Correlation Study Between Serum Free Light Chain And The Severity And Stages Of Chronic Obstructive Pulmonary Disease

Objective To analyze the level of serum free light chain (sFLC) in different groupsof chronic obstructive pulmonary disease (COPD) and to explore the correlation betweensFLC and the severity and stages of COPD.Methods78outpatients or inpatients with COPD were selected as research objectfrom January2013to June2013in our hospital（45patients with acute exacerbation stageof COPD and33patients with stable stage of COPD）and30cases of health physicalexamination persons were selected as control group at the same period. The smokinginformation was recorded. Routinely, serum tumor necrosis factor-α（TNF-α）,interleukin-8（IL-8）, blood neutrophils(PMN) and lung function were measured. The levelof sFLC(κFLC and λFLC)were detected by immuno-nephelometric assays. The correlationbetween sFLC and TNF-α, IL-8, PMN, lung function, were analyzed. Respectively, thedifferences of sFLC, TNF-α, IL-8, PMN and lung function were compared between controlgroup, acute exacerbation stage group and stable stage group of COPD. The differences ofsFLC, TNF-α, IL-8, and PMN were compared between control group and different diseaseseverity groups of COPD. The differences of sFLC, TNF-α and IL-8were comparedbetween smokers and non-smokers of control group and COPD group.Results The level of sFLC, TNF-α and IL-8with COPD groups were obviouslyhigher than control group(P <0.05). The level of sFLC, TNF-α and IL-8in severe andvery severe COPD group were obviously higher than mild and moderate COPD group (P <0.05). The level of sFLC, TNF-α and IL-8in acute exacerbation stage group of COPDwere obviously higher than stable stage group of COPD (P <0.05). The level of serumκFLC with smokers in COPD group and control group were significantly higher thannon-smokers (P <0.05). The level of serum λFLC with smokers in COPD group wassignificantly higher than non-smokers (P <0.05), and the level of serum λFLC with smokers in control group was higher than non-smokers, but there was no statisticaldifferences (P>0.05). The level of sFLC was positively correlated with TNF-α, IL-8, PMNand negatively correlated with lung function in COPD patients.Conclusion Compared with control group, sFLC of COPD group is significantlyhigh. The level of sFLC has a certain correlation with the severity of COPD, which may beserved as an index of evaluating the severity of COPD. The level of sFLC also has acertain correlation with the stages of COPD, and monitoring sFLC may be used to reflectthe dynamic changes of COPD stages. Smoking is one of factors which can elevate sFLClevel in COPD patients.