strong positive reaction of C3a in small cardiac vessels was observed in all specimens. Furthermore, the expression of CD4 and CD8 showed a strong positive reaction in pericardium and valvular endocardium, and a lesser positivity in myocardial specimens. TNF appears to have played a major proinflammatory role in this fatal case.