Estudo da influência da infecção pelo HCV na ocorrência de inibidores em pacientes com Hemofilia A: avaliação de biomarcadores da resposta imune

Abstract

Patients with hemophilia A were at high risk of acquiring blood-borne infectious diseases, such as HCV, until the mid-1990s. This problem has been overcome and currently the development of FVIII inhibitors (anti-FVIII) represents a major problem in the management of hemophilia A. This study aimed to investigate the influence of HCV infection on the occurrence of inhibitors in patients to analyze biomarkers of the immune response (plasma cytokines and chemokines). Patients (n=197) who were followed up at Hemocentro de Belo Horizonte, Fundação Hemominas between 1985 and 2018, were classified in different groups: seronegative (negative for HCV, HBV, HIV, HTLV, Syphilis and Chagas Disease) and without history of inhibitor development (SNINB-, n=62); seronegative and with history of inhibitor development (SNINB+, n=34); exposed to HCV (anti-HCV reactive) and without history of inhibitor development (HCVINB-, n=50); exposed to HCV and with history of inhibitor development (HCVINB+, n=51). Quantification of cytokines (IL-2, IL-4, IL-6, IL-10, TNF, IFN-γ and IL-17A) and chemokines (CXCL8/IL-8, CCL5/RANTES, CXCL9/MIG, CCL2/MCP-1 and CXCL10/IP-10) was performed on plasma samples by flow cytometry. Retrospective patients’ data were obtained from medical records and compared between seronegative and exposed to HCV groups. Older age, more frequent use of cryoprecipitate and fresh frozen plasma, severe hemophilia, history of inhibitor development, lower levels of inhibitor and comorbidities were significantly associated with exposure to HCV. Among patients exposed to HCV, 30% achieved viral clearance and 60.6% of those with chronic infection did not have liver disorders. The analysis of biomarkers showed higher plasma concentrations for most of the cytokines measured in the INB+ individuals compared to the INB-. The SNINB- group showed high concentrations of IL-4; the SNINB+ group, high concentrations of IFN-γ, TNF, IL-4 and IL-10; the HCVINB- group, low concentrations of all cytokines, but high concentrations of the chemokines CXCL8 and CCL2; and the HCVINB+ group, reduced levels of IFN-γ and TNF, but high concentrations of IL-2, IL-6, IL-17A and IL-10, in addition to high concentration of CXCL9 and CXCL10 chemokines. Multivariate analysis of plasma concentrations of biomarkers showed differentiated clusters of patients according to status of HCV infection and inhibitor occurrence. The Heatmap matrix showed clustering of patients into three main profiles: HCVINB+: with higher concentrations of CXCL9 and CXCL10, medium to low levels of IL-4 and IFN-γ; HCVINB-: with low concentrations of CXCL9 and IFN-γ and the lowest levels of IL-4; seronegative patients with or without inhibitor (SNINB-/INB +): with low concentrations of CXCL9 and CXCL10, and higher levels of IL-4, TNF and IFN-γ. Thus, IL-4 and IFN-γ appear to be the main indicators of inhibitor occurrence, while CXCL9 and CXCL10 of response to HCV. We propose that HCV may be a factor that potentiates the initiation of the anti-FVIII antibody formation response by inducing a Th1 response, but at the same time, it can be an immunomodulator of this humoral response, probably by decreasing the Th2 response, which is important in maintaining high levels of inhibitor. These findings suggest new perspectives for future studies with patients with hemophilia to establish a model to explain the immunomodulation between HCV infection and the formation of inhibitors.