Author + information
- Received June 5, 1989
- Revision received September 19, 1989
- Accepted October 9, 1989
- Published online March 1, 1990.
- Ahvie Herskowitz, MD∗∗,†,
- Aftab Ahmed-ansari, PhD§,
- David A. Neumann, PhD†,
- William E. Beschorner, MD‡,
- Noel R. Rose, MD, PhD∗,†,
- Lisa M. Soule, MA†,
- C. Lynne Burek, PhD∗,
- Kenneth W. Sell, MD, PhD§ and
- Kenneth L. Baughman, MD, FACC†
- ↵∗Address for reprints: Ahvie Herskowitz, MD, Cardiology Division, The Johns Hopkins Hospital, 600 North Wolfe Street, Carnegie 568, Baltimore, Maryland 21205.
The histologic diagnosis of active myocarditis is frequently difficult to establish. A nonhistologic marker of immune activation would be clinically useful in identifying cases of immune-mediated myocarditis. A viral etiology with subsequent autoimmunity to cardiac antigens has been implicated in human myocarditis. Because autoimmunity and viral disease are commonly associated with increased expression of major histocompatibility complex (MHC) antigens on targeted tissue, we examined endomyocardial biopsy samples from patients with active myocarditis for abnormal levels of MHC antigen expression. Thirteen patients with active myocarditis and eight control patients with other well-defined cardiac diagnoses (coronary disease, amyloidosis or neoplasm) were studied.
A sensitive radioimmunoassay was developed that utilized monoclonal antibodies to human MHC class I and class II antigens in order to quantitate the expression of both of these antigens within each biopsy. Abnormal MHC class I and class II antigen expression was present in 11 of 13 myocarditis specimens and 1 of 8 control samples (specificity 88%, sensitivity 84.6%). Active myocarditis samples had approximately a 10-fold increase in MHC class I and class II expression. Immunoperoxidase staining localized abnormal MHC expression primarily within microvascular endothelium and along myocyte surfaces (11 of 13).
This study is the first to demonstrate a marked increase in major histocompatibility complex antigen expression within the myocardium of patients with active myocarditis. The identification of abnormal histocompatibility antigen expression within an endomyocardial biopsy may prove a useful adjunct to the histologic diagnosis of myocarditis.
☆ This work was supported by Public Health Service Grants 5T32-HLO7227 and ROI-A125566-01 from the National Institutes of Health, Bethesda, Maryland. Computational assistance was received from CLINFO, sponsored by National Institutes of Health Grant RR-00035.
- Received June 5, 1989.
- Revision received September 19, 1989.
- Accepted October 9, 1989.