Evaluation of desmin activity using immunohistochemical and immunofluorescent staining of myocardial biopsies in patients with chronic heart failure. Comparison of the two methods.

BACKGROUND Desmin plays one of the key roles in cardiomyocytes. The protein protects the integration of the cell and has the following actions: mechanical, structural and regulatory. Observed abnormalities of its activity have been associated with worsening of heart failure (HF). AIM Evaluation of desmin activity detected with immunohistochemical (IHC) and immunofluorescent (IF) staining in cardiomyocytes in patients with chronic HF. METHODS The study population comprised 37 patients (mean age 46.5+/-15.28 years, 83.8% males) with diagnosed HF of unknown aetiology, who underwent myocardial biopsy. Coronary angiography was performed to exclude presence of significant coronary artery disease. Heart failure was diagnosed based on clinical assessment and echocardiography showing left ventricular ejection fraction below 45%. RESULTS The IHC and IF evaluation of cardiomyocyte desmin showed that these methods were consistent with respect to classification of 31 specimens (83.8%), while being discrepant in 6 (16.2%) cases. Desmin detection in myocardial biopsy specimens with IHC staining showed normal amounts of this protein in 11 (29.8%) cases, excess in 18 (48.6%) patients and deficiency in 8 (21.6%) cases, whereas in IF stained specimens respective values were 12 (32.4%), 15 (40.6%) and 10 (27%). No significant differences were found between all desmin groups (i.e. normal level, excessive and deficiency) evaluated with IHC and IF staining (p=0.39; p=0.25; p=0.31, respectively). CONCLUSIONS The IHC and IF methods allow evaluation of desmin activity in cardiomyocytes and division into three types of expression. Both methods have high consistency. The IHC, which is the more available method, seems to be a sufficient assay.