Abstract:
BACKGROUND : Chronic inflammation, possibly exacerbated by cigarette smoking, is considered to be the primary cause of
pulmonary damage in patients with tuberculosis (TB). However, the mechanisms which underpin these harmful inflammatory
responses, have not been well documented.
OBJECTIVES : The current study was undertaken to determine possible associations between systemic biomarkers of inflammation
(acute phase reactants, stress hormones, leukocyte vitamin C) and smoking status in patients (n=71, 20 smokers) with
newly-diagnosed pulmonary TB presenting at a tertiary hospital, Johannesburg, South Africa.
METHODS : Plasma concentrations of C-reactive protein (CRP), ferritin, cortisol, epinephrine, norepinephrine, dopamine and leukocyte
vitamin C were measured using a combination of immunonephelometric, radioimmunoassay, immunochromatographic
and spectrophotometric procedures. Demographic, clinical and laboratory data was captured and analysed by parametric and
non-parametric analyses where appropriate.
RESULTS : Smokers were predominantly males (P<0.0001), of older age (P<0.0003) with a significantly lower body mass index
(P<0.03). Plasma levels of CRP, ferritin and dopamine were higher in the group of smokers in the setting of lower levels of
epinephrine, and leukocyte vitamin C, with CRP and vitamin C attaining statistical significance (P<0.04 and P<0.02 respectively).
Those of cortisol and norepinephrine were comparable to those of non-smokers, as were radiographic changes and clinical
indices of disease activity.
CONCLUSION : Cigarette smoking is associated with an exaggerated systemic inflammatory response in pulmonary TB in the setting
of decreased concentrations of leukocyte vitamin C. Although no significant associations with radiographic changes and
most clinical indices of disease activity were evident on presentation, these pro-inflammatory interactions may have prognostic
significance.
