Periodontal tissue diseases, in particular, generalized periodontitis, are one of the most common problems of dentistry of the present. Determination of the peculiarities of the course of this pathology, depending on the group membership of blood of patients, in particular the data of the leukogram, will allow to develop in the future a complex of targeted, prophylactic and therapeutic measures that will improve and optimize the ways of solving this problem.
 The aim of our study was to find out the dynamics of the data of leukograms in patients with generalized periodontitis with different blood groups.
 The material and research methods. 855 males aged 20 - 55 years were examined. The total blood count was determined using an automatic hematologic analyzer. Morphological study of formed blood elements was performed using a light microscope according to a unified method. On the basis of the obtained data of "white blood" in patients of the study groups we have calculated the simplified leukocyte index of intoxication.
 Results of the research and their discussion. As a result of the study, it was established that in the patients with GP, carriers of O (I) and AB (IV) blood groups the quantitative composition of blood leucocytes increased the same, while in the representatives of A (II) and B (III), the blood groups were slightly smaller.
 The maximum increase in the neutrophil content in the blood was studied in patients with GP, carriers of AB (IV) blood group, a minimum increase was in patients with B (III) blood group, and in patients of the main group of O (I) and A (II) blood groups, the neutrophil content in the blood increased equally.
 The maximum increase in the value of the bands neutrophils in the blood was investigated in patients with GP with AB (IV) and A (II) blood groups, somewhat lower was the increase in the level of bands neutrophils in representatives of the O (I) blood group, and the minimum value of the analyzed data in patients with GP with B (III) blood group.
 The maximum reduction in lymphocytes was determined in the carriers of A (II) and AB (IV) blood groups, the level of lymphocytes in the blood of the representatives of О (I) blood group decreased somewhat less, however, in patients with B (III) blood group, the level of lymphocytes increased in the blood.
 The maximum reduction in the content of eosinophils in the blood was investigated from the representatives of the O (I) and AB (IV) blood groups, the level of values of the analyzed data in carriers A (II) and B (ІІІ) blood groups decreased less.
 The maximum increase in the content of basophils in the blood was investigated in patients with A (II) and B (III) blood groups, somewhat less increase was found in patients with the O (I) blood group, and in patients with GP, carriers of AB (IV) blood groups, level of the analyzed index in the blood was 0.70 ± 0.39% in the absence of this cell component in the study group of comparison.
 On average, the monocyte content in the blood of the subjects was the same in the main and comparative groups.
 The maximum increase in the values of the index of intoxication leukocyte was determined from the representatives of the O (I) and A (II) blood groups, and the values of the LII in patients with GP with AB (IV) and B (III) blood groups were slightly increased.
 Conclusions Thus, in patients with GP endogenous intoxication phenomena can be traced, which, according to the grading scale, corresponds to a slight degree of severity and is due to metabolic disorders, barrier functions of the membranes, regulatory systems, excessive presence of inflammatory mediators, and microbial toxins of immuno-foreign products.
 Prospects for further research. It is planned to continue the study of the course of generalized periodontitis in people with different blood groups, taking into account the correction of its polypeptide drugs.