Bron: SpirFind FAQ: http://boulderdiagnostics.com/us/?page_id=33
What is the Difference between the SpiroFind Test and an LTT Test?
The SpiroFind Test measures the specific trained response of the monocyte immune cells to an active borrelia infection. When these immune cells are exposed to an active infection, they will emit a cytokine protein signal during the SpiroFind assay. We quantify this signal over a range of concentrations of borrelia stimulus to make sure that we differentiate from unspecific high immune activity.
The LTT test, on the other hand, does not score a specific immune signal response. While the LTT test does expose the immune system to the borrelia organism, it then measures simply how those immune cells proliferate. This cell proliferation is not necessarliy a specific reaction to the borrelia. Therefore, the LTT test is generally not regarded as a specific test for Lyme borreliosis.