Concordance of four commercial enzyme immunoassay and three immunoblot formats for the detection of Lyme borreliosis antibodies in human serum: the two-tier approach remains

Abstract

Serological tests show considerable variation in their ability to correctly diagnose Lyme borreliosis (LB). This study compared four commercially available screening enzyme immunoassays (EIA) for the detection of LB IgG using either whole cell lysate (WCL) antigens, purified proteins or recombinant antigens with the second-tier whole cell sonicate (WCS) western immunoblots or recombinant antigen line blots. A consensus between three EIA results from 222 patient sera was designated as a point of comparison for each method which gave 66 positive and 156 negative results. The positive predictive values (PPV) of WCL EIA were 40% for the MarDx Diagnostics Borrelia burgdorferi EIA 'combined' IgG and IgM (Trinity Biotech) and 55% for the EUROIMMUN plus VlsE IgG. These were significantly lower PPVs than that produced by the recombinant antigen-based EIA NovaLisa Borrelia burgdorferi IgG-ELISA (NovaTec Immunodiagnostica) and the EUROIMMUN Anti-Borrelia Select ELISA IgG (90% and 100%, respectively; p = 0.02). The WCS western immunoblot using B. burgdorferi and B. afzelii separately showed a high PPV of 91% but its positive agreement with consensus EIA result was only 65%. Another WCL western immunoblot with purified extracts of Osp C and VlsE, the Trinity Biotech EU Lyme + VlsE IgG Western Blot had a PPV of 92% while the recombinant line blot from EUROIMMUN, the Anti-Borrelia (IgG) EUROLINE-RN-AT, demonstrated a significantly reduced PPV of 70% with some non-specific reactions in sera containing antibodies to Leptospira species, Helicobacter pylori and Treponema pallidum. The use of recombinant antigens in EIA for LB IgG screening significantly improves the predictive values of serological results above those of WCL antigen EIA. Second tier WCS western immunoblots offer high PPVs, especially with added specific purified proteins, more so than in one recombinant line blot.

Keywords: Borrelia burgdorferi; Lyme disease; laboratory diagnosis; serology.