Plasma esterases in cystic fibrosis: the impact of a respiratory exacerbation and its treatment.
OBJECTIVE
To determine the effect of an exacerbation of respiratory symptoms in cystic fibrosis (CF) on the activities of plasma benzoylcholinesterase and butyrylcholinesterase.


METHODS
Twenty-nine patients with CF in a respiratory exacerbation and 27 healthy volunteers matched for age and sex were recruited. Blood was obtained from the patients when commencing antibiotic treatment and 14 days later on completion of treatment. One blood sample was taken from the healthy volunteers. The activities of benzoylcholinesterase and butyrylcholinesterase were determined by spectrophotometric assay. The circulating inflammatory markers, C-reactive protein and neutrophil elastase-alpha1antiproteinase complex were also measured.


RESULTS
Benzoylcholinesterase activity was significantly (P = 0.001) lower in patients at the start of a respiratory exacerbation, compared with healthy controls [mean (SD): 917 (274) versus 1191(298) nmol x ml(-1) x min(-1)]. Benzoylcholinesterase activity increased significantly in patients to 1013 (237) nmol x ml(-1) x min(-1), following a course of antibiotic treatment (P = 0.006). Butyrylcholinesterase activity was also lower (P = 0.001) in patients at the start of a respiratory exacerbation, compared with healthy controls [5.54 (1.64) versus 7.01 (1.79) micromol x ml(-1) x min(-1)], and increased significantly in the patients to 6.31 (1.58) micromol x ml(-1) x min(-1) following treatment (P = 0.006).


CONCLUSIONS
We demonstrated significant suppression of plasma esterase activities during an exacerbation of respiratory symptoms in CF, which was only partially reversed after antibiotic treatment. Further studies are needed to examine other pathways of drug metabolism in this group of chronically infected patients.
Abou-Hatab
K
K
Department of Geriatric Medicine, Academic Centre, Llandough Hospital, Penarth, UK.
Nixon
L S
LS
O'Mahony
M S
MS
Newsway
V
V
Patel
S
S
Shale
D J
DJ
Woodhouse
K W
KW
D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology* / Q000627:therapeutic use; D015415:Biomarkers / Q000097:blood; D002091:Butyrylcholinesterase / Q000097:blood*; D002097:C-Reactive Protein / Q000378:metabolism*; D003550:Cystic Fibrosis / Q000150:complications / Q000201:enzymology*; D005260:Female; D006801:Humans; D019272:Leukocyte Elastase / Q000097:blood / Q000378:metabolism*; D008297:Male; D011552:Pseudomonas Infections / Q000188:drug therapy*; D011550:Pseudomonas aeruginosa; D012141:Respiratory Tract Infections / Q000188:drug therapy*; D013053:Spectrophotometry; D000515:alpha 1-Antitrypsin / Q000378:metabolism*
D000900:Anti-Bacterial Agents; D015415:Biomarkers; D000515:alpha 1-Antitrypsin; D002097:C-Reactive Protein; D002091:Butyrylcholinesterase; D019272:Leukocyte Elastase