RT Journal Article
SR Electronic
T1 Cystic fibrosis and survival to 40 years: a study of CFTR function
JF European Respiratory Journal
JO Eur Respir J
FD European Respiratory Society
SP erj00790-2010
DO 10.1183/09031936.00079010
A1 N.J. Simmonds
A1 L. D'Souza
A1 M. Roughton
A1 E.W.F.W. Alton
A1 J.C. Davies
A1 M.E. Hodson
YR 2010
UL http://erj.ersjournals.com/content/early/2010/09/16/09031936.00079010.abstract
AB Significant survival heterogeneity exists in cystic fibrosis (CF). Our aim was to determine whether residual function of the cystic fibrosis transmembrane conductance regulator (CFTR) is present in long-term survivors with severe mutations.Nasal potential difference (PD) and sweat chloride were measured in 34 long-term survivors (aged ≥40 years) - compared to young patients (18–23 years) with severe (n=30) and mild (n=31) lung disease.Baseline PD was not significantly different across the three groups (long-term survivors, −42.8(range −71.0 to −20.5)mV; young/mild, −40.5(−58.8 to −19.5); young/severe,−46.3(−74.0 to −20.0)). Response to amiloride (ΔAmil) was significantly different across the three groups (p=0.01); long-term survivors had values (27.8 (8.5–46)mV) which were not different to either young group but the young/severe group had significantly higher values (29.5 (11–47)mV) than those in the young/mild group (22.0 (7–39)mV; p<0.01). Baseline PD and ΔAmil were associated with FEV1 (co-efficient −0.13 (95% CI −0.23, −0.03; p=0.009) and −0.12 (95% CI (−0.20, −0.04; p=0.003), respectively). Sweat chloride was lowest (p<0.05) in the young/severe group (93.5 (74–111)mmol·l−1 vs. 98.8 (76.5–116.0; long-term survivors) and 99.5 (80.0–113.5; young/mild)).ΔAmil is associated with FEV1 but our findings indicate that long-term survival cannot be explained by residual CFTR function when measurements are taken in later life.