Method and apparatus for distinguishing Crohn's disease from ulcerative colitis and other gastrointestinal diseases by detecting the presence of fecal antibodies to Saccharomyces cerevisiae
A method and apparatus for the differentiation of Crohn's disease from other gastrointestinal illnesses, such as ulcerative colitis and irritable bowel syndrome, using the presence of fecal anti- Saccharomyces cerevisiae antibodies (ASCA) as a marker for Crohn's disease are provided. The apparatus includes an enzyme-linked immunoassay or other immunoassay that utilizes antibodies specific to human immunoglobins for the measurement of total endogenous ASCA in a human fecal sample. The method and apparatus may be used by healthcare providers to distinguish Crohn's disease from other gastrointestinal illnesses, such as ulcerative colitis and irritable bowel syndrome.
1. A method for diagnosing Crohn's disease, the method comprising:
obtaining a fecal sample from a person; and
determining whether the fecal sample contains an elevated level of endogenous anti- Saccharomyces cerevisiae antibodies, wherein an elevated level of the endogenous anti- Saccharomyces cerevisiae antibodies is an indicator of Crohn's disease.
2. The method of claim 1 , wherein the elevated level of the endogenous fecal anti- Saccharomyces cerevisiae antibodies differentiates Crohn's disease from ulcerative colitis.
3. The method of claim 1 , wherein elevated level of the fecal endogenous anti- Saccharomyces cerevisiae antibodies differentiates Crohn's disease from irritable bowel syndrome.
4. The method of claim 1 , wherein the endogenous fecal anti- Saccharomyces cerevisiae antibodies comprise the total anti- Saccharomyces cerevisiae antibodies.
5. The method of claim 1 , wherein the endogenous fecal anti- Saccharomyces cerevisiae antibodies comprise secretory IgA.
6. The method of claim 1 further comprises diluting the fecal sample.
7. The method as recited in claim 6 , wherein the diluting step comprises diluting the fecal sample to 1:20 dilution.
8. The method of claim 6 , wherein the determination of the elevated level of the endogenous fecal anti- Saccharomyces cerevisiae antibodies in the sample includes contacting the fecal sample with an extract of Saccharomyces cerevisiae to create a treated sample.
9. The method of claim 8 , wherein the step of determining the elevated level of the endogenous fecal anti- Saccharomyces cerevisiae antibodies further includes contacting the treated sample with enzyme-linked polyclonal antibodies to create a readable sample.
10. The method of claim 9 , wherein the step of determining the elevated level of the endogenous fecal anti- Saccharomyces cerevisiae antibodies further includes determining the optical density of the readable sample at 450 nm, wherein the optical density corresponds to an elevated level of the anti- Saccharomyces cerevisiae antibodies in the readable sample.
11. The method of claim 10 , wherein if the optical density of the readable sample is greater than or equal to 0.200, the fecal sample is determined to have an elevated level of the endegenous anti- Saccharomyces cerevisiae antibodies.
12. The method of claim 1 , wherein the fecal sample includes human feces and mucosal secretions.
13. A diagnostic assay for diagnosing Crohn's disease comprising:
obtaining a human fecal sample;
diluting the fecal sample;
contacting the fecal sample with an extract Saccharomyces cerevisiae to create a treated sample;
contacting the treated sample with enzyme-linked polyclonal antibodies to create a readable sample;
adding an enzyme substrate for color development to the readable sample; and
determining the optical density of the readable sample at 450 nm to determine whether the readable sample contains an elevated level of endogenous anti- Saccharomyces cerevisiae antibodies as compared to a reference value for healthy patients.
14. The diagnostic assay of claim 13 , wherein the elevated level of the endogenous anti- Saccharomyces cerevisiae antibodies is an indicator of Crohn's disease.
15. The diagnostic assay of claim 14 , wherein an optical density of the readable sample greater than or equal to 0.200 at 450 nm is an indicator of the presence of an elevated level of the endogenous anti- Saccharomyces cerevisiae antibodies in the fecal sample.