Immunoblot reactivity at follow-up in treated patients with Lyme neuroborreliosis and healthy controls.

About 5-20% of the general population in endemic areas have seroprevalence for anti-borrelial antibodies. Previous studies have shown a high rate of 25-97% of persisting anti-borrelial antibodies in patients with treated Lyme neuroborreliosis (LNB) at follow-up. These studies used immunoblots with antigens from whole-cell sonicates, which could be less specific than modern recombinant antigens. We assessed the seroprevalence of anti-borrelial antibodies in serum from patients with definite LNB and healthy controls with a line immunoblot using highly specific recombinant antigens. We retrospectively identified patients with treated definite LNB who were treated at the Medical Center-University of Freiburg. Serum from LNB patients at a mean follow-up period of 4.9 years (SD: 3.3) and serum from healthy controls were assessed for anti-borrelial antibodies with a line immunoblot with recombinant antigens. A total of 45 patients with definite LNB and 40 healthy controls were included. Ten LNB patients (22.7%) had persisting antibodies (IgG and/or IgM) in serum at follow-up. Serum samples from six healthy controls (15%) were positive for anti-borrelial antibodies (IgG and or IgM). Prevalence of positive IgM or IgG antibodies showed no statistically significant difference between LNB patients at follow-up and healthy controls (IgM p = 0.32, IgG p = 0.54). Immunoblot reactivity patterns at follow-up in LNB patients did not have statistically significant differences from healthy controls. The discrepancy regarding earlier studies reporting higher amounts of LNB patients with persisting antibodies could be due to a higher specificity of the antigens used in recombinant immunoblots compared to other immunoblots (e.g., whole-cell sonicates). The results of our study should be replicated in a larger prospective multi-center study.

Range sensing based on shearing interferometry.

We report an optical range sensor that combines the advantages of focus sensing and interferometry. It works for specularly reflecting objects and for diffusely reflecting objects. The sensor is simple, robust against vibrations, and has high depth resolution. The aperture is very small, hence the sensor is small and minimizes shading problems. The sensor is based on the following principle: A light spot is projected onto the object under test. The radius of the wave that is scattered at the object is measured with high accuracy by shearing interferometry.