Transthyretin for the routine assessment of malnutrition: A clinical dilemma highlighted by an international survey of experts in the field.

The value of transthyretin (TTR) measurement for assessing malnutrition is under debate due to its sensitivity to inflammation and frequent confusion over its meaning (i.e. as a marker of diagnosis, prognosis, or efficacy of refeeding). Moreover, there is still no ESPEN/ASPEN guideline on its use and cut-off values. Here the aim was to evaluate the overall perception of the value of this parameter and its utilization worldwide. A panel of international experts in the field were surveyed on the use of TTR in clinical practice in their country, on the guidelines issued by their national health authorities, and on the cut-off values used to diagnose malnutrition. A total of 31 experts (nutrition [n = 9], surgery [n = 8], critical care [n = 4], geriatrics [n = 4], biology [n = 3], pediatrics [n = 1], internal medicine [n = 1] and gastroenterology [n = 1]) from 16 countries participated. TTR only appears in Italian, Polish, British and French national guidelines giving cut-off values for mild/moderate/severe malnutrition. TTR is frequently used in research yet rarely if ever in clinical practice in most countries, the reasons cited being lack of evidence for its usefulness, lack of specificity, or its high cost/effectiveness ratio. Given the difficulty of finding a consensus tool for the diagnosis of malnutrition, there is every reason to consider such a simple and inexpensive marker as TTR. However, further studies are needed to define and unify international guidelines on the use of TTR in terms of inflammation level and the associated cut-off values.