RETN and infectious disease: Moreover detection of systemic hyper resistinemia in severe, sepsis or septic shock also suggests a plausible role of resistin in infectious disease[19, 20] Given to these, the study was design to determine firstly the circulating serum resistin level among the healthy subjects not addicted to khat and healthy subjects addicted to khat, to ascertain whether khat addiction does have an effect on serum resistin levels, followed by assessing their levels in khat addicted and non khat addicted tuberculosis patients.