Transient hyperphosphatasemia in children revisited.

OBJECTIVE: Although transient hyperphosphatasemia (TH) has been well known for decades, its etiology and pathophysiology remain unclear. We aimed to study the clinical characteristics of children diagnosed with TH compared to older studies in order to expand our knowledge and understanding of this condition and to try and find a subgroup of children who are more prone to develop TH. METHODS: We retrospectively studied 60 children diagnosed at Maccabi Health Services and Bnai Zion Medical Center, Haifa, Israel with TH between the years 2003-08. One hundred and twenty-two children matched by age, gender and presenting symptoms served as the control group. The patients were divided into four subgroups by their presenting symptoms: infectious disease 33%, failure to thrive 28%, diarrhea 15% and other 23%. The Hydragel 7 ISO-PAL and Hydragel 15 ISO-PAL kits were used for the identification and quantification of ALP isoenzymes in human serum. RESULTS: The ALP levels of the study group were 805-8619 U\L (mean 2311 U\L), without differences between the subgroups. The mean duration of TH was 12 weeks. ALP isoenzymes levels were measured in one-third of the patients, and showed that the bone isoenzyme was elevated in most. Forty-three (71%) subjects were diagnosed in the second half of the calendar year. CONCLUSIONS: We could not establish an etiological explanation for TH. We presume that it is a complex mechanism in which different stimuli led to upregulation of the enzyme.

Intractable secretory diarrhea in a Japanese boy with mitochondrial respiratory chain complex I deficiency.

The etiology of secretory diarrhea in early life is often unclear. We report a Japanese boy who survived until 3 years of age, despite intractable diarrhea commencing soon after birth. The fecal sodium content was strikingly high (109 mmol/L [normal range, 27-35 mmol/L]) and the osmotic gap was decreased (15 mOsm/kg), consistent with the findings of congenital sodium diarrhea. We examined the mitochondrial respiratory chain function by blue native polyacrylamide gel electrophoresis (BN-PAGE) in-gel enzyme staining, BN-PAGE western blotting, respiratory chain enzyme activity assay, and immunohistochemistry. Liver respiratory chain complex (Co) I activity was undetectable, while other respiratory chain complex activities were increased (Co II, 138%; Co III, 153%; Co IV, 126% versus respective control activities). Liver BN-PAGE in-gel enzyme staining and western blotting showed an extremely weak complex I band, while immunohistochemistry showed extremely weak staining for the 30-kDa subunit of complex I, but normal staining for the 70-kDa subunit of complex II. The patient was, therefore, diagnosed with complex I deficiency. The overall complex I activity of the jejunum was substantially decreased (63% of the control activity). The immunohistochemistry displayed apparently decreased staining of the 30-kDa complex I subunit, together with a slightly enhanced staining of the 70-kDa complex II subunit in intestinal epithelial cells. These data imply that intestinal epithelial cells are also complex I-deficient in this patient. Complex I deficiency is a novel cause of secretory diarrhea and may act via disrupting the supply of adenosine triphosphate (ATP) needed for the maintenance of ion gradients across membranes.

Disaccharidase activity in infants and comparison based on symptoms and histological changes.

OBJECTIVES: There is uncertainty regarding disaccharidase activity (DA) in infants. In this study, values for DA in infants were established and compared with symptoms and intestinal mucosal histological appearance. PATIENTS AND METHODS: Disaccharidase activity and histological appearance of endoscopically obtained intestinal mucosal biopsy specimens from 131 infants (75 males; mean age 180 days; range 20-364 days) obtained during an 8-year period were reviewed. Patients were divided into 2 groups on the basis of absence (group 1; n = 56) or presence (group 2; n = 75) of failure to thrive (FTT) and/or diarrhea. These groups were subdivided into 3 subgroups on the basis of histological findings: normal histological appearance (A), mild histological abnormalities (B), and moderate to severe histological abnormalities (C). RESULTS: The DA from patients in group 1A represent values in infants who were free of diarrhea/FTT and who had normal intestinal mucosal histological appearance. The geometric means (95% CI) in units of DA were as follows: lactase 33.7 (normal range 29.0-39.1), sucrase 48.9 (normal range 44.2-54.1), maltase 160.5 (normal range 144.4-178.3), and palatinase 11.2 (normal range 9.7-12.9). Differences in DA were not related to symptoms, in the absence of histological abnormalities (1A vs 2A), but rather on the presence of histological abnormalities even in the absence of symptoms (1A vs 1B). Differences were also found when patients with FTT and/or diarrhea with abnormal histological appearance (2B and 2C) were compared with patients with no FTT and/or diarrhea with a normal brush border (1A). CONCLUSIONS: We outline DA values in a large cohort of infants. DA in infants, as in children, relates to intestinal mucosal histological appearance rather than to symptoms.

[The relationship of serum mitochondrial creatine kinase and rotavirus gastroenteritis in pediatric patients].

The objective of this study was to investigate the relationship between serum mitochondrial creatine kinase(mCK) and rotavirus gastroenteritis in pediatric patients. Stool and serum specimens were simultaneously collected from 45 patients(25 males and 20 females) with suspected rotavirus gastroenteritis from January to December 1998. Stool specimens were tested by rotavirus latex agglutination assay. Fourteen patients(10 males, 4 females) were proved as positive, and peak season was in winter and early spring(7 positive cases in March). Six of the 14 were younger than one and 7 were between one and two. Total serum CK activity was measured by The Japan Society of Clinical Chemistry (JSCC) recommended method, and mCK activity was calculated from mCK fraction % obtained by CK isoenzyme electrophoresis. Patients' mCK activities were as follows, rotavirus antigen positive patients(n = 14): 60.0 +/- 20.6 U/l and rotavirus antigen negative patients(n = 31): 7.2 +/- 5.5 U/l. Significant difference was observed between rotavirus antigen positive group and rotavirus antigen negative group(p < 0.01), and control children group(n = 105): 7.1 +/- 2.9 U/l, (p < 0.01). The clinical implications and mechanisms of increased serum mCK activity are unclear. It is known that histological study of the small intestine from rotavirus gastroenteritis patients reveal shortened villi and mononuclear cell infiltration of the lamia propria; electron microscopy shows mitochondrial swelling and sparse irregular microvilli. Elevated serum mCK level of rotavirus gastroenteritis patient may therefore reflect diffused intestinal epithelial cell damage.

Actividad lactásica en niños con enfermedad diarreica por Giardia Lambia / The Beta-galactosidase performance in children with diarrheal disease due to Giardia lamblia

Se realizó un estudio prospectivo, de corte transversal y analítico, con el propósito de establecer posibles diferencias en el comportamiento de la actividad lactásica en niños menores de 2 años con enfermedad diarreica por Giardia lamblia tratados en el Servicio de Diarreas del Hospital Pediátrico Docente "Dr Angel A. Aballi", en el período de diciembre de 1994 a noviembre de 1995. Se determinaron los niveles de la actividad enzimática según diferentes categorías de variables de caracterización del niño, y que tal actividad tiene un comportamiento diferencial asociado con la edad, estado nutricional y grado de atrofia de la mucosa

Anticuerpos monoclonales en la evaluación de enzimas del ribete estriado yeyunal de lactantes con diarrea persistente / Monoclonal antibodies in the assessment of the jejunal striatum border enzymes in infants with longstanding diarrhea

En las biopsias de mucosa yeyunal de 10 pacientes con diarrea persistente se estudió expresión de las enzimas lactasa, sacarasa-isomaltasa, maltasa y aminopeptidasa, del ribete estriado, mediante anticuerpos monoclonales y los resultados se contrastaron con los síntomas y signos clínicos, morfológicos (microscopía de luz), actividad disacaridásica (Dahlqvist) y la expresión de lactasa por un método histoquímico. Se obtuvo expresión de aminopeptidasa en criptas y vellosidades, mediante los anticuerpos correspondientes. La expresión por anticuerpos histoquímica y actividad enzimática (Dahlqvist) fueron concordantes para la expresión de lactasa en las vellosidades, mientras en las criptas se registró positividad sólo en 2 casos. En las vellosidades los anticuerpos monoclonales tendieron a producir más reacciones positivas para sacarasa-isomaltasa en los casos con menos daño morfológico, excepto en uno de deficiencia primaria; en las criptas el resultado fue positivo en todos, menos dos pacientes, en los que tampoco hubo positividad en las vellosidades. Los anticuerpos monoclonales pueden aportar información útil para entender mejor los mecanismos de daño y reparación de las enzimas del ribete estriado y estimar el pronóstico de la lesión

Mitochondrial DNA rearrangements with onset as chronic diarrhea with villous atrophy.

We report two unrelated children with onset of chronic diarrhea and villous atrophy in the first years of life. Elevated plasma lactate concentrations and lactate/pyruvate and ketone body molar ratios suggested a genetic defect of oxidative phosphorylation. Analysis of the mitochondrial respiratory chain showed a complex III deficiency in muscle of both patients. Southern blot analysis provided evidence of heteroplasmic mitochondrial DNA rearrangements that involve deletion and deletion-duplication. Directly repeated sequences (10 and 11 base pairs, respectively) were present in the wild type of mitochondrial genome at the boundaries of the deletion. Neither parent of either patient had rearranged molecules in their circulating lymphocytes. It appears that a mitochondrial disorder can have chronic diarrhea and villous atrophy as the initial clinical feature. On the basis of these observations, we suggest that genetic defects of mitochondrial energy supply be considered in elucidating the origin of unexplained chronic diarrheas, especially when other, unrelated symptoms occur in the course of the disease.

The constitutive exocytotic pathway in microvillous atrophy.

Microvillous atrophy is a disorder within the intractable diarrhea of infancy syndrome. The disease is believed to stem from a transport defect that prevents exocytosis of brush border-related material. We investigated this hypothesis by examining the direct constitutive exocytotic pathway using sucrase-isomaltase as a representative protein. We also studied various other brush border and lysosomal marker enzymes. The biosynthesis and localization of selected intestinal epithelial enzymes were studied in small-intestinal mucosal biopsy specimens from a total of nine children with microvillous atrophy by: (a) metabolic labeling in organ culture, (b) radioiodination and immunoprecipitation, (c) indirect immunoperoxidase immunocytochemistry, and (d) immunogold electron microscopy. The results demonstrated that brush border enzymes were synthesized normally and could be located in the apical brush border membrane and on microvillous membrane within microvillous inclusions. Brush border enzymes were not detected in the "secretory granules" that accumulated within the apical cytoplasm of epithelial cells. Lysosomal enzymes were only detected within lysosomal bodies. Thus, the direct constitutive pathway is not involved in microvillous atrophy, and a disturbance of endocytosis or the indirect constitutive pathway is unlikely. Any transport defect in the disease probably involves a different, unidentified exocytotic pathway.

Mosaic expression of brush-border enzymes in infants with chronic diarrhea and malnutrition.

The chronic diarrhea observed in young malnourished infants that is sensitive to dietary glucose and other carbohydrates is associated with variable degrees of patchy mucosal villous atrophy. To explore intrinsic mucosal function in the pathogenesis of this alimentary intolerance, we have conducted an immunohistologic investigation of brush-border enzyme proteins of clinically obtained, mucosal biopsy samples. We used a group of monoclonal antibodies against human brush-border aminopeptidase, sucrase/isomaltase (SI), maltase, and lactase enzyme proteins. SI was strongly and uniformly expressed in crypts and villi of 11 of the 14 subjects; in 3 subjects, however, SI was expressed in a mosaic pattern. Maltase and lactase were occasionally absent, but more commonly were expressed in a mosaic distribution. The mosaic expression of brush-border enzyme proteins has been reported in congenital enzyme deficiencies associated with normal intestinal histology. We report the mosaic expression of brush-border enzyme proteins as a functional alteration associated with a pathological lesion of the mucosa in infants with chronic diarrhea. Our observation challenges the existing concept of ontogenic regulation of brush-border enzyme activity.

Studies on small intestinal mucosal morphology lactase activity and lactose hydrolysis rate in childhood with diarrhea.

Small intestinal mucosal morphology, lactase activity and lactose hydrolysis were examined by peroral intestinal biopsy and intraluminal perfusion of the small intestine in 28 patients with acute and chronic diarrhea. This study shows that lactase deficiency and mucosal damage are more common in childhood diarrhea, and there are positive correlations among intestinal morphology, lactase activity and lactose hydrolysis. A small bowel biopsy is useful both in establishing the diagnosis and guiding dietary treatment for infants with chronic diarrhea. The pathophysiologic mechanism of diarrhea is also discussed.

Histologic findings are not correlated with disaccharidase activities in infants with protracted diarrhea.

Histologic assessment as well as information about the disaccharidase activity of the small intestinal mucosa can be useful in the management of patients with small intestinal mucosal damage. In an effort to determine whether the degree of small intestinal mucosal damage would be reflected in a corresponding reduction in disaccharidase activity, we compared small intestinal mucosal histology with the results of disaccharidase activity measured in per oral suction small intestinal biopsies obtained from 21 infants with protracted diarrhea. The degree of small intestinal mucosal damage was graded using a subjective score (i.e., 0 to 4+ damage) by a pathologist (P) and by a computer-assisted digitizing system (to assess villus surface area, VSA, and villus/crypt ratio, V/C) in a blinded fashion. The mean (+/- SD) age of the infants was 2.5 +/- 1.5 months, and the duration of diarrhea was 25.2 +/- 11.5 days. There was good correlation between the results obtained from the digitizing system and from the pathologist: VSA versus P, r = 0.695; V/C versus P, r = 0.791; p = 0.0004. All infants demonstrated some degree of small intestinal mucosal damage. The mean (+/- SD) values for P, VSA, and V/C were 2.2 +/- 1.3, 2.9 +/- 0.9, and 0.9 +/- 0.5, respectively. The mean values for lactase, sucrase, and maltase were 17.1 +/- 17.0, 71.1 +/- 54.0, and 224.3 +/- 233 mumol/min/g protein, respectively. No correlation was observed between the histologic scoring results and lactase, sucrase, or maltase measurements. Expressing the disaccharidase activities per unit wet weight of tissue did not improve the correlations. Log transformation of the data also failed to improve the correlations.(ABSTRACT TRUNCATED AT 250 WORDS)

Intestinal glucoamylase & other disaccharidases in children with protracted diarrhoea.

Brush border lactase, sucrase and glucoamylase activities were assessed in jejunal mucosal biopsy specimens from 34 children (median age 11 months; range 1.5-38) having protracted diarrhoea with failure to thrive and 8 well nourished children with normal jejunal mucosal histology (median age 10.2 months; range 2-37). All enzymes showed progressive decrease in activity which was directly in relation to increasing degree of mucosal injury (P less than 0.002). Lactase was significantly reduced even in patients with protracted diarrhoea and normal mucosa (P less than 0.05). Glucoamylase and sucrase were significantly reduced only in the presence of mucosal injury (P less than 0.01). Our data suggest that most children with protracted diarrhoea may not tolerate lactose containing feeds and may need lactose-free diets preferably based on starch. A small number of children with protracted diarrhoea, who have severe mucosal injury may not be able to handle even starch and may require diets based on short chain glucose polymers. The findings of this study, need to be corroborated with well-controlled metabolic balance studies.

[Malabsorption and developmental retardation due to secondary trypsin deficiency].

A 1.5-year-old girl was admitted with chronic diarrhea of 10 months duration and retarded physical and psychomotor development. Duodenal tryptic activity was absent on testing with secretin and cholecystokinin. With pancreatic enzyme replacement diarrhea ceased and growth recommenced. Duodenal tryptic activity returned to normal within 6 months. A 10-year follow-up revealed normal physical and mental growth. Secondary deficiency of trypsin is a rare cause of malabsorption in childhood; correct and timely treatment can avoid severe, irreversible developmental defects.

Ultrastructural and biochemical changes in human jejunal mucosa associated with enteropathogenic Escherichia coli (0111) infection.

A case of prolonged diarrhoea following Escherichia coli 0111 gastroenteritis is reported. Electron microscopy of the jejunal biopsy revealed effacement of the brush border and attachment of bacteria by pedestal formation. Specific activities of brush border enzymes showed marked depression of disaccharidases, zinc-resistant alpha-glucosidase, and alkaline phosphatase. In contrast, marker enzymes for basolateral membranes and endoplasmic reticulum were unaffected. The biochemical changes support the pathogenic mechanism suggested by ultrastructural studies previously reported.

Disaccharidase activities, jejunal morphology, and carbohydrate tolerance in children with chronic diarrhea.

Children with chronic diarrhea were examined for their carbohydrate tolerance, small bowel morphology, and specific disaccharidase activities to determine whether disaccharidase enzymatic activity is related to villus height and thus may be viewed as an independent variable that controls digestive capacity. Results indicated that 65-78% of all abnormal biopsy samples had specific disaccharidase activities that fell within the normal range. Clinical disaccharide tolerance studies indicated that specific enzyme activity did not correlate with disaccharide tolerance.

Congenital microvillous atrophy: specific diagnostic features.

Proximal small intestinal and colonoscopic mucosal biopsies from two children with the intractable diarrhea of infancy syndrome were examined by electron microscopy. Microvillous involutions were found in the small and large bowel of both patients. We suggest that this is a specific diagnostic finding for congenital microvillous atrophy, a distinct disorder within the intractable diarrhoea syndrome which has an extremely poor prognosis.