In the case of Lyme disease, there are significantly more Borrelia strains present in Europe than in North America.
In Europe, in vitro diagnostic tests are now governed by the IVDR (In Vitro Diagnostic Regulation) (EU Regulation No 746/2017), which requires detailed testing and rigorous accreditation of the testing process. Assessment of compliance with the IVDR is a prerequisite for manufacturers and distributors to obtain the certificate required to place their products on the European market. Diagnostic methods compliant with the Regulation bear the CE mark, which ensures that the test meets the performance standards required in Europe. This is particularly important when testing for diseases where epidemiological conditions in Europe differ from those in other geographical regions. Lyme disease is one such example, as there are significantly more Borrelia strains present in Europe than in North America.
In the United States, the FDA (US Food and Drug Administration) applies similarly strict regulations; however, there is no automatic recognition between the two systems. Recently, a number of tests have become available in Hungary and across Europe that are registered only with the US FDA or were developed specifically for the United States. This summary discusses the usability of these tests and the necessary precautions to be taken.
Clinical validation as the highest level of evidence
The highest level of evidence is provided by a so-called prospective, pre-planned clinical trial, in which the test method must, ‘blindly’ (without knowing the subjects’ group allocation) to determine which group each subject belongs to.
Both the IVDR and US FDA regulations permit lower levels of validation, such as so-called ‘analytical’ tests carried out on samples collected in advance from a biobank or prepared in a laboratory. Where clinical trial protocols are drawn up at all, manufacturers (sponsors) upload them in advance to independent websites, such as clinicaltrials.gov or clinicaltrialsregister.eu.
Where clinical trials, including internal trials, are conducted, they are often published, which may also form part of marketing activities. It is difficult to verify the quality of such publications, but in the case of a high-quality journal, this is generally not available for purchase. It is important to note that a licensed laboratory in both the US and Europe may carry out tests that have not been approved by the competent authority, meaning they do not have either FDA or EU (CE) registration.
Viramed/Virachip, one of the most commonly used serological methods in Hungary
Serological tests provide important information about the patient’s immune response. However, in the case of Borrelia infection, the results depend to a large extent on whether an immune response develops at all and how it fluctuates. The Virachip test operates using an automated testing and reading system, which contains the antigens involved in the reaction on a microchip. The principle of operation is similar to that of a Western blot test.
The test was evaluated in a prospective study on 41 positive and 87 negative (a total of 128) samples from the Borrelia B31 (American) strain in a prospective study involving 41 positive and 87 negative samples (128 in total), which does not meet the most basic, generally accepted statistical requirements. There is no trace of the clinical trial on any independent website. In addition, preliminary and post-hoc analytical studies were also conducted; the data from the latter were published in the Journal of Clinical Microbiology (impact factor 2.78) in 2018. Another version of the test was evaluated on samples of unspecified origin (106 positive, 134 negative, 240 in total), but no prospective clinical trial is listed in any independent database. The results provide simple ‘positive-negative-indeterminate’ information regarding IgM and IgG antibodies.
Vibrant Wellness Tickborne Panel
This test is also serology-based, and is therefore an indirect test that relies on an immune response. The test is carried out exclusively within the USA; samples are collected by local representatives and sent to the laboratory. According to the small print in the results, the panel is not approved by the US FDA and does not hold CE registration. There is no evidence of a prospective clinical trial on any independent website.
The results of internal analytical tests were reported, which were carried out using 90 positive samples from the US CDC biobank and 142 samples from healthy volunteers. The results were published in the journal Scientific Reports (impact factor 1.0). The report is nearly 20 pages long and contains detailed information on the extent of the reaction to each antigen, as well as positive and negative assessments according to both the US CDC’s criteria and an alternative interpretation method.
In addition to common Borrelia strains, the test also provides information on the immune response to co-infections occurring in the US. The panel also includes a PCR test based on DNA analysis; however, this method generally has very low sensitivity in blood samples, detecting infection in less than one in ten cases.
It is clear from the above that particular care is required when interpreting the results of tests developed in the USA that have not been validated in accordance with European requirements, or have not been validated on the basis of prospective clinical trials.
Sources:
https://pubmed.ncbi.nlm.nih.gov/30135227/https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7581523/https://www.scimagojr.comViramed and Vibrant test kit descriptions
(C) Lyme Borreliosis Foundation
