Influence of inflammatory response, infection, and pulmonary function in cystic fibrosis.

AIMS

Recurrent infections and activation of the inflammatory response affect the prognosis of cystic fibrosis (CF). We investigated the relationship between inflammatory response, infection, and pulmonary function in CF.

MAIN METHODS

A clinical-cross-sectional study was conducted with 86 subjects: control group (CG, n=31, the same age and sex of the CF group), and CF group (CFG, n=55, age: 1-16 years), further distributed into CFG negative or positive bacteriology (CFGB(-)/CFGB(+)), and CFG negative or positive Pseudomonas aeruginosa (CFGPa(-)/CFGPa(+)). Using the Wald test, multiple linear regression (95% confidence interval) was performed between CG and CFG, and between CG and each of the CF subgroups (CFGB(-)/CFGB(+) and CFGPa(-)/CFGPa(+)). The inflammatory markers evaluated were myeloperoxidase (MPO), adenosine deaminase (ADA) activities, interleukin-1beta (IL-1β), tumor necrosis factor-alpha (TNF-α), C-reactive protein (CRP), nitric oxide metabolites (NOx) levels, and total and differential leukocyte counts.

KEY FINDINGS

After adjusting for sex and age, CFG compared to CG revealed an increase of MPO, IL-1β (P<0.001 in all subgroups), and CRP: CFG (P=0.002), CFGB(-) (P=0.007), CFGB(+) (P=0.009), CFGPa(-) (P=0.004) and CFGPa(+) (P=0.020). NOx (P=0.001, P<0.001), leukocytes (P=0.002, P=0.001), and neutrophils (P=0.003, P<0.001) were increased in CFGB(+) and CFGPa(+), respectively. A negative correlation between FEV1 and leukocytes (P=0.008) and FEV1 and neutrophils (P=0.031) resulted in CFG.

SIGNIFICANCE

The inflammatory response characterized by the increase of MPO, IL-1β, and CRP is determinant for CF. Also leukocytosis due to neutrophilia determines the pulmonary function deficiency in this disease.