PT  - JOURNAL ARTICLE
AU  - Takeda, Atsuhito
AU  - Murayama, Kei
AU  - Okazaki, Yasushi
AU  - Imai-Okazaki, Atsuko
AU  - Ohtake, Akira
AU  - Takakuwa, Emi
AU  - Yamazawa, Hirokuni
AU  - Izumi, Gaku
AU  - Abe, Jiro
AU  - Nagai, Ayako
AU  - Taniguchi, Kota
AU  - Sasaki, Daisuke
AU  - Tsujioka, Takao
AU  - Basgen, John M
TI  - Advanced pathological study for definite diagnosis of mitochondrial cardiomyopathy
AID  - 10.1136/jclinpath-2020-206801
DP  - 2021 Jun 01
TA  - Journal of Clinical Pathology
PG  - 365--371
VI  - 74
IP  - 6
4099  - http://jcp.bmj.com/content/74/6/365.short
4100  - http://jcp.bmj.com/content/74/6/365.full
SO  - J Clin Pathol2021 Jun 01; 74
AB  - Aims Mitochondrial cardiomyopathy (MCM) is difficult to make a definite diagnosis because of various cardiovascular phenotypes and no diagnostic criteria in the pathology examination. We aim to add myocardial pathology to the diagnostic criteria for mitochondrial respiratory chain disorders.Methods Quantitative analysis of mitochondria using electron microscopy and immunohistopathological analysis with respiratory chain enzyme antibodies were performed in 11 patients with hypertrophic or restrictive cardiomyopathy who underwent endomyocardial biopsy for possible MCM . Respiratory chain enzymatic assay in biopsied myocardium and genetic studies were also performed in all the subjects to define MCM.Results Four patients were diagnosed with MCM according to the recent criteria of mitochondrial respiratory chain disorders. Using electron microscopy with quantitative analysis, the volume density of mitochondria within cardiac muscle cells was significantly increased in the MCM group compared with the non-MCM group (p=0.007). Immunohistopathological results were compatible with the result of the respiratory chain enzymatic assay.Conclusions Pathological diagnosis of MCM could be confirmed by a quantitative study of electron microscopy and immunohistopathological analysis using the mitochondrial respiratory chain enzyme subunit antibody.Data are available in a public, open access repository. The data that support the findings of this study are available from the corresponding author on reasonable request.