Tumour necrosis factor-alpha and nitric oxide response in different categories of tuberculosis patients.

OBJECTIVE: To compare the magnitude of tumour necrosis factor alpha (TNF-α) and nitric oxide (NO) response in different categories of active tuberculosis (TB) patients by ex vivo experiment. DESIGN: New, relapsed (recurrent), miliary and pleural effusion TB cases were recruited with matched healthy controls. TNF-α and NO were measured from the culture supernatant of peripheral blood monocytes derived from cases and controls with and without challenge with live Mycobacterium tuberculosis H37Rv. RESULTS: TNF-α and NO production varied significantly among the different categories of TB patients. The magnitude was highest among patients with pleural effusion and lowest in miliary TB cases. In between, progressive decreases in response were noted in new and relapse cases. Overall, positive correlations between TNF-α and NO were noted among the diseased and healthy groups. CONCLUSION: Distinct TNF-α and NO levels appear to be associated with different clinical forms of TB and might help to assess prognosis and contribute to a better understanding of underlying immunopathological mechanisms.