In November 1998 issue of American Journal of Gastroenterology under “What's New in GI” R. L. Young reviewed a paper on ASCA marker in Crohn’s disease (1). There has been a surge of papers in the past six months (1-3) confirming that Anti-Saccharomyces cerevisiae mannan antibodies (ASCA) should be considered as a significant diagnostic tool. In this review the author notes that “we all need help in differentiating tough cases of ulcerative colitis from Crohn's disease” which was shown to be possible by combining ASCA and pANCA tests, but also states that “this test is not available for clinical use”. Although the group from France authored the paper under review, one of the co-authors was Stephan Targan, Director of Gastroenterology and the IBD Center, Cedar Sinai Medical Center, Los Angeles. Through the IBD Center we were introduced to Prometheus Labs, where ASCA testing is commercially available. Prometheus accepts clinical specimens from around the world for evaluation using their proprietary testing systems. Located in San Diego, California, Prometheus is interested in professional collaborations with GI disease and IBD researchers worldwide, and will serve as a technological development center to bring exciting new diagnostic reagents and assay systems to the medical community. For additional information on Prometheus visit the Internet site: http://www.prometheus-labs.com/organization/, call 1-888-423-5227 or (619) 824-0895, Fax: (619) 824-0896 or E-mail: [email protected].
References:
1. Quinton JF, Sendid B, Reumaux D, at al. Anti-Saccharomyces Cerevisiae Mannan Antibodies Combined With Antineutrophil Cytoplasmic Autoantibodies In Inflammatory Bowel Disease: Prevalence And Diagnostic Role. Gut, 1998 Jun, 42:6, 788-91
2. Sendid B, Quinton JF, Charrier G, et al. Anti-Saccharomyces Cerevisiae Mannan Antibodies In Familial Crohn’s Disease. Am J Gastroenterol, 1998 Aug, 93:8, 1306-10
3. Ruemmele FM, Targan SR, Levy G, et al. Diagnostic Accuracy Of Serological
Assays In Pediatric Inflammatory Bowel Disease. Gastroenterology, 1998
Oct, 115:4, 822-9
and here are the abstracts of mentioned papers:
ASCA—NEW MARKER FOR CROHN'S DISEASE!?
R. L. Young, M.D. , Am J Gastroenterol,1998 Nov, 93:11, 2020-2020
Review of: Quinton JF, Sendid B, Reumauz D, et al. Anti-Saccharomyces
cerevisiae mannan antibodies combined with antineutrophil cytoplasmic autoantibodies
in inflammatory bowel disease:
Prevalence and diagnostic role. Gut 1998;42:788-91.
Serum samples were obtained from patients with Crohn's disease, ulcerative
colitis, normal
controls, and other patients with diarrhea. Determinations of pANCA
and ASCA (an ELISA
anti-Saccharomyces cerevisiae mannan antibodies test) were made. The
combination of a positive ASCA test and a negative pANCA test yielded
a sensitivity (49%), specificity (97%), and positive predictive value (96%)
for Crohn's disease. This early study suggests ASCA may be of benefit
in helping to diagnose Crohn's disease and may be a marker in helping to
delineate ulcerative colitis from Crohn's disease.
This test is not available for clinical use, but we should watch for
further multicenter and prospective studies for this ASCA test. We all
need help in differentiating tough cases of ulcerative colitis from
Crohn's disease.
DIAGNOSTIC ACCURACY OF SEROLOGICAL ASSAYS IN PEDIATRIC INFLAMMATORY
BOWEL DISEASE [SEE COMMENTS]
Ruemmele FM; Targan SR; Levy G; Dubinsky M; Braun J; Seidman EG, Division of Gastroenterology-Nutrition, Department of Pediatrics, Ste-Justine Hospital, University of Montreal, Montreal, Quebec, Canada. Gastroenterology, 1998 Oct, 115:4, 822-9
BACKGROUND & AIMS: Accurate serological assays are desirable for
the diagnosis of inflammatory bowel disease (IBD) types in the pediatric
age group. The aim of this study was to test the diagnostic accuracy of
modified assays for perinuclear (p) antineutrophil cytoplasmic antibodies
(ANCAs) and anti-Saccharomyces cerevisiae antibodies (ASCAs) in patients
with pediatric ulcerative colitis (UC) and Crohn’s disease (CD) and in
those without IBD. METHODS: With observers blinded to patients’ diagnoses,
serum specimens were analyzed for immunoglobulin (Ig) A and IgG ASCAs and
ANCAs by enzyme-linked immunosorbent assay. The perinuclear location of
ANCAs visualized by indirect immunofluorescence was confirmed by its disappearance
after administration of deoxyribonuclease. RESULTS: IgA and IgG ASCA
titers were significantly greater and highly specific for CD (95% for either,
100% if both positive). pANCA was 92% specific for UC and absent in all
non-IBD controls. The majority of patients with CD positive for pANCA had
a UC-like presentation. Disease location, duration, activity, complications,
and treatment with immunosuppressive drugs did not have an impact on the
ASCA or pANCA assay results. After resection, UC patients remained pANCA
positive, in contrast to patients with CD, in whom ASCA titers decreased
toward normal values postoperatively. CONCLUSIONS: ASCA and pANCA
assays are highly disease specific for CD and UC, respectively. These serological
tests can assist clinicians in diagnosing and categorizing patients with
IBD and may be useful in making therapeutic decisions.
ANTI-SACCHAROMYCES CEREVISIAE MANNAN ANTIBODIES IN FAMILIAL CROHN’S DISEASE.
Sendid B; Quinton JF; Charrier G; Goulet O; Cortot A; Grandbastien B; Poulain D; Colombel JF, Service d’Hépato-Gastroentérologie et Registre des Maladies Inflammatoires du Tube Digestif du Nord-Ouest de la France (EPIMAD), CHRU Lille. Am J Gastroenterol, 1998 Aug, 93:8, 1306-10
OBJECTIVE: Anti-Saccharomyces cerevisiae mannan antibodies (ASCA) are
associated with Crohn’s disease. The aim of this study was to determine
the prevalence of ASCA in families in which at least two members were affected
with Crohn’s disease. METHODS: A total of 20 families including two (n=15)
or more (n=5) patients with Crohn’s disease were tested for ASCA with use
of an ELISA method. Overall, 51 affected members, 66 healthy first degree
relatives, and 163 healthy control subjects were studied. RESULTS: ASCA
were detected in 35 of 51 (69%) patients with Crohn’s disease and in 13
of 66 (20%) healthy relatives versus one of 163 healthy control subjects
(p < 0.0001 and p < 0.001). ASCA-positive relatives were distributed
in 12 of 20 families. ASCA were present in eight healthy parents
and four healthy siblings. The prevalence of ASCA in relatives did not
depend on the ASCA status of affected members. CONCLUSION: ASCA in 20%
of healthy first degree relatives of patients with Crohn’s disease suggest
that these antibodies might be a subclinical marker for Crohn’s disease
in families. Whether ASCA reflect environmental or genetic factors
or a combination of both is unknown.
ANTI-SACCHAROMYCES CEREVISIAE MANNAN ANTIBODIES COMBINED WITH ANTINEUTROPHIL CYTOPLASMIC AUTOANTIBODIES IN INFLAMMATORY BOWEL DISEASE: PREVALENCE AND DIAGNOSTIC ROLE.
Quinton JF; Sendid B; Reumaux D; Duthilleul P; Cortot A; Grandbastien B; Charrier G; Targan SR; Colombel JF; Poulain D, Service d’HÆepato-GastroentÆerologie, HÈopital Huriez, Lille, France. Gut, 1998 Jun, 42:6, 788-91
BACKGROUND: Perinuclear antineutrophil cytoplasmic autoantibodies (pANCA)
are a well recognised marker for ulcerative colitis. Antibodies to oligomannosidic
epitopes of the yeast Saccharomyces cerevisiae (ASCA) are a new marker
associated with Crohn’s disease. AIMS: To assess the value of detecting
pANCA and/or ASCA for the diagnosis of ulcerative colitis and Crohn’s disease.
METHODS: Serum samples were obtained from 100 patients with Crohn’s disease,
101 patients with ulcerative colitis, 27 patients with other miscellaneous
diarrhoeal illnesses, and 163 healthy controls. Determination of pANCA
and ASCA was performed using the standardised indirect immunofluorescence
technique and an ELISA, respectively. RESULTS: The combination of a
positive pANCA test and a negative ASCA test yielded a sensitivity, specificity,
and positive predictive value of 57%, 97%, and 92.5% respectively for ulcerative
colitis. The combination of a positive ASCA test and a negative pANCA test
yielded a sensitivity, specificity, and positive predictive value of 49%,
97%, and 96% respectively for Crohn’s disease. Among patients with
miscellaneous non-inflammatory bowel disorders, three were ASCA positive
and two were pANCA positive. One control was ASCA positive. The presence
of ASCA in patients with Crohn’s disease was associated with small bowel
involvement. CONCLUSION: ASCA and pANCA are strongly associated with Crohn’s
disease and ulcerative colitis, respectively. Combination of both tests
could help the diagnosis of inflammatory bowel disease.
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