Cytokine gene polymorphisms and susceptibility to cachexia

Abstract

Cachexia is a progressive deterioration of body habitus associated with chronic diseases. The finding that only a proportion of patients with chronic disease develop cachexia has prompted studies looking for genetic polymorphisms that may underlie differential susceptibility. The aim of this review is to explore how inflammation and gene polymorphisms influence susceptibility to cachexia. There has been evidence that certain cytokine gene polymorphisms are associated with cachexia. However, only the IL10 -1082 G allele, which is associated with an increased risk of developing cachexia has been replicated in more than one study. Variation in genes outwith inflammation pathways (e.g. genes involved in protein metabolism) is also likely to contribute the susceptibility of developing cachexia. The insertion/deletion angiotensin converting enzyme (ACE) gene polymorphism has recently been linked with lower lean body mass in cancer patients with cachexia. Although there is an increasing body of evidence of genetic susceptibility to cachexia, most studies so far have only focussed on a small number of polymorphisms and have small sample sizes. Large-scale candidate gene studies or genome-wide association studies are required to further elucidate the link between genotype and cachexia.