Dynamic Analysis of Peripheral Cytokines,C-reactive Protein,and Lymphocyte Counts in H1N1 Flu Patients with Complicated Pneumonitis

Objective To explore the changes of plasma cytokines,C-reactive protein(CRP),and lymphocyte counts in H1N1 patients with complicated pneumonitis and to provide reference for early diagnosis and early treatment. Methods Changes of plasma cytokines[interferon γ(IFN-γ),interleukin 6(IL-6),interleukin 8(IL-8),transforming necrosis factor α(TNF-α),transforming growth factor β1(TGF-β1)],C-reactive protein(CRP) and T cell counts in 16 hospitalized H1N1 patients with complicated pneumonitis were investigated.These patients were classified as severe(PaO260 mm Hg,9 cases) and mild(PaO2≥60 mm Hg,7 cases) according to partial pressure of oxygen at admission.Eight healthy medical professionals were enrolled as controls. Results Cytokine profiles showed no changes in IFN-γ,IL-6,IL-8,and TNF-α levels throughout the observation period(P0.05)as well as among groups(P0.05).TGF-β1 was significantly higher in the severe group than in the mild group before treatment(P0.05) and no significant differences were noted after treatment(P0.05).Signs of pulmonary fibrosis including normal body temperature,alleviated short breath,and normal PaO2 were noted in some cases during the recovery period.Elevated CRP levels and lymphopenia were common in both the severe and the mild group.Lymphocyte counts in the severe group were significantly lower than in the mild group before treatment(P0.05) while after treatment,a noticeable elevation in lymphocyte count was noted in both groups(both P0.05).CRP decrease was merely seen in the mild group(P0.05).Lymphocyte counts and CRP levels rapidly recovered to normal levels in all survivors after treatment;otherwise the patients would end up with poor prognosis. Conclusion Serial measurements of cytokines shows that only TGF-β1 is overproduced,possibly due to the early use of corticosteroids,which may have down-regulated the immune responses to H1N1 infection.Pretreatment plasma TGF-β1 concentrations and absolute lymphocyte counts are possible predictors of severity.However,the role of elevated TGF-β1 levels in H1N1 infection-associated pulmonary fibrosis requires further investigation.