Significance of pathological parameters of endomyocardial biopsy in clinical outcome of patients of dilated cardiomyopathy--II. Value of cardiac immune complexes and heart reactive antibodies.

We have evaluated the status of cardiac immune complexes and heart reactive antibodies in endomyocardial biopsies (EMB) and patients' sera from cases of dilated cardiomyopathy (DCM) using immunofluorescence. This was done with an aim to test whether this parameter can be of diagnostic and/or prognostic value in cases of DCM in its inflammatory and non inflammatory stages. Deposition of IgG was consistently observed in all cases of DCM regardless of the presence or absence of inflammation. Complement was detected in only a few while IgG and C3 together was seen to be deposited in only 4 cases. IgA and IgM were noted in an occasional case only. Heart reactive antibodies were seen in 13 of the 23 cases of DCM. Light microscopically, in 7 of the 23 biopsies mild focal lymphocytic myocarditis was detected. Presence of IgG in EMB and a low left ventricular ejection fraction (LVEF 35%) in almost all the cases, highlight the prognostic significance of IgG (in EMB) as an independent parameter. Based on this small study, it is difficult to attach significance to these observations as regards predicting the outcome of these patients. Nevertheless, the present study initiates evaluation of one of the parameters which is accessible and can be easily carried out in most routine laboratories for diagnosis, prognosis, and eventually monitoring of therapy in patients of DCM. Importance of immunofluorescence technique can be further strengthened by evaluating a larger number of cases with varying duration of symptoms and a follow up study of cases of DCM.