title: CD4+ and CD8+ T lymphocytes in lung tissue of NSIP: correlation with T lymphocytes in BALF.
abstract: BACKGROUND
  Nonspecific interstitial pneumonia (NSIP) is characterized by the interstitial infiltration T lymphocytes (TLs). Bronchoalveolar lavage fluid (BALF) has been used to analyze the inflammatory cells infiltrating in lung. The controversy about whether the BALF cellular profile reflects T lymphocytes in lung tissue still persists. Some studies found a positive correlation of cell composition between BALF and lung tissue, but others gave opposite conclusion.
  
  
  OBJECTIVE
  To investigate CD4+ and CD8+ T lymphocytes distribution in lung tissue of NSIP and the relationship with T lymphocytes in bronchoalveolar lavage.
  
  
  METHODS
  Thirty-seven patients diagnosed as NSIP were included. The pathological and BALF date were reviewed. The characteristics of TLs infiltration in different lung regions were investigated.
  
  
  RESULTS
  The study included 28 women. The median age was 48 years. In lung tissue, CD4+ and CD8+ lymphocytes (counts/0.1mm2) were separately accounted in lymphoid follicle region (156.51 ± 90.70 vs 85.30 ± 43.75), small blood vessel region (66.58 ± 31.99 vs 58.43 ± 30.24), interstitial region (37.60 ± 19.40 vs 47.12 ± 33.42) and small airway region (26.59 ± 17.04 vs 40.18 ± 34.02). CD4+/CD8+ ratios in lymphoid follicle and small vessel > 1, in interstitium and small airway <1. The number of CD8+ lymphocytes in BALF was correlated with CD8+ lymphocytes around small airway (r = 0.360, p = 0.029) and in interstitial region (r = 0.451, p = 0.005). CD4+/CD8+ ratio in BALF was correlated with that in small airway region (r = 0.437, p = 0.007) and interstitial region (r = 0.468, p = 0.003).
  
  
  CONCLUSIONS
  In NSIP, T lymphocytes were distributed in different regions of lung tissue. The CD8+ T lymphocytes and CD4+/CD8+ ratio in BALF reflect those in interstitium regions and around small airway of the lung.
authors.affiliation: Department of Internal Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100730, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Qin
authors.forename: Wen-Ze
authors.initials: WZ
authors.lastname: Wang
authors.forename: Hong-Rui
authors.initials: HR
authors.lastname: Liu
authors.forename: Wen-Bing
authors.initials: WB
authors.lastname: Xu
authors.forename: Ming-Wei
authors.initials: MW
authors.lastname: Qin
authors.forename: Zhu-Hua
authors.initials: ZH
authors.lastname: Zhang
authors.forename: Yi
authors.initials: Y
authors.lastname: Xiao
authors.forename: Wen-Jie
authors.initials: WJ
authors.lastname: Zhen
authors.forename: Ju-Hong
authors.initials: JH
authors.lastname: Shi
mesh_terms: D000328:Adult; D000368:Aged; D001706:Biopsy; D001992:Bronchoalveolar Lavage Fluid / Q000276:immunology*; D016516:CD4-CD8 Ratio; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D054988:Idiopathic Interstitial Pneumonias / Q000276:immunology* / Q000473:pathology; D008168:Lung / Q000276:immunology* / Q000473:pathology; D018655:Lymphocyte Count; D016131:Lymphocyte Subsets / Q000276:immunology; D008297:Male; D008875:Middle Aged; D055815:Young Adult