Serum retinol binding protein as an indicator of vitamin A status in cirrhotic patients with night blindness

Abstract

Background/Aim:Vitamin A deficiency is known to be associated with night blindness. Plasma retinol binding protein (RBP) estimation highly correlates with plasma retinol concentration to predict vitamin A status. Serum RBP estimation is reasonably simple, inexpensive, and highly applicable in less technologically developed settings. We studied the correlation of plasma vitamin A levels (by RBP estimation) and ocular manifestation in patients with liver cirrhosis.Materials and Methods:This prospective, cohort study included 137 patients with liver cirrhosis. Ocular manifestations in these patients were recorded along with detailed history and clinical examination. Blood samples after overnight fasting were measured for RBP levels. The characteristics of cirrhotic patients with and without eye findings were compared.Results:Out of 137 patients, 55% were males. The causes of cirrhosis were hepatitis C virus in 61%, hepatitis B virus in 32%, alcoholics in 3%, and primary biliary cirrhosis in 3%. Ocular manifestations were found in 47% patients. RBP levels were found to be low in 44%, normal in 40%, and relatively high in 16% patients. Low levels of RBP compared to normal were associated with opthalmological findings of hypovitaminosis A (P < 0.001).Conclusion:The measurement of plasma RBP as an alternative to serum retinol estimation to detect relative hypovitaminosis A is simple, easy and reliable. Vitamin A level is strongly related to the severity of liver disease. Opthalmological manifestations in patients with liver cirrhosis may be preventable by early detection of hypovitaminosis A with serum RBP level, but larger studies are required before recommendation of vitamin A supplementation.

Serum retinol‐binding protein: a novel biomarker for recalcitrant cutaneous warts

“…On the other hand, it was revealed that serum RBP level showed significant discrimination between patients with recalcitrant warts and healthy control groups ( P ≤ 0.001) at a cutoff value ≤1034.6 μ g/ml with sensitivity and specificity at 100% each. This finding is consistent with and supportive of the previous observation regarding low serum RBP as a reliable indicator of retinol deficiency . As retinol is crucial to the normal development of immune cells including neutrophils, monocytes, macrophages, NK cells, B cells, and T cells, both innate and adaptive cell‐mediated immunity are important for the elimination of HPV infection …”

“…Vitamin A (retinol) is transported to the tissues in the form of retinol bound to RBP in a 1 : 1 complex. Plasma RBP concentrations highly correlate with plasma retinol as they exist in the circulation in equimolar concentrations with 93% sensitivity for predicting marginal vitamin A status and 91% sensitivity for predicting vitamin A deficiency; the corresponding specificities are 75 and 94%, respectively . RBP is less photo‐ and heat‐sensitive than retinol, where laboratory and refrigeration facilities are poor, and more accurate results may be obtained by measuring RBP rather than retinol concentrations as an indicator of vitamin A status …”

Prevalence of Vitamin A Deficiency in South Asia: Causes, Outcomes, and Possible Remedies

“…Some studies in Pakistan validated the efficacy of vitamin A-fortified cookies, and promising results were achieved for baking and storage stability of the product, thus suggesting fortification of cookies with retinyl acetate (14,68,69). However, the selection and levels of appropriate fortificant need to be particularly considered for fortification, e.g.…”

“…Increased risk of blindness was assessed in North West Frontier Province of Pakistan (NWFP) among children aged 6 years or less (9,10), and 16% of the anaemic children in primary schools in Karachi, Pakistan, were shown to be vitamin A-deficient. The risk of VAD in Pakistan is around 70% in pregnant and lactating mothers (11-14). …”

Effect of dietary protein against excess vitamin A induced hepatotoxicity in rats

“…RBP is responsible for the transport of vitamin A from liver to plasma 19 . The situation was reversed in liver when protein intake was more due to excess transport of vitamin A from liver to plasma.…”