Changes of Plasma Interleukin-1 Receptor Antagonist, Interleukin-8 and other Serologic Markers during Chemotherapy in Patients with Active Pulmonary Tuberculosis

BACKGROUND The human immune response to Mycobacterium tuberculosis is mediated by macrophages and T-lymphocytes. The alveolar macrophage phagocyting mycobacterium produces interleukin (IL)-1 as an inflammatory mediator, and IL-8 as a cytokine for leukocyte recruitment and granuloma formation. Interleukin-1 receptor antagonist (IL-1ra) is an internal antagonist of IL-1. METHODS Plasma levels of IL-1ra and IL-8 and other serologic markers were measured in 18 patients with active tuberculosis before treatment and after 2 months and 6 months of treatment. RESULTS During treatment with antituberculous medication, patients showed significant changes in hemoglobin, hematocrit, white blood cells (WBC), platelet, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), ferritin and plasma IL-1ra. After 2 months of treatment, ESR and CRP diminished significantly; after 6 months, hemoglobin increased while WBC, platelet, ESR, CRP and ferritin decreased significantly compared to their pre-treatment levels. There were two groups: patients with delayed therapeutic responses, and patients with early responses. At each point of observation, the former group of patients showed lower body weight and lower levels of hemoglobin and hematocrit, and higher levels of WBC, platelet, ESR, IL-8 and IL-1ra than the latter group. During the course of the treatment, we observed considerable differences in body weight, body mass index, hemoglobin, hematocrit, WBC and platelet counts, ESR, CRP and ferritin in both the early-response and delayed-response groups. CONCLUSION We believe that the plasma concentrations of IL-1ra and IL-8, which showed different peaks during the course of treatment, reflected their different functions and patterns of secretion. Moreover the concentrations did not seem as sensitive as other inflammatory markers to evaluate disease activity during antituberculosis treatment. However, IL-1ra can be considered a marker for disease activity and response to treatment.