A new study published in the October issue of the Archives of Dermatology has found that dialysis patients and kidney transplant patients exposed to gadolinium contrast dyes face a higher risk of developing the devastating disease, nephrogenic systemic fibrosis (NSF).
The study involved 94,917 patients exposed to gadolinium agents at the Mayo Clinic between January 1, 1999 and December 31, 2006. Of that group, 3,779 patients were on hemodialysis, 1,694 patients had undergone a kidney transplant, and 717 patients had liver transplants. A total of 61 patients had a clinical diagnosis of NSF.
The study found that 1% of patients undergoing hemodialysis, and 0.8% of patients who have undergone kidney transplant were at risk of developing NSF. The risk for liver transplant patients was 0%. This means that dialysis patients had a 77-fold higher risk of NSF, while kidney transplant patients had a 69-fold higher risk of the disease.
NSF is a debilitating disease that leads to excessive formation of connective tissue in the skin and internal organs. It is characterized by high blood pressure, burning, itching, swelling and hardening of the skin. Other symptoms include red or dark patches on the skin; pain deep in the hip bones or ribs and muscle weakness. NSF can progress to the point of causing severe stiffness in joints, and it can lead to death.
It appears that NSF only develops in people with pre-existing kidney disease who are exposed to the gadolinium agents. In September 2007, the U.S. Food & Drug Administration (FDA) asked the manufacturers of all gadolinium contrast dyes to add a black box warning to the product labels about its association with NSF. The FDA also warned that patients with kidney disease should avoid gadolinium contrast agents, and that the lowest possible dosage should be administered to such patients if use of the dyes cannot be avoided.
On Wednesday, we reported that an FDA review had found that OptiMARK, Magnevist and Omniscan carried a higher risk of NSF than other gadolinium agents on the market. Though the agency’s drug safety unit said the risk associated with the gadolinium contrast dyes “does not compel removal of specific (imaging agents) from the U.S. market”, it has recommended that the drug labels note the varying levels of risks with each product. An outside panel of experts will take up the issue in December.
