Nephrogenic systemic fibrosis an unsolved riddle

Nephrogenic systemic fibrosis (NSF) is an emergent scleroderma-like disease progressively inducing a skin and joint severe dermal fibrosis. Until now there have been about 215 cases reported in NSF registry, linked to the use of Gadolinium as contrast agent for Magnetic Resonance. The pathogenesis of NSF is unexplained, and the factor or factors triggering the onset of the disease are a matter of debate. The toxic Gd effect on tissues of uremic patients may be linked to the long Gd half-life. Alternatively, according to the transmetallation theory, Gd may easily be released from linear versus cyclic chelating agents exchanged with other metals. Despite many studies indicating exposure to Gd in end-stage renal disease (ESRD) or hemodialysis as a trigger of NSF, a certain cause-effect relationship has still not been found. Other epidemiological studies report cases of NSF without previous Gd infusion. Another intriguing hypothesis is the possible role of lanthanum carbonate, which like Gd is a rare earth element. The lanthanum toxicity theory may explain the diffusion of Gd-induced NSF only in countries where the use of lanthanum carbonate was introduced some years ago (e.g., United States and northern Europe). In spite of the tight linkage reported between Gd infusion and NSF occurrence in ESRD and HD patients,the prevalence of this dermal severe disease ranges from 0.4 to 0.7%. Therefore the nephrologist, must keep this in mind and advise patients that the risk of renal impairement induced by iodinated contrast media infusion, is exceedingly more elevated than the occurrence of Gd-induced NSF which is below 1%.