Dynamics of the Cytokine Response to Mycobacterium ulcerans during Antibiotic Treatment for M-ulcerans Disease (Buruli Ulcer) in Humans

We have studied the evolution of the gamma interferon (IFN-gamma) and interleukin 10 (IL-10) responses after Mycobacterium ulcerans sonicate stimulation of whole blood from patients with early M. ulcerans lesions during treatment with rifampin and streptomycin for 8 weeks. Among the 26 patients, secretion of IFN-gamma increased during treatment, with a significant increase at 4 weeks and a further increase after 8 weeks overall. The increase was more rapid in patients with large or ulcerative lesions, becoming significant by 4 weeks. For small lesions, there was only a minor increase, which did not reach significance. There was no significant change in the median IL-10 response during antibiotic therapy, and there was no inverse correlation between IFN-gamma and IL-10 responses. These results demonstrate that an IFN-gamma secretory response to M. ulcerans developed, independently of IL-10 secretion, in patients whose M. ulcerans disease healed during antibiotic therapy.