PB0183 - The Effect of Regulatory T Cell Functions and Cytokines on the Development of Inhibitor

Sunday, July 10, 2022

6:30 PM – 7:30 PM

Location: Exhibition

Presentation Format: In-Person

Presenting Author(s)

Sema Genc

Prof. Dr. ,Department of Biochemistry
Acibadem Hospital, Maslak
Istanbul, Istanbul, Turkey

Co-Author(s)

EA

Emre Akkaya

Department of Biochemistry
Istanbul University, Istanbul Faculty of Medicine
Istanbul, Istanbul, Turkey
Basak Koc, MD

Assoc. Prof.
Istanbul University, Oncology Institute
İstanbul, Istanbul, Turkey
Bulent Bulent Zulfikar, MD

Prof. Dr. O. Bulent Zulfikar, Pediatric Hematology and Oncology
Istanbul University Oncology Institute
Istanbul, Istanbul, Turkey

Background: The most important complication in hemophilia A(HA) is the development of inhibitors, which interfere FVIII function.

Aims: The purpose of this study was to investigate the roles of CD4+, CD4+CD25+ T cells, and the the cytokines secreted from Tcells in the pathogenesis of inhibitor development in the patients with inhibitor and no inhibitor.

Methods: The study consisted 20patients, who were previously diagnosed and followed up in Istanbul University Oncology Institute and 10 healthy subjects. The patients were classified in two groups depending on presence of inhibitor[INH(+), INH(-)]. FVIII was measured by one-stage clotting assay using SiemensCS-2500. CD4+ and CD4+CD25+T cells were isolated from the PBMCs, cultured for 72 to 120h, and induced with rFVIII(iFVIII)/phytohemagglutinin(i-PHA), or not-induced(NI). TNF-α, IFN-ϒ, IL-2, IL-10, IL-13, TGF-β concentrations were measured by ELISA method in supernatants of cell culture.

Results: Various changes were obtained in CD4+, CD4+CD25+ T cells and Tregs in INH(+) group compared with control and INH(-) group. These differences were significant in CD4+CD25+ T cells of INH(+) compared with INH(-)group in NI and i-FVIII conditions(p=0.023,p=0.028), and in CD4+ and Tregs in INH(+) group compared with control in NI condition(p=0.028, p=0.050). Tregs, CD4+T cells in NI group(p=0.033,p=0.023) and CD4+,CD4+CD25+ in i-FVIII group were also significantly different(p=0.011,p=0.013) between INH(-) and control group. Increased IL-10, IL-13 levels in i-FVIII and decreased TNF-α in NI were obtained compared with control(p=0.05, p=0.017, p=0.032),however only IL-10 was significantly high between INH(-) and controls. Also,significant alterations were found in TNF-α and TGF-β between INH+ and INH- in NI condition.

Conclusion(s): Our findings revealed the role of CD4+D25+ and Tregs in inhibitor development in patients with HemophiliaA. In particular, the changes in TNF-α and TGF-β levels and the increase in IL-10, which shows exacerbation of the anti-inflammatory effect with rFVIII stimulation, show that the immune system controlling effect of IL-10 is abolished with rFVIII treatment.