No abstract

Background: Fecal calprotectin (FC) has been proposed as a marker of inflammatory bowel disease (IBD), but few studies have evaluated its usefulness in patients with chronic diarrhea of various causes. We evaluated the diagnostic accuracy of a FC assay in identifying "organic" causes of chronic diarrhea in consecutive adults and children. Methods: We consecutively enrolled 70 adult patients (30 males, 40 females; median age, 35 years) and 50 children (20 males, 30 females; median age, 3.5 years) with chronic diarrhea of unknown origin. All patients underwent a complete work-up to identify the causes of chronic diarrhea. FC was measured by ELISA. Results: In adult patients, FC showed 64% sensitivity and 80% specificity with 70% positive and 74% negative predictive values for organic causes. False-positive results (8 of 40 cases) were associated with the use of aspirin (3 cases) or nonsteroidal antiinflammatory drugs (1 case) and with the presence of concomitant liver cirrhosis (3 cases). False-negative results mainly included patients suffering from celiac disease (5 cases). Patients with IBD (9 cases) were identified with 100% sensitivity and 95% specificity. In pediatric patients, sensitivity was 70%, specificity was 93%, and positive and negative predictive values were 96% and 56%.

Adrenal autoantibodies (AA) were found in 23 of 2571 (0.9%) patients with organ-specific autoimmune diseases, in one of 632 first-degree relatives of insulin-dependent diabetic patients, and in none of 375 normal controls. In AA-positive subjects the prevalence of human leucocyte antigens (HLA)-A1, -B8 and -DR3 was significantly higher with respect to the general population. Two groups were followed (15 subjects persistently positive for AA and 51 negative subjects) for a mean period of 3.2 years. Yearly tests were made for AA and adrenal function. Of the 15 subjects persistently positive for AA, six developed Addison's disease after a period varying from 6 months to 10 years. Of the 51 subjects initially negative, two became positive during follow-up, and one of these developed Addison's disease 15 months later. In contrast, all the remaining 49 persistently negative subjects maintained normal adrenal function tests. Overall, of the 17 positive subjects, seven (41%) developed Addison's disease, three (18%) showed various degrees of subclinical adrenocortical failure and the remaining seven maintained normal glandular function. In the positive patients the yearly incidence of detriment in adrenal function was 19%. Patients who developed Addison's disease showed significant association with HLA-B8 phenotype. The development from normal adrenocortical function to overt Addison's disease seemed to progress through four distinct stages of functional impairment: increased plasma renin activity with normal/low aldosterone (stage 1), low cortisol response after i.v. administration of ACTH (stage 2), increased ACTH (stage 3), and low basal cortisol (stage 4).(ABSTRACT TRUNCATED AT 250 WORDS)

SUMMARY BackgroundMany coeliac disease patients with atypical symptoms remain undiagnosed.

No abstract