R. Fiandra

Intestinal permeability in Crohn's disease patients and their first degree relatives.

BACKGROUND Family studies suggested that an altered intestinal permeability plays a role in the genesis of Crohns disease. AIM Aim of the present study was to investigate a possible genetic alteration of the mucosal barrier in Crohns disease. SUBJECTS 16 Crohns disease patients and 26 of their cohabiting first degree relatives were studied. METHODS To investigate intestinal permeability, Cellobiose/Mannitol test was administered to both groups. RESULTS In the two groups, we found that the median intestinal permeability values were higher and statistically different from those obtained in 32 healthy control subjects as well as in five healthy control families. Six (37.5%) Crohns disease patients and three (11.5%) of their first degree relatives showed increased individual intestinal permeability values. Intestinal permeability alteration in Crohns disease patients was unrelated to sex, age, disease activity, localisation, duration, treatment schedule, as well as to serum anti-Saccharomyces cervisiae antibody positivity in a pilot study conducted in 7 Crohns disease patients; anti-Saccharomyces cervisiae antibody values were negative in all 10 first degree relatives investigated. CONCLUSIONS These findings demonstrate the increase in IP in 37% of the patients and in 11% of their relatives. More extensive investigation of the correlation between ASCA alterations and IP will be needed in both patients with Crohns disease and their relatives.

Cellobiose and lactulose coupled with mannitol and determined using ion-exchange chromatography with pulsed amperometric detection, are reliable probes for investigation of intestinal permeability

Lactulose/mannitol and cellobiose/mannitol tests are currently used in the investigation of intestinal permeability (IP) in many gastrointestinal diseases. The aim of this study was to produce a good technique for the determination and comparison of the above-mentioned sugar probes to overcome the problem caused by the presence of significant glycosuria in patients affected by particular metabolic disorders such as diabetes mellitus. Tests were performed in 25 healthy volunteers, using either cellobiose (Ce) (5 g) and mannitol (Ma) (2 g), or lactulose (La) (5 g) and mannitol (2 g), given as oral isosmolar loads. Sugars were recovered in urine collected for 5 h. Analysis was carried out by using anion-exchange chromatography (AEC) with pulsed amperometric detection (PAD). Baseline separation of the above carbohydrates was achieved within 13 min by using a Carbopac PA-100 column and linear gradient elution. Carbohydrate quantification was performed by an internal standard method. The calibration curve for each sugar is linear to 40 mM. The limit of sugar detection is 0.01 mM. Recovery of sugar probes is between 98.2 and 100%. The %La, %Ce, %Ma in urine were evaluated and their ratios (Ce/Ma and La/Ma) were calculated. No significant difference in IP parameters were shown (La/Ma to Ce/Ma 0.018+/-0.014 vs. 0.012+/-0.007; the attendant probability of the null hypothesis being P=0.0714). Ce/Ma and/or La/Ma tests result similarly reliable in the clinical investigation of IP and the described new method is also helpful in urine even with high glucose concentration, without any interference.