Bile acid malabsorption as a cause of chronic diarrhea: Diagnostic usefulness of 7α-hydroxy-4-cholesten-3-one in serum

Monitoring hepatic cholesterol 7α-hydroxylase activity by assay of the stable bile acid intermediate 7α-hydroxy-4-cholesten-3-one in peripheral blood

“…We obtained an average plasma C4 level of 12 ng/ml using human samples from five normal males. This level is in good agreement with previously published data where averages from 8 ng/ml to 19 ng/ml have been reported (21,27,28,31,32). Our data on the relative differences of the C4 levels in rats, mice, and humans in the current investigation are in agreement with previously published data on the enzymatic activity of C7␣OH in these species.…”

“…Previous studies have shown a good relationship between plasma C4 and the 75 SeHCAT test in patients with diarrhea (28)(29)(30) and also between plasma C4 and the enzymatic activity of C7␣OH in the liver when comparing untreated gallstone patients with gallstone patients treated with ursodeoxycholic acid, chenodeoxycholic acid, or cholestyramine (21). To the best of our knowledge, there are no data available regarding the use and significance of C4 in laboratory animals.…”

Diarrea pos colecistectomía, enfoque diagnóstico y terapéutico

“…En la literatura se han descrito pruebas para evidenciar la mala-absorción de AB con la medición directa o indirecta de AB (17)25% to 50% of patients with functional diarrhea or diarrhea-predominant irritable bowel syndrome (IBS-D. Uno de los métodos directos, es la medición de C4 en sangre que tiene una sensibilidad del 90%, especificidad del 79%, valor predictivo positivo 74% y valor predictivo negativo del 98% al compararlo con la prueba de Se75HCAT, recalcando la importancia de la utilidad como una prueba de tamización para mala-absorción de AB por su alto valor predictivo negativo (36). Aunque se debe estandarizar el momento de la toma de la prueba ya que presenta variabilidad diurna (37).…”

Chronic diarrhea caused by idiopathic bile acid malabsorption: an explanation at last

“…This intermediate in bile acid biosynthesis spills over into plasma in direct proportion to its synthesis rate. Thus, plasma C4 levels increase when bile acid biosynthesis increases, and C4 levels are markedly increased in patients with bile acid mal absorption [40][41][42]. As yet, this interesting and potentially valuable diagnostic test is only available in research laboratories.…”