Publication:

Elevated levels of serum sialic acid and C-reactive protein: markers of systemic inflammation in patients with chronic obstructive pulmonary disease

Background Chronic obstructive pulmonary disease (COPD) is a systemic chronic inflammatory disease with pulmonary and extra-pulmonary manifestations involving lungs causing airways dysfunction. C-reactive protein (C-RP) is a positive acute phase reactant and albumin a negative phase reactant during inflammation in COPD patients. Sialic acid (SA) prevalent in mucus rich tissues is gaining importance as biochemical marker in inflammatory immune response. Purpose of present study was to measure serum C-reactive protein (C-RP), total sialic acid and albumin levels in COPD patients and establish there association in COPD and compare with healthy controls.

Methods Seventy five clinically confirmed COPD patients, both male and female between the age group of 38-70 years were selected for the study and age/ sex matched healthy volunteers as controls were selected for comparison. Serum samples were analyzed for C-RP (mg/dl) by nephalometry and TSA (mmol/L) by periodate resorcinol method and albumin by dye binding method by spectrophotometer.

Results The mean value of serum C-RP in cases was 3.26±2.0 (mg/dl) and in controls 0.57±0.34 (mg/dl) with p<0.001. TSA in cases was 3.53±1.41 (mmol/L) compared to controls 1.81±0.53 (mmol/L), p<0.001. There was a statistically significant positive correlation between C-RP and TSA (r=0.755, p<0.001). The mean value of Albumin in cases decreased (2.54±0.87) as compared to control (4.07±0.66) (p<0.001) showed negative correlation with C-RP (r= -0.418, p<0.01) and TSA (r= -0.728, p<0.001). There was a significant decrease in BMI among cases 19.95±3.17 compared to control 21.17±1.78 p<0.001.

Conclusions C- reactive protein in association with TSA has increased in COPD as a marker of systemic inflammation. Albumin and BMI decreased as a result of nutritional depletion. Patients with low BMI and low serum albumin level have greater risk of having exacerbation, acute respiratory failure than patients with normal BMI.