Higher Viral Load and Prolonged Viral Shedding Period is Associated with Impaired Th17 Cell Response in Patients with H1N1 Influenza A

Abstract

Abstract Objective To explore whether age, disease severity, cytokines and lymphocytes in H1N1 influenza A patients correlate with viral load and clearance. Methods Total of 70 mild and 16 severe patients infected with H1N1 influenza A virus were enrolled in this study. Results It was found that the patients under 14 years old and severe patients displayed significantly higher viral loads and prolonged viral shedding periods compared with the patients over 14 years old and mild patients, respectively (P < 0.05). Moreover, the patients under 14 years old and severe patients displayed significantly lower Th17 cell frequency than the patients over 14 years old and mild patients (P < 0.01). The viral shedding period inversely correlated with the frequency of IL-17+IFN-γ-CD4+ T cells. Additionally, the decreased concentration of serum TGF-β correlated with the decreased frequency of IL-17+IFN-γ-CD4+ T cells. Conclusions Both younger and severe patients are associated with higher viral loads and longer viral shedding periods, which may partially be attributed to the impaired Th17 cell response.