Conclusions

In conclusion, we observed a significant decrease in CD4/CD8 ratio, percentage of CD4+ T-cells expressing the activation marker CD69 and number of mast cells in patients responding to six months infliximab therapy. Also our results indicate that the percentage of Tregs decrease in most patients irrespective of response.
Given the knowledge that T-cells and mast cells may interact and propagate inflammatory processes, we speculate that the T-cell alveolitis and Treg dysfunction in sarcoidosis may lead to activation of mast cells further promoting the inflammation. Infliximab treatment seems to interfere in this process in a positive way reflected by less pronounced chest radiographic changes and improved lung function. In future studies, as we continue to collect patient data, we need to study these cells more in detail to gain knowledge in what way they contribute to the sarcoid inflammation, which also may have implications for altered therapy with regard to optimal dose, treatment interval and duration.