Assessment of in vitro cytokine response in hemophilia A patients with or without factor VIII inhibitory antibody.
Factor VIII (FVIII) inhibitor antibodies are produced in a proportion of hemophilia A patients. Development of anti-FVIII inhibitor antibodies is a T cell-dependent response, mediated by FVIII specific CD4(+) T cells. This study was performed to investigate the contribution of T helper (Th) cell-mediated cytokine response in inhibitor production. Peripheral blood mononuclear cells (PBMCs) were obtained from hemophilia A patients with (n = 14) or without inhibitor (n = 14) and from normal individuals (n = 14). Following stimulation of PBMCs with rFVIII and phytohemagglutinin (PHA) mitogen, the secreted cytokines, interferon-gamma (IFN-gamma), interleukin-10 (IL-10), and transforming growth factor-beta1 (TGF-beta1), in culture supernatant and the proliferative response were assessed using sandwich ELISA and (3)H-thymidine incorporation, respectively. No significant proliferative response to FVIII was observed, whereas PHA induced a strong response in all groups. No cytokine secretion was observed in response to FVIII stimulation. Although PHA induced IL-10, TGF-beta1 and IFN-gamma secretion in all groups, the level of IFN-gamma was significantly lower in hemophilia A patients than in normal individuals (p < 0.0001). The levels of TGF-beta1 and IL-10 were similarly higher in patients compared with normal subjects, but the difference was not statistically significant. Lack of FVIII-induced proliferative response and cytokine production together with reduced secretion of PHA-induced IFN-gamma in both groups of patients suggest involvement of nonspecific immunosuppression possibly due to hepatitis C virus (HCV) infection observed in the majority of patients.
Towfighi
Farzaneh
F
Department of Immunology, School of Public Health, Tehran University of Medical Sciences, Tehran 14155, Iran.
Gharagozlou
Soheila
S
Kardar
Gholam-Ali
GA
Sharifian
Ramazan-Ali
RA
Karimi
Katayoon
K
Lak
Manijheh
M
Pourfathollah
Ali-Akbar
AA
Soleimani
Sedigheh
S
Shokri
Fazel
F
D000293:Adolescent; D000328:Adult; D000818:Animals; D002478:Cells, Cultured; D002648:Child; D016207:Cytokines / Q000096:biosynthesis* / Q000378:metabolism; D005169:Factor VIII / Q000037:antagonists & inhibitors / Q000276:immunology* / Q000502:physiology; D005260:Female; D006467:Hemophilia A / Q000097:blood / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D007518:Isoantibodies / Q000096:biosynthesis* / Q000097:blood*; D007963:Leukocytes, Mononuclear / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D008297:Male; D051379:Mice; D008875:Middle Aged; D008934:Mitogens / Q000494:pharmacology; D010835:Phytohemagglutinins / Q000494:pharmacology