Aim. In this paper we investigate the impacts of co-incubation of Borrelia miyamotoi with neutrophils. Materials and methods. Spirochetes B. miyamotoi, strain HT31, were incubated 3 hours at 37°C with neutrophils of healthy donors (5*10 6 cells/ml) in a 1:1 ratio. The incubation medium contained also non-immune serum of healthy blood donors (SHD) and, in some experiments, high-immune serum of patients recovered from ITBB-BM (S-ITBB-BM). The proportion of neutrophils that bound borrelia, as well as the number and viability (mobility) of free borrelia, was estimated by dark-field microscopy. Results. Free-swimming borrelia remain viable in SHD or heat-inactivated S-ITBB-BM, but about 10% of borrelia are associated with neutrophils. In S-ITBB-BM with neutrophils, the proportion of viable borrelia among free ones decreases by approximately 10% compared to S-ITBB-BM without neutrophils; in addition about 15% of bor-relia become bound by neutrophils. If chemoattractant fMLP was added, the proportion of neutrophils binding borrelia increases to 25%, and the proportion of immobilized non-bound bor-relia reaches 40%. Conclusion. Although neutrophils are able to destroy borrelia with or without direct contact, under model conditions the combined effect of blood neutrophils and high-immune human serum does not provide 100% elimination of B. miyamotoi.

The content of cystatin C in serum in Ixodidea tick borreliosis caused B. miyamotoi was studied. To confirm the specific diagnosis, PCR technique was used. The patients were divided into 2 groups by the presence of clinical-laboratory signs of renal pathology. For each group a number of indicators were evaluated characterizing the filtration and concentration functions of kidney. The correlation of these parameters with the content of cystatin C serum was studied. It was shown that serum cystatin C is a more sensitive marker of glomerular dysfunction than urea and creatinine levels in a single study.

The purpose of the study the clinical picture of a «new» infection — ixodic Lyme borreliosis caused by B. miyamotoi. The work is based on the results of a prospective observation of 76 patients with disease caused by B. miyamotoi. Diagnosis is confirmed by PCR. The study shows that a syndrome of fever and a manifestation of intoxication — headache, fatigue, myalgia, vomiting and other substances are at the heart of a typical clinical picture. In some cases, for unclear reasons, the pathological process involves internal organs — lungs, liver, kidney, gastrointestinal tract, heart. This fact may be the cause of a diagnostic error.

Сlinico-functional analysis of the heart in 48 patients with tick-borne borreliosis in the acute period was conducted. It were evaluated the data of physical, electrocardiographic and echocardiographic studies, as well as the activity of cardiospecific enzymes in blood serum. Presented clinical symptoms of heart disease, the frequency of patients with borreliosis, caused by borrelia burgdorferi sensu lato and borrelia myamotoi. ECG abnormalities, echocardiogram picture of heart disease were described. Identified clinical and functional changes fit into the manifestations of benign myocardiodystrophy and less favorable myocarditis.