Preventive Tuberculosis Services Reduces the Risk of Local Forms of Tuberculosis Development in Children on Immunosuppressive Therapy: Retrospective Cohort Study

Background. Long-term immunosuppressive therapy in children (including genetically engineered biologic drugs, GEBD) is associated with a high risk of local tuberculosis (TB) development. Objective. The aim of the study was to examine efficacy of tuberculosis services in children with high risk of developing tuberculosis associated with immunosuppressive therapy.Methods. The study included children at the age from 0 to 17 years on immunosuppressive therapy due to autoimmune disease and who were referred to phthisiatrician consultation. The incidence of TB was estimated one year after in groups receiving preventive TB services (isoniazid and pyrazinamide for 3–6 months) due to the high risk of TB development (contact with TB patients and/or controversial or positive test results with tubercular recombinant allergen) or not receiving such therapy (no indications for preventive treatment, parents’ refusal). The source of any data was medical documentation.Results. Preventive tuberculosis service was performed in 167 (60%) out of 279 children included in the study, 112 children did not receive such treatment (5 cases — parents’ refusal, 107 cases — lack of indications for preventive treatment). TB was detected in 1 (0.6%) child after one year in the preventive treatment group, and in 14 (12.5%) children (p < 0.001) in the group without preventive treatment. Thoracic lymph nodes tuberculosis was diagnosed in 4 (27%) patients among all who has developed TB, tuberculous primary complex — in 3 (20%) patients, focal tuberculosis in 7 (46%) patients, disseminated tuberculosis in 1 (7%) patient.Conclusion. Preventive tuberculosis service reduces the risk of tuberculosis in children on administration of immunosuppressive drugs, including GEBD

Biocompatibility of Small-Diameter Vascular Grafts in Different Modes of RGD Modification

Modification with Arg-Gly-Asp (RGD) peptides is a promising approach to improve biocompatibility of small-calibre vascular grafts but it is unknown how different RGD sequence composition impacts graft performance. Here we manufactured 1.5 mm poly(3-hydroxybutyrate-co-3-hydroxyvalerate)/poly(ε-caprolactone) grafts modified by distinct linear or cyclic RGD peptides immobilized by short or long amine linker arms. Modified vascular prostheses were tested in vitro to assess their mechanical properties, hemocompatibility, thrombogenicity and endothelialisation. We also implanted these grafts into rat abdominal aortas with the following histological examination at 1 and 3 months to evaluate their primary patency, cellular composition and detect possible calcification. Our results demonstrated that all modes of RGD modification reduce ultimate tensile strength of the grafts. Modification of prostheses does not cause haemolysis upon the contact with modified grafts, yet all the RGD-treated grafts display a tendency to promote platelet aggregation in comparison with unmodified counterparts. In vivo findings identify that cyclic Arg-Gly-Asp-Phe-Lys peptide in combination with trioxa-1,13-tridecanediamine linker group substantially improve graft biocompatibility. To conclude, here we for the first time compared synthetic small-diameter vascular prostheses with different modes of RGD modification. We suggest our graft modification regimen as enhancing graft performance and thus recommend it for future use in tissue engineering