title: Changes in blood monocyte Toll-like receptor and serum surfactant protein A reveal a pathophysiological mechanism for community-acquired pneumonia in patients with type 2 diabetes.
abstract: BACKGROUND
  The lung is one of the target organs of microangiopathy in diabetes mellitus (DM); patients with type 2 diabetes mellitus (T2DM) are vulnerable to pneumonia, and a variety of pathophysiological mechanisms has been described.
  
  
  OBJECTIVE
  This study aimed to determine the pathophysiological mechanism of community-acquired pneumonia (CAP) in T2DM patients.
  
  
  METHODS
  A total of 90 individuals was included in this study comprised of three groups (n = 30): healthy control, T2DM and T2DM+ CAP groups. Toll-like receptor (TLR)2 and 4 protein and messenger RNA expression in peripheral blood monocytes(PBMC) was assessed by western blot and reverse transcription-polymerase chain reaction, respectively, and surfactant protein A (SP-A) levels were examined in serum samples by enzyme-linked immunosorbent assay.
  
  
  RESULTS
  In T2DM and T2DM+CAP groups, levels of both TLR2/4 protein and mRNA in PBMC were decreased compared with controls (P <0.05), with lower levels observed in the T2DM+CAP group in comparison with T2DM patients (P <0.05). The serum SP-A levels in T2DM+CAP individuals were significantly higher than the values obtained for T2DM patients (P <0.05). It also showed apparent increases when compared with that in controls although no statistical significance was detected.
  
  
  CONCLUSIONS
  In T2DM patients with pneumonia, TLR2/4 levels in PBMC and serum SP-A were altered, maybe playing an important role in the susceptibility to pneumonia in T2DM patients.
authors.affiliation: Department of Endocrinology and Metabolism, Zhongnanshan Hospital Xiamen University, Xiamen, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Que
authors.affiliation: Department of Endocrinology and Metabolism, Zhongnanshan Hospital Xiamen University, Xiamen, China.
authors.forename: X
authors.initials: X
authors.lastname: Shen
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D017714:Community-Acquired Infections / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000175:diagnosis / Q000453:epidemiology; D005260:Female; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D009000:Monocytes / Q000378:metabolism; D011014:Pneumonia / Q000097:blood* / Q000175:diagnosis / Q000453:epidemiology; D037662:Pulmonary Surfactant-Associated Protein A / Q000097:blood*; D051195:Toll-Like Receptor 2 / Q000097:blood*; D051197:Toll-Like Receptor 4 / Q000097:blood*
chemical_list: D015415:Biomarkers; D037662:Pulmonary Surfactant-Associated Protein A; C495342:TLR2 protein, human; C495345:TLR4 protein, human; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4
keywords: SP-A; TLR2; TLR4; community-acquired pneumonia; type 2 diabetes mellitus