The value of proximal small intestinal biopsy in the differential diagnosis of chronic diarrhoea

Congenital Diarrheal Syndromes

Congenital diarrheal disorders are heterogeneous conditions characterized by diarrhea with onset in the first years of life. They range from simple temporary conditions, such as cow's milk protein intolerance to irreversible complications, such as microvillous inclusion disease with significant morbidity and mortality. Advances in genomic medicine have improved our understanding of these disorders, leading to an ever-increasing list of identified causative genes. The diagnostic approach to these conditions consists of establishing the presence of diarrhea by detailed review of the history, followed by characterizing the composition of the diarrhea, the response to fasting, and with further specialized testing.

The Burden of Enteropathy and "Subclinical" Infections

Environmental enteropathy is a chronic condition of the small intestine associated with increased intestinal permeability, mucosal inflammation, malabsorption, and systemic inflammation. It is commonly accompanied by enteric infections and is misleadingly considered a subclinical disease. Potential effects of enteric infections and enteropathy on vaccine responses, child growth, cognitive development, and even later life obesity, diabetes, and metabolic syndrome are increasingly being recognized. Herein, we review the evolving challenges to defining environmental enteropathy and enteric infections, current evidence for the magnitude and determinants of its burden, new assessment tools, and relevant interventions.

Effect of a gluten-free diet on growth and small-bowel histology in children with celiac disease in India

BACKGROUND AND AIM

Follow-up studies on growth and histological recovery of children with celiac disease (CD) while on a gluten-free diet (GFD) are lacking from Asia. We therefore assessed the effects of this diet.

METHODS

Forty-two children with CD were enrolled. Weight and height were expressed as weight for height (WfH) and height standard deviation scores (HSDS), respectively. Twenty-five children had repeated duodenal biopsies after 1-2 years and 14 had a third biopsy after 3-7 years of GFD. Compliance was checked by regular interview and IgA antiendomysial antibody estimation (EMA).

RESULTS

At diagnosis (n = 25), mean HSDS was -3.3 +/- 1.6 with 76% having a HSDS of <-2; 60% were undernourished (WfH mean 81.6 +/- 5.7). Over a mean follow up of 3.7 years, HSDS improved to -1.3 +/- 1.7 and 84% cases achieved normal nutrition. Mean height velocity was 13.9 cm during first year and 5.6 cm in subsequent years. Small-bowel biopsies at diagnosis showed subtotal villous atrophy (Marsh IIIb) in 18 (72%) and partial villous atrophy (Marsh IIIa) in seven (28%) patients. Repeat biopsy at 1-2 years showed shift from subtotal to partial villous atrophy in 94% (n = 17/18) and normalization in one patient. In patients with Marsh IIIa improvement of partial villous atrophy was observed in all. Immunoglobulin A endomysial antibody was negative in 81%. Repeat biopsies at 5 years of GFD showed improvement to Marsh I-II, but none normalized.

CONCLUSION

The majority of children with CD show normalization of nutrition and growth after GFD. Small-bowel histology improves markedly but does not normalize even after 5 years of GFD.

Best practice in primary care pathology: review 6

This sixth best practice review examines four series of common primary care questions in laboratory medicine: (1) laboratory monitoring in hypertension and heart failure abnormalities; (2) markers of inflammatory joint disease; (3) laboratory investigation of chronic diarrhoea; and (4) mumps and chickenpox. The review is presented in question-answer format, referenced for each question series. The recommendations represent a precis of guidance found using a standardised literature search of national and international guidance notes, consensus statements, health policy documents and evidence-based medicine reviews, supplemented by Medline Embase searches to identify relevant primary research documents. They are not standards but form a guide to be set in the clinical context. Most are consensus based rather than evidence based. They will be updated periodically to take account of new information.

The prevalence of celiac disease in average-risk and at-risk Western European populations: a systematic review

Until recently, celiac disease (CD) was felt to be a rare disease in the United States. The aim of this study was to conduct a systematic review of the prevalence of CD in general Western populations and in populations at high risk for CD. Standard systematic review methodology was used. A literature search was conducted in MEDLINE (1966 to October 2003) and EMBASE (1974 to December 2003) databases. Qualitative and quantitative prevalence estimates were produced after assessing study heterogeneity. The prevalence of CD in general Western populations is close to 1% and is somewhat higher in certain Western European populations. The prevalence of CD in populations at risk for CD is as follows: 3%-6% in type 1 diabetic patients, up to 20% in first-degree relatives, 10%-15% in symptomatic iron-deficiency anemia (IDA), 3%-6% in asymptomatic IDA, and 1%-3% in osteoporosis. The prevalence of CD in patients suspected of having CD varied depending on the reasons for suspecting CD and on whether the study was conducted in a referral center. In general, the prevalence ranged from 5% to 15%, but was up to 50% in symptomatic patients evaluated in a tertiary referral center. CD is a common medical condition. The prevalence is higher still in high-risk groups. Clinicians in a variety of specialties should have a high index of suspicion for the diagnosis of CD and in particular need to pay close attention to the identified high-risk groups.

Lysinuric protein intolerance masquerading as celiac disease: a case report

A 5 1/2-year-old boy presented with delayed growth, chronic diarrhea, and hypoproteinemia. Clinical presentation, initial laboratory data, and evaluation of an intestinal biopsy specimen suggested a diagnosis of celiac disease. Symptoms did not resolve on a gluten-free diet. The development of hyperammonemia prompted further studies that led to the diagnosis of lysinuric protein intolerance. Lysinuric protein intolerance, although a rare disorder, should be included in the differential diagnosis of conditions associated with intestinal villous atrophy.

Comparison of milk and maize based diets in kwashiorkor

The dual sugar test of intestinal permeability is a reliable non-invasive way of assessing the response of the small intestinal mucosa to nutritional rehabilitation.

AIM

To compare a local mix of maize-soya-egg to the standard milk diet in the treatment of kwashiorkor.

DESIGN

The diets were alternated three monthly in the sequence milk-maize-milk. There were a total of 533 kwashiorkor admissions of at least five days during the study who received either milk or maize. Intestinal permeability was assessed at weekly intervals by the lactulose-rhamnose test in 100 kwashiorkor cases, including 55 on milk and 45 on the maize diet.

RESULTS

Permeability ratios (95% confidence interval) on the milk diet improved by a mean of 6.4 (1.7 to 11.1) compared with -6.8 (-16.8 to 5.0) in the maize group. The improved permeability on milk occurred despite more diarrhoea, which constituted 34.8% of hospital days (29.8 to 39.8) compared with 24.3% (17.8 to 30.8) in the maize group. Case fatality rates for all 533 kwashiorkor admissions were 13.6% v 20.9%, respectively, giving a relative risk of death in the maize group of 1.54 (1.04 to 2.28). The maize group also had more clinical sepsis (60% v 31%) and less weight gain (2.9 v 4.4 g/kg/day) than the milk group.

IMPLICATIONS

Milk is superior to a local maize based diet in the treatment of kwashiorkor in terms of mortality, weight gain, clinical sepsis, and improvement in intestinal permeability.

Surface features of small-intestinal mucosa in childhood diarrheal disorders

The pathophysiology of diarrhea, especially in the otherwise healthy child, is still poorly understood. The aim of this study was to use the scanning electron microscope (SEM) to examine the surface of the jejunal mucosa of children with chronic nonspecific diarrhea (CNSD) (n = 9) and to compare the findings with specimens obtained from children with (n = 21) and without (n = 11) other gastrointestinal diseases. Light microscopy of the specimens from children with CNSD was normal. However, SEM showed the presence of bacterial colonization with predominantly coccoid organisms in 100% of cases. This colonization was associated with loss of glycocalyx and clumping of the microvilli. The children with celiac disease (n = 9) all showed characteristic appearances with light microscopy, but only one had bacterial colonization on SEM. The surface features of specimens from children with other gastrointestinal disorders (food intolerance, postenteritis syndrome, protracted diarrhea of infancy, and immune deficiency states) were very similar to those from the CNSD group. Bacteria were visible on 89% of specimens, and in half of these cases the organisms were bacilli. SEM of specimens from children with no gastrointestinal disease (ages 11-107 months) suggested an increased density of villi/unit area with advancing age. Bacteria were present in only two cases and did not include bacilli. The findings suggest that bacterial colonization of the surface of the small intestine is common in children with several gastrointestinal diseases and may play a part in their pathogenesis. Routine SEM examination of jejunal biopsies provides information not available from standard light microscopy, which may be relevant to the treatment of children with chronic diarrhea.

Chronic nonspecific diarrhea of childhood: pathophysiology and management

Chronic nonspecific diarrhea, or toddler's diarrhea, is a frequently encountered disorder of defecation in otherwise healthy children. Although the precise pathophysiology remains to be elucidated, evidence suggests that toddler's diarrhea primarily is a gut motility disorder, modulated by dietary factors. Although the role of low-fat diets has since long been established, the liberal consumption of fruit juices and soft drinks is considered an equally important factor. Normalization of the child's diet, especially with regard to fat, fiber, fluids, and fruit juices, usually suffices to attain resolution of the diarrhea.

Intractable diarrhoea in infancy in the 1990s: a survey in Italy

A "quick" prevalence study of intractable diarrhoea (defined as diarrhoea lasting more than 3 weeks and dependent on parenteral nutrition [PN] for more than 50% of daily caloric intake) was conducted by FAX. All 35 paediatric gastroenterology services which had been contacted answered questionnaire sent by FAX. 20 cases of intractable diarrhoea were identified in 9 centres. In 12 cases PN was administered at home, the other 8 cases being treated as inpatients for an average duration of 9.5 months. A diagnosis had been established in 11 out of 20 cases. Auto-immune enteropathy was the most frequent diagnosis (5 cases); congenital microvillous atrophy (3 cases); chronic pseudo-obstruction (2 cases) and multiple food intolerance (1 case). Undefined 9/20 cases presented atrophy of intestinal mucosa. The age of the beginning of diarrhoea varied from 2 days to 12 years, but was more than 16 months only in some cases with auto-immune enteropathy.

CONCLUSION

Intractable diarrhoea has a low prevalence in Italy and remains a rare but very intricating problem. Long-term PN is recommended in most cases: autoimmune enteropathy is the most frequent cause but in about half of the cases the aetiopathogenetic diagnosis is still not defined.

Failure to thrive

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Diarrhoeal disease: current concepts and future challenges. Malnutrition and infection

In individual children in developed countries it is possible to follow a sequence of infection of the gastrointestinal tract leading to chronic diarrhoea which, if it long persists, may in turn lead to undernutrition. Both in individuals and epidemiologically in developing countries it is, by contrast, often difficult to be certain whether infection precedes under-nutrition or vice versa. Chronic diarrhoea is heterogeneous and aetiology varies from community to community. Unlike acute diarrhoea, for which there is highly effective unitary therapy (oral rehydration therapy), diverse therapies are required for chronic diarrhoea based on specific diagnoses and so render community strategies difficult. The importance of adequate calorie intake is emphasized but when there is intolerance to food ingested this is counter-productive. The relative importance of post-infective food intolerance remains controversial and in many communities is unknown. Increasing emphasis is now given to the role of infection in pathogenesis of diarrhoea and malnutrition, e.g. the acquired immune deficiency syndrome and Helicobacter pylori. Hospital-based case studies including small intestinal biopsy in individual communities, by virtue of an 'iceberg effect', may prove useful for insights into aetiology and pave the way for interventions, e.g. antibiotics or dietary therapy.