What is nephrogenic systemic fibrosis?
Nephrogenic systemic fibrosis (NSF) is a rare disease that can affect different parts of the body. It most commonly first appears as swelling or itching of the skin. It can lead to thickening or hardening of the skin and deposits in other parts of the body.
The disease was first observed in 1997, and was thought to only affect the skin. Only later was the risk to other organs recognized.
Although the condition was first seen in patients with severe kidney problems (often people who were on dialysis), only a small minority of patients were affected. These patients often had other problems that could lead to inflammation in the body, such as recent major surgery, blood clot, cancer or infection.
Nephrogenic systemic fibrosis may be a progressive condition. As it gets worse, it can go well beyond the skin and cause multiple organs to fail. It can be fatal.
What causes nephrogenic systemic fibrosis?
Most, if not all, cases of nephrogenic systemic fibrosis are caused by exposure to gadolinium-based contrast agents (GBCA). Exposure occurs when the chemical element gadolinium is used to enhance images gathered in magnetic resonance imaging (MRI).
Nephrogenic systemic fibrosis occurs in patients who have acute kidney injury (AKI), chronic kidney disease (CKD) or those on dialysis (ESRD). Additional patients at risk include those with diabetes mellitus, hypertension, kidney transplant, a single kidney or history of kidney surgery.
There have been reports of patients who have not been exposed to gadolinium in an MRI developing nephrogenic systemic fibrosis. However, most of those patients have in fact been exposed to gadolinium in one way or another, such as in another test or a surgery, an injury or an infection.
About 4% of patients with severe kidney problems will develop nephrogenic systemic fibrosis after exposure to gadolinium. About 30% of cases are reported to be fatal but that number could be much higher as the condition is often misdiagnosed or not reported accurately because it is not well understood.
Gadolinium has been used since the late 1980s. Exactly how gadolinium leads to nephrogenic systemic fibrosis is unclear. However, it does appear that the risk of developing the condition goes up as a person is exposed to certain types called linear gadolinium and as a higher amount of gadolinium is given.
Since 2009, no new cases of NSF have been reported. This finding reflects the use of more stable, less toxic gadolinium agents and limiting the use of gadolinium in patients with renal failure. Agents that are macrocytic are much less toxic. As a result, the safe use of gadolinium and avoidance of fibrosis has increased.
What are the symptoms of nephrogenic systemic fibrosis?
Patients can develop symptoms of nephrogenic systemic fibrosis as early as the day they are exposed to gadolinium-based contrast agents, or up to several months later. In one study, 50% of patients had symptoms within 12 days after exposure. The likelihood of a patient developing NSF differs after exposure to different formulations of GBCAs and as a higher amounts of gadolinium are given.
- Early symptoms tend to be itchy, red bumps that may be hard. These bumps may gather to form a dimply appearance that can resemble an orange peel. The bumps are most common on the arms and legs, as well as the torso. They rarely affect the face.
- Patients also can develop pain in their joints that can become disabling. This can be followed by hardening and thickening of the skin especially over the arms, legs and trunk.
- Fibrosis can progress with deposits in the muscles, lungs, esophagus and heart that damage these organs. This condition can be fatal.