C‐reactive protein is not a useful indicator of intermittent bacterial colonization in early lung disease of patients with cystic fibrosis

Abstract

C-reactive protein (CRP) is a general marker of the systemic inflammatory response to bacterial infection. Serial measurement of CRP is useful in monitoring respiratory exacerbations in patients with cystic fibrosis (CF) and chronic infection with Pseudomonas aeruginosa. We hypothesized that regular monitoring of CRP in young children with CF prior to colonization with P. aeruginosa might provide an objective guide to the need for antibiotic treatment. Twenty-two children were studied prospectively over a 6 month period. We measured CRP every 2 months and at the beginning and end of respiratory exacerbations. In samples taken when the children were well, median CRP was 0.45 microgram/mL compared with 1.92 micrograms/mL when they were symptomatic with positive culture results (P < 0.05). Despite this difference there was considerable overlap between CRP levels for infected and noninfected patients. A CRP value of > 1.82 micrograms/mL (the upper 95% confidence interval for a control group of well children without CF) had a sensitivity of 49% and a specificity of 83% in determining a symptomatic exacerbation. We conclude that in this group of patients CRP measurements were of little value in monitoring respiratory exacerbations in patients who become intermittently infected with either Haemophilus influenzae or Staphylococcus aureus.

Cystic fibrosis and survival to 40 years: a case-control study

“…The insignificant impact of H. influenzae and S. aureus is consistent with other studies. A European cross-sectional study demonstrated that S. aureus was not associated with worse pulmonary status and others have shown a deleterious effect on symptoms only, including the risk of massive haemoptysis [24][25][26]. The finding of a survival benefit for patients receiving oral antibiotics (without aerosolised or i.v.…”

Serum procalcitonin is not an early marker of pulmonary exacerbation in children with cystic fibrosis

“…C-reactive protein (CRP) is well known as a general marker of the systemic inflammatory response to bacterial infection. It has been suitably studied as an indicator of early respiratory exacerbations in CF patients, but was proven to be insignificant [23]. CRP does have some value in differentiating between respiratory exacerbations and acute exacerbations of asthma, but a high sensitivity and specificity is only seen in values significantly greater than most of our patients admitted for intravenous (IV) antibiotics [1,5].…”

Platelet proinflammatory activity in clinically stable patients with CF starts in early childhood

“…CRP, IgG and fibrinogen levels were measured in all patients and controls with commercially available kits from Roche Diagnostics (Grenzach, Germany) and Dade Behring (Marburg, Germany). Levels of CRP and IgG have been shown to be suitable markers of inflammation in CF previously [13][14][15]. Pulmonary function and Chrispin-Norman (CN)-score were recorded from the patients' files.…”