Frequency of ASCA seropositivity in children with cystic fibrosis.
OBJECTIVE
To determine the frequency of anti-Saccharomyces cerevisiae antibodies (ASCA) seropositivity in pediatric patients with cystic fibrosis (CF) and correlate ASCA with clinical features.


METHODS
Prospective study of children with CF aged 2 to 21 years enrolled from The Children's Hospital Cystic Fibrosis Center. Exclusion criteria included Crohn disease, immunodeficiency or immunoglobulin A deficiency. The frequency of ASCA (ASCA immunoglobulin A and immunoglobulin G) was measured by an enzyme-linked immunosorbent assay kit provided by Inova, Inc. (San Diego, CA). The CF Foundation database was queried for clinical data on ASCA seropositive patients.


RESULTS
Seventeen (20.7%) of 82 patients were seropositive for ASCA. Of these, eight had immunoglobulin A antibodies, six had immunoglobulin G antibodies and three had both. ASCA seropositivity in CF patients was significantly greater than the general population (20.7% versus 4%, P < 0.0001), using an exact binomial test on a single proportion. The 95% confidence limits around our observed proportion were 12.6% to 31.1%. Of 17 ASCA positive patients, 1 (5.8%) had a history of meconium ileus, 14 (82.4%) had DeltaF508 gene mutation, 9 (52.9%) had positive sputum cultures for fungal organisms, and 17 (100%) had an ideal body weight % >or=85%.


CONCLUSIONS
Patients with CF have a higher frequency of ASCA seropositivity than the general population. When evaluating CF patients for Crohn disease, ASCA should be used with caution. The reasons for higher ASCA seropositivity in CF patients are unknown, but may include exposure to fungal organisms via intestinal or pulmonary sources.
Condino
Adria A
AA
The Children's Hospital, University of Colorado Health Sciences Center, Department of Pediatrics, Denver, USA.
Hoffenberg
Edward J
EJ
Accurso
Frank
F
Penvari
Chureeporn
C
Anthony
Meg
M
Gralla
Jane
J
O'Connor
Judith A
JA
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000908:Antibodies, Fungal / Q000097:blood*; D002648:Child; D003550:Cystic Fibrosis / Q000097:blood / Q000150:complications*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005260:Female; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D008297:Male; D009181:Mycoses / Q000150:complications / Q000453:epidemiology*; D011446:Prospective Studies; D012441:Saccharomyces cerevisiae / Q000276:immunology*; D016036:Seroepidemiologic Studies
D000908:Antibodies, Fungal; D007070:Immunoglobulin A; D007074:Immunoglobulin G