Evaluation of the usefulness of the ELISA method for detection of enterovirus antibodies in serum samples of patients with myocarditis.
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 enteroviruses that can cause myocarditis, and to the serological cross reactions among them. The goal of our research was to determine the usability of the ELISA test and the complement fixation reaction (CFR) in diagnostic testing of the serum of patients with myocarditis.


METHODS
The research material consisted of 117 serum samples collected from patients with myocarditis. In all these samples we measured the concentration of IgG and IgM enterovirus antibodies using the ELISA method, and the height of the titer using the CFR method.


RESULTS
The presence of IgM antibodies is a confirmation of current infection. A positive result was obtained for 61% of the patients. On the other hand, if one accepts as confirmation of infection a titer significantly different from the level observed in the healthy population, namely > or =16 for CFR 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 titer nor the concentration of IgG antibodies constitutes a clear confirmation of infection, if the criterion of evaluation is based on a measure in a single serum sample. In this case it is necessary to test for a significant increase in the titer. The use of the average titer for the population at large to evaluate results leads to both false positives and false negatives. Testing for IgM antibodies in a single serum sample is a faster method which confirms the current presence of infection. Our results indicate that the ELISA test can be used to diagnose myocarditis, since it is more sensitive and faster than CFR, and allows for the differentiation of antibody classes.
Wielkopolska
Anna
A
Department of Virusology, Institute of Public Hygiene, Warsaw, Poland.
Gut
Włodzimierz
W
Binduga-Gajewska
Iwona
I
Jarzabek
Zdzisław
Z
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000906:Antibodies / Q000097:blood*; D002624:Chemistry, Clinical / Q000379:methods; D004770:Enterovirus / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D008875:Middle Aged; D009205:Myocarditis / Q000097:blood* / Q000276:immunology*
D000906:Antibodies; D007074:Immunoglobulin G; D007075:Immunoglobulin M