Malabsorption of fat-soluble vitamins is a major complication of chronic cholestatic liver disease.
The most accurate way to assess vitamin A status in children who have cholestasis is unknown.
Dr Andrew Feranchak and colleagues from Colorado assessed the accuracy of noninvasive tests to detect vitamin A deficiency.
The team studied 23 children with chronic cholestatic liver disease and10 with noncholestatic liver disease.
The research team identified 10 cholestatic patients as vitamin A-deficient based on the relative dose response.
Compared with the relative dose response, the sensitivity and specificity to detect vitamin A deficiency for each test was 90% and 78% with serum retinol.
The researchers found that the sensitivity to detect vitamin A deficiency with retinol-binding protein was 40% and the specificity was 91%.
Retinol/ retinol-binding protein molar ratio had a sensitivity of 60% and specificity of 74%.
|Modified oral retinol-binding had a sensitivity of 80% and a specificity of 100%|
The team noted that with conjunctival impression cytology, sensitivity was 44% and specificity was 48%.
With slit-lamp examination, the team observed that the sensitivity was 20% and specificity was 66%.
Tear film break-up time had a sensitivity of 40% and specificity of 69%, while Schirmer's test had a 20% sensitivity and 78% specificity.
The research team developed a modified oral retinol-binding protein.
This was developed via oral coadministration of d-alpha tocopheryl polyethylene glycol-1000 succinate and retinyl palmitate.
The team reported that this test had a sensitivity of 80% and a specificity of 100% to detect vitamin A deficiency.
Dr Feranchak's team concludes, “Vitamin A deficiency is relatively common in children who have chronic cholestatic liver disease.”
“Our data suggest that serum retinol level as an initial screen followed by confirmation with a modified oral retinol-binding protein test is the most effective means of identifying vitamin A deficiency in these subjects.”