Nephrogenic Systemic Fibrosis

The safety of magnetic resonance imaging contrast agents

Gadolinium-based contrast agents are increasingly used in clinical practice. While these pharmaceuticals are verified causal agents in nephrogenic systemic fibrosis, there is a growing body of literature supporting their role as causal agents in symptoms associated with gadolinium exposure after intravenous use and encephalopathy following intrathecal administration. Gadolinium-based contrast agents are multidentate organic ligands that strongly bind the metal ion to reduce the toxicity of the metal. The notion that cationic gadolinium dissociates from these chelates and causes the disease is prevalent among patients and providers. We hypothesize that non-ligand-bound (soluble) gadolinium will be exceedingly low in patients. Soluble, ionic gadolinium is not likely to be the initial step in mediating any disease. The Kidney Institute of New Mexico was the first to identify gadolinium-rich nanoparticles in skin and kidney tissues from magnetic resonance imaging contrast agents in rodents. In 2023, they found similar nanoparticles in the kidney cells of humans with normal renal function, likely from contrast agents. We suspect these nanoparticles are the mediators of chronic toxicity from magnetic resonance imaging contrast agents. This article explores associations between gadolinium contrast and adverse health outcomes supported by clinical reports and rodent models.

Uptake of Gadolinium-Based Contrast Agents by Blood Cells During Contrast-Enhanced MRI Examination

OBJECTIVES

Gadolinium-based contrast agents (GBCAs) are routinely used in magnetic resonance imaging (MRI) examinations. However, there is limited knowledge about the interaction with and distribution of the drug in human cells. This lack of knowledge is surprising, given that the first interaction of the drug occurs with blood cells. Moreover, recent studies reported gadolinium (Gd) deposition within organs, such as the brain. Hence, this study is aiming to determine the uptake of GBCA in blood cells of patients undergoing contrast-enhanced MRI (ce-MRI) examination.

MATERIALS AND METHODS

Human blood was exposed to either gadoterate meglumine (Gd-DOTA) or Eu-DOTA in vitro or was collected from patients undergoing ce-MRI with Gd-DOTA. Uptake of contrast agents (CAs) by blood cells was quantified by Gd measurements using single-cell inductively coupled plasma mass spectrometry (SC-ICP-MS) or, to confirm Gd-DOTA uptake, by a complementary method using Eu-DOTA by time-resolved fluorescence spectroscopy, respectively.

RESULTS

Uptake of Gd-DOTA or Eu-DOTA into white blood cells (WBCs) ex vivo was detectable by SC-ICP-MS and time-resolved fluorescence spectroscopy. The intracellular concentrations were estimated to be in the range of 1-3 μM. However, no CA uptake into erythrocytes was detected with either method. In total, 42 patients between 30 and 84 years old (24 men, 18 women) were enrolled. White blood cells' uptake of Gd was measured by SC-ICP-MS. Isolated WBCs from patients who underwent ce-MRI examination showed substantial Gd uptake; however, the studied patient group showed an inhomogeneous distribution of Gd uptake. Measurements immediately after MRI examination indicated 21-444 attogram/WBC, corresponding to an intracellular Gd concentration in the range from 0.2 to 5.5 μM.

CONCLUSIONS

This study confirms the ex vivo uptake of GBCA by WBCs and provides the first evidence that GBCA is indeed taken up by WBCs in vivo by patients undergoing ce-MRI examination. However, the observed Gd uptake in WBCs does not follow a log-normal distribution commonly observed in the fields of environmental studies, biology, and medicine. Whether cellular uptake of GBCA is linked to the observed deposition of Gd remains unclear. Therefore, studying the interaction between GBCA and human cells may clarify crucial questions about the effects of Gd on patients after MRI examinations.

Comparison of different analytical methods for speciation of seven gadolinium-based magnetic resonance imaging contrast agents and the applications in wastewater and whole blood

Three methods, high-performance liquid chromatography hyphenated with inductively coupled plasma mass spectrometry, high-performance liquid chromatography-tandem mass spectrometry, and ion chromatography, were compared for simultaneous speciation of seven commercial gadolinium-based contrast agents for magnetic resonance imaging. Optimizations of experimental conditions for individual method were conducted, respectively. Methods of high-performance liquid chromatography hyphenated with inductively coupled plasma mass spectrometry and high-performance liquid chromatography-tandem mass spectrometry showed the capability of speciation for all seven target compounds, whereas ion chromatography was only suitable for three of them when using electronic conductivity detector. The limits of detection and limits of qualification by the three methods were compared, and high-performance liquid chromatography hyphenated with inductively coupled plasma mass spectrometry was found to be the most sensitive one. The limits of detection for seven target compounds by high-performance liquid chromatography hyphenated with inductively coupled plasma mass spectrometry were in the range of 0.15-0.55 pg. Thus, high-performance liquid chromatography hyphenated with inductively coupled plasma mass spectrometry was chosen as the final method and successfully applied to speciation analysis of seven gadolinium-based contrast agents in wastewater and whole blood. Compounds of gadoxetic acid disodium, gadobenate dimeglumine, gadodiamide, and gadobentetate dimeglumine were found in wastewater.

β2-Microglobulin Elevates COL5A1 mRNA in the Subsynovial Connective Tissue of Patients Receiving Hemodialysis With Carpal Tunnel Syndrome

Background Although carpal tunnel syndrome (CTS) is frequently observed in patients undergoing long-term hemodialysis (HD), exactly how CTS arises is unknown. Here, we examined levels of COL5A1 in the subsynovial connective tissue (SSCT) of patients receiving HD and studied its potential regulation by β2-microglobulin (Β2-MG) in SSCT-derived cells (SSCTCs). Methods We extracted SSCT samples from 67 patients with CTS (49 non-HD and 18 HD) during carpal tunnel release. The samples were subjected to quantitative polymerase chain reaction (qPCR) to determine COL5A1 expression. Further, to examine the potential regulation of COL5A1 expression by Β2-MG, SSCTCs were stimulated in the absence (control) or presence of 10 µg/ml Β2-MG. Results The HD group showed significantly elevated COL5A1 levels compared to the non-HD group (P=0.027). Moreover, treating SSCTCs with Β2-MG for 24 h increased the mRNA expression of COL5A1 relative to control conditions (P=0.013). Conclusions Elevated COL5A1 expression may form part of the mechanism underlying the development of CTS, and Β2-MG may play a role in promoting COL5A1 expression in HD patients.

Preclinical Profile of Gadoquatrane: A Novel Tetrameric, Macrocyclic High Relaxivity Gadolinium-Based Contrast Agent

OBJECTIVES

The aim of this report was to characterize the key physicochemical, pharmacokinetic (PK), and magnetic resonance imaging (MRI) properties of gadoquatrane (BAY 1747846), a newly designed tetrameric, macrocyclic, extracellular gadolinium-based contrast agent (GBCA) with high relaxivity and stability.

MATERIALS AND METHODS

The r1-relaxivities of the tetrameric gadoquatrane at 1.41 and 3.0 T were determined in human plasma and the nuclear magnetic relaxation dispersion profiles in water and plasma. The complex stability was analyzed in human serum over 21 days at pH 7.4 at 37°C and was compared with the linear GBCA gadodiamide and the macrocyclic GBCA (mGBCA) gadobutrol. In addition, zinc transmetallation assay was performed to investigate the kinetic inertness. Protein binding and the blood-to-plasma ratio were determined in vitro using rat and human plasma. The PK profile was evaluated in rats (up to 7 days postinjection). Magnetic resonance imaging properties were investigated using a glioblastoma (GS9L) rat model.

RESULTS

The new chemical entity gadoquatrane is a macrocyclic tetrameric Gd complex with one inner sphere water molecule per Gd ( q = 1). Gadoquatrane showed high solubility in buffer (1.43 mol Gd/L, 10 mM Tris-HCl, pH 7.4), high hydrophilicity (logP -4.32 in 1-butanol/water), and negligible protein binding. The r1-relaxivity of gadoquatrane in human plasma per Gd of 11.8 mM -1 ·s -1 (corresponding to 47.2 mM -1 ·s -1 per molecule at 1.41 T at 37°C, pH 7.4) was more than 2-fold (8-fold per molecule) higher compared with established mGBCAs. Nuclear magnetic relaxation dispersion profiles confirmed the more than 2-fold higher r1-relaxivity in human plasma for the clinically relevant magnetic field strengths from 0.47 to 3.0 T. The complex stability of gadoquatrane at physiological conditions was very high. The observed Gd release after 21 days at 37°C in human serum was below the lower limit of quantification. Gadoquatrane showed no Gd 3+ release in the presence of zinc in the transmetallation assay. The PK profile (plasma elimination, biodistribution, recovery) was comparable to that of gadobutrol. In MRI, the quantitative evaluation of the tumor-to-brain contrast in the rat glioblastoma model showed significantly improved contrast enhancement using gadoquatrane compared with gadobutrol at the same Gd dose administered (0.1 mmol Gd/kg body weight). In comparison to gadoterate meglumine, similar contrast enhancement was reached with gadoquatrane with 75% less Gd dose. In terms of the molecule dose, this was reduced by 90% when compared with gadoterate meglumine. Because of its tetrameric structure and hence lower number of molecules per volume, all prepared formulations of gadoquatrane were iso-osmolar to blood.

CONCLUSIONS

The tetrameric gadoquatrane is a novel, highly effective mGBCA for use in MRI. Gadoquatrane provides favorable physicochemical properties (high relaxivity and stability, negligible protein binding) while showing essentially the same PK profile (fast extracellular distribution, fast elimination via the kidneys in an unchanged form) to established mGBCAs on the market. Overall, gadoquatrane is an excellent candidate for further clinical development.

Use of Real-Life Safety Data From International Pharmacovigilance Databases to Assess the Importance of Symptoms Associated With Gadolinium Exposure

OBJECTIVE

Recent scientific publications have reported cases of patients who complained from a variety of symptoms after they received a gadolinium-based contrast agent (GBCA). The aim of this study was to appreciate the importance of these clinical manifestations in the overall population by assessing the weight of "symptoms associated with gadolinium exposure" (SAGE) among the bulk of safety experiences reported to major health authorities.

MATERIALS AND METHODS

Symptoms associated with gadolinium exposure were identified from a review of the scientific literature, and the corresponding preferred terms were searched in each system organ class (SOC) category recorded in the European and North American pharmacovigilance databases EudraVigilance (EV) and FDA Adverse Event Reporting System (FAERS), respectively. The numbers of SAGE per preferred term, and cumulatively per SOC, were recorded and their weights in the overall spectrum of adverse events (AEs) were determined for each GBCA.

RESULTS

The analysis of the selected AEs revealed a significantly higher SAGE weight for gadobenate dimeglumine (EV: 25.83%, FAERS: 32.24%) than for gadoteridol (EV: 15.51%; FAERS: 21.13%) and significantly lower SAGE weights for gadobutrol (EV: 7.75%; FAERS: 13.31%) and gadoterate meglumine (EV: 8.66%; FAERS: 12.99%). A similar ranking was found for most of the SOCs except for "nervous system disorders," probably owing to a limitation in the methods of data selection. Furthermore, this analysis showed a greater percentage of reports mentioning a decrease in the quality of life of the patients when they were exposed to gadobenate dimeglumine or gadoteridol than to gadobutrol or gadoterate meglumine.

CONCLUSION

This study showed that SAGE represent a significant percentage of the bulk of AEs reported to the health authorities for each GBCA. It provided real-life arguments suggesting that SAGE may be more prevalent with linear than macrocyclic GBCAs and that gadoteridol may present a higher SAGE risk than the other macrocyclic contrast agents.

Mild Dissolution/Recomplexation Strategy for Speciation Analysis of Gadolinium from MR Contrast Agents in Bone Tissues by Means of HPLC-ICP-MS

A species-dependent and total gadolinium quantification strategy for the analysis of bone and bone marrow samples was developed and applied to femurs of rats previously treated with different gadolinium-based contrast agents (GBCAs). A combined mild dissolution/recomplexation strategy allows the quantification of total Gd as well as the quantification of intact GBCA in bones within one analysis for the first time. Samples of rat bones and bone marrow were dissolved in low concentrations of hydrochloric acid and diethylenetriamine pentaacetate (DTPA). This is followed by the addition of excess In(III) to recomplex all free ligands, previously added DTPA as well as the ligands of GBCAs that were not stable during the dissolution step. Separation and quantification were carried out by means of high-performance liquid chromatography (HPLC) on a hydrophilic interaction liquid chromatography (HILIC) column with subsequent inductively coupled plasma-mass spectrometry (ICP-MS). The results show that the investigated GBCA with a macrocyclic ligand shows a higher tendency to stay intact in the bone tissues over time, while a GBCA with a linear ligand is decomplexed more rapidly four weeks after GBCA administration. Additionally, for all macrocyclic GBCAs, a similar limited gadolinium accumulation was observed in the bone and bone marrow. Whereas linear GBCAs showed a higher gadolinium accumulation, a difference was observed between bone and bone marrow, indicating a different biodistribution behavior.

Potential toxicity evaluation and comparison within multiple mice organs after repeat injections of linear versus macrocyclic gadolinium-based contrast agents: A comprehensive and time course study

As nephrogenic systemic fibrosis (NSF) and increased signal intensities in deep cerebellar nuclei (DCN) were successively discovered in renal insufficiency patients and healthy persons after gadolinium-based contrast agents (GBCAs) exposure, an awareness of potential toxicity with GBCAs exposure has been heightening. Herein, we performed a multi-organ/tissue toxicity assessment after different GBCAs administration with a large number of samples, and long-term, time-course schedule investigation. ICR mice were randomized to five exposure groups (n = 42/group) and received intravenous injection of GBCAs (2.5 mmol Gd/kg) or saline four time a week for 5 consecutive weeks. Gadolinium concentration detection, sensory tests, histological and hematological analyses were performed at corresponding timepoints (4th or 6th or 10th week). Our results showed that (i) gadodiamide could cause reversible vacuolar changes in the renal tubular epithelial cells, which appeared at 6th week and recovered at 10th week, and severe skin lesion in mice tail with consecutive injection for 10 weeks, that (ii) linear GBCAs (gadodiamide and gadopentetate dimeglumine) markedly elevated heat hyperalgesia and white blood cells of mice at 6th week and most of these changes could recovery at 10th week, and that (iii) linear GBCAs exhibited more gadolinium retention in multi-organ/tissue versus macrocyclic GBCAs and in most case, linear GBCAs showed faster accumulation and regression speed in examined tissues than macrocyclic GBCAs excepting gadodiamide in skin which showed slowest regression speed. Collectively, macrocyclic GBCAs presents more stable, lower propensity to release Gd and safer profiles versus linear GBCAs.

Is Small Fiber Neuropathy Induced by Gadolinium-Based Contrast Agents?

OBJECTIVES

In recent years, complaints of patients about burning pain in arms and legs after the injection of gadolinium-based contrast agents (GBCAs) have been reported. In the current study, we investigated changes of small fibers in the epidermis as a potential cause of the patient complaints in a mouse model.

METHODS

Six groups of 8 mice were intravenously injected with either a macrocyclic GBCA (gadoteridol, gadoterate meglumine, gadobutrol), a linear GBCA (gadodiamide or gadobenate dimeglumine) (1 mmol/kg body weight), or saline (NaCl 0.9%). Four weeks after injection, animals were euthanized, and footpads were assessed using immunofluorescence staining. Intraepidermal nerve fiber density (IENFD) was calculated, and the median number of terminal axonal swellings (TASs) per IENFD was determined.

RESULTS

Nonparametric Wilcoxon signed-rank test revealed significantly lower IENFDs for all GBCAs compared with the control group (P < 0.0001) with the linear GBCAs showing significantly lower IENFDs than the macrocyclic GBCAs (P < 0.0001). The linear GBCAs presented significantly more TAS per IENFD than the control group (P < 0.0001), whereas no significant increase of TAS per IENFD compared with the control group was found for macrocyclic GBCAs (P < 0.237).

INTERPRETATION

It is unclear whether or at what dosage the decrease of IENFDs and the increase of TAS per IENFD found in the current animal model will appear in humans and if it translates into clinical symptoms. However, given the highly significant findings of the current study, more research in this field is required.

Use of Superparamagnetic Iron Oxide Nanoparticles (SPIONs) via Multiple Imaging Modalities and Modifications to Reduce Cytotoxicity: An Educational Review

The aim of the present educational review on superparamagnetic iron oxide nanoparticles (SPIONs) is to inform and guide young scientists and students about the potential use and challenges associated with SPIONs. The present review discusses the basic concepts of magnetic resonance imaging (MRI), basic construct of SPIONs, cytotoxic challenges associated with SPIONs, shape and sizes of SPIONs, site-specific accumulation of SPIONs, various methodologies applied to reduce cytotoxicity including coatings with various materials, and application of SPIONs in targeted delivery of chemotherapeutics (Doxorubicin), biotherapeutics (DNA, siRNA), and positron emission tomography (PET) imaging applications.

Gadolinium retention in rat abdominal organs after administration of gadoxetic acid disodium compared to gadodiamide and gadobutrol

PURPOSE

To compare gadolinium retention in the abdominal organs after administration of gadoxetic acid disodium, a liver-specific contrast agent, compared to gadodiamide and gadobutrol.

METHODS

Three types of gadolinium-based contrast agents (GBCAs) were administered to rats. A single (gadodiamide and gadobutrol, 0.1 mmol/kg; gadoxetic acid disodium, 0.025 mmol/kg) or double label-recommended dose was intravenously administered once (Group 1), a single dose was administered 4 times (Group 2) and a single dose with or without a chelating agent (intraperitoneal injection immediately after each GBCA administration) was administered (Group 3). Rats were sacrificed after 1, 4, and 12 weeks and gadolinium concentrations in the liver, spleen, kidney, muscle, and bone were measured by inductively coupled plasma mass spectrometry. P values less than 0.05 were considered statistically significant.

RESULTS

More gadolinium was retained with a double dose compared to a single dose, but there was no observed significant difference in gadolinium retention after a double dose compared to a single dose (P > .05). Gadodiamide was retained the most in all tissues followed by gadobutrol and gadoxetic acid disodium. Residual gadolinium was significantly less at 4 weeks compared to 1 week (P < .05), but no further decrease was observed after 4 weeks (P > .05). The presence of the chelating agent did not significantly decrease the concentration of residual gadolinium (P > .05).

CONCLUSION

Gadolinium was retained the least in abdominal organs after gadoxetic acid disodium was administered and most of the residual gadolinium was excreted 4 weeks after GBCA administration when a label-recommended dose was administered. A commercially available chelation therapy agent could not reduce gadolinium retention.

Incidence of nephrogenic systemic fibrosis after administration of gadoteric acid in patients on renal replacement treatment

PURPOSE

Nephrogenic system fibrosis (NSF) is a rare complication detected in patients with renal insufficiency exposed to gadolinium-based contrast agents (GBCAs). The aim of our study is to evaluate the prevalence of NSF in a cohort of patients on renal replacement treatment who underwent GBCA-enhanced magnetic resonance imaging (MRI).

METHOD

We retrospectively reviewed all the charts of kidney transplant (KT) recipients, patients on hemodialysis (HD) and peritoneal dialysis (PD) who received a uniform protocol for contrast material enhanced-MRI with gadoteric acid at our center from January 2004 to December 2017.

RESULTS

Three-hundred forty-four patients (44.1% on HD, 11.3% on PD and 44.4% KT recipients) underwent 551 gadoteric acid-enhanced MRI. The median age of the patients was 58 years (IQR, 45-70 years) and 65.1% were men. Sixty-three patients (18.3%) had skin punch biopsy after integumentary assessment performed by a dermatologist. No cases of NSF were detected after a median follow-up of 4.5 years (IQR, 1.9-8.2 years). During this period of observation, 116 (33.7%) patients died and 11 (3.1%) were lost at follow-up.

CONCLUSIONS

None of the patients exposed to gadoteric acid developed NSF. Our results, in line with more recent studies, suggest that the use of gadoteric acid, a macrocyclic GBCA, appears safe even in chronic kidney disease (CKD) patients receiving dialysis.

Gadolinium-based contrast agents: why nephrologists need to be concerned

PURPOSE OF REVIEW

The hegemony of gadolinium-based contrast agent-induced adverse events stretches beyond those who have renal impairment. 'Nephrogenic' systemic fibrosis is a misnomer: gadolinium-based contrast agents are the known trigger for the disease; kidney impairment is a risk factor. Impaired (true) glomerular filtration may be one catalyst for gadolinium-based contrast agent-induced adverse events, but it is increasingly evident that the same cluster of symptoms occurs in patients with normal renal function.

RECENT FINDINGS

It has been known for nearly 30 years that gadolinium-based contrast agents distribute and are cleared according to a three compartment model. Single doses of gadolinium-based contrast agents can trigger 'nephrogenic' systemic fibrosis in nondialysis dependent patients. Manifestations have occurred years after exposure. Renal insufficiency alone is not an adequate explanation for 'nephrogenic' systemic fibrosis, and the continuum of its symptoms with the adverse events reported by patients with normal renal function clearly indicate that the physiologic reactions are largely undefined.

SUMMARY

Gadolinium-based contrast agents should be used with extreme caution.

A Systematic Review of 639 Patients with Biopsy-confirmed Nephrogenic Systemic Fibrosis

Background Although nephrogenic systemic fibrosis (NSF) affects the use of gadolinium-based contrast agents (GBCAs) in MRI, there continues to be limited knowledge because of the small number of patients with NSF. Purpose To perform a systematic review of NSF. Materials and Methods PubMed database was searched by using the term "Nephrogenic systemic fibrosis" from January 2000 to February 2019. Articles reporting details on individual patients with NSF diagnosis on the basis of both clinical presentations and biopsy confirmation were included. Data were pooled and authors were contacted for clarifications. Rates of NSF were compared through 2008 versus after 2008 and for group I versus group II GBCAs, assuming equal market share. Results Included were 639 patients from 173 articles. Data regarding sex were found for 295 men and 254 women. Age at NSF symptom onset was reported for 177 patients (mean, 49 years ± 16 [standard deviation]; age range, 6-87 years). There were 529 patients with documented exposure to GBCAs including gadodiamide (n = 307), gadopentetate dimeglumine (n = 49), gadoversetamide (n = 6), gadobutrol (n = 1), gadobenate dimeglumine (n = 1), multiple (n = 41), and unknown (n = 120). Among patients with previous exposure, only seven patients were administered GBCA after 2008, yielding a lower rate of NSF after 2008 (P < .001). There were motion limitations in 70.8% (296 of 418) of patients, indicating a more serious debilitation. Associated factors reported for NSF included exposure to GBCA group I (P < .001), dialysis, proinflammatory conditions, hyperphosphatemia, β-blockers, and epoetin. For 341 patients with follow-up, 12 patients were cured and 72 patients partially improved including one during pregnancy. Among those 84 patients reported as cured or improved, in 34 patients cure or improvement occurred after renal function restoration. Four deaths were attributed to NSF. Conclusion Although 639 patients with biopsy-confirmed nephrogenic systemic fibrosis were reported, only seven were after gadolinium-based contrast agent exposure after 2008, indicating that regulatory actions and practice changes have been effective preventive measures. Improvement and sometimes cure with renal function restoration are now possible. © RSNA, 2019 See also the editorial by Davenport in this issue.

Dechelation (Transmetalation): Consequences and Safety Concerns With the Linear Gadolinium-Based Contrast Agents, In View of Recent Health Care Rulings by the EMA (Europe), FDA (United States), and PMDA (Japan)

The issue of dechelation (transmetallation) in vivo after administration of the linear gadolinium-based contrast agents, and potential safety concerns, is considered on the basis of an extensive, focused literature review. Early indications of potential problems included the high level of excess ligand used in the formulation of 2 agents (indeed the 2 least stable thermodynamically) and interference with laboratory tests when blood was drawn from patients relatively soon after administration of these same agents. The advent of nephrogenic systemic fibrosis in the late 2000s raised additional major concerns.The correlation in 2014 of dentate nucleus hyperintensity on precontrast T1-weighted scans with multiple prior injections of linear gadolinium chelates, in patients with normal renal function, has driven subsequent research concerning dechelation of these agents in vivo. Unexpectedly high levels of gadolinium in the bone, skin, and liver have been found long term after administration, in animal models and in humans, although the latter data are limited. Bone may serve as a long-term reservoir, with a residual excretion phase for gadolinium after intravenous injection of the linear agents due to a subsequent slow release from bone. Many different patient populations could be vulnerable and potentially later develop clinical symptoms, although at this stage there are only limited data and small retrospective uncontrolled studies. Possible vulnerable populations include children, menopausal women, patients with osteoporosis (who are predisposed to fractures and often slow to heal or heal poorly), those receiving multiple doses, those with proinflammatory conditions, moderate renal dysfunction, or an undefined genetic predisposition. Of particular concern would be nephrogenic systemic fibrosis-like symptoms-including particularly pain and skin/joint symptoms, or disease related to the incorporation of gadolinium in hydroxyapatite in bone, in small subgroups of patients with a not yet defined propensity and/or cofactor. These concerns have led to withdrawal of the linear agents from the largest clinical market, Europe, with the exception of the hepatobiliary agents for delayed liver imaging, an indication that cannot be fulfilled by the current macrocyclic gadolinium chelates (for which these concerns do not apply).

Pediatric Brain: Gadolinium Deposition in Dentate Nucleus and Globus Pallidus on Unenhanced T1-Weighted Images Is Dependent on the Type of Contrast Agent

PURPOSE

The aim of this study was to identify the signal intensity (SI) changes in the dentate nucleus (DN) and the globus pallidus (GP) on unenhanced T1-weighted magnetic resonance (MR) images after multiple administration of gadolinium-based contrast agents (GBCAs) in children and compare those changes between linear and macrocyclic GBCAs.

MATERIALS AND METHODS

This retrospective study was approved by the institutional review board and the requirement for informed consent was waived. We identified 92 children who underwent at least 4 consecutive MR examinations exclusively using either linear GBCA (gadodiamide or gadopentetate dimeglumine, n = 41) or macrocyclic GBCA (gadoterate meglumine, n = 51). Signal intensity ratio changes in the DN to pons and GP to thalamus between the first and last MR examinations were calculated.

RESULTS

The SI ratios in the linear group increased significantly between the first and last MR examinations (mean difference: DN to pons, 0.0461 ± 0.0480, P < 0.001; GP to thalamus, 0.0332 ± 0.0385, P < 0.001), but not in the macrocyclic group (mean difference: DN to pons, -0.0010 ± 0.0371, P = 0.855; GP to thalamus, 0.0007 ± 0.0294, P = 0.867). In the linear regression analysis, the numbers of administrations of gadodiamide and gadopentetate dimeglumine were highly associated with the differences in SI ratios (DN to pons, P < 0.001 and P = 0.003; GP to thalamus, P < 0.001 and P = 0.002, respectively).

CONCLUSION

The SIs of the DN and GP on unenhanced T1-weighted images increased after serial administrations of linear GBCA, but not macrocyclic GBCA, in children. The number of linear GBCA administration had a linear association with the SI changes in the DN and GP.

The Issue of Gadolinium Retained in Tissues: Insights on the Role of Metal Complex Stability by Comparing Metal Uptake in Murine Tissues Upon the Concomitant Administration of Lanthanum- and Gadolinium-Diethylentriamminopentaacetate

OBJECTIVES

The aim of the study was to explore the role of the stability of metal complexes in the processes that lead to the metal retention in the brain and other tissues of mice administered with lanthanides-based contrast agents. This issue was tackled by the simultaneous injection of gadolinium (Gd)-diethylentriamminopentaacetate (DTPA) and lanthanum-DTPA, which have the same charge and structure but differ in their thermodynamic stability by 3 orders of magnitude.

MATERIALS AND METHODS

A total of 20 healthy BALB/c mice were administered by a single intravenous injection with a dose consisting of 0.6 mmol La-DTPA/kg and 0.6 mmol Gd-DTPA/kg. Then the animals were killed at different time points: 4, 24, 48, and 96 hours (5 mice each group).In an additional protocol, 5 mice were administered with 9 doses of 0.3 mmol La-DTPA/kg and 0.3 mmol of Gd-DTPA/kg every 2 days over a period of 3 weeks. The sacrifice time was set to 3 weeks after the last administration. After sacrifice, the Gd and La content in liver, spleen, kidney, muscle, cerebrum, cerebellum, bone, eye, skin, blood, and urine was determined by inductively coupled plasma-mass spectrometry.

RESULTS

A general decrease in the content of both the lanthanides was observed upon delaying the sacrifice time. At relatively short times after the injection (up to 96 hours), in the spleen, kidney, muscle, skin, and eye, almost the same content of La and Gd was detected, whereas in the cerebrum, cerebellum, bones, and liver, the amount of retained La decreased much slower than that of Gd, yielding a progressive increase in La/Gd ratio. The amount of retained La in the various tissues 21 days after the last of 9 administrations of La-DTPA and Gd-DTPA was always significantly higher than that of Gd. The concentration of both La and Gd decreased rapidly both in blood and in urine samples.

DISCUSSION

The departure from the 1:1 ratio in the amounts of La and Gd determined in the investigated tissues has been used to gain information on the role of the complex stability and "wash-out" kinetics. The behavior of the less s` La-DTPA highlights processes occurring for Gd-DTPA at a slower rate.The herein obtained results support the view that most of the La/Gd retained in the brain arises from the intact chelate that has extravasated immediately after the intravenous administration. Long-term deposition of metal ions from internal reservoirs seems particularly relevant for liver and spleen.

Histology and Gadolinium Distribution in the Rodent Brain After the Administration of Cumulative High Doses of Linear and Macrocyclic Gadolinium-Based Contrast Agents

Supplemental digital content is available in the text.

Objectives

Retrospective studies in patients with primary brain tumors or other central nervous system pathologies as well as postmortem studies have suggested that gadolinium (Gd) deposition occurs in the dentate nucleus (DN) and globus pallidus (GP) after multiple administrations of primarily linear Gd-based contrast agents (GBCAs). However, this deposition has not been associated with any adverse effects or histopathological alterations. The aim of this preclinical study was to systematically examine differences between linear and macrocyclic GBCAs in their potential to induce changes in brain and skin histology including Gd distribution in high spatial resolution.

Materials and Methods

Fifty male Wistar-Han rats were randomly allocated into control (saline, n = 10 rats) and 4 GBCA groups (linear GBCAs: gadodiamide and gadopentetate dimeglumine, macrocyclic GBCAs: gadobutrol and gadoteridol; n = 10 rats per group). The animals received 20 daily intravenous injections at a dose of 2.5 mmol Gd/kg body weight. Eight weeks after the last GBCA administration, the animals were killed, and the brain and skin samples were histopathologically assessed (hematoxylin and eosin; cresyl violet [Nissl]) and by immunohistochemistry. The Gd concentration in the skin, bone, brain, and skeletal muscle samples were analyzed using inductively coupled plasma mass spectroscopy (ICP-MS, n = 4). The spatial Gd distribution in the brain and skin samples was analyzed in cryosections using laser ablation coupled with ICP-MS (LA-ICP-MS, n = 3). For the ultra-high resolution of Gd distribution, brain sections of rats injected with gadodiamide or saline (n = 1) were assessed by scanning electron microscopy coupled to energy dispersive x-ray spectroscopy and transmission electron microscopy, respectively.

Results

No histological changes were observed in the brain. In contrast, 4 of 10 animals in the gadodiamide group but none of the animals in other groups showed macroscopic and histological nephrogenic systemic fibrosis–like skin lesions. The Gd concentrations observed in the skin/brain samples (in nanomole Gd per gram of tissue) for each agent were as follows: gadodiamide: 1472 ± 115/11.1 ± 5.1, gadopentetate dimeglumine: 80.8 ± 6.2/13.1 ± 7.3, gadobutrol: 1.1 ± 0.5/0.7 ± 0.4, and gadoteridol: 1.7 ± 0.8/0.5 ± 0.2. The average detected residual Gd concentration in the brain was approximately 15-fold higher for linear than for macrocyclic GBCAs. The highest amounts of Gd found in brain corresponded to less than 0.0002% of the injected dose per gram of tissue. Using LA-ICP-MS, high Gd concentrations in the deep cerebellar nuclei and in the granular layer of the cerebellar cortex were detected only for linear gadodiamide and gadopentetate dimeglumine but not for gadoteridol or gadobutrol. The energy dispersive x-ray spectroscopy analysis revealed Gd-containing spots in the skin of animals administered gadodiamide and gadopentetate dimeglumine. Transmission electron microscopy revealed several Gd-containing spots in the region of the dentate nuclei in the brain of 1 animal injected with gadodiamide.

Conclusions

After repeated high dosing, nephrogenic systemic fibrosis–like macroscopic and histopathological lesions of the skin were observed only in some of the gadodiamide-treated animals. No histopathological findings were detected in the rodent brain. The administration of linear GBCAs was associated with significantly higher Gd concentrations in the brain and skin compared with macrocyclic GBCA administration. The results of LA-ICP-MS demonstrated local accumulation of Gd within the deep cerebellar nuclei and the granular layer only after the administration of linear agents. In summary, the detected low Gd concentrations in the skin and brain were well correlated with the higher kinetic stability of macrocyclic GBCA.

Erythema nodosum masking nephrogenic systemic fibrosis as initial skin manifestation

Background

Nephrogenic systemic fibrosis (NSF) is a complication of the gadolinium-based contrast agent used in imaging studies. It is typically characterised by hard, erythematous and indurated skin plaques with surrounding subcutaneous oedema. Distinct papules and subcutaneous nodules can also be seen. Fibrocytes in NSF are immunohistochemically positive for CD34.

Case presentation

We present a case of NSF occurred after gadolinium exposure in which the initial presentation mimics an erythema nodosum (EN)-like picture. An initial skin biopsy showed EN. Subsequently the patient developed progressive skin and joints contracture. A repeated skin biopsy done three months later confirmed the diagnosis of NSF. As far as we are aware, this is the second reported case of NSF that mimicked the presentation of EN in the early phase of the disease.

Conclusions

The appearance of EN-like disease can be one of the early manifestations of NSF. We hope that early recognition of this unusual presentation can alert the physician or nephrologist to the potential diagnosis of NSF.

Observational study on the safety profile of gadoterate meglumine in 35,499 patients: The SECURE study

Purpose

To investigate the safety of gadoterate meglumine and identify the incidence of nephrogenic systemic fibrosis (NSF).

Materials and Methods

An international prospective observational study was conducted from November 2008 to June 2013. A total of 35,499 adults and children who were scheduled to undergo contrast‐enhanced MRI using gadoterate meglumine were analyzed (female, 53.1%; mean age: 49.5 years; range: 0‐98 years). At least 3‐month follow‐up was planned for patients with an estimated creatinine clearance or glomerular filtration rate <60 mL/min (/1.73 m2) to detect any suspicion or occurrence of NSF. Adverse events (AEs) were prospectively recorded. Demographic data, risk factors, indications for MRI examinations, characteristics of gadoterate meglumine administration, and efficacy were documented.

Results

MRI examinations were mainly for central nervous system (61%). The most frequent risk factor was renal insufficiency (14.7%). Seventy AEs were observed in 44 patients (0.12%). Among the 70 AEs, 38 in 32 patients (0.09% of all patients) were considered related to gadoterate meglumine and classified as adverse drug reaction (ADR).The most frequent ADRs were urticaria (9 patients, 0.03%), nausea (7 patients, 0.02%), and vomiting (4 patients, 0.01%). Within the pediatric population (1,629 patients), only one AE (vomiting) was observed. Nine adult patients (0.03%) experienced serious AEs. Moderate to severe renal insufficiency at inclusion was reported in 514 patients (1.5%). Among them, 476 (92.6%) were followed‐up. No patients were suspected of having NSF and no cases of NSF were observed.

Conclusion

Our study confirms the excellent safety profile of gadoterate meglumine in routine practice.

Level of Evidence: 1

J. Magn. Reson. Imaging 2017;45:988–997

Balanced regulation of the CCN family of matricellular proteins: a novel approach to the prevention and treatment of fibrosis and cancer

The CCN family of matricellular signaling proteins is emerging as a unique common link across multiple diseases and organs related to injury and repair. They are now being shown to play a central role in regulating the pathways to the initiation and resolution of normal wound healing and fibrosis in response to multiple forms of injury. Similarly, it is also emerging that they play a key role in regulating the establishment, growth, metastases and tissue regeneration in many forms of cancer via the interaction of cancer cells with the tumor stroma. Evidence has been recently provided that these proteins do not act independently but are co-regulated working in a yin/yang manner to alter the outcome of both normal physiological processes as well as pathology. The purpose of this review is to twofold. First, it will summarize work to date supporting CCN2 as a therapeutic target in the formation and progression of renal, skin, and other organ fibrosis, as well as cancer stroma formation. Second, it will highlight recent evidence for CCN3 as a counter-regulator and a potential therapeutic agent in these diseases with an exciting, novel potential to both treat and then restore tissue homeostasis in those afflicted by these devastating disorders.

Practice advisory on anesthetic care for magnetic resonance imaging: an updated report by the american society of anesthesiologists task force on anesthetic care for magnetic resonance imaging

The American Society of Anesthesiologists Committee on Standards and Practice Parameters and the Task Force on Anesthetic Care for Magnetic Resonance Imaging presents an updated report of the Practice Advisory on Anesthetic Care for Magnetic Resonance Imaging.

Supplemental Digital Content is available in the text.

Incidence of nephrogenic systemic fibrosis in patients undergoing dialysis after contrast-enhanced magnetic resonance imaging with gadolinium-based contrast agents: the Prospective Fibrose Nephrogénique Systémique study

BACKGROUND

Nephrogenic systemic fibrosis (NSF) has been related to the use of gadolinium-based contrast agents (GBCAs) in patients undergoing dialysis. The Prospective Fibrose Nephrogénique Systémique study, a French prospective study supported by the French drug regulatory agency (Agence Nationale de Sécurité du Médicament) and the French Societies of Nephrology, Dermatology, and Radiology, aimed at determining the incidence of NSF in patients undergoing long-term dialysis.

MATERIALS AND METHODS

Adult patients undergoing long-term dialysis receiving a magnetic resonance imaging (MRI) examination prescribed between January 15, 2009 and May 31, 2011, with or without GBCA were included. The methodology was based on a patient form intended to detect any dermatological event (DE) that may occur within 4 months after the examination. Further investigations were planned with their physicians if a DE was reported.

RESULTS

A total of 571 patients were included. A total of 50.3% received GBCA. Among them, 93.4% received a macrocyclic GBCA, usually gadoteric acid (88.9%). All in all, 22 patients (3.9%) reported a DE. Dermatological diagnoses did not reveal any evidence of NSF.

CONCLUSIONS

The incidence of NSF after a single dose of a macrocyclic GBCA is null in our sample of 268 patients undergoing dialysis (hemodialysis and peritoneal dialysis). This incidence is just lower than 0.5%. When contrast-enhanced MRI can be essential, or even decisive, to the diagnosis, these results are important and reassuring if physicians need to perform contrast-enhanced MRI in patients undergoing dialysis.

Reaction of gadolinium chelates with ozone and hydroxyl radicals

Gadolinium chelates are used in increasing amounts as contrast agents in magnetic resonance imaging, and their fate in wastewater treatment has recently become the focus of research. Oxidative processes, in particular the application of ozone, are currently discussed or even implemented for advanced wastewater treatment. However, reactions of the gadolinium chelates with ozone are not yet characterized. In this study, therefore, rate constants with ozone were determined for the three commonly used chelates Gd-DTPA, Gd-DTPA-BMA, and Gd-BT-DO3A, which were found to be 4.8 ± 0.88, 46 ± 2.5, and 24 ± 1.5 M(-1) s(-1), respectively. These low rate constants indicate that a direct reaction with ozone in wastewater is negligible. However, application of ozone in wastewater leads to substantial yields of (•)OH. Different methods have been applied and compared for determination of k((•)OH+Gd chelate). From rate constants determined by pulse radiolysis experiments (k((•)OH+Gd-DTPA) = 2.6 ± 0.2 × 10(9) M(-1) s(-1), k((•)OH+Gd-DTPA-BMA) = 1.9 ± 0.7 × 10(9) M(-1) s(-1), k((•)OH+Gd-BT-DO3A) = 4.3 ± 0.2 × 10(9) M(-1) s(-1)), it is concluded that a reaction in wastewater via (•)OH radicals is feasible. Toxicity has been tested for educt and product mixtures of both reactions. Cytotoxicity (MTT test) and genotoxicity (micronuclei assay) were not detectable.

Nanoparticles for imaging and treating brain cancer

Brain cancer tumors cause disruption of the selective properties of vascular endothelia, even causing disruptions in the very selective blood-brain barrier, which are collectively referred to as the blood-brain-tumor barrier. Nanoparticles (NPs) have previously shown great promise in taking advantage of this increased vascular permeability in other cancers, which results in increased accumulation in these cancers over time due to the accompanying loss of an effective lymph system. NPs have therefore attracted increased attention for treating brain cancer. While this research is just beginning, there have been many successes demonstrated thus far in both the laboratory and clinical setting. This review serves to present the reader with an overview of NPs for treating brain cancer and to provide an outlook on what may come in the future. For NPs, just like the blood-brain-tumor barrier, the future is wide open.

Safety of meglumine gadoterate (Gd-DOTA)-enhanced MRI compared to unenhanced MRI in patients with chronic kidney disease (RESCUE study)

Objective

To prospectively compare the renal safety of meglumine gadoterate (Gd-DOTA)-enhanced magnetic resonance imaging (MRI) to a control group (unenhanced MRI) in high-risk patients.

Methods

Patients with chronic kidney disease (CKD) scheduled for MRI procedures were screened. The primary endpoint was the percentage of patients with an elevation of serum creatinine levels, measured 72 ± 24 h after the MRI procedure, by at least 25 % or 44.2 μmol/l (0.5 mg/dl) from baseline. A non-inferiority margin of the between-group difference was set at −15 % for statistical analysis of the primary endpoint. Main secondary endpoints were the variation in serum creatinine and eGFR values between baseline and 72 ± 24 h after MRI and the percentage of patients with a decrease in eGFR of at least 25 % from baseline. Patients were screened for signs of nephrogenic systemic fibrosis (NSF) at 3-month follow-up.

Results

Among the 114 evaluable patients, one (1.4 %) in the Gd-DOTA-MRI group and none in the control group met the criteria of the primary endpoint [Δ = −1.4 %, 95%CI = (−7.9 %; 6.7 %)]. Non-inferiority was therefore demonstrated (P = 0.001). No clinically significant differences were observed between groups for the secondary endpoints. No serious safety events (including NSF) were noted.

Conclusion

Meglumine gadoterate did not affect renal function and was a safe contrast agent in patients with CKD.

Key points

• Contrast-induced nephropathy (CIN) is a potential problem following gadolinium administration for MRI.

• Meglumine gadoterate (Gd-DOTA) appears safe, even in patients with chronic kidney disease.

• Gd-DOTA only caused a temporary creatinine level increase in 1/70 such patients.

• No case or sign of NSF was detected at 3-month follow-up.

Understanding nephrogenic systemic fibrosis

Nephrogenic systemic fibrosis (NSF) is a rare and a debilitating disease noted uncommonly in patients with impaired renal function when exposed to low-stability gadolinium-based contrast agents (Gd-CAs). According to experimental studies, cytokines released by the stimulation of effector cells such as skin macrophages and peripheral blood monocytes activate circulating fibroblasts which play a major role in the development of NSF lesions. The presence of permissive factors, presumably, provides an environment conducive to facilitate the process of fibrosis. Multiple treatment modalities have been tried with variable success rates. More research is necessary to elucidate the underlying pathophysiological mechanisms which could potentially target the initial steps of fibrosis in these patients. This paper attempts to collate the inferences from the in vivo and in vitro experiments to the clinical observations to understand the pathogenesis of NSF. Schematic representations of receptor-mediated molecular pathways of activation of macrophages and fibroblasts by gadolinium and the final pathway to fibrosis are incorporated in the discussion.

Gadolinium-induced fibrosis testing by protein targeting assay and superparamagnetic iron oxide nanoparticle-based magnetic resonance microscopy of skin and kidneys

Gadolinium-based magnetic resonance imaging (MRI) contrast agents cause undefined fibrosis in kidneys and skin damage. Magnetic resonance microimaging of rat skin and kidney was used first time to identify the physical factors modulating the gadolinium Omniscan®-induced fibrosis by protein targeting. A 500-MHz MR imaging was done to visualize fibrosis in gadolinium-treated animals. Cationic superparamagnetic iron oxide magnetoferritin (SPIOM) was injected in rat to target basement membrane (in rat kidney and different skin structures including epidermis glycolipids and dermis proteins. After MR imaging, excised rat skin and kidneys tissues were imaged by ex vivo 900 MHz MR microimaging to confirm renal fibrosis and skin epidermis thickening. The proton density-weighted images visualized micro details of skin structures and nephron territories while T2-weighted images showed better contrast of tissue structures in both skin and kidney. The gadolinium further enhanced the image contrast and targeted the proteins in renal basement membrane and viable proteins in epidermis. SPIOM enhanced the tissue contrast due to dephasing effect caused by SPIOM on structural changes in nephron and epidermis. Conclusion: Tissue membrane protein and chelate ligand group binding with gadolinium biophysical interaction at molecular level may develop fibrosis. SPIOM injection improved the dephased image contrast of different structures in both skin and nephrons. The epidermis thickening and nephrofibrosis changes may be associated with nephrogenic systemic fibrosis or fibrosing dermatopathy.

Gadolinium-induced fibrosis is counter-regulated by CCN3 in human dermal fibroblasts: a model for potential treatment of nephrogenic systemic fibrosis

We recently show that CCN3 is a counter-regulatory molecule for the pro-fibrotic protein CCN2, and a potentially novel fibrosis therapy. The goal of this study was to assess the role of CCN3 in fibroproliferative/fibrotic responses in human dermal fibroblasts exposed to Omniscan, one of the gadolinium-based contrast agents associated with development of nephrogenic systemic fibrosis (NSF) a rare but life-threatening disease thought to be complication of NMR diagnostics in renal impaired patients. Human dermal fibroblasts were exposed to Omniscan; or to platelet-derived growth factor (PDGF) and transforming growth factor-β (TGF-β) as controls. Proliferation was assessed along with matrix metalloproteinase-1, tissue inhibitor of metalloproteinases-1 and type 1 procollagen in the absence and presence of CCN3. In parallel, CCN3 production was assessed in control and Omniscan-treated cells. The results showed that PDGF stimulated fibroblast proliferation, production of Timp-1 and MMP-1 whereas exogenous CCN3 inhibited, in a dose response manner, cell proliferation (approx. 50 % max.) and production of MMP-1 (approx 35 % max.) but had little effect on TIMP-1. TGF-β stimulated type 1 procollagen production but not proliferation, Timp-1 or MMP-1 compared to non-TGF-ß treated control cells, and CCN3 treatment blocked (approx. 80 % max.) this up-regulation. Interestingly, untreated, control fibroblasts produced high constitutive levels of CCN3 and concentrations of Omniscan that induced fibroproliferative/fibrogenic changes in dermal fibroblasts correspondingly suppressed CCN3 production. The use of PDGF and TGF-β as positive controls, and the study of differential responses, including that to Omniscan itself, provide the first evidence for a role of fibroblast-derived CCN3 as an endogenous regulator of pro-fibrotic changes, elucidating possible mechanism(s). In conclusion, these data support our hypothesis of a role for fibroblast-derived CCN3 as an endogenous regulator of pro-fibrotic changes in these cells, and suggest that CCN3 may be an important regulatory molecule in NSF and a target for treatment in this and other fibrotic diseases.

Nephrogenic systemic fibrosis: review of 370 biopsy-confirmed cases

Discovery of an association between gadolinium-based contrast agents (GBCAs) and nephrogenic systemic fibrosis (NSF) has led to less use of GBCA-enhanced magnetic resonance imaging in dialysis patients and patients with severe renal failure at risk of NSF, and the virtual elimination of new cases of NSF. But shifting patients with renal failure to alternative imaging methods may subject patients to other risks (e.g., ionizing radiation or iodinated contrast). This review paper examines 370 NSF cases reported in 98 articles to analyze NSF risk factors. Eliminating multiple risk factors by limiting GBCA dose to a maximum of 0.1 mmol/kg, dialyzing patients undergoing dialysis quickly following GBCA administration, delaying GBCA in acute renal failure until after renal function returns or dialysis is initiated, and avoiding nonionic linear GBCA in patients with renal failure especially when there are proinflammatory conditions may substantially reduce the risk of NSF.

Stimulation of fibroblast proliferation by insoluble gadolinium salts

The purpose of this study was to assess insoluble salts containing gadolinium (Gd(3+)) for effects on human dermal fibroblasts. Responses to insoluble Gd(3+) salts were compared to responses seen with Gd(3+) solubilized with organic chelators, as in the Gd(3+)-based contrast agents (GBCAs) used for magnetic resonance imaging. Insoluble particles of either Gd(3+) phosphate or Gd(3+) carbonate rapidly attached to the fibroblast cell surface and stimulated proliferation. Growth was observed at Gd(3+) concentrations between 12.5 and 125 μM, with toxicity at higher concentrations. Such a narrow window did not characterize GBCA stimulation. Proliferation induced by insoluble Gd(3+) salts was inhibited in the presence of antagonists of mitogen-activated protein kinase and phosphatidylinositol 3-kinase signaling pathways (similar to chelated Gd(3+)) but was not blocked by an antibody to the platelet-derived growth factor receptor (different from chelated Gd(3+)). Finally, high concentrations of the insoluble Gd(3+) salts failed to prevent fibroblast lysis under low-Ca(2+) conditions, while similar concentrations of chelated Gd(3+) were effective. In conclusion, while insoluble Gd(3+) salts are capable of stimulating fibroblast proliferation, one should be cautious in assuming that GBCA dechelation must occur in vivo to produce the profibrotic changes seen in association with GBCA exposure in the subset of renal failure patients that develop nephrogenic systemic fibrosis.

Gadolinium-induced nephrogenic systemic fibrosis

Nephrogenic systemic fibrosis is a new disease whose incidence has peaked and receded over the past decade. It occurs in the presence of significant renal impairment, either acute or chronic (MDRD creatinine clearance of <30 mL/min/1.73 m(2)), and is associated with the administration of gadolinium-based contrast (GBC). Since 2006, the incidence of this disease has decreased markedly in patients with renal impairment, mainly owing to protocols that have not administered GBC to patients with creatinine clearances of less than 30 mL/min/1.73 m(2), and in some cases with the use of less toxic and lower doses of GBC. The purpose of this article is to review the current status of GBC use for imaging in patients with kidney disease.