Cytokine gene expression in peripheral blood mononuclear cells (PBMC) from patients with pharmacologically treated cystic echinococcosis

The influence of pharmacological treatment on the immune response of patients with Echinococcus granulosus infection was evaluated by reverse transcriptase‐polymerase chain reaction (RT‐PCR) to determine mRNA expression for IL‐12 p35, IL‐12 p40, interferon‐gamma (IFN‐γ), tumour necrosis factor‐alpha (TNF‐α) and IL‐4 in PBMC from 12 patients before and after chemotherapy and from seven uninfected controls. Most patients' PBMC showed measurable amounts of IL‐12 p35, IL‐4, IFN‐γ and TNF‐α mRNA in parasite antigen‐stimulated and unstimulated cultures. Conversely, IL‐12 p40 mRNA was detected almost exclusively in successfully treated patients (86%) after therapy. In these patients semiquantitative analysis of RT‐PCR products showed a significant difference between IL‐12 p40 mRNA mean levels before and after therapy (P = 0.03 in parasite antigen‐stimulated cultures; P = 0.001 in unstimulated cultures). IL‐4 mRNA was weakly expressed before therapy and more highly so after treatment in both groups of patients and under both culture conditions; IL‐4 mRNA reached its highest level in post‐therapy PBMC from patients in whom therapy failed (stimulated cultures). IFN‐γ and TNF‐α mRNA expression increased in patients who responded to therapy and decreased in patients who did not. In contrast to IL‐12 p35, IFN‐γ and TNF‐α mRNAs, IL‐12 p40 and IL‐4 mRNAs were detected exclusively in patients, suggesting a close relationship between these two cytokines and cystic echinococcosis. Our findings indicate that chemotherapy influences the immune response, thus determining changes in Th1/Th2 cytokine mRNA patterns, predominantly in IL‐12 p40 and IL‐4 mRNA expression.