Nephrogenic systemic fibrosis is found only among gadolinium-exposed patients with renal insufficiency: a case-control study from Denmark.

BACKGROUND: Nephrogenic systemic fibrosis (NSF) is a systemic fibrosing disease associated with exposure to gadolinium-based contrast agents (GBCA) in patients with renal insufficiency. OBJECTIVES: To report the prevalence of NSF in a well-defined cohort of patients with renal insufficiency exposed to GBCA, to investigate if GBCA-unexposed controls showed signs of NSF and to evaluate selected risk factors among NSF cases and GBCA-exposed controls. METHODS: A study among GBCA-exposed patients with renal insufficiency (n=565) was conducted to identify cases of NSF. The NSF cases found were age and sex matched and clinically compared with GBCA-exposed and unexposed patients with renal insufficiency in a case-control study. RESULTS: We identified 17 NSF cases. No signs of NSF were observed among the controls. The prevalence of NSF was 4·7%, highest among patients with chronic kidney disease (CKD) stage 5 exposed to GBCA and undergoing haemodialysis or peritoneal dialysis. Three NSF cases were identified among patients with CKD stage 3 and 4. Three patients developed NSF after macrocyclic GBCA exposure. NSF cases had a tendency to have higher serum phosphate concentrations than GBCA-exposed controls. CONCLUSIONS: Our study supports the view that GBCA is a major risk factor for NSF. Importantly, we found that patients with CKD stage 3 and 4 can be at risk of NSF. NSF may also be triggered by macrocyclic GBCA. Further, we observed a trend for higher phosphate levels in NSF cases compared with controls. The important findings drawn from this case-control study indicate that NSF is not an overlooked condition among patients with renal insufficiency not exposed to GBCA.

Quantification of gadolinium in fresh skin and serum samples from patients with nephrogenic systemic fibrosis.

BACKGROUND: Nephrogenic systemic fibrosis (NSF) is a rare, potentially fatal fibrosing disorder associated with renal insufficiency and gadolinium (Gd)-based contrast exposure. The cause remains unknown. To date, all efforts to investigate skin Gd concentrations in patients with NSF have been performed on paraffin-embedded samples, and Gd deposition has not been correlated with disease activity by a statistically significant analysis. OBJECTIVE: We sought to: (1) quantify Gd concentration in fresh tissue skin biopsy specimens; (2) quantify and compare synchronous Gd concentration of affected skin and unaffected skin in patients with NSF (n = 13) with a control group (n = 13); and (3) quantify serum Gd. METHODS: We used inductively coupled plasma mass spectrometry. RESULTS: In patients with NSF, the mean ratio of paired Gd concentrations of affected skin to unaffected skin was 23.1, ranging from 1.2 to 88.9. Mean serum Gd concentrations in patients with NSF were 4.8 ng/mL, which is more than 10 times the level in control patients. A statistically significant correlation existed between serum and affected skin Gd concentrations (r(2) = .74, P < .0001). LIMITATIONS: Because of the feasibility of this study, the main limitation was the small sample size (n = 13 affected and 13 control). CONCLUSIONS: Determination of Gd concentrations in fresh skin samples and serum using inductively coupled plasma mass spectrometry demonstrates significant differences in the amounts of Gd in involved versus nonlesional skin of patients with NSF. This supports the role of differential free Gd deposition from Gd-based contrast in the pathogenesis of NSF.

Hyperphosphataemia sensitizes renally impaired rats to the profibrotic effects of gadodiamide.

BACKGROUND AND PURPOSE: Hyperphosphataemia is common in patients with nephrogenic systemic fibrosis (NSF). NSF has been linked to administration of gadolinium (Gd) chelates (GCs) and elevated serum phosphate levels accelerate the release of Gd from linear, non-ionic GCs but not macrocyclic GCs. Hence, we determined whether hyperphosphataemia is a cofactor or risk factor for NSF by investigating the role of hyperphosphataemia in renally impaired rats. EXPERIMENTAL APPROACH: Firstly, the clinical, pathological and bioanalytical consequences of hyperphosphataemia were investigated in subtotal nephrectomized (SNx) Wistar rats following i.v. administration of the non-ionic, linear GC gadodiamide (5 × 2.5 mmol·kg(-1) ·day(-1) ). Secondly, the effects of several GCs were compared in these high-phosphate diet fed rats. Total Gd concentration in skin, femur and plasma was measured by inductively coupled plasma mass spectrometry (ICP-MS) and free Gd(3+) in plasma by liquid chromatography coupled to ICP-MS. Relaxometry was used to measure dissociated Gd in skin and bone. KEY RESULTS: Four out of seven SNx rats fed a high-phosphate diet administered gadodiamide developed macroscopic and microscopic (fibrotic and inflammatory) skin lesions, whereas no skin lesions were observed in SNx rats treated with saline, the other GCs and free ligands or in the normal diet, gadodiamide-treated group. Unlike the other molecules, gadodiamide gradually increased the r(1) relaxivity value, consistent with its in vivo dissociation and release of soluble Gd. CONCLUSIONS AND IMPLICATIONS: Hyperphosphataemia sensitizes renally impaired rats to the profibrotic effects of gadodiamide. Unlike the other GCs investigated, gadodiamide gradually dissociates in vivo. Our data confirm that hyperphosphataemia is a risk factor for NSF.

Nephrogenic systemic fibrosis: late skin manifestations.

BACKGROUND: Nephrogenic systemic fibrosis (NSF) is a serious disease that occurs in patients with severe renal disease and is believed to be caused by gadolinium-containing contrast agents. A detailed description of the late skin manifestations of NSF is important to help dermatologists and nephrologists recognize the disease. OBSERVATIONS: We studied 17 patients with NSF late in the disease. All patients showed epidermal atrophy and hairlessness of the affected regions, primarily the lower legs. Affected areas were symmetrically distributed and hyperpigmented in most cases. Eleven patients showed confluent dermal plaques with thickening and hardening. In contrast, 3 patients presented with wrinkled, redundant skin as seen in cutis laxa. Patients with NSF had significantly poorer scores than control patients on the Daily Life Quality Index (mean [SD], 11. 4 [7.4] vs 1.5 [2. 3]; P < .001). CONCLUSIONS: This descriptive case series of patients with NSF gives a detailed clinical picture of the skin manifestations late in the disease. It demonstrates that the clinical picture in the late stage has a varied presentation and that NSF has a significant effect on the quality of life.

Detection of clonal T cells in the circulation of patients with nephrogenic systemic fibrosis.

BACKGROUND: Nephrogenic systemic fibrosis is a sclerodermalike disease in patients with acute or chronic renal insuffiency related to administration of gadolinium-containing contrast agents. Previous studies have demonstrated clonal T-cell populations in the blood of patients with systemic sclerosis, suggesting that these cells may be involved in the pathogenesis of the disease. Facing the clinical similarities of both diseases, we hypothesized that clonal expansion of T cells could be present in nephrogenic systemic fibrosis as well. OBSERVATIONS: Findings from polymerase chain reaction and high-resolution capillary electrophoresis for T-cell receptor gamma gene rearrangement analysis showed that all 6 prospectively evaluated patients (100%) with nephrogenic systemic fibrosis had detectable clonal T cells in their peripheral blood. In contrast, only 4 of the 15 control patients (27%) with chronic renal failure and none of the 12 healthy individuals analyzed in this study had evidence for T-cell clonality using the same type of examination. Clonal T-cell-positive patients with systemic sclerosis have previously been reported to better respond to extracorporeal photopheresis. However, this was not the case in 2 of our patients with nephrogenic systemic fibrosis. Conclusion As in systemic sclerosis, clonally expanded T-cell populations could play a critical role in the pathogenesis of nephrogenic systemic fibrosis, probably as an in vivo-activated inflammatory response to gadolinium exposure.