Title : Single step immunoblot tests with recombinant protein antigens for detecting IgG and IgM antibodies in Lyme disease
Abstract:
Detection of specific antibodies is important for diagnosing Lyme disease (LD). Until recently, this required two separate tests termed the standard two-tier tests (STTTs). The develop Detection of specific antibodies is important for diagnosing Lyme disease (LD). Until recently, this required two separate tests termed the standard two-tier tests (STTTs). The development of one-step immunoblot (IB) tests for detecting IgG and IgM antibodies in patient sera, termed iDartTM IgG and IgM IB tests, are described here. Recombinant proteins from several US and European Borrelia species and strains causing LD were applied as antigens in separate lines on nitrocellulose strips for the IB tests. IgG and IgM antibodies in patient sera reacting with protein antigens on the strips were then detected with specific anti-human IgG and anti-human IgM secondary antibodies, respectively. Specificity of the IB tests was established with sera from healthy persons living in LD-endemic and non-endemic areas, and persons with potentially confounding medical conditions and infections. Sensitivity of the tests was determined with LD patient sera from a US CDC test panel and a different collection of sera from US patients with acute-phase LD. The diagnostic performance of the iDart IgG and IgM IB tests was comparable to a US FDA-cleared STTT and better overall for detecting antibodies in early-stage LD. The iDart IgG IB test and a modified version of the iDart IgM described here have been approved by the US FDA for diagnostic use.
