Nephrogenic Systemic Fibrosis in Patients With Chronic Kidney Disease Who Received Gadopentetate Dimeglumine:

Data mining and analysis of the adverse events derived signals of 4 gadolinium-based contrast agents based on the US Food and drug administration adverse event reporting system

BACKGROUND

To detect and analyze risk signals of the drug-related adverse events (AEs) of 4 gadolinium-based contrast agents (GBCAs) (gadopentetate dimeglumine (Gd-DTPA), gadobenate dimeglumine (Gd-BOPTA), gadoteridol (Gd-HP-DO3A), and gadobutrol (Gd-BT-DO3A)) according to the US Food and Drug Administration Adverse Event Reporting System (FAERS) database and ensure the clinical safety.

RESEARCH DESIGN AND METHODS

The AEs that are associated with the 4 GBCAs were collected from the FAERS database from 2004Q1 to 2022Q3. The risk signals were mined using reporting odds ratio (ROR) and proportional reporting ratio (PRR).

RESULTS

424 risk signals were excavated, in which 151 risk signals were associated with Gd-DTPA, 93 risk signals were related to Gd-BOPTA, 79 risk signals were relevant to Gd-HP-DO3A, and 101 risk signals were associated with Gd-BT-DO3A. The AE signals involved 20 system organ classes (SOCs). Two of the top four SOCs were identical, namely 'skin and subcutaneous tissue disorders' and 'general disorders and administration site conditions.'

CONCLUSIONS

The safety signals of 4 GBCAs were detected, and the SOCs associated with the AEs of the 4 GBCAs were different. Besides, some AEs obtained in this study were not mentioned in the package inserts, which need more attention and research to ensure the clinical safety.

Gadolinium-Cyclic 1,4,7,10-Tetraazacyclododecane-1,4,7,10-Tetraacetic Acid-Click-Sulfonyl Fluoride for Probing Serine Protease Activity in Magnetic Resonance Imaging

Serine protease is linked to a wide range of diseases, prompting the development of robust, selective, and sensitive protease assays and sensing methods. However, the clinical needs for serine protease activity imaging have not yet been met, and the efficient in vivo detection and imaging of serine protease remain challenging. Here, we report the development of the gadolinium-cyclic 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid-click-Sulfonyl Fluoride (Gd-DOTA-click-SF) MRI contrast agent targeting serine protease. The HR-FAB mass spectrum confirmed the successful formation of our designed chelate. The molar longitudinal relaxivity (r₁) of the Gd-DOTA-click-SF probe (r₁ = 6.82 mM^-1 s^-1) was significantly higher than that of Dotarem (r₁ = 4.63 mM^-1 s^-1), in the range of 0.01-0.64 mM at 9.4 T. The in vitro cellular study and the transmetallation kinetics study showed that the safety and stability of this probe are comparable to those of conventional Dotarem. Ex vivo abdominal aortic aneurysm (AAA) MRI revealed that this probe has a contrast-agent-to-noise ratio (CNR) that is approximately 51 ± 23 times greater than that of Dotarem. This study of superior visualization of AAA suggests that it has the potential to detect elastase in vivo and supports the feasibility of probing serine protease activity in T1-weighted MRI.

Safety of gadoterate meglumine in over 1600 children included in the prospective observational SECURE study

Background

To date, few data on the safety profile of gadoterate meglumine in pediatric patients are available.

Purpose

To assess the safety profile of gadoterate meglumine in routine practice, to detect any case of nephrogenic systemic fibrosis (NSF) suspicion and to collect efficacy data.

Material and Methods

The pediatric population of the observational SECURE study comprised 1631 patients scheduled for contrast-enhanced magnetic resonance imaging (MRI) with gadoterate meglumine (dose: 0.1 mmol/kg). Risk factors, MRI types and immediate adverse events (AEs) were systematically recorded. Patients with moderate to severe renal impairment were followed up for at least 3 months for detection of any NSF suspicion. Efficacy was assessed by the on-site radiologist in terms of image quality and ability to come to diagnosis.

Results

The population included 106 children (6.5%) aged <2 years, 815 (50.0%) aged 2 to <12 years and 710 (43.5%) aged 12 to <18 years, with a mean (± SD) age of 10.2 (± 4.9) years. Central nervous system exploration was the most frequent MRI type (80.4%) and main risk factors were any stage of renal insufficiency (9.8%) and allergies (5.2%). Only one AE (vomiting) that was deemed doubtfully related to gadoterate meglumine was observed. No suspicions of NSF were reported. Good to very good image quality was obtained for 98.4% of pediatric patients and diagnosis was established in 99.6% of cases.

Conclusion

This study confirmed the good safety profile of gadoterate meglumine in routine practice in a large pediatric population. The study is registered on https://clinicaltrials.gov/ with the identifier NCT01523873.

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.

Influence of excess ligand on Nephrogenic Systemic Fibrosis associated with nonionic, linear gadolinium-based contrast agents

BACKGROUND

The molecular structure, charge, thermodynamic and kinetic stability are approximately the same for gadodiamide and gadoversetamide, the main substantive difference is that gadodiamide is manufactured with 5% free ligand to form Omniscan® and gadoversetamide with 10% free ligand to form OptiMARK®.

PURPOSE

To determine the relative risk of Nephrogenic Systemic Fibrosis (NSF) between gadodiamide (Omniscan®) and gadoversetamide (OptiMARK®) and to explore the potential contribution of the amount of excess ligand added to their commercial formulations.

MATERIALS AND METHODS

In this retrospective observational study, the number of doses and NSF cases associated with these agents were calculated based on two different approaches: the number of doses was determined based on pharmaceutical companies' information, and the number of unconfounded NSF cases was obtained from the previously published literature based on a legal database. A second analysis estimates the number of doses and NSF cases from the Food and Drug Administration (FDA) Adverse Event Reporting System (FAERS).

RESULTS

Approximately 87 million and 12 million doses of Omniscan® and OptiMARK®, respectively, have been administered worldwide since their original approval for use in the various countries throughout the world. A total of 197 and 8 unconfounded cases of NSF have been reported with Omniscan® and OptiMARK®, rendering an incidence of 2.3/million and 0.7/million for these agents, respectively. The FAERS analysis suggested reported incidences of 13.1/million and 5.0/million.

CONCLUSION

There is an approximately 3-fold greater incidence of NSF from Omniscan® than OptiMARK®. The difference in incidence might reflect the lesser quantity of added free ligand to the formulation of Omniscan®.

Biomineral Nano-Theranostic agent for Magnetic Resonance Image Guided, Augmented Radiofrequency Ablation of Liver Tumor

Theranostic nanoparticles based on biocompatible mineral compositions can significantly improve the translational potential of image guided cancer nano-therapy. Here, we report development of a single-phase calcium phosphate biomineral nanoparticle (nCP) with dual-mode magnetic resonance contrast (T1-T2) together with radiofrequency (RF) mediated thermal response suitable for image-guided RF ablation of cancer. The nanoparticles (NP) are engineered to provide dual MR contrast by an optimized doping concentration (4.1 at%) of paramagnetic ion, Fe³⁺, which also renders lossy dielectric character for nCP leading to thermal response under RF exposure. In vivo compatibility and dual-mode MR contrast are demonstrated in healthy rat models. MRI and T2 mapping suggest hepatobiliary clearance by ~96 hours. MRI guided intratumoral injection in subcutaneous rat glioma and orthotopic liver tumor models provide clear visualization of NP in MRI which also helps in quantifying NP distribution within tumor. Furthermore, by utilising RF mediated thermal response, NP treated tumor could be ablated using clinically approved RF ablation system (10 W,13.3 GHz). Real-time in vivo thermal imaging exhibits 119 ± 10% increase in temperature change (ΔT) for NP treated orthotopic liver tumor (ΔT = 51.5 ± 2 °C), compared to untreated healthy liver control (ΔT = 21.5 ± 2 °C). In effect, we demonstrate a promising nano-biomineral theranostic agent for dual-mode MRI combined with radiofrequency ablation of solid tumors.

Incidence of Nephrogenic Systemic Fibrosis Using Gadobenate Dimeglumine in 1423 Patients With Renal Insufficiency Compared With Gadodiamide

OBJECTIVE

The purpose of this study was to assess the incidence of nephrogenic systemic fibrosis (NSF) before and after educational interventions, implementation of a clinical screening process, and change to gadobenate dimeglumine in patients who had an estimated glomerular filtration rate (eGFR) of 30 mL/min per 1.72 m or less.

METHODS

This is a Health Insurance Portability and Accountability Act compliant, institutional review board exempt study. Two periods were studied-July 2005 to June 2006, during which gadodiamide was utilized as our magnetic resonance (MR) contrast agent, and November 2006 to August 2014, during which gadobenate dimeglumine was used as our MR contrast agent in patients who had an eGFR 30 mL/min per 1.72 m or less. In addition to a change in the MR contrast agent, education of our staff physician to the risks of NSF with MR contrast agents and the implementation of a clinical screening process occurred. The rate of NSF before and after the interventions was compared using the χ test.

RESULTS

There was a statistically significant difference in the incidence of NSF in patients with an eGFR 30 mL/min per 1.72 m or less between the 2 periods: July 2005 to June 2006, 6 of 246 patients were diagnosed with NSF (P < 0.001), versus November 2006 to August 2014, 0 of 1423 patients were diagnosed with NSF.

CONCLUSIONS

Our data demonstrates a marked decrease in the incidence of NSF after education of our referring physicians, implementation of clinical screening process, and change to gadobenate dimeglumine from gadodiamide in patients with renal insufficiency. This approach potentially provides an acceptable risk-benefit profile for patients with renal insufficiency that required MR imaging for clinical care.

Impact of Impaired Renal Function on Gadolinium Retention After Administration of Gadolinium-Based Contrast Agents in a Mouse Model

OBJECTIVES

The aim of this study was to investigate the impact of impaired renal function on gadolinium (Gd) retention in various organs after Gd-based contrast agent injection.

MATERIALS AND METHODS

After local animal care and review committee approval, 23 normal mice and 26 with renal failure were divided into 4 treatment groups (Gd-DTPA-BMA, 5 mmol/kg; Gd-DOTA, 5 mmol/kg; GdCl3, 0.02 mmol/kg; and saline, 250 μL). Each agent was intravenously administered on weekdays for 4 weeks. Samples were collected on days 3 (short-term) and 45 (long-term) after the last injection. Gadolinium concentrations were quantified by inductively coupled plasma-mass spectrometry.

RESULTS

Three mice with renal failure and 2 normal mice in the GdCl3 group and 1 mouse with renal failure in the Gd-DTPA-BMA group died. In the Gd-DTPA-BMA group, impaired renal function increased short-term Gd retention in the liver, bone, spleen, skin, and kidney (P < 0.01) but did not affect long-term Gd retention. Gd-DTPA-BMA showed higher Gd retention than Gd-DOTA. Although Gd retention in the Gd-DOTA group was generally low, impaired renal function increased only long-term hepatic Gd retention. Hepatic and splenic Gd retentions were significantly higher than other organs' Gd retention in the GdCl3 group (P < 0.01). Renal function did not affect brain Gd retention, regardless of the Gd compound used.

CONCLUSIONS

The tendency of Gd retention varied according to the agent, regardless of renal function. Although renal impairment increased short-term Gd retention after Gd-DTPA-BMA administration, long-term Gd retention for Gd-based contrast agents was almost unaffected by renal function, suggesting that the chemical structures of retained Gd may not be consistent and some Gd is slowly eliminated after initially being retained.

Human Organ Culture: Updating the Approach to Bridge the Gap from In Vitro to In Vivo in Inflammation, Cancer, and Stem Cell Biology

Human studies, critical for developing new diagnostics and therapeutics, are limited by ethical and logistical issues, and preclinical animal studies are often poor predictors of human responses. Standard human cell cultures can address some of these concerns but the absence of the normal tissue microenvironment can alter cellular responses. Three-dimensional cultures that position cells on synthetic matrices, or organoid or organ-on-a-chip cultures, in which different cell spontaneously organize contacts with other cells and natural matrix only partly overcome this limitation. Here, we review how human organ cultures (HOCs) can more faithfully preserve in vivo tissue architecture and can better represent disease-associated changes. We will specifically describe how HOCs can be combined with both traditional and more modern morphological techniques to reveal how anatomic location can alter cellular responses at a molecular level and permit comparisons among different cells and different cell types within the same tissue. Examples are provided involving use of HOCs to study inflammation, cancer, and stem cell biology.

Gadolinium-Based Contrast Agent Accumulation and Toxicity: An Update

In current practice, gadolinium-based contrast agents have been considered safe when used at clinically recommended doses in patients without severe renal insufficiency. The causal relationship between gadolinium-based contrast agents and nephrogenic systemic fibrosis in patients with renal insufficiency resulted in new policies regarding the administration of these agents. After an effective screening of patients with renal disease by performing either unenhanced or reduced-dose-enhanced studies in these patients and by using the most stable contrast agents, nephrogenic systemic fibrosis has been largely eliminated since 2009. Evidence of in vivo gadolinium deposition in bone tissue in patients with normal renal function is well-established, but recent literature showing that gadolinium might also deposit in the brain in patients with intact blood-brain barriers caught many individuals in the imaging community by surprise. The purpose of this review was to summarize the literature on gadolinium-based contrast agents, tying together information on agent stability and animal and human studies, and to emphasize that low-stability agents are the ones most often associated with brain deposition.

Vascular Imaging With Ferumoxytol as a Contrast Agent

OBJECTIVE

Ferumoxytol is increasingly reported as an alternative to gadolinium-based contrast agents for MR angiography (MRA), particularly for patients with renal failure. This article summarizes more than 3 years of clinical experience with ferumoxytol-enhanced MRA for a range of indications and anatomic regions.

CONCLUSION

Ferumoxytol-enhanced MRA has many advantages including that it is safe for patients with renal failure and provides a lengthy plateau of vascular signal as a blood pool agent that allows longer navigated MRA sequences.

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.

A comparison of arterial spin labeling perfusion MRI and DCE-MRI in human prostate cancer

Perfusion MRI has the potential to provide pathophysiological biomarkers for the evaluating, staging and therapy monitoring of prostate cancer. The objective of this study was to explore the feasibility of noninvasive arterial spin labeling (ASL) to detect prostate cancer in the peripheral zone and to investigate the correlation between the blood flow (BF) measured by ASL and the pharmacokinetic parameters K(trans) (forward volume transfer constant), kep (reverse reflux rate constant between extracellular space and plasma) and ve (the fractional volume of extracellular space per unit volume of tissue) measured by dynamic contrast-enhanced (DCE) MRI in patients with prostate cancer. Forty-three consecutive patients (ages ranging from 49 to 86 years, with a median age of 74 years) with pathologically confirmed prostate cancer were recruited. An ASL scan with four different inversion times (TI = 1000, 1200, 1400 and 1600 ms) and a DCE-MRI scan were performed on a clinical 3.0 T GE scanner. BF, K(trans), kep and ve maps were calculated. In order to determine whether the BF values in the cancerous area were statistically different from those in the noncancerous area, an independent t-test was performed. Spearman's bivariate correlation was used to assess the relationship between BF and the pharmacokinetic parameters K(trans), kep and ve. The mean BF values in the cancerous areas (97.1 ± 30.7, 114.7 ± 28.7, 102.3 ± 22.5, 91.2 ± 24.2 ml/100 g/min, respectively, for TI = 1000, 1200, 1400, 1600 ms) were significantly higher (p < 0.01 for all cases) than those in the noncancerous regions (35.8 ± 12.5, 42.2 ± 13.7, 53.5 ± 19.1, 48.5 ± 13.5 ml/100 g/min, respectively). Significant positive correlations (p < 0.01 for all cases) between BF and the pharmacokinetic parameters K(trans), kep and ve were also observed for all four TI values (r = 0.671, 0.407, 0.666 for TI = 1000 ms; 0.713, 0.424, 0.698 for TI = 1200 ms; 0.604, 0.402, 0.595 for TI = 1400 ms; 0.605, 0.422, 0.548 for TI = 1600 ms). It can be seen that the quantitative ASL measurements show significant differences between cancerous and benign tissues, and exhibit strong to moderate correlations with the parameters obtained using DCE-MRI. These results show the promise of ASL as a noninvasive alternative to DCE-MRI.

Nephrogenic systemic fibrosis in Denmark--a nationwide investigation

Background

Nephrogenic systemic fibrosis is a debilitating and painful disorder with an increased stimulation of the connective tissue in the skin and systemic tissues. The disease is associated with exposure to gadolinium-based contrast agent used in magnetic resonance imaging in patients with renal impairment.

Methods

The prevalence of nephrogenic systemic fibrosis has so far never been determined at a national level. In 2009, Denmark was the first country to design a guideline for the tracing of nephrogenic systemic fibrosis patients. The aim of this paper is to communicate the main findings of this quest.

Results

The outcome of the nationwide investigation revealed that Denmark had 65 patients with nephrogenic systemic fibrosis and thereby the highest prevalence of nephrogenic systemic fibrosis worldwide with 65 per 5.6 million inhabitants, or 12 per million.

Conclusions

The nationwide investigation in Denmark revealed the highest prevalence of NSF worldwide. This may be rooted in a high level of awareness of NSF both among doctors, politicians and, not least, the media, combined with the fact that a nationwide NSF investigation was initiated.

Nephrogenic systemic fibrosis

OBJECTIVE

The purpose of this article is to discuss nephrogenic systemic fibrosis (NSF) in detail regarding its history, possible pathophysiology, clinical and pathologic presentations, diagnosis, and implications for the radiology community.

CONCLUSION

NSF is a potentially lethal disorder that occurs in patients with reduced kidney function. Current evidence suggests a strong association with gadolinium-based contrast agents--mostly used in MRI--in this patient group. This has urged the radiology community to emphasize careful screening for the presence of renal dysfunction among patients for whom gadolinium-enhanced MRI is contemplated. Appropriate selection of gadolinium-based contrast agent type, avoidance of nonstandard dosage, patient education, and informed consent have been recommended by authorities.

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.

Safety of older generations of gadolinium in mild-to-moderate renal failure

Nephrogenic systemic fibrosis (NSF) is a rare disease that is mostly reported in patients with chronic kidney disease (CKD) who have received gadolinium as a contrast in imaging techniques. The exact pathogenetic role of renal failure or gadolinium is not known. The aim of this study is to show whether mild-to-moderate renal failure is a risk for NSF as it is described in severe renal failure. In this cross-sectional study, we enrolled 164 patients with serum creatinine levels >1.5 mg/dL who were in different stages of CKD and had received gadolinium (gadopentetate). The average lag time between the gadolinium administration and the study was 4 months. The most prevalent skin symptom was itching (19%) and the least frequent was induration and papules (<1%). At the follow-up, all skin lesions were relieved. No patients had characteristic lesions of NSF. Twenty-five percent of patients had acute kidney injury at the time of gadolinium exposure. No patients had liver disease and only five were receiving erythropoietin. None of our patients were taking immunosuppressive agents, but all of them suffered from cardiovascular diseases. We conclude that in patients with mild-to-moderate renal failure, it seems that gadolinium is associated with no or very low risk for NSF. We did not find any NSF in patients with severe renal failure. However, because of the rarity of NSF, the low number of such patients in the study, and the high mortality, the use of gadolinium in these patients should be avoided.

Fibroblast response to lanthanoid metal ion stimulation: potential contribution to fibrotic tissue injury

The purpose of this study was to compare each of the 14 naturally occurring lanthanoid metal ions for ability to stimulate pro-fibrotic responses in human dermal fibroblasts. When fibroblasts were exposed to individual lanthanoids over the concentration range of 1-100 μM, increased proliferation was observed with each of the agents as compared with control cells that were already proliferating rapidly in a growth factor-enriched culture medium. Dose-response differences were observed among the individual metal ions. Matrix metalloproteinase-1 (MMP-1) and tissue inhibitor of metalloproteinase-1 levels were also increased in response to lanthanoid exposure but type I procollagen production was not. A dose-response relationship between induction of proliferation and increased MMP-1 was observed. Non-lanthanoid transition metal ions (aluminum, copper, cobalt, iron, magnesium, manganese, nickel, and zinc) were examined in the same assays; there was little stimulation with any of these metals. When epidermal keratinocytes were examined in place of dermal fibroblasts, there was no growth stimulation with any of the lanthanoids. Several of the lanthanoid metals inhibited keratinocyte proliferation at higher concentrations (50-100 μM).

Fibroblast response to gadolinium: role for platelet-derived growth factor receptor

OBJECTIVE

The purpose of this study was to assess the effects of gadolinium (Gd3+), provided as gadolinium chloride, on fibroblast function.

MATERIALS AND METHODS

Human dermal fibroblasts in monolayer culture and intact skin in organ culture were exposed to the lanthanide metal (1-20 μM).

RESULTS

Increased proliferation was observed, in association with upregulation of matrix metalloproteinase-1 and tissue inhibitor of metalloproteinases-1, without an apparent increase in production of type I procollagen. A platelet-derived growth factor (PDGF) receptor-blocking antibody inhibited fibroblast proliferation in response to Gd3+ as did inhibitors of signaling pathways--that is, mitogen-activated protein kinase and phosphatidylinositol-3 kinase pathways--that are activated by PDGF.

CONCLUSION

The responses to gadolinium chloride are similar to responses previously seen with chelated Gd3+ in clinically used magnetic resonance imaging contrast agents. Fibroblast responses appear to reflect Gd3+-induced PDGF receptor activation and downstream signaling. Increased dermal fibroblast proliferation in conjunction with effects on matrix metalloproteinase-1 and tissue inhibitor of metalloproteinases-1 could contribute to the fibroplastic/fibrotic changes seen in the lesional skin of individuals with nephrogenic systemic fibrosis.

Advances in diagnostic radiology

Recent advances in diagnostic radiology are discussed on the basis of current publications in Investigative Radiology. Publications in the journal during 2009 and 2010 are reviewed, evaluating developments by modality and anatomic region. Technological advances continue to play a major role in the evolution and clinical practice of diagnostic radiology, and as such constitute a major publication focus. In the past 2 years, this includes advances in both magnetic resonance and computed tomography (in particular, the advent of dual energy computed tomography). An additional major focus of publications concerns contrast media, and in particular continuing research involving nephrogenic systemic fibrosis, its etiology, and differentiation of the gadolinium chelates on the basis of in vivo stability.

Development and haematotoxicological evaluation of doped hydroxyapatite based multimodal nanocontrast agent for near-infrared, magnetic resonance and X-ray contrast imaging

Multimodal molecular imaging provides both anatomical and molecular information, aiding early stage detection and better treatment planning of diseased conditions. Here, we report development and nanotoxicity evaluation of a novel hydroxyapatite nanoparticle (nHAp) based multimodal contrast agent for combined near-infrared (NIR), MR and X-ray imaging. Under optimised wet-chemical conditions, we achieved simultaneous doping of nHAp (size ∼50 nm) with indocyanine green and Gd(3+) contributing to NIR contrast (∼750-850 nm), paramagnetic behaviour and X-ray absorption suitable for NIR, MR and X-ray contrast imaging, respectively. Haematocompatibility studies using stem cell viability, haemolysis, platelet activation, platelet aggregation and coagulation time analysis indicated excellent compatibility of doped nHAp (D-nHAp). Further, the immunogenic function studies using human lymphocytes (in vitro) showed that D-nHAp caused no adverse effects. Collectively, our studies suggest that D-nHAp with excellent biocompatibility and multifunctional properties is a promising nanocontrast agent for combined NIR, MR and X-ray imaging applications.

Nephrogenic systemic fibrosis: review of 408 biopsy-confirmed cases

Nephrogenic systemic fibrosis (NSF) has now been virtually eliminated by the discovery of its association with gadolinium-based contrast agents (GBCAs) and the consequent reduced use of GBCA-enhanced magnetic resonance imaging (MRI) in severe renal failure patients. This review of 408 biopsy-confirmed cases shows how to minimize NSF risk when performing GBCA-enhanced MRI or magnetic resonance angiography. The absence of any NSF cases in patients less than 8 years old or greater than 87 years old suggests that infants and elderly patients are already protected. Limiting GBCA dose to a maximum of 0.1 mMol/kg, dialyzing dialysis patients quickly following GBCA administration, delaying administration of GBCA in acute renal failure until after renal function returns or dialysis is initiated, and avoiding nonionic linear GBCA in renal failure patients, especially when there are pro-inflammatory conditions, appear to have reduced NSF risk to the point where safe GBCA-enhanced MRI is possible in most patients.

Clinical, biological, and skin histopathologic effects of ionic macrocyclic and nonionic linear gadolinium chelates in a rat model of nephrogenic systemic fibrosis

OBJECTIVE

the purpose of this study was to compare the clinical, pathologic, and biochemical effects of repeated administrations of ionic macrocyclic or nonionic linear gadolinium chelates (GC) in rats with impaired renal function.

MATERIAL AND METHODS

rats submitted to subtotal nephrectomy were allocated to single injections of 2.5 mmol/kg of gadodiamide (nonionic linear chelate), nonformulated gadodiamide (ie, without the free ligand caldiamide), gadoterate (ionic macrocyclic chelate), or saline for 5 consecutive days. Blinded semi-quantitative histopathologic and immunohistochemical examinations of the skin were performed, as well as clinical, hematological, and biochemical follow-up. Rats were killed at day 11. Long-term (up to day 32) follow-up of rats was also performed in an auxiliary study.

RESULTS

epidermal lesions (ulcerations and scabs) were found in 4 of the 10 rats treated with nonformulated gadodiamide. Two rats survived the study period. Inflammatory signs were observed in this group. No clinical, hematological, or biochemical signs were observed in the saline and gadoterate- or gadodiamide-treated groups. Plasma fibroblast growth factor-23 levels were significantly higher in the gadodiamide group than in the gadoterate group (day 11). Decreased plasma transferrin-bound iron levels were measured in the nonformulated gadodiamide group. Histologic lesions were in the range: nonformulated gadodiamide (superficial epidermal lesions, inflammation, necrosis, and increased cellularity in papillary dermis) > gadodiamide (small superficial epidermal lesions and signs of degradation of collagen fibers in the dermis) > gadoterate (very few pathologic lesions, similar to control rats).

CONCLUSIONS

repeated administration of the nonionic linear GC gadodiamide to renally impaired rats is associated with more severe histologic lesions and higher FGF-23 plasma levels than the macrocyclic GC gadoterate.

Effects of magnetic resonance imaging contrast agents on human umbilical vein endothelial cells and evaluation of magnetic resonance imaging contrast media-triggered transforming growth factor-beta induction in dermal fibroblasts (HSF) as a model for nephrogenic systemic fibrosis

RATIONALE AND OBJECTIVES

The objective of this study was to evaluate effects of 6 commercially available magnetic resonance contrast media (CM) on human umbilical vein endothelial cells (HUVEC) and the induction of transforming growth factor-beta (TGF-β) in dermal fibroblasts (HSF) as a possible model for the pathogenesis of nephrogenic systemic fibrosis.

METHODS

HUVECs were incubated with 10× and 20× of the molar standard blood concentration achieved with CM applications for magnetic resonance imaging examinations (10× and 20× concentration) for 24 hours using gadolinium-based CM Gadovist, Magnevist, Multihance, and Omniscan, as well as Teslascan (Manganese-based), and Resovist (Iron-based). Proliferation kinetics (PK), colony formation, and viability assays were performed. Additionally, human dermal fibroblasts (HSF) were incubated for 24 hours with 1× and 20× concentration in all 6 CM, and TGF-β levels were assessed directly after the incubation period as well as on days 3 and 8 postincubation.

RESULTS

HUVEC PK data show similar gains in cell numbers for all 6 CM in both concentration groups over the 17-day assessment period. Only cells incubated with Omniscan and Teslascan differed from the other groups on days 3 and 7 postincubation (P < 0.05). After day 7, a cell regain occurred in the Omniscan and Teslascan groups reaching the numbers of the other groups in sequel. Differences in colony formation were consistent with PK results with a statistically significant reduction in clonogenic activity for Teslascan and Omniscan in HUVEC cells, P < 0.05. No reduction in viability was seen for all groups and conditions. TGF-β expression of HSF cells incubated with 1× concentration and all CM did not differ significantly from control cells for any point in time investigated. At 20× concentration directly after incubation, TGF-β was significantly reduced for the Teslascan and Resovist group as 3 compared with control and all other CM groups, P < 0.05. On day 3 postincubation, only Resovist-incubated HSF cells showed a significant reduction of TGF-β (1.614, standard deviations: 89) as compared with the control group (2.883, standard deviations: 30) and the other CM. TGF-β was slightly reduced for all CM groups 8 days after incubation (not statistically significant, P > 0.05).

CONCLUSIONS

After 24 hours of incubation with Omniscan and Teslascan (10× and 20× concentration), considerable short-term antiproliferative effects in HUVECs were observed. HSF cells (20× concentration) showed a reduction of TGF-β for Resovist and Teslascan directly after incubation, whereas TGF-β levels in HSF cells were slightly reduced for all CM 8 days after incubation. Therefore, TGF-β-mediated proliferative effects on fibroblasts or on collagen synthesis potentially leading to nephrogenic systemic fibrosis may mainly be triggered by tissue monocytes and macrophages in the peripheral blood instead of dermal fibroblasts.

Ablation of the decorin gene enhances experimental hepatic fibrosis and impairs hepatic healing in mice

Accumulation of connective tissue is a typical feature of chronic liver diseases. Decorin, a small leucine-rich proteoglycan, regulates collagen fibrillogenesis during development, and by directly blocking the bioactivity of transforming growth factor-β1 (TGFβ1), it exerts a protective effect against fibrosis. However, no in vivo investigations on the role of decorin in liver have been performed before. In this study we used decorin-null (Dcn-/-) mice to establish the role of decorin in experimental liver fibrosis and repair. Not only the extent of experimentally induced liver fibrosis was more severe in Dcn-/- animals, but also the healing process was significantly delayed vis-à-vis wild-type mice. Collagen I, III, and IV mRNA levels in Dcn-/- livers were higher than those of wild-type livers only in the first 2 months, but no difference was observed after 4 months of fibrosis induction, suggesting that the elevation of these proteins reflects a specific impairment of their degradation. Gelatinase assays confirmed this hypothesis as we found decreased MMP-2 and MMP-9 activity and higher expression of TIMP-1 and PAI-1 mRNA in Dcn-/- livers. In contrast, at the end of the recovery phase increased production rather than impaired degradation was found to be responsible for the excessive connective tissue deposition in livers of Dcn-/- mice. Higher expression of TGFβ1-inducible early responsive gene in decorin-null livers indicated enhanced bioactivity of TGFβ1 known to upregulate TIMP-1 and PAI-1 as well. Moreover, two main axes of TGFβ1-evoked signaling pathways were affected by decorin deficiency, namely the Erk1/2 and Smad3 were activated in Dcn-/- samples, whereas no significant difference in phospho-Smad2 was observed between mice with different genotypes. Collectively, our results indicate that the lack of decorin favors the development of hepatic fibrosis and attenuates its subsequent healing process at least in part by affecting the bioactivity of TGFβ1.

Gadolinium exposure disrupts iron homeostasis in cultured cells

Human exposure to gadolinium-based contrast agents can be complicated by nephrogenic systemic fibrosis (NSF). Demonstration of significant quantities of insoluble gadolinium in the skin of NSF patients suggested transmetallation as a mechanism of toxicity of this injury. An alternative pathway for the biological effect of gadolinium is a disruption of iron homeostasis. We tested the postulate that cell exposure to gadolinium increases iron uptake to disrupt intracellular metal homeostasis and impact inflammatory events. Alveolar macrophages, THP1 cells, NHBE cells, and BEAS-2B cells all demonstrated a capacity to import gadolinium from both GdCl(3) and Omniscan. All four cell types similarly imported iron following exposure to ferric ammonium citrate (FAC). Exposure of all cell types to gadolinium and iron resulted in increased iron import relative to cell concentrations following incubation with FAC alone. To analyze for further evidence of changes in iron homeostasis, cell ferritin concentration was determined. Relative to incubation with FAC alone, co-incubation of BEAS-2B cells with gadolinium and FAC resulted in significant increases in ferritin level. Finally, potential effects of gadolinium uptake and associated changes in iron homeostasis on the inflammatory response were evaluated by measuring IL-8. Co-incubation of BEAS-2B cells with both gadolinium and iron resulted in diminished release of IL-8 relative to levels of the cytokine following incubation with gadolinium alone. We conclude that gadolinium impacts cell iron homeostasis to change import and storage of the metal and biological effects of exposure.

Responses of human skin in organ culture and human skin fibroblasts to a gadolinium-based MRI contrast agent: comparison of skin from patients with end-stage renal disease and skin from healthy subjects

OBJECTIVE

Nephrogenic systemic fibrosis is a clinical syndrome occurring in a small subset of patients with end-stage renal disease (ESRD). Exposure to certain of the gadolinium-based contrast agents during magnetic resonance imaging appears to be a trigger. The pathogenesis of the disease is largely unknown. The present study addresses potential pathophysiologic mechanisms.

MATERIALS AND METHODS

We have compared responses in organ-cultured skin and skin fibroblasts from individuals with ESRD to responses of healthy control subjects to Omniscan treatment.

RESULTS

Treatment of skin from ESRD patients with Omniscan stimulated production of matrix metalloproteinase-1 and tissue inhibitor of metalloproteinases-1, but not type I procollagen. The same treatment also stimulated an increase in hyaluronan production. Similar results were seen with skin from normal controls but basal levels were higher in ESRD patients. Fibroblasts in monolayer culture gave the same responses, but there were no differences based on whether the cells were isolated from the skin of healthy subjects or those with ESRD.

CONCLUSION

These data indicate that Omniscan exposure alters an enzyme/inhibitor system responsible for regulating collagen turnover in the skin and directly stimulates hyaluronan production. The higher basal levels of type I procollagen, matrix metalloproteinase-1, tissue inhibitor of metalloproteinases-1, and hyaluronan in the skin from ESRD patients could contribute to the sensitivity of this patient population to fibrotic changes, which might be induced by exposure to some of the gadolinium-based contrast agents.

Collagenolytic activity is suppressed in organ-cultured human skin exposed to a gadolinium-based MRI contrast agent

OBJECTIVE

Human skin produces increased amounts of matrix metalloproteinase-1 (MMP-1) when exposed in organ culture to Omniscan, one of the gadolinium-based MRI contrast agents (GBCA). MMP-1, by virtue of its ability to degrade structural collagen, contributes to collagen turnover in the skin. The objective of the present study was to determine whether collagenolytic activity was concomitantly up-regulated with increased enzyme.

MATERIALS AND METHODS

Skin biopsies from normal volunteers were exposed in organ culture to Omniscan. Organ culture fluids obtained from control and treated skin were examined for ability to degrade type I collagen. The same culture fluids were examined for levels of MMP-1, tissue inhibitor of metalloproteinases-1 (TIMP-1), and complexes of MMP-1 and TIMP-1.

RESULTS

Although MMP-1 was increased in culture fluid from Omniscan-treated skin, there was no increase in collagenolytic activity. In fact, collagenolytic activity declined. Increased production of TIMP-1 was also observed in Omniscan-treated skin, and the absolute amount of TIMP-1 was greater than the amount of MMP-1. Virtually all of the MMP-1 was present in MMP-1-TIMP-1 complexes, but the majority of TIMP-1 was not associated with MMP-1. When human dermal fibroblasts were exposed to TIMP-1 (up to 250 ng/mL), no increase in proliferation was observed, but an increase in collagen deposition into the cell layer was seen.

CONCLUSION

Gadolinium-based MRI contrast agent exposure has recently been linked to a fibrotic skin condition in patients with impaired kidney function. The mechanism is unknown. The increase in TIMP-1 production and concomitant reduction in collagenolytic activity demonstrated here could result in decreased collagen turnover and increased deposition of collagen in lesional skin.

Risk factors for NSF: a literature review

Emerging evidence linking gadolinium-based contrast agents (GBCAs) to nephrogenic systemic fibrosis (NSF) has changed medical practice patterns toward forgoing GBCA-enhanced magnetic resonance imaging (MRI) or substituting other imaging methods, which are potentially less accurate and often radiation-based. This shift has been based on reports of high NSF incidence at sites where a confluence of risk factors occurred in patients with severe renal dysfunction. This review article explores the factors that affect NSF risk, compares risks of alternative imaging procedures, and demonstrates how risk can be managed by careful selection of GBCA dose, timing of injection with respect to dialysis, and other factors. Nearly half of NSF cases are a milder form that does not cause contractures or reduce mobility. It appears that eliminating even a single risk factor can reduce NSF incidence/risk at least 10-fold. Elimination of multiple risk factors by using single-dose GBCA, dialyzing dialysis patients quickly following GBCA administration, avoiding GBCA in acute renal failure while serum creatinine is rising, and avoiding nonionic linear GBCA in renal failure patients may reduce NSF risk more than a thousand-fold, thereby allowing safe GBCA-enhanced MRI in virtually all patients. J. Magn. Reson. Imaging 2009;30:1298-1308. (c) 2009 Wiley-Liss, Inc.

Regulation of collagen turnover in human skin fibroblasts exposed to a gadolinium-based contrast agent

OBJECTIVE

Nephrogenic systemic fibrosis is a clinical syndrome linked with exposure in renal failure patients to gadolinium-based contrast agents (GBCAs) during magnetic resonance imaging. Recently, we demonstrated that GBCA exposure led to increased matrix metalloproteinase-1 (MMP-1) and tissue inhibitor of metalloproteinases-1 (TIMP-1) levels in human skin fibroblasts. The goals of the present work were to assess the relationship between altered MMP-1/TIMP-1 expression and collagen production/deposition, and the intracellular signaling events that lead from GBCA stimulation to altered MMP-1 and TIMP-1 production.

MATERIALS AND METHODS

Human dermal fibroblasts were treated with one of the currently used GBCAs (Omniscan). Proliferation was quantified as were levels of MMP-1, TIMP-1, procollagen type I, and collagen type I. Signaling events were concomitantly assessed, and signaling inhibitors were used.

RESULTS

Fibroblasts exposed to Omniscan had increases in both MMP-1 and TIMP-1 levels. Omniscan treatment interfered with collagen turnover, leading to increased type I collagen deposition without an increase in type I procollagen production. U0126, an inhibitor of mitogen-activated protein kinase signaling, and LY294002, a phosphatidylinositol-3 kinase inhibitor, reduced MMP-1 levels. U0126 also reduced TIMP-1 levels, but LY294002 increased TIMP-1.

CONCLUSION

These data provide evidence for complex regulation of collagen deposition in Omniscan-treated skin. They suggest that the major effect of Omniscan exposure is on an enzyme/inhibitor system that regulates collagen breakdown rather than on collagen production, per se.