To our knowledge, up until now no one has succeeded in making OspC (25kDa) - the IgM reactive antigen that is particularly important for the detection of a fresh Borrelia infection - in recombinant form in the quality needed for diagnostics. Expression systems are not (yet) capable of generating OspC epitopes in the same way as cultured Borrelia. Attempts have been made to increase the low sensitivity of recombinant OspC by applying more antigen, but this just leads to an unacceptable loss in specificity: every fifth blood donor reacts positively in blot tests - with the result that clinicians generally turn a blind eye regarding these bands and only count strong reactions. But many true positive reactions fall through, for whose sake the test is performed. For us that is not acceptable.

Therefore, as a confirmatory test in two-stage borreliosis diagnostics EUROIMMUN has always favoured classic Westernblots, which are based on Borrelia cultures. Recombinant antigens are then applied additionally (EUROLINE-WB), when they are at least on a par with the native antigens or cannot be expressed in Borrelia cultures (e.g. VlsE: Borrelia only form this anitgen in the host organism when the corresponding immunological reaction is triggered). Many customers are delighted with our Anti-Borrelia EUROLINE-WB, especially since evaluation can now be peformed automatically and reations archived electronically using EUROLineScan.

In the meantime further Borrelia antigens have been identified (several of them in our own reaserach laboratories), which are produced in insufficient quantities in cultured Borrelia, or membrane lipids, which are not presented in classic Westernblots. Moreover, we have generated completely new recombinant designer antigens - these are described in the enclosed information sheet. The latest advance is a state-of-the-art blot system, the Anti-Borrelia EUROLINE-RN-AT, in which recombinant and native antigens are placed next to each other. With the new product we are reaching out to users who wish to evaluate their Borrelia blots visually, but prefer line blots because the identification of Westernblot bands is too complicated. This blot can also be evaluated completely automatically. Reactions are scanned in the incubation bath, and interpretation of results and archiving for 48 blot strips takes less than one minute. The broadening of the antigen spectrum allows more rare antibody constellations to be detected, which helps increase the sensitivity. So, for example, native (specifically reacting) OspC from B. afzelii is supplemented with OspC from the genospecies B. burgdorferi and B. garinii, and in fresh infections 10% more positive IgM reactions are detected.

As well as the new Anti-Borrelia EUROLINE-RN-AT EUROIMMUN offers a complete package for Borrelia diagnostics that leaves no wishes unfulfilled. This is based on international guidelines for two-strep diagnosis of Borrelia (DGHM; RKI, Berlin, Germany; CDC, Atlanta, USA) and for CSF diagnostics. All reagents are CE certified and there are comprehensive automation concepts for all test systems – we are happy to provide extensive validation data on request.

* Includes ready-to-use, colour-coded controls for checking incubation/calculation of results