Background:Apoptosis plays an important role in the control of the immune system, and its impairment may be associated with autoimmune responses. Different bacterial and viral pathogens interfere with the regulation of apoptosis. This may take place in Lyme borreliosis, in which pathological autoimmune reactions are likely to occur.Material/Methods:A study group consisted of 15 patients with erythema migrans (group I), 15 with Lyme arthritis (group II) and 9 with neuroborreliosis (group III); the control group consisted of 10 healthy subjects. The concentrations of the factors involved in apoptosis regulation – transforming growth factor-beta1 (TGF- beta 1), soluble Fas (sFas), soluble Fas ligand (sFasL) and protein bcl-2 – were measured in serum before (examination 1) and after (examination 2) four weeks of antibiotic treatment.Results:The mean concentration of sFas was significantly higher in all study groups compared to controls in examination 1 and 2, and showed a tendency to increase during treatment. The concentration of sFasL was significantly increased in groups II and III in examination 2. Conclusions:The concentrations of soluble factors involved in the regulation of apoptosis were increased in serum of patients with different forms of Lyme borreliosis. Further studies are necessary to confirm if inappropriate apoptosis of immune cells may contribute to the pathogenesis of Lyme disease.

Keywords: Anti-Bacterial Agents - therapeutic use, Antigens, CD95 - blood, Erythema - blood, Erythema - pathology, Fas Ligand Protein, Lyme Disease - blood, Lyme Disease - drug therapy, Lyme Disease - pathology, Lyme Neuroborreliosis - blood, Lyme Neuroborreliosis - pathology, Membrane Glycoproteins - blood, Proto-Oncogene Proteins c-bcl-2 - blood, Transforming Growth Factor beta - blood