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Increased cortisol: cortisone ratio in acute pulmonary tuberculosis
R W Baker1, B R Walker, R J Shaw
1Centre for Infectious Diseases and Department of Bacteriology, University College and Royal Free School of Medicine, London, UK.
American Journal of Respiratory and Critical Care Medicine
|November 9, 2000
Summary
In active pulmonary tuberculosis (TB), the body produces more active cortisol due to altered metabolism, particularly in the lungs. This shift may explain the immune suppression seen in progressive TB.
Area of Science:
- Endocrinology
- Immunology
- Infectious Diseases
Background:
- Progressive tuberculosis (TB) is associated with immunoparesis.
- Altered cortisol metabolism is a potential factor in TB-related immunoparesis.
Purpose of the Study:
- To investigate the role of altered cortisol metabolism in mediating immunoparesis in progressive TB.
- To study the hypothalamic-pituitary-adrenal (HPA) axis and 11beta-hydroxysteroid dehydrogenase (11-HSD) activities in TB patients.
Main Methods:
- Measured cortisol/cortisone metabolite ratios in 24-h urine.
- Assessed cortisone-to-cortisol conversion in peripheral plasma after oral cortisone administration.
- Analyzed cortisol/cortisone ratios in bronchoalveolar lavage fluid and plasma.
- Evaluated HPA axis responses to dexamethasone, CRH, and ACTH stimulation.
Main Results:
- Active pulmonary TB (PTB) showed a shift towards cortisol in urine metabolites compared to cured TB (CTB) and healthy volunteers (HV).
- Cortisone-to-cortisol conversion was higher in PTB patients.
- Cortisol/cortisone ratio was elevated in bronchoalveolar lavage fluid in PTB but not plasma.
- HPA axis responses to stimulation tests were normal in PTB patients.
Conclusions:
- Central HPA axis control of glucocorticoid production is normal in pulmonary TB.
- Peripheral cortisol metabolism, especially in the lungs, is altered in PTB, favoring the active cortisol metabolite.
- This altered peripheral metabolism offers a potential mechanism for the immunoparesis observed in progressive pulmonary TB.