Plasma and BAL fluid concentrations of antimicrobial peptides in patients with Mycobacterium avium-intracellulare infection

Chest. 2001 Apr;119(4):1131-7. doi: 10.1378/chest.119.4.1131.


Study objectives: To investigate the roles of human alpha-defensin (HAD), human beta-defensin (HBD)-1, and HBD-2, novel antimicrobial peptides, in patients with Mycobacterium avium-intracellulare infection (MAI).

Patients: The study included 25 patients (10 men) with MAI who visited our hospital between June 1998 and August 1999.

Measurements and results: In patients with pulmonary MAI, we measured HAD and HBD-1, and HBD-2 levels in plasma and in BAL fluid (BALF) by radioimmunoassay. Plasma concentrations of HAD and HBD-2 in those patients were higher than those in control subjects, whereas HBD-1 levels were similar to those in the control subjects. High levels of HAD and HBD-2, but not HBD-1, also were observed in the BALF of MAI patients. There was a positive correlation between HAD and interleukin (IL)-8 concentrations in the BALF of patients with MAI. BALF HBD-2 concentrations also correlated positively with those of plasma HBD-2 and BALF IL-1 beta in MAI patients. Patients with cavity formation on the chest roentgenogram had higher HAD and HBD-2 levels in their BALF than those of patients without cavity formation. Treatment with clarithromycin combined with two or three other antibiotics, including ethambutol, rifampicin, ofloxacin, or ciprofloxacin, for at least 6 months resulted in a significant fall in plasma HBD-2 concentrations in responders, but not in nonresponders.

Conclusion: Our findings suggest that HAD and HBD-2 may participate in host defense and local remodeling of the respiratory tract in patients with MAI and that plasma HBD-2 levels may be a useful marker of disease activity in patients with pulmonary MAI.

MeSH terms

  • Anti-Bacterial Agents
  • Bronchoalveolar Lavage Fluid / chemistry*
  • Bronchoalveolar Lavage Fluid / cytology
  • Cell Count
  • Defensins / analysis*
  • Defensins / blood
  • Drug Therapy, Combination / therapeutic use
  • Female
  • Humans
  • Interleukin-1 / analysis
  • Interleukin-8 / analysis
  • Male
  • Middle Aged
  • Mycobacterium avium-intracellulare Infection / drug therapy
  • Mycobacterium avium-intracellulare Infection / metabolism*
  • Radioimmunoassay


  • Anti-Bacterial Agents
  • Defensins
  • Interleukin-1
  • Interleukin-8