To Evaluate the Serum Levels of suPAR and Interlukin-6 and Their Associations to Severity in Chronic Obstructive Pulmonary Disease Patients: A Case Control Study

Background: Chronic Obstructive Pulmonary Disease (COPD) is characterized by an abnormal inflammatory response of airways. The disease progress can be diagnosed at the early stage of pulmonary inflammation by using a novel biomarkers like soluble urokinase-type plasminogen activator receptor (suPAR) and Interleukin-6. Materials and Methods: Study participants were grouped into cases- COPD (n=35) and healthy controls (n=35) and recruited for the study after obtaining informed consent. As specified by GOLD criteria, COPD group participants were graded into grades I-IV. Serum suPAR and IL-6 assays were done for all the study participants. Results: The level of suPAR among COPD grades I-IV (5.75±0.544 ng/ml; 5.88±0.942 ng/ml; 6.78±1.05 ng/ml; 15.0±15.8 ng/ml respectively) were high compared to healthy controls (4.12± 6.17 ng/ml) and was statistically significant. The levels of IL-6 among COPD grade I-IV (8.06± 0.839 pg/ml; 11.0±2.40 pg/ml; 12.9±3.76 pg/ml; 13.4±2.67 pg/ml respectively) were high compared to healthy controls (4.37± 1.44 pg/ml) and was statistically significant. The spirometry readings- FEV1, FVC values were significantly lower among patients with COPD when compared with the healthy controls (P<0.05). It was observed that an inverse correlation was found between serum level of suPAR, IL-6 levels versus FEV1, FVC values which was statistically significant ( p<0.05). Our study indicated that serum suPAR and IL-6 may play an important role in the inflammatory process of COPD particularly in grades II, III and IV COPD. Hence, serum suPAR and IL-6 measurements may be useful for the evaluation and prognosis of COPD patients. Conclusion: We conclude that cases of moderate to severe grades of COPD with greater degrees of obstruction of the airways have higher levels of suPAR, IL-6 in serum. The serum levels of these cytokines can therefore be utilized as the clinical and prognostic parameters for evaluation of the disease severity and tailored therapy for the same.