New England Journal of Medicine, May 2, 1996 -- Volume 334, Number 18
Kenneth D. Fine
The following are comments on this article by Karoly Horvath, M.D., Ph.D., of Baltimore, Maryland, USA. If you have any questions you can e-mail him at: email@example.com
Date: 05/02/96 - 08:20:20 AM. Subject: Re: Fecal Occult Blood, Plus Elevated Liver Enzymes FECAL OCCULT BLOOD:
The cited NEJM paper found occult intestinal bleeding in patients who had some degree (partial and total) of intestinal villous atrophy. However, this paper have certain methodological problems. The first, and most important -as you can read in the editorial comment- that they did not place the patient on a specific diet before collecting the stool. It is a rule that the patients should be on a diet which eliminate all the peroxidase containing food. So this may increase the number of false positive cases.
The second problem that the hemoccult test is only a screening method, which does not give information about the degree of blood loss. The test can be positive in the presence of small amount of blood in the stool. While this paper has limitations, I should accept that patients with mucosal atrophy and inflammation have small amount of blood loss. So I do not have any doubt regarding the final conclusion of paper, that patients with active celiac disease have blood loss in the stool. This is not surprising and not a novel finding.
To avoid any panic in the celiac community I do not recommend to post this finding without appropriate comment to the Celiac List. We should emphasize one sentence from this paper: ALL THE PATIENTS WITH PREVIOUSLY DIAGNOSED AND TREATED CELIAC SPRUE HAD NEGATIVE TESTS FOR FECAL OCCULT BLOOD.
It is well known that patient with intestinal inflammation may have elevated liver enzymes. The well known examples are patients with inflammatory bowel disease. Because patients with active celiac disease have significant accumulation of inflammatory cells in the mucosa it is not surprising that a percentage of patients with active celiac disease have elevated liver enzymes. However, this is a temporary elevation, which disappears on gluten-free diet.
The explanation is not clear for this finding. The simplified explanation is that there is an increased permeability in the inflamed intestinal segments and different toxins, which normally are detoxified by the enterocyte Cytochrom P450 enzyme system, enter the portal circulation and there is an increased toxin load into the liver.