RESUMO
<p><b>OBJECTIVE</b>To investigate the effect of pulmonary surfactant (PS) on the Th1/Th2 balance and serum levels of interleukin-4 (IL-4), interferon-γ (IFN-γ) and IgE in neonates with respiratory distress syndrome (RDS).</p><p><b>METHODS</b>A total of 58 neonates with RDS were divided into control (n=20) and PS treatment groups (n=38). The control group underwent mechanical ventilation and other conventional treatment, while the PS treatment group received with bovine PS treatment within 1 hour of being admitted to the hospital together with mechanical ventilation and other conventional treatment. Enzyme-linked immunosorbent assay was used to measure serum levels of IL-4, IFN-γ and IgE before treatment and 24, 48 and 72 hours after treatment. Simultaneously, arterial blood gas, respiratory system compliance, and other ventilator parameters were recorded.</p><p><b>RESULTS</b>Compared with the control group, the PS treatment group showed significantly shorter duration of mechanical ventilation and oxygen exposure time (P<0.05), significantly better respiratory system compliance and significantly lower oxygenation index 24, 48 and 72 hours after treatment (P<0.05). At 48 and 72 hours after treatment, serum levels of IFN-γ were significantly lower in the PS treatment group than in the control group (120±46 ng/L vs 229±59 ng/L, P<0.05; 141±40 ng/L vs 282±44 ng/L, P<0.05), and serum levels of IL-4 were significantly higher in the PS treatment group than in the control group (263±48 pg/mL vs 152±45 pg/mL, P<0.05; 417±49 pg/mL vs 201±46 pg/mL, P<0.05). At 72 hours after treatment, serum level of IgE was significantly lower in the PS treatment group than in the control group (115±44 pg/mL vs 199±43 ng/mL; P<0.05).</p><p><b>CONCLUSIONS</b>PS treatment can shorten the duration of mechanical ventilation and oxygen exposure time, regulate serum levels of IFN-γ, IL-4 and IgE, and influence Th1/Th2 balance in neonates with RDS, thus inhibiting lung inflammatory response and reducing lung injury.</p>