Abetalipoproteinemia, caused by mutations in the gene encoding microsomal triglyceride transfer protein, causes fat malabsorption, pigmentary degeneration of the retina, progressive ataxic neuropathy, and acanthocytosis. Many of the features are caused by secondary vitamin E deficiency. It has now been recognized that patients also have immune defects with altered presentation of self and microbial lipid antigens by CD1 molecules, caused by an increased degradation of CD1 molecules (Zeissig et al., 2010, J Clin Invest 120:2889-99).Â Calogera M. SimonaroÂ et al. hypothesized that inflammation was involved in the bone and joint pathology of mucopolysaccharidoses. They bred MPS VII mice with mice deficient in Toll-like receptor 4 (TLR4), and showed decreased bone pathology. This effect was also seen when using the anti-TNF-Î± drug Remicade (Simonaro et al., 2010, Proc Natl Acad Sci U S A 107:222-7).
Posted by Philippe Campeau, MD