title: Increased absolute number but not proportion of gamma/delta T-lymphocytes in the bronchoalveolar lavage fluid of patients with active pulmonary tuberculosis.
abstract: METHODS
  The proportions and absolute cell count of gamma/delta T-lymphocytes in the peripheral blood of patients with pulmonary tuberculosis (PTB) remains controversial. Since PTB is an infections airway disease, bronchoalveolar T-lymphocytes should be a better indicator of local immune T-cell reaction after TB infection than peripheral blood T-lymphocytes.
  
  
  OBJECTIVE
  To quantitate the absolute cell count and proportions of gamma/delta T-lymphocytes in the bronchoalveolar lavage fluid (BALF) of patients with active PTB.
  
  
  METHODS
  Bronchoalveolar lavage (BAL) and analysis of lymphocytes in the BALF was performed in 25 patients with active PTB and 16 normal controls. All of the patients were negative for HIV infection and none was immunocompromised. BALF and blood were prepared for cell differential count and flow cytometry analysis using monoclonal antibodies CD3, CD4, CD8, CD25, HLA-DR and gamma/delta as well as alpha/beta T-lymphocyte receptors.
  
  
  RESULTS
  The number of cells per volume of recovered BALF was significantly higher in the patients with active PTB than in normal controls. BALF from active PTB patients also showed increased percentage of lymphocytes and neutrophils. The absolute number of total lymphocytes, CD3+ lymphocytes and CD3+ gamma/delta T-lymphocytes were significantly higher in the BALF, but not in the blood, of patients with TB, however, the proportions of CD3+ gamma/delta T-lymphocytes in BALF of patients with TB was comparable to that of normal controls. gamma/delta T-lymphocytes in the BALF rarely expressed CD4, CD25, and HLA-DR in both groups.
  
  
  CONCLUSIONS
  These results suggest that gamma/delta T-lymphocytes are not the major subpopulation of CD3+ lymphocytes in the BALF that react to mycobacterial infection in the patients with clinically established active TB.
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Chang Gung Memorial Hospital, Taipei, Taiwan. drtsao@adm.cgmh.com.tw
authors.forename: T C
authors.initials: TC
authors.lastname: Tsao
authors.forename: K C
authors.initials: KC
authors.lastname: Tsao
authors.forename: M C
authors.initials: MC
authors.lastname: Lin
authors.forename: C C
authors.initials: CC
authors.lastname: Huang
authors.forename: C T
authors.initials: CT
authors.lastname: Yang
authors.forename: S K
authors.initials: SK
authors.lastname: Liao
authors.forename: K S
authors.initials: KS
authors.lastname: Chang
mesh_terms: D000328:Adult; D001992:Bronchoalveolar Lavage Fluid / Q000276:immunology*; D005260:Female; D006801:Humans; D018655:Lymphocyte Count; D016131:Lymphocyte Subsets; D008297:Male; D008875:Middle Aged; D013601:T-Lymphocytes; D014397:Tuberculosis, Pulmonary / Q000276:immunology*