[The imbalance of Th1/Th2 cytokine expression in peripheral blood mononuclear cell from asthmatic patients and the effect of erythromycin on these cytokines].

OBJECTIVE: To observe the state of Th1/Th2 cytokine expression in peripheral blood mononuclear cells (PBMCs) from asthmatic patients and the effect of erythromycin (Ery) on it. METHODS: 23 asthmatic patients and 10 healthy volunteers were included. The mRNA expression for Th1/Th2 cytokines in PBMC before and after the culture with Ery were detected by RT-PCR, considering IL-2 and IFN-gamma as Th1 cytokines, and IL-4, IL-6, IL-10 as Th2 ones. RESULTS: The positive rate of mRNA expression for Th2-derived IL-4, IL-6, IL-10 in the study group were 18/23, 19/23 and 10/23 respectively, and those for IFN-gamma and IL-2 produced by Th1 cells were 1/23 and 13/23, respectively. In the control group, the positive rate for IL-4, IL-6, IL-10 were 0/10, 2/10 and 1/10, respectively, and those for IL-2 and IFN-gamma were both 1/10. Comparing with the control group, the positive rate of mRNA expression for IL-4 and IL-6 in PBMC from asthmatic patients were significantly higher (P = 0.00003, 0.001 respectively). After the culture with Ery for 48 h, the positive rate for IL-4 expression in the study group decreased from 18/23 to 5/23 (P = 0.0006), and IL-6 from 19/23 to 9/23 (P = 0.006). The positive rate for IFN-gamma expression was elevated while IL-2 decreased(But both had no statistical significance). There was no difference observed before and after the culture with Ery in the control group. CONCLUSIONS: There is a predominant expression of Th2-type cytokines in PBMC from asthmatic patients. Ery can down-regulate the mRNA expression for IL-4 and IL-6 in asthmatic patients, and might convert the imbalance of Th1/Th2 cytokine expression in asthmatic patients.