BACKGROUND: Enteroviruses are among the etiological factors in myocarditis.In the majority of cases it is impossible to obtain a direct confirmation of the presence of the virus,and typologically specific methods are of limited applicability, due both to the number of enterovirusesthat can cause myocarditis, and to the serological cross reactions among them. The goal of our researchwas to determine the usability of the ELISA test and the complement fixation reaction (CFR) in diagnostictesting of the serum of patients with myocarditis. MATERIAL/METHODS: The research material consistedof 117 serum samples collected from patients with myocarditis. In all these samples we measured the concentrationof IgG and IgM enterovirus antibodies using the ELISA method, and the height of the titer using the CFRmethod. RESULTS: The presence of IgM antibodies is a confirmation of current infection. A positive resultwas obtained for 61% of the patients. On the other hand, if one accepts as confirmation of infectiona titer significantly different from the level observed in the healthy population, namely > or =16 forCFR and > or =11 for ELISA-IgG (cf. positive results of 33% for CFR and 18.8% for ELISA IgG in our patients),the results may be disproportional. If one assumes as a test criterion a significant increase in titer,the presence of infection was confirmed in 28.5% of cases for CFR and 62% for ELISA-IgG. CONCLUSIONS:An analysis of the results obtained here justify the conclusion that neither the height of the CFR titernor the concentration of IgG antibodies constitutes a clear confirmation of infection, if the criterionof evaluation is based on a measure in a single serum sample. In this case it is necessary to test fora significant increase in the titer. The use of the average titer for the population at large to evaluateresults leads to both false positives and false negatives. Testing for IgM antibodies in a single serumsample is a faster method which confirms the current presence of infection. Our results indicate thatthe ELISA test can be used to diagnose myocarditis, since it is more sensitive and faster than CFR, andallows for the differentiation of antibody classes.

Keywords: Adolescent, Antibodies, Chemistry, Clinical, Enterovirus, Enzyme-Linked Immunosorbent Assay, Immunoglobulin G, Immunoglobulin M, myocarditis