Comparison of four Mycoplasma pneumoniae IgM-, IgG- and IgA-specific enzyme immunoassays in blood donors and patients.

Mycoplasma pneumoniae antibodies were studied in 504 blood donors and 102 patients with infections not caused by M. pneumoniae with the use of enzyme immunoassay kits from ThermoLabsystems (L), Savyon (S), Bio-Rad (B) and Novitec (N). Detection frequencies of M. pneumoniae IgM in blood donors were 14.9% (L), 16.0% (S), 2.8% (B) and 3.8% (N), and in patients were 40.2% (L), 42.2% (S), 9.8% (B) and 16.7% (N). Detection frequencies of M. pneumoniae IgA were 68.5% (L) and 22.8% (S), and in 65 respiratory disease patients were 100% (L) and 53.8% (S). Thus, use of some kits may lead to overdiagnosis of M. pneumoniae infections.