P62 Immunological analysis and clinical profile of Chronic Hepatitis B Virus (HBV) infection in the younger patient

Abstract

BACKGROUND: Establishing disease phase in chronic HBV is a critical step in long-term management. This classification is of more significance at a younger age, where a proportion of eAg positive patients are labelled 'immune tolerant' and treatment is deferred. However, disease phase is diagnosed on clinical phenotype with little insight into immunological activity. The aim of this study was to investigate the immunological profile in HBV infected children {&} young adults across different disease phases and compare the HBV-specific response with those of older HBV infected patients. PATIENTS {&} METHODS: 45 children {&} young adults (median age 19, range 12-30) were recruited and followed longitudinally for a minimum of 12 months. Clinical profile included ALT, HBV DNA, quantitative HBsAg and, where available, biopsy fibrosis stage {&} NI scores. This was compared with the immunological analysis comprising: global T cell cytokine profile (frequency of T cells producing IFN$γ$, IL-2, IL-4, TNF$α$ {&} ILs; 17, 8, 21, 22 {&} MIP-1a after PMA stimulation), quantity of T cells (CD4 {&} CD8) expressing exhaustion markers (PD-1, Lag-3, CTTL-4) and the presence of functional HBV-specific T cells (PBMC stimulated with overlapping HBV peptides covering envelope, core {&} E proteins). RESULTS: Frequency of T cells producing immunosuppressive or Th2 cytokines (IL-10, IL-4) {&} (IL-8, IL-21) is similar between age matched HBV infected and uninfected young adults, while T cells with pro-inflammatory cytokines (IFN$γ$, TNF$α$, IL-17) were increased in the HBV infected group (p={