Bile Acid Diarrhea: Prevalence,Pathogenesis, and Therapy

Bile acid diarrhea (BAD) is usually seen in patients with ileal Crohn’s disease or ileal resection. However, 25% to 50% of patients with functional diarrhea or diarrhea-predominant irritable bowel syndrome (IBS-D) also have evidence of BAD. It is estimated that 1% of the population may have BAD. The causes of BAD include a deficiency in fibroblast growth factor 19 (FGF-19), a hormone produced in enterocytes that regulates hepatic bile acid (BA) synthesis. Other potential causes include genetic variations that affect the proteins involved in BA enterohepatic circulation and synthesis or in the TGR5 receptor that mediates the actions of BA in colonic secretion and motility. BAs enhance mucosal permeability, induce water and electrolyte secretion, and accelerate colonic transit partly by stimulating propulsive high-amplitude colonic contractions. There is an increased proportion of primary BAs in the stool of patients with IBS-D, and some changes in the fecal microbiome have been described. There are several methods of diagnosing BAD, such as ⁷⁵selenium homotaurocholic acid test retention, serum C4, FGF-19, and fecal BA measurement; presently, therapeutic trials with BA sequestrants are most commonly used for diagnosis. Management involves the use of BA sequestrants including cholestyramine, colestipol, and colesevelam. FXR agonists such as obeticholic acid constitute a promising new approach to treating BAD.     

Incidence and predictive factors for positive 75SeHCAT test: improving the diagnosis of bile acid diarrhoea

Aims: To determine the value of ⁷⁵SeHCAT retention in determining bile acid diarrhoea (BAD), treatment response and predictors of a positive result.

Methods: Retrospective casenote review of consecutive patients undergoing ⁷⁵SeHCAT from 2008 to 2014, including gender, age, history, clinical, and laboratory parameters. This included diseases associated with Type 1 BAD (ileal resection, Crohn’s disease) and Type 3 BAD. Chi-squared test and logistic regression determined factors predictive of BAD. Subjective response to treatment with bile acid sequestrants (BAS) was analysed with respect to the ⁷⁵SeHCAT result.

Results: Of 387 patients, 154 (39.7%) were male and average age was 50 years. Ninety-five patients (24.5%) were investigated for Type 1 BAD, 86 (22.2%) for Type 3, and 206 patients (53.2%) for Type 2 or idiopathic BAD. There was a large increase in the number performed with time but no difference in percentage positive tests. One hundred and seventy-nine patients (46.2%) had BAD. Positive result was commonest in possible Type 1 and they had most severe BAD. Ninety-nine patients had severe BAD (<5% ⁷⁵SeHCAT retention), 47 moderate BAD (5% to <10% retention), and 33 mild BAD (10% to <15% retention). Predictors of a positive ⁷⁵SeHCAT were right hemicolectomy (OR 4.88), cholecystectomy (OR 2.44), and Crohn’s (OR 1.86). A positive ⁷⁵SeHCAT predicted a good or partial response to BAS of 66.7% (mild), 78.6% (moderate), or 75.9% (severe BAD).

Conclusion: ⁷⁵SeHCAT test use increased in 2008–2014, with high positive results throughout. Ileal resection, Crohn’s, and cholecystectomy independently predict BAD. ⁷⁵SeHCAT predicted response to BAS.     

Serum Levels of Fibroblast Growth Factor 19 Correlate with the Severity of Diarrhea and Independently from Intestinal Inflammation in Patients with Inflammatory Bowel Disease or Microscopic Colitis

BackgroundIn chronic diarrhea patients, massive over-reporting symptom-based criteria for functional bowel disorders are pitfalls. There is currently no objective biomarker that may provide a correct correlation with the severity of chronic diarrhea. To clarify the role of fibroblast growth factor-19 (FGF-19) as a biomarker of objective measurements of the severity of diarrhea in comparison with a patient-reported outcome, based on the Bristol Stool Form (BSF) Scale.MethodsConsecutive 100 patients with chronic diarrhea underwent standard investigations with laboratory tests, fecal calprotectin (FC), endoscopy with biopsies, and serum FGF-19. All patients and 14 healthy controls completed a diary recording, BSF, and stool frequency. ResultsWe found that irritable bowel syndrome with diarrhea (IBS-D) n = 21/23 (91%) reported a high number on BSF ≥6, compared to patients with inflammatory bowel diseases (IBD) 56/77 (72%) with BSF ≥ 6 (P = .011). FGF-19 median serum levels were significantly lower in Microscopic colitis (0.010 pg/mL) and IBD patients (0.009 pg/mL) compare to IBS-D (266.9 pg/mL) and high levels in healthy subjects (463 pg/mL) (P < .001). Strong inverse correlation of FGF-19 with the stool frequency/day and stool index was found (r = −0.800, P < .001; r = −0.739, P < .001), independently from disease activity (r = −0.718, P = .001; r = −0.792, P = .001).ConclusionSerum FGF-19 can become a new biomarker for evaluating the severity of diarrhea with objectively and independently from intestinal inflammation. FC and FGF-19 are predictive biomarkers for the organic cause of diarrhea.     

Effect of olsalazine on sodium-dependent bile acid transport in rat ileum

Olsalazine (OLZ), a relatively new form of 5-aminosalicylic acid (5-ASA), is being used for the treatment of colitis. A major side effect of olsalazine is diarrhea, reported in 12–25% of patients. One suggested mechanism for this side effect is enhanced ileal water and electolyte secretion. We propose that OLZ may also inhibit ileal bile acid (BA) transport, resulting in choleretic diarrhea. This would result in excess BAs reaching the colon, with consequent BA-induced secretory diarrhea. Therefore, we studied the effect of OLZ on rat ileal absorption of taurocholate. BA uptake was determined in rat ileal segments, everted sacs, brush border membrane vesicles (BBMV), andXenopus laevis oocytes. Segments and everted sacs were treated with 5 mM OLZ for 30 min prior to and throughout 10-min taurocholate (Tc) uptake. Terminal ileal BBMV were used to study the effect of OLZ on sodium-dependent bile acid uptake independent of cellular metabolism. Direct effects on the bile acid carrier were examined usingXenopus laevis oocytes expressing the cloned apical rat ileal BA transporter. In ileal segments 5 mM OLZ inhibited 10-min Tc uptake by 69.4±8.8% (P<0.01) (N=10 animals). Increasing concentrations of OLZ resulted in a dose-dependent inhibition of Tc uptake. Ten-minute Tc uptake with 0.5, 1.0, 2.0, 2.5, and 5 mM OLZ was inhibited by 13.5, 39.6, 49.7, and 70.5%, respectively. In BBMV, OLZ inhibited 45-sec Tc uptake in a dose-dependent manner but did not effect Na-dependentl-alanine uptake. Kinetic analysis revealed a noncompetitive inhibition by 2 mM olsalazine. Olsalazine, 5 mM, also inhibited Na-dependent uptake of Tc into oocytes, which expressed the rat ileal sodium-dependent bile acid transporter (8.0±3.7 vs 2.6±2.0 pmol/oocyte/hr,P<0.001). OLZ inhibits sodium-dependent Tc uptake and transmucosal transport in the rat ileum in a dose-dependent manner. This inhibition is relatively specific, noncompetitive, and does not require intact cellular mechanisms. This effect of OLZ on ileal function may contribute to the diarrhea frequently observed with this drug.Supported in part by a grant from Reach Out For Youth with IBD and a gift from Ruth & Leonard Litwin and by grants from the National Institute of Health (DK02076,34989,43509, HD07388, HD20632 and HD27757).This work was presented in part at the American Gastroenterological Association meeting, Boston, Massachusetts, May 19, 1993.Address for reprint requests: Dr. Anupama Chawla, Pediatric Gastroenterology, North Shore University Hospital-Cornell University Medical College, 300 Community Drive, Manhasset, New York 11030.     

Changes in bile acids,FGF-19 and sterol absorption in response to bile salt hydrolase active L. reuteri NCIMB 30242

The size and composition of the circulating bile acid (BA) pool are important factors in regulating the human gut microbiota. Disrupted regulation of BA metabolism is implicated in several chronic diseases. Bile salt hydrolase (BSH)-active Lactobacillus reuteri NCIMB 30242, previously shown to decrease LDL-cholesterol and increase circulating BA, was investigated for its dose response effect on BA profile in a pilot clinical study. Ten otherwise healthy hypercholesterolemic adults, recruited from a clinical trial site in London, ON, were randomized to consume delayed release or standard release capsules containing L. reuteri NCIMB 30242 in escalating dose over 4 weeks. In another aspect, 4 healthy normocholesterolemic subjects with LDL-C below 3.4 mmol/l received delayed release L. reuteri NCIMB 30242 at a constant dose over 4 weeks. The primary outcome measure was the change in plasma BA profile over the intervention period. Additional outcomes included circulating fibroblast growth factor (FGF)-19, plant sterols and LDL-cholesterol as well as fecal microbiota and bsh gene presence. After one week of intervention subjects receiving delayed release L. reuteri NCIMB 30242 increased total BA by 1.13 ± 0.67 μmol/l (P = 0.02), conjugated BA by 0.67 ± 0.39 μmol/l (P = 0.02) and unconjugated BA by 0.46 ± 0.43 μmol/l (P = 0.07), which represented a greater than 2-fold change relative to baseline. Increases in BA were largely maintained post-week 1 and were generally correlated with FGF-19 and inversely correlated with plant sterols. This is the first clinical support showing that a BSH-active probiotic can significantly and rapidly influence BA metabolism and may prove useful in chronic diseases beyond hypercholesterolemia.     

Changes in bile acids,FGF-19 and sterol absorption in response to bile salt hydrolase active L. reuteri NCIMB 30242

The size and composition of the circulating bile acid (BA) pool are important factors in regulating the human gut microbiota. Disrupted regulation of BA metabolism is implicated in several chronic diseases. Bile salt hydrolase (BSH)-active Lactobacillus reuteri NCIMB 30242, previously shown to decrease LDL-cholesterol and increase circulating BA, was investigated for its dose response effect on BA profile in a pilot clinical study. Ten otherwise healthy hypercholesterolemic adults, recruited from a clinical trial site in London, ON, were randomized to consume delayed release or standard release capsules containing L. reuteri NCIMB 30242 in escalating dose over 4 weeks. In another aspect, 4 healthy normocholesterolemic subjects with LDL-C below 3.4 mmol/l received delayed release L. reuteri NCIMB 30242 at a constant dose over 4 weeks. The primary outcome measure was the change in plasma BA profile over the intervention period. Additional outcomes included circulating fibroblast growth factor (FGF)-19, plant sterols and LDL-cholesterol as well as fecal microbiota and bsh gene presence. After one week of intervention subjects receiving delayed release L. reuteri NCIMB 30242 increased total BA by 1.13 ± 0.67 μmol/l (P = 0.02), conjugated BA by 0.67 ± 0.39 μmol/l (P = 0.02) and unconjugated BA by 0.46 ± 0.43 μmol/l (P = 0.07), which represented a greater than 2-fold change relative to baseline. Increases in BA were largely maintained post-week 1 and were generally correlated with FGF-19 and inversely correlated with plant sterols. This is the first clinical support showing that a BSH-active probiotic can significantly and rapidly influence BA metabolism and may prove useful in chronic diseases beyond hypercholesterolemia.     

Bile acid malabsorption in chronic diarrhea: Pathophysiology and treatment

BACKGROUND:

Bile acid malabsorption (BAM) is a common but frequently under-recognized cause of chronic diarrhea, with an estimated prevalence of 4% to 5%.

METHODS:

The published literature for the period 1965 to 2012 was examined for articles regarding the pathophysiology and treatment of BAM to provide an overview of the management of BAM in gastroenterology practice.

RESULTS:

BAM is classified as type 1 (secondary to ileal dysfunction), type 2 (idiopathic) or type 3 (secondary to gastrointestinal disorders not associated with ileal dysfunction). The estimated prevalence of BAM is >90% in patients with resected Crohn disease (CD) and 11% to 52% of unresected CD patients (type 1); 33% in diarrhea-predominant irritable bowel syndrome (type 2); and is a frequent finding postcholecystectomy or postvagotomy (type 3). Investigations include BAM fecal bile acid assay, 23-seleno-25-homo-tauro-cholic acid (SeHCAT) testing and high-performance liquid chromatography of serum 7-α-OH-4-cholesten-3-one (C4), to determine the level of bile acid synthesis. A less time-consuming and expensive alternative in practice is an empirical trial of the bile acid sequestering agent cholestyramine. An estimated 70% to 96% of chronic diarrhea patients with BAM respond to short-course cholestyramine. Adverse effects include constipation, nausea, borborygmi, flatulence, bloating and abdominal pain. Other bile acid sequestering agents, such as colestipol and colesevelam, are currently being investigated for the treatment of BAM-associated diarrhea.

CONCLUSIONS:

BAM is a common cause of chronic diarrhea presenting in gastroenterology practice. In accordance with current guidelines, an empirical trial of a bile acid sequestering agent is warranted as part of the clinical workup to rule out BAM.     

胆汁酸性腹泻的发生机制与诊断

胆汁酸性腹泻（BAD）是慢性腹泻的常见病因,发病率较高但多被漏诊。近年来欧美国家对于该疾病关注度逐渐提高,但国内对此仍知之甚少,本文介绍了BAD发生的机制与国际上BAD常用的诊断方式,并对各种方式的优缺点进行探讨。     

Effect of cholecystectomy on bile acid synthesis and circulating levels of fibroblast growth factor 19

Background and rationale for the study. FGF19/15 is a gut-derived hormone presumably governing bile acid (BA) synthesis and gallbladder (GB) refilling. FGF19 mRNA is present in human GB cholangiocytes (hGBECs); however, the physiological significance of GB-derived FGF19 remains unknown. We investigated whether hGBECs secrete FGF19 and the effects of cholecystectomy on serum FGF19 ([FGF19]_s) and BA synthesis.Material and methods. FGF19 expression was assessed by qRT-PCRs and immunostaining in hGBECs and terminal ileum, and quantified in bile and serum by ELISA. Basal and BA (chenodexycholic acid, CDCA) induced FGF19 expression and secretion was analyzed in primary cultured hGBECs and GB-d1 cell line. Pre and postprandial serum changes in [FGF19]_s, 7α-hydroxy-4-cholestene-3-one (C4, a marker of BA synthesis) and BA were evaluated in plasma of gallstone disease patients at baseline and after cholecystectomy.Results. FGF19 mRNA levels were -250-fold higher in hGBECs compared to distal ileum. GB bile contained -23-fold higher FGF19 levels compared to serum (p < 0.0001). CDCA induced dose-dependent expression and secretion of FGF19 in hGBECs and GB-d1 cells. Cholecystectomy increased plasma BA synthesis ≥ 2-fold (p < 0.0001), and altered the diurnal rhythm and significantly reduced [FGF19]_s noon peak. BA serum levels, serum cholesterol and triglyceride content remained unchanged.Conclusions. In conclusion human GB cholangiocytes constitutively express and secrete high levels of FGF19 in a process regulated by BA. Resection of this organ doubles BA synthesis concomitantly with changes in [FGF19]_s. These findings suggest a potential connection between GB cholangiocytes-derived FGF19 and BA metabolism that could lead to metabolic dysregulation following cholecystectomy.     

Characterization of adenosine deaminase (ADA)-negative B-lymphoblastoid cells cocultured with ADA-positive fibroblasts

Abstract: A cell line, BAD05, derived from B lymphocytes of an adenosine deaminase (ADA; EC 3,5,4,4)-deficient patient could not proliferate in a serum-free medium containing 100 μmol/l deoxyadenosine. When BAD05 was cultured with ADA-positive fibroblasts, the proliferation of BAD05 was improved. BAD05 cell density increased when the initially mixed ratio of fibroblasts/BAD05 was 1/10 or higher, but decreased when the ratio was 1/20 or lower. Deoxyadenosine concentrations in the medium and ATP and deoxyATP (dATP) levels in the BAD05 were measured after 4 hours of coculture at initial BAD05 cell densities of 1 × 10⁵and 1 × 10⁶cells/ml. Deoxyadenosine concentrations in the medium decreased as the density of fibroblasts increased. The dATP level decreased as the mixed ratio rose. The ratio of fibroblasts/BAD05 rather than the cell density of fibroblasts had a larger effect on the dATP levels in BAD05. Under our experimental conditions, ADA-negative cells proliferated well when the ratio of ADA-positive cells/ADA-negative cells was over 1/10.     

Pronounced variation in bile acid synthesis in humans is related to gender, hypertriglyceridaemia and circulating levels of fibroblast growth factor 19

Abstract. Gälman C, Angelin B, Rudling M. (Karolinska Institutet at Karolinska University Hospital, Stockholm). Pronounced variation in bile acid synthesis in humans is related to gender, hypertriglyceridaemia and circulating levels of fibroblast growth factor 19 (Rapid Communication). J Intern Med 2011; doi:10.1111/j.1365‐2796.2011.02466.x Background. Bile acid (BA) synthesis is essential in cholesterol and lipid homoeostasis. Methods. Serum samples from 435 normal and 23 cholecystectomized subjects were obtained after overnight fasting and assayed for markers of BA and cholesterol synthesis, as well as cholesterol absorption. We determined whether BA synthesis was related to fibroblast growth factor 19 (FGF19; a circulating metabolic regulator that is thought to inhibit BA synthesis), gender, age and serum lipids. Results. Bile acid synthesis varied more than 9‐fold in normal individuals and was 29% higher in men than in women. Whilst low‐density lipoprotein cholesterol increased with age, BA and cholesterol synthesis were stable. BA production was positively correlated with serum triglycerides (TGs), and 35% of individuals with a high level (>95th percentile) of BA synthesis had hypertriglyceridaemia (HTG) (>95th percentile). Serum FGF19 levels varied by 7‐fold in normal individuals and were related inversely to BA synthesis but were not related to gender, plasma lipids or history of cholecystectomy. Conclusions. Bile acid synthesis has a wide inter‐individual variation, is lower in women than in men and is correlated positively with serum TGs. High BA production is frequently linked to HTG. Age‐related hypercholesterolaemia is not associated with changes in BA or cholesterol production, nor to an increase in cholesterol absorption. In humans, the circulating level of FGF19 may regulate hepatic BA production under fasting conditions.     

Increased risk of nephrolithiasis in patients with steatorrhea

Patients with ileal disease have increased absorption of dietary oxalate, hyperoxaluria, and an increased incidence of nephrolithiasis. Patients with steatorrhea of varying etiologies also have hyperoxaluria. To determine whether steatorrheaper se is associated with nephrolithiasis, we reviewed the charts of all adult patients who had a 72-hr fecal fat analysis from 1968 to 1978. The 159 patients with steatorrhea were compared to 162 patients without steatorrhea. The two groups were comparable in age, sex, urine specific gravity, and serum uric acid and phosphorus; serum calcium was slightly less in the steatorrhea group (8.7±0.1 vs 9.0±0.1,P<0.02). Although 19 patients with steatorrhea had nephrolithiasis compared to 7 control patients (P=0.01), 15 of these 19 patients had ileal disease and only 4 of the 118 patients with steatorrhea but without ileal disease had stones. Categorical data analysis revealed that steatorrhea, diarrhea (stool weight >225 g/day), male sex, and ileal disease were significantly associated with nephrolithiasis with a relative risk of 3.0, 2.7, 3.1, and 8.0, respectively. When patients without ileal disease were analyzed separately, however, steatorrhea, diarrhea, and sex were no longer risk factors. In contrast, in patients with ileal disease the incidence of nephrolithiasis increased with the severity of steatorrhea. The relative risk of nephrolithiasis in male patients with ileal disease and fecal fat >20 g/day was 26.3 (P<0.01). Thus, the presence of both ileal disease and steatorrhea greatly increases the risk of nephrolithiasis; however, neither steatorrhea alone nor ileal disease alone are risk factors for nephrolithiasis.These studies were supported by USPHS Research Grant (AM20570) from the National Institute of Arthritis. Metabolism and Digestive Diseases. Dr. Dobbins is the recipient of a Research Career Development Award (AM 00647) from the National Institute of Arthritis Metabolism and Digestive Diseases.     

Mechanisms of triglyceride metabolism in patients with bile acid diarrhea

Bile acids(BAs) are essential for the absorption of lipids. BA synthesis is inhibited through intestinal farnesoid X receptor(FXR) activity. BA sequestration is known to influence BA metabolism and control serum lipid concentrations. Animal data has demonstrated a regulatory role for the FXR in triglyceride metabolism. FXR inhibits hepatic lipogenesis by inhibiting the expression of sterol regulatory element binding protein 1c via small heterodimer primer activity. Conversely, FXR promotes free fatty acids oxidation by inducing the expression of peroxisome proliferator-activated receptor α. FXR can reduce the expression of microsomal triglyceride transfer protein, which regulates the assembly of very low-density lipoproteins(VLDL). FXR activation in turn promotes the clearance of circulating triglycerides by inducing apolipoprotein C-Ⅱ, very low-density lipoproteins receptor(VLDL-R) and the expression of Syndecan-1 together with the repression of apolipoprotein C-Ⅲ, which increases lipoprotein lipase activity. There is currently minimal clinical data on triglyceride metabolism in patients with bile acid diarrhoea(BAD). Emerging data suggests that a third of patients with BAD have hypertriglyceridemia. Further research is required to establish the risk of hypertriglyceridaemia in patients with BAD and elicit the mechanisms behind this, allowing for targeted treatment.     

Review: Bile acid diarrhoea: pathophysiology,diagnosis and management

The actual incidence of bile acid diarrhoea (BAD) is unknown, however, there is increasing evidence that it is misdiagnosed in up to 30% with diarrhoea-predominant patients with irritable bowel syndrome. Besides this, it may also occur following cholecystectomy, infectious diarrhoea and pelvic chemoradiotherapy.BAD may result from either hepatic overproduction of bile acids or their malabsorption in the terminal ileum. It can result in symptoms such as bowel frequency, urgency, nocturnal defecation, excessive flatulence, abdominal pain and incontinence of stool. Bile acid synthesis is regulated by negative feedback loops related to the enterohepatic circulation, which are dependent on the farnesoid X receptor and fibroblast growth factor 19. Interruption of these feedback loops is thought to cause bile acid overproduction leading to BAD. This process may occur idiopathically or following a specific trigger such as cholecystectomy. There may also be an interplay with the gut microbiota, which has been reported to be significantly different in patients with severe BAD.Patients with suspected BAD are investigated in various ways including radionucleotide imaging such as SeHCAT scans (though this is not available worldwide) and blood tests. However, other methods such as bile acid measurement in stool (either spot test or 48 hours samples) and urine tests have been explored. Importantly, delay in diagnosis and treatment of BAD greatly affects patient’s quality of life and may double the overall cost of diagnosis.     

Cholesterol precursors and their diurnal rhythm in lipoproteins of patients with jejuno-ileal bypass and ileal dysfunction

Cholesterol synthesis and its diurnal variation was studied by measuring squalene, free and esterified methyl sterols and cholesterol, and triglycerides in serum lipoproteins every four hours over a period of 24 hours in controls and in patients with jejunoileal bypass or ileal exclusion. Fat absorption, as indicated by postprandial increase of very-low-density lipoprotein (VLDL) lipids (including chylomicrons) and fecal fat, was markedly impaired in jejunoileal bypass. Fecal analysis indicated that bile acid malabsorption enhanced cholesterol synthesis about sixfold in ileal dysfunction, and twofold in jejunoileal bypass with moderate bile acid and cholesterol malabsorption. The squalene contents were not increased consistently in the VLDL and combined low-density plus high-density lipoproteins (LDL + HDL) of the two operated groups and, in contrast to the controls, the diurnal variation was inconsistent. The levels of unesterified methyl sterols, Δ⁸-dimethylsterol and Δ⁸-methostenol in particular, were several times higher throughout the 24 hour period in the lipoproteins of the two patient groups than of the controls, were higher in ileal dysfunction than jejunoileal bypass, exhibited a constant diurnal rhythm in the controls but only in the relatively small VLDL fraction (not in the large LDL + HDL) of the operated groups, and were positively correlated with cholesterol synthesis in the three groups combined (for methyl sterols in VLDL r = 0.740 and in LDL + HDL r = 0.869). Esterified methyl sterols were also increased in the operated groups but were not correlated with cholesterol synthesis. The findings suggest that circadian rhythm regulates cholesterol synthesis, even at a high rate of production, that long-lasting stimulation of cholesterol synthesis modifies conversion of squalene to cholesterol, and that the response of the methyl sterol contents of serum lipoproteins to enhanced fecal elimination of cholesterol is mainly determined by the magnitude of increased cholesterol synthesis most likely in the liver.     

Bone age and factors affecting skeletal maturation at diagnosis of paediatric Cushing’s disease

Paediatric Cushing’s disease (CD) is usually associated with growth retardation, but there are only few published data on skeletal maturation at diagnosis. We analysed factors contributing to skeletal maturation and final height in Asian Indian patients with paediatric CD. We conducted retrospective analysis of 48 patients (29 males; 19 females) with mean age: 14.84 years at diagnosis (range 9–19 years). A single observer using the Greulich Pyle method determined the bone age (BA) of each child. BA delay, i.e. the difference between chronological age (CA) and BA, was compared with clinical and biochemical variables. BA delay was present in 35/48 (73%) patients (mean delay 1.6 years, range 0.5–5 years) and correlated negatively with height SDS (r = −0.594, P < 0.001) and positively with CA at diagnosis (r = 0.247, P < 0.05). There was no correlation with duration of symptoms before diagnosis, basal cortisol, midnight cortisol, ACTH or percentage suppression of low dose dexamethasone suppression cortisol (LDDST). We could not demonstrate any relationship between the duration of history before diagnosis and height SDS at final height. Mean final height SDS in patients was −1.84. We found that most children with CD had delayed BA and correlated significantly with CA and height SDS at diagnosis. Early diagnosis may reduce delay in skeletal maturation and thus contribute to optimal catch-up growth.     

Fibroblast growth factor-2 and epidermal growth factor modulate prolactin responses to TRH and dopamine in primary cultures

Fibroblast growth factor-2, (FGF-2) and epidermal growth factor (EGF) are expressed in most tissues of the organism including pituitary, FGF-2 increases PRL levels and PRL mRNA in GH3 cells and primary cultures, and it has been involved in the lactotroph proliferation and hyperplasia. EGF also increases PRL levels in vitro. However, the effects of these two factors in the responses of lactotroph cells to TRH and dopamine (DA) remain to be clarified. In the present work we have studied the modulator activity of FGF-2 and EGF on in vitro PRL in responses to TRH and DA in primary cultures from in vivo vehicle-or estrogen (E2)-treated rats. We have found that FGF-2 (2×10⁻¹¹ M) prevents the EGF-induced dose-dependent increase in PRL levels in control cells, and reversed the EGF-stimulating effects in cells from E2-treated rats. Both FGF-2 (2×10⁻¹¹ M) and EGF (6.6×10⁻⁹ M) significantly increase (>30% and >120%, respectively) the PRL levels in response to TRH (10⁻⁶ 10⁻⁵ M). FGF-2 blocked the inhibitory effects of low doses of DA (10⁻⁹ M). EGF was unable to do so, although markedly increased (>200%) the post-DA PRL rebound. In cells from in vivo E2-treated rats, FGF-2 increased (>50%) the PRL secretion in response to TRH, while EGF reduced responses to high doses of TRH (10⁻⁶, 10⁻⁵ M). In addition, FGF-2 reversed and EGF increased the inhibitory effects of DA. Both FGF-2 and EGF completely blocked the post-DA PRL rebound, in these cells. Taken together our data suggest that FGF-2 and EGF are important regulators of lactotroph responsiveness to TRH and DA in vitro, although their actions are highly dependent on estrogenic milieu.     

Absence of Dysfunctional Ileal Sodium?Bile Acid Cotransporter Gene Mutations in Patients with Adult-Onset Idiopathic Bile Acid Malabsorption

Background: A congenital form of idiopathic intestinal bile acid malabsorption (IBAM) has been associated with dysfunctional mutations in the ileal apical sodium-dependent bile acid transporter (ASBT). The aim of this study was to determine whether mutations in the ASBT gene (SLC10A2) predispose to the development of adult-onset idiopathic bile acid malabsorption and chronic watery diarrhea. Methods: Genomic DNA was obtained from 13 adult IBAM patients previously diagnosed on the basis of clinical data, response to cholestyramine, and abnormal ⁷⁵Se-homocholic acid taurine (SeHCAT) test values. The ASBT gene was screened for the presence of mutations or polymorphisms by single-stranded conformation polymorphism analysis (SSCP) and DNA sequencing. Results: ASBT gene polymorphisms were detected in 5 of the 13 adult IBAM patients. Four patients were heterozygous for a common polymorphism in exon 3, leading to an alanine to serine substitution at codon 171 (A171S). An additional subject was heterozygous for a polymorphism in exon 1 that causes a valine to isoleucine substitution at codon 98 (V98I). These functional polymorphisms were also found in unaffected subjects and do not appear to affect ASBT function. Conclusions: Adult-onset IBAM is not directly related to dysfunctional mutations in the coding region or intron/exon junctions of the SLC10A2 gene. In the absence of apparent ileal disease or intestinal motility defects, inappropriate down-regulation of the ileal bile acid transporter or defects in ileocyte transfer of bile acids into the portal circulation could explain this form of adult IBAM.     

The Influence of Ileal Pouch-Anal Anastomosis for Ulcerative Colitis on Ileal Glycoprotein Synthesis

Restorative proctocolectomy and ileal pouch-anal anastomosis are frequently associated with the onset of low-grade inflammation, colonic metaplasia, and pouchitis. The influence of intestinal adaptation and inflammatory activity on ileal glycoprotein synthesis (GS) has been assessed. Ileal GS activity in controls (n = 13, 28.9 ± 3.6) was similar to that of patients with ulcerative colitis (n = 18, 26.4 ± 3.6) irrespective of the presence of backwash ileitis (n = 6, 22.0 ± 4.0). Ileoanal pouch construction was not associated with a significant change in ileal GS activity regardless of the presence of low-grade inflammation (n = 19, 25.9 ± 2.2), frank pouchitis (n = 5, 24.4 ± 4.6), or transformation to a colonic type of mucosa (n = 6, 25.4 ± 5.2). The transformation of ileal mucosa from an absorptive to a storage function is associated with characteristic morphologic and inflammatory changes but does not produce a protective response mediated by increased GS.     

Endoscopic insertion of oesophageal stents without fluoroscopic guidance

Objectives. Bile acid (BA) malabsorption may occur after cholecystectomy. Bile may flow more freely into the duodenum after endoscopic sphincterotomy (EST), in part resembling the situation after cholecystectomy. The ⁷⁵SeCHAT test used to diagnose BA malabsorption correlates inversely with synthesis and faecal excretion of BAs. The BA intermediate 7α-hydroxy-4-cholesten-3-one (C4) mirrors BA and lathosterol cholesterol synthesis. The aim was to study whether EST causes BA diarrhoea and alterations in BA synthesis or lipid profiles. Material and methods. Twelve patients underwent the ⁷⁵SeHCAT test prior to and 3 months after undergoing EST and a further 22 only after EST. The Gastrointestinal Symptom Rating Scale (GSRS), 1 week daily stool frequency and consistency, C4, lathosterol, cholesterol and triglycerides were investigated. The ⁷⁵SeHCAT values of 29 healthy subjects served as controls. Results. Stool frequency (median 1/day, IQR (interquartile range): 0.7) and consistency (median: 3, IQR: 0.65) were normal and none reported diarrhoea after EST (n=34). The GSRS scores were normal. There was no significant change in ⁷⁵SeHCAT (median 22%, IQR 29% versus 19.5%, IQR 25, n=12). There was a trend towards lower ⁷⁵SeHCAT after EST compared with the controls (median 26%, IQR 32, n=34 versus median 38%, IQR 19.5, n=29, p=0.075) and higher lathosterol (median 47.1 mg/mole, IQR 32.7 versus median 52.5 mg/mole, IQR 35.6, n=14, p=0.055). The C4 and lipids did not change significantly. Conclusions. EST did not induce diarrhoea and in line with this BA synthesis and serum lipids are unaltered.