was to establish the impact of injecting drug use on cellular immunity and to evaluate the significance of drug useas a factor contributing to HIV infection and affectingthe course of disease in HIV-positivepatients.

The study included 144 subjects: 109patients (49 – with drug addiction, 23 – withHIV infection, 37 – with drug addiction and HIV infection) and35 virtually healthy individuals.

Thetotal amount of T-lymphocytesdoes not depend on HIVstatus, drug addiction orgender, aswell as on the combinedeffect of these factors. The total number of lymphocytes, the percentage and the absolute countof B cells (CD19 + lymphocytes) and CD4 +25+ cells (mainly T-regulatorylymphocytes) in blood was significantly lower in HIV-positive patients comparedto HIV-negative ones; drugaddiction andgender do not havea significant effect onthese parameters. Injecting drug use potentiatesthe effects caused by HIV infection: reducedpercentage of T-helpercells (CD4+lymphocytes), number of T-NK-cells(CD3+16+56+ lymphocytes),percentage and absolutecount of NK cells (CD3-16+56+ cells), increasedpercentage of cytotoxicT lymphocytes (CD8+cells), percentageand absolute number of T-lymphocytes with signs of activation(CD3+HLA-DR+ cells).

Injectingdrug use increases therisk of infection inHIV-negative IDUs andreduces the antiviralresponse in HIV-positivepatients, significantly potentiatingeffects of HIVinfection: reduced blood levelof T-helpers, T-NKand NK cells, regulatorycells, immunehyperactivation – allof this may contribute tothe disease progression.