Background and objectives: Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory disease, mainly due to tobacco smoke. Pulmonary function tests (PFTs) are mandatory to diagnose COPD which shows irreversible airway obstruction. This study was aimed at understanding the behavior of biochemical parameters such as high sensitive C-reactive protein (hs-CRP) and lactate dehydrogenase (LDH) isoenzymes in COPD. Cytoplasmic cellular enzymes, such as LDH in the extracellular space, although of no further metabolic function in this space, are of benefit because they serve as indicators suggestive of disturbances of the cellular integrity induced by pathological conditions. The lung pattern is characterized by proportional increases in isoenzymes 3, 4, and 5. Hs-CRP indicates low grade of systemic inflammation.
Materials and methods: Total (n = 45) patients of COPD (diagnosed on PFTs) were included. We followed the guidelines laid by the institute ethical committee. Investigations performed on the serum were the serum for hs-CRP, LDH isoenzymes on agarose gel electrophoresis.
Results: The results obtained showed that the value of hs-CRP was 4.6 ± 0.42 mg/L. The isoenzymes pattern was characterized by an increase in LDH-3 and LDH-4 fractions. This is evident even in those patients with normal LDH (n = 13) levels.
Interpretation and conclusion: This study states that there is a moderate positive correlation in between CRP and LDH-3 (r = 0.33; P = 0.01). Raised LDH-3 levels do not correlate with FEV(1) % (forced expiratory volume in first second) predicted. Moreover, it associates positively with hs-CRP and smoking status and negatively with body mass index. This underlines the potential of these parameters to complement the present system of staging which is solely based upon FEV(1) % predicted.
Keywords: COPD; LDH-3 isoenzyme; hs-CRP.