Isolated Lactase Deficiency in Humans

Welsh, Jack D.

doi:10.1097/00005792-197007000-00001

Cited by 105 publications

(32 citation statements)

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“…Disaccharidase activities in biopsy specimens were measured for all patients and controls participating in the study. Initial disaccharidase activities in specimens obtained from normal control patients were comparable to those reported by others (17)(18)(19). In general disaccharidase adtivity increased during organ culture although not to the same degree as alkaline phosphatase activities.…”

supporting

confidence: 88%

An in vitro model of gluten-sensitive enteropathy. Effect of gliadin on intestinal epithelial cells of patients with gluten-sensitive enteropathy in organ culture.

Falchuk¹,

Gebhard²,

Sessoms³

et al. 1974

J. Clin. Invest.

158

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A BS TRA C T Jejunal biopsy specimens from patients with gluten-sensitive enteropathy (GSE) (obtained during gluten challenge) as well as from normal individuals and patients with other gastrointestinal abnormalities were cultured in vitro for 48 h in the presence or absence of a peptic-tryptic digest (P-T digest) of gliadin.In the absence of gliadin the alkaline phosphatase activity in the biopsy specimens obtained from normal control individuals increased from an initial value of 384+ 83 U to a 48 h value of 561±151 U (mean+SD) (dif-ference significant at P < 0.01). The initial alkaline phosphatase activity of specimens obtained from patients with GSE was strikingly lower than that of normals, 117±79 U, and increased to a 48 h value of 399+ 203 U (difference significant at P < 0.01). The biochemical change in cultured biopsy specimens of GSE patients correlated with increases in the length and regularity of brush borders of epithelial cells as seen with the electron microscope.In the presence of a P-T digest of gliadin, the alkaline phosphatase activity of biopsy specimens of control individuals increased from an initial value of 384±83 U to a 48 h value of 578±156 U. In contrast, the alkaline phosphatase activity of biopsy specimens of patients with GSE in exacerbation showed a markedly diminished increase in activity during 48 h of culture; in this case the initial activity was 117+79 U and the final activity was 203±93 U. This inhibitory effect on increase of alkaline phosphatase activity during organ culture was specific Received for publication 3 May 1973 and in revised form 15 October 1973. in that a P-T digest of casein (a protein not toxic in vivo to patients with GSE) had no effect on alkaline phosphatase increases in culture. Finally, these results obtained with biopsy specimens taken from patients with GSE in exacerbation were compared with results obtained from patients with GSE in remission. Alkaline phosphatase activity of specimens obtained from the latter group of patients also increased during culture but in this instance P-T digest of gliadin in the culture medium had no significant inhibitory effect.In conclusion, the inhibitory effect of gliadin on intestinal epithelial cells in organ culture represents an in vitro model of gluten-sensitive enteropathy. Inasmuch as this effect of gliadin is not seen in cultures of specimens taken from patients in remission, it appears that gliadin is not directly toxic to GSE jejunal mucosa per se, but rather toxicity requires the participation of an endogenous effector mechanism which must first be stimulated in vivo.

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supporting

confidence: 88%

An in vitro model of gluten-sensitive enteropathy. Effect of gliadin on intestinal epithelial cells of patients with gluten-sensitive enteropathy in organ culture.

Falchuk¹,

Gebhard²,

Sessoms³

et al. 1974

J. Clin. Invest.

158

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“…The measured enzyme activity was used as the criterion oflow and elevated lactase, because the available data indicate that lactase enzyme activity is a direct function of the amount of lactase protein present (9). Since sucrase activity does not decrease in lactase-deficient patients (10)(11)(12), the ratio of sucrase activity to lactase activity provides a useful index of "lactase deficiency." Two independent studies encompassing more than 100 patients apiece, in which both lactose tolerance and enzyme activities were analyzed (10, 1 1), demonstrated that the ratio ofsucrase to lactase activity correlated well with lactose tolerance or intolerance.…”

Section: Introductionmentioning

confidence: 99%

Molecular basis of lactase levels in adult humans.

Escher

Koning²,

Engen³

et al. 1992

J. Clin. Invest.

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MethodsThe molecular basis of adult human "lactase deficiency" has long been a subject of controversy. To address this issue, small intestinal biopsies from oriental, black, and white patients were analyzed. Adjacent samples were assayed for lactase and sucrase specific activities and the sucrase/lactase ratio (high ratio signifies lactase deficiency), and the results were compared to lactase steady-state mRNA levels detected in Northern blots probed with a human lactase cDNA. All oriental patients had high ratios and no detectable lactase mRNA. Four black patients had a similar pattern; two with low ratios had detectable mRNA. The group of white patients displayed a range of findings, from high ratio/no mRNA to low ratio/considerable mRNA. Elevated levels of lactase mRNA always correlated with the presence of elevated levels of lactase enzyme activity, suggesting that the difference in levels of adult human intestinal lactase activity among racial groups may be regulated at the level of gene transcription. (J. Clin. Invest. 1992. 89:480-483.)

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“…The abdominal distention found in the patient groups may be due initially to liquid in the small intestine rather than due to gas in the colon as described by Welsh [22]. The abdominal distention was associated with meteorism, borborygmi, and abdominal colic.…”

Section: Discussionmentioning

confidence: 52%

Lactase Deficiency in Patients with Intestinal Schistosomiasis

et al. 1993

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Sixty patients having schistosomiasis mansoni infection were studied for lactase deficiency by different methods including lactase assay in intestinal biopsies. Thirty patients suffering from simple intestinal (Group I) and 30 patients suffering from hepatointestinal (Group II) schistosomiasis were compared to 60 controls (Group III). Lactase deficiency was evaluated by symptoms of lactose intolerance, stool pH and osmolarity, oral lactose tolerance test (OLTT), oral lactose hydrogen breath test (OLHBT) and lactase activity (LA) in small intestinal biopsies. OLTT showed intolerance in 36.7% of Group I and 40% of Group II compared to 23.3% of the controls. OLHBT showed intolerance in 26.7%, 30% and 18% for the three groups respectively, indicating a significance in Groups I and II. Abdominal symptoms of hypolactasia had higher scores in the patient groups compared to the controls, and was even higher in Group I than Group II. The mean lactase activity measured by micromol/gm wet wt/min was not statistically higher in Group I but higher in Group II than the controls. No correlation was found between lactase activity in the mucosa and the symptoms of hypolactasia in Group I. Hence, other factors in intestinal schistosomiasis may affect lactose hydrolysis. The study showed also that OLHBT is the most sensitive, specific and efficient among the non-invasive tests.

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Isolated Lactase Deficiency in Humans

Cited by 105 publications

References 0 publications

An in vitro model of gluten-sensitive enteropathy. Effect of gliadin on intestinal epithelial cells of patients with gluten-sensitive enteropathy in organ culture.

An in vitro model of gluten-sensitive enteropathy. Effect of gliadin on intestinal epithelial cells of patients with gluten-sensitive enteropathy in organ culture.

Molecular basis of lactase levels in adult humans.

Lactase Deficiency in Patients with Intestinal Schistosomiasis

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