Preliminary Study On The Circulating Changes Of Th22 Cells In Patients With Hepatic Hydatid Disease

background: Hepatic hydatid disease,also known as hepatic hydatid disease,is caused by the infection with the larval stage of tapeworms belonging to the genus Echinococcus granulosus or Echinococcus multilocularis.Hepatic hydatid disease is spread via faecal-oral(or stool to mouth)approach when human or livestocks ingest dog feces.Cases are widely distributed and have been reported on all continents except Antarctica.In China,five types of Echinococcus tapeworm are distributed,in addition,cystic hepatic echinococcosis caused by Echinococcosis graulosus and hepatic alveolar echinococcosis caused by Echinococcosis multiloculatis are both prevalent,98% of the which are mainly reported in Tibet,Sichuan,Inner Mongolia,Xinjiang and Qinghai,Gansu,Ningxia province.The estimated number of patients in 2004 was about 380,000,with a prevalence of about 0.3%-4.8%,in high prevalence areas up to 12%,causing an economic loss of more than 30 hundred million yuan per year,limiting the local economic development and causing public health issues.As the immunological research moves on,researchers have a better understanding of the pathogenesis of the many disease mechanism.Previous reports have shown that CD4+ helper T cells play an important role in echinococcosis infection.During the chronic infection of hydatid cysts,the host gradually shifted from a strong Th1-type immune response to a predominantly Th2-type immune response.Th1/Th2 exert their biological effects via the production of IFN-? and IL-4.Similarly,the imbalance of Th17/Treg in the peripheral circulation of patients with hydatid cysts is also related to echinococcosis infection.Th22 cell is a new type of CD4+ helper T cell which is considered to be different from Th1/Th2 or Th17.Its main effector cytokine IL-22 is an anti-inflammatory as well as proinflammatory cytokine,which has been reported involved in many infectious diseases.However,few report showed the potential role of Th22 cells and IL-22 in this two types of liver hydatid disease.Objective: 1)Investigate the frequency of Th22 and the plasma level of its major effector cytokine IL-22 in peripheral blood of patients with cystic hepatic echinococcosis and hepatic alveolar echinococcosis repectively.2)Analyze the correlation between IL-22 and related IL-22+ CD4 cells to discuss their potential role in the chronic echinococcosis infection.Methods: Healthy controls and the patients were enrolled who were diagnosed with liver cystic echinococcosis and hepatic alveolar echinococcosis,and the general clinical data was collected.The changes of the frequencies of Th22,Th17,Th1,IL-22 Th17 and IL-22+ Th1 in peripheral blood were detected by flow cytometry.The level of IL-22 in plasma was detected by enzyme linked immunosorbent assay.Results: The frequency of Th22 cell in the peripheral blood in the patients with hepatic alveolar echinococcosis was significantly higher than healthy control group,and the proportion of Th1 cells was significantly lower when compared with healthy control group,while we didn't observed any significant differences about the frequencies of Th17 cells and il-22+Th1 cells between patients group and healthy controls.The levels of plasma IL-22 in patients with hepatic alveolar echinococcosis was significantly higher than healthy control group.And it were positively correlated with the expression of the circulating Th22 cells,but not with the frequencies of IL-22+Th17 cells and IL-22+Th1 cells.The frequency of Th22 cells in patients with hepatic alveolar echinococcosis was significantly lower when ones at 1 month after operation,and the level of plasma IL-22 did not change significantly after operation.No statistically significant difference was observed in the frequencies of Th22 and Th1 cells in the peripheral blood of patients with cystic hepatic hydatid disease when compared with healthy control group,while the frequency of Th17 cell was lower than that healthy control group,and the IL-22 level in plasma was not statistically different from healthy controls.We didn't observed any significant difference between the proportion of Th22,Th17 or Th1 cells in the peripheral blood of patients with hepatic cystic echinococcosis when compared with ones at 1month after operation.And no statistically changes was observed after the surgery in patients with cystic liver echinococcosis.In addition,we also didn't find any statistical difference between patients who has removed lesions completely and the healthy controls.Conclusion:Th22 cells and IL-22 may play an important role in the pathogenesis of hepatic alveolar echinococcosis.The frequency of circulating Th22 cells and the plasma level IL-22 are different between hepatic cystic echinococcosis and hepatic alveolar echinococcosis,which may be related to the different immunopathogenesis process caused by this two tapeworms.Our study reported for the first time the frequency of circulating Th22 cells and related cytokine IL-22 in patients with hepatic cystic echinococcosis and alveolar echinococcosis,giving a better understanding of the interaction between Echinococcus tapeworm and human immune system,which may provide new ideas for future prevention and new immunotherapy.