Histological findings of striated muscle biopsies from patients with endomyocardial fibrosis in Mulago Hospital: A pilot study
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Introduction: Endomyocardial fibrosis (EMF) is globally rare, but is commonly seen in some countries like Uganda, India, Nigeria and Mozambique. It is strongly associated with poverty, dietary deficiencies, certain ethnicities and blood eosinophilia. Echocardiography is currently the diagnostic tool of choice and is closely associated to the gold standard – autopsy. In a recent study on peritoneal biopsies, two specimens serendipitously sampled abdominal wall striated muscle, both of which revealed muscle fibrosis on histology. Objective: This was to describe histological changes in striated skeletal muscle biopsies in EMF patients and to compare these changes with type of EMF, clinical and hematological features of EMF. This was a cross sectional explorative study to describe the histology of skeletal muscle taken from the medial head of gastrocnemius and short head of biceps. It was conducted at Mulago hospital cardiology unit, Uganda Heart Institute and Medical out patient department- cardiac clinic between September 2009 and December 2009. All patients with an echocardiographic diagnosis of EMF meeting the selection criteria were consecutively recruited. Using a standardised questionnaire, data on clinical variables was collected. Blood was examined for eosinophilia. Muscle was biopsed from the gastrocnemius and biceps and examined for histological changes using haematoxylin and eosin stain for muscle pathology and Masson’s trichrome staining technique for demonstration of fibrosis. The proportion of patients with EMF having striated muscle changes was determined. Results: Social demographic characteristics of the 25 patients with EMF enrolled were similar to those previously seen. There were twice as many females as males most of them in early adulthood. The main symptoms of patients at presentation were easy fatigability, abdominal swelling and gross ascitis. Eosinophilia long thought to have an association with EMF was observed in 26% of patients in agreement with findings from earlier studies. 13,20,22,23. Major histological changes observed were muscle atrophy seen in 24(96%) of participants, muscle fibrosis occurred in 23(92%) participants while degenerative muscle changes occurred in 15(60%). Although a small number of patients were seen, there was no correlation between striated muscle changes and age, sex or the various clinical, haematological parameters studied except pedal oedema (P. value 0.001). Conclusion: Striated muscle fibrosis, atrophy and degenerative muscle changes were the predominant striated muscle changes observed in the EMF patients studied. Striated muscle involvement appears to be patchy in the majority of patients. There appears to be no correlation between EMF type and striated muscle fibrosis. Eosinophilia seems to play a role in tissue pathology in the EMF patients seen in this study. With this evidence showing skeletal muscle fibrosis, atrophy and degenerative muscle changes together with previous evidence of peritoneal involvement in EMF patients, it is probable that EMF maybe a systemic disease rather than a disease restricted to the heart.