Affiliations: State Key Lab of the Respiratory Disease, Guangzhou
Institute of Respiratory Disease, First Affiliated Hospital of Guangzhou
Medical College, Guangdong, China
Note: [] Corresponding author: Rong-Chang Chen, State Key Lab of the
Respiratory Disease, Guangzhou Institute of Respiratory Disease, First
Affiliated Hospital of Guangzhou Medical College, Guangdong, China. Tel.: +86
20 83062870; Fax: +86 20 83062729; E-mail: chenrc@163.vip.com
Abstract: Background: Surfactant protein D (SP-D) is a lung-specific protein
proposed to predict clinical outcomes in patients with chronic obstructive
pulmonary disease (COPD). However, the changes in serum SP-D during acute
exacerbation (AECOPD) episodes and the relationship of serum SP-D with the
overall severity of the disease in stable COPD (SCOPD) remain unclear. Methods: Serum SP-D levels were analyzed in three groups, including
AECOPD (n=40), SCOPD (n=71), and controls (n=60). In AECOPD group, serum SP-D
levels were determined at 1, 5, 14, and 30 days post-exacerbation. In SCOPD
group, BODE (body mass index, airflow obstruction, dyspnea, exercise capacity)
index was evaluated for severity assessment. Results: Serum SP-D levels were sequentially elevated from the
controls to the SCOPD, and then to the AECOPD (p< 0.001). During an AECOPD
episode, the raised serum SP-D levels subsided at day 5 (p> 0.05), fell
markedly at day 14 (p< 0.001), and continued to decline at day 30 (p<
0.001). Among patients with SCOPD, serum SP-D levels correlated positively with
the BODE index (p< 0.01). Conclusions: The longitudinal changes in serum SP-D levels during an
AECOPD episode suggest that SP-D may be a potential systemic biomarker for COPD
exacerbation. The correlation of serum SP-D levels with the BODE index suggests
that circulating SP-Ds can reflect the overall severity of SCOPD.
Keywords: BODE index, COPD, exacerbation, surfactant protein D (SP-D), airflow limitation
