Rapid improvement of nephrogenic systemic fibrosis with rapamycin therapy: Possible role of phospho-70-ribosomal-S6 kinase

The Clinical Manifestations and Efficacy of Different Treatments Used for Nephrogenic Systemic Fibrosis: A Systematic Review

Aim

Nephrogenic systemic fibrosis (NSF) is a rare disorder that occurs in association majorly with chronic kidney disease (CKD). The lack of collective quantitative data on its clinical manifestations and the different treatment options' efficacy, call the need for our investigation.

Methods

A systematic review was conducted covering a timeline from inception up to July 2022 without any restrictions. Article screening and data extraction were performed independently on PubMed, Google Scholar, ScienceDirect, and Cochrane Library. The keywords that we used were CKD, NSF, Gadolinium enduced fibrosis, etc; shortlisted articles were assessed for risk of bias. Data were presented as frequencies and percentages, with a confidence interval of 95%. A chi-square test was also done to find significant relationships, with a p-value <0.05 considered significant.

Results

We had 83 patients in this review consisting of 44 (55.7%) females with a mean age of 51.4±14.6 years. Sixty-nine (83.1%) patients had chronic kidney disease predisposition to NSF. Previous exposure to gadolinium-based contrast dyes was seen in 66 (79.5%) patients). The most common symptom in patients was cutaneous lesions in 69 (83.1%) patients. The most used treatments were ultraviolet therapy, renal transplant, and extracorporeal photopheresis; in 13.3% of the patients each. Condition in most patients either improved (67.1%) or remained stable (11.8%). Chi-square testing found that the treatments offered were also seen to be significantly related to outcome (p=0.015).

Conclusion

The findings in this study provide a quantitative measurement of NSF's presentations and treatment efficacies. This serves to make way for researchers to form comprehensive guidelines on the presentation-based treatment of NSF.

Gadolinium chloride promotes proliferation of HEK293 human embryonic kidney cells by activating EGFR/PI3K/Akt and MAPK pathways

Prolonged exposure to gadolinium-based contrast agents has been reported to trigger nephrogenic systemic fibrosis in end stage renal disease patients. However, the exact molecular mechanisms are not fully understood, and no effective therapy is available to date. In the present study, we report that gadolinium chloride (Gd³⁺) concentration- and time-dependently promoted the proliferation of HEK293 human embryonic kidney cells by increasing DNA synthesis. Gd³⁺ treatment increased the protein levels of phosphorylated Akt and MAPKs. Inhibition of Akt and ERK by pharmacological inhibitors abolished the increased proliferation and cell cycle progression. Furthermore, Gd³⁺ activated EGFR signaling possibly by enhancing EGFR clustering on the cell membrane. Inhibition of EGFR by gefitinib blocked Gd³⁺-induced proliferation. Gd³⁺ exposure also upregulated the mRNA levels of TGFβ-1, TGFβR1, TNFα, TIMP-1 and integrin αV, β1 which could also be attenuated by the inhibition of Akt and ERK signaling. Our study provides new clues for the etiological role of Gd³⁺ in the pathogenesis of nephrogenic systemic fibrosis, and suggests the inhibition of EGFR/Akt/ERK signaling as a potential treatment strategy.

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.

[Non-iodinated contrast media nephrotoxicity]

The development of interventional radiology techniques regularly exposes patients to the potential renal toxocity of iodinated contrast media. Faced with this risk of nephrotoxicity, gadolinium-based contrast agents have long been considered as a safe alternative to iodinated contrast media, especially in sensitive or at risk patients. However, these gadolinium-based contrast agents are not devoid of nephrotoxicity and present another risk, a complication related to renal failure, the nephrogenic systemic fibrosis. European and US recommendations from health agencies have recently come closer, defining groups of patients at risk of nephrogenic systemic fibrosis according to their level of renal function and the type of gadolinium-based contrast agent used. What are the real renal risks for these products? How to evaluate the benefit-risk balance of the patient to choose a radiological examination in an informative, effective and safe way? This article focuses on the description of the risks of gadolinium-based contrast agents, reviews existing recommendations and best practices to guide the choice of clinicians.

Anti-fibrotic effects of pirfenidone and rapamycin in primary IPF fibroblasts and human alveolar epithelial cells

BACKGROUND

Pirfenidone, a pleiotropic anti-fibrotic treatment, has been shown to slow down disease progression of idiopathic pulmonary fibrosis (IPF), a fatal and devastating lung disease. Rapamycin, an inhibitor of fibroblast proliferation could be a potential anti-fibrotic drug to improve the effects of pirfenidone.

METHODS

Primary lung fibroblasts from IPF patients and human alveolar epithelial cells (A549) were treated in vitro with pirfenidone and rapamycin in the presence or absence of transforming growth factor β1 (TGF-β). Extracellular matrix protein and gene expression of markers involved in lung fibrosis (tenascin-c, fibronectin, collagen I [COL1A1], collagen III [COL3A1] and α-smooth muscle actin [α-SMA]) were analyzed. A cell migration assay in pirfenidone, rapamycin and TGF-β-containing media was performed.

RESULTS

Gene and protein expression of tenascin-c and fibronectin of fibrotic fibroblasts were reduced by pirfenidone or rapamycin treatment. Pirfenidone-rapamycin treatment did not revert the epithelial to mesenchymal transition pathway activated by TGF-β. However, the drug combination significantly abrogated fibroblast to myofibroblast transition. The inhibitory effect of pirfenidone on fibroblast migration in the scratch-wound assay was potentiated by rapamycin combination.

CONCLUSIONS

These findings indicate that the combination of pirfenidone and rapamycin widen the inhibition range of fibrogenic markers and prevents fibroblast migration. These results would open a new line of research for an anti-fibrotic combination therapeutic approach.

A unique case of nephrogenic systemic fibrosis from gadolinium exposure in a patient with normal eGFR

A 57-year-old woman presented with swelling and thickening of the skin of the lower extremities. Three months prior to presentation, patient had MRI with gadolinium as part of an evaluation for suspected pancreatic malignancy. Creatinine levels at the time of gadolinium exposure were 0.9-1.2 mg/dL, with a corresponding estimated glomerular filtration rate of 64 mL/min/1.73m2 by modification of diet in renal disease equation. Twenty-four-hour urine creatinine clearance was performed as an outpatient following development of symptoms. This revealed a creatinine clearance of 23 mL/min, suggestive of advanced chronic kidney disease despite an estimated glomerular filtration rate of 64 mL/min/1.73m2 Skin biopsy was positive for sclerosing dermopathy. These findings, in addition to the temporal association with gadolinium exposure, led to the diagnosis of nephrogenic systemic fibrosis.

Role of Sirolimus in Advanced Kaposiform Hemangioendothelioma

Kaposiform hemangioendothelioma (KHE) is an infiltrative vascular tumor that classically presents in infancy. Management typically focuses on treating Kasabach-Merritt phenomenon (KMP), a disorder of severe and at times life-threatening platelet trapping. However, the morbidity of KHE extends beyond KMP. The infiltrative nature of the tumor can lead to long-term disability and often makes complete surgical resection impossible. We report the case of a 10-year-old boy with a KHE of his right distal thigh who was unable to walk without assistance due to fibrotic change and right knee contracture. He had no laboratory evidence of KMP at the time of representation. Rapamycin was started in hopes of reducing the tumor burden. Within 2 months of therapy, fibrotic areas softened, his contracture nearly resolved, and there was marked improvement in his mobility. Rapamycin has been previously reported to be effective in managing cases of KHE complicated by KMP. Our report emphasizes the role for rapamycin in the treatment of KHE in the absence of KMP through the inhibition of vasculogenesis and fibrotic pathways.

Gadolinium and nephrogenic systemic fibrosis: an update

Nephrogenic systemic fibrosis (NSF) is a multisystem disease seen exclusively in patients with renal impairment. It can be severely debilitating and sometimes fatal. There is a strong association with gadolinium-based contrast agents used in magnetic resonance imaging (MRI). Risk factors include renal impairment and proinflammatory conditions, e.g. major surgery and vascular events. Although there is no single effective treatment for NSF, the most successful outcomes are seen following restoration of renal function, either following recovery from acute kidney injury or following renal transplantation. There have been ten biopsy-proved pediatric cases of NSF, with no convincing evidence that children have a significantly altered risk compared with the adult population. After implementation of guidelines restricting the use of gadolinium-based contrast agents in at-risk patients, there has been a sharp reduction in new cases and no new reports in children. Continued vigilance is recommended: screening for renal impairment, use of more stable gadolinium chelates, consideration of non-contrast-enhanced MRI or alternative imaging modalities where appropriate.

Cutaneous manifestations of ESRD

A broad range of skin diseases occurs in patients with ESRD: from the benign and asymptomatic to the physically disabling and life-threatening. Many of them negatively impact on quality of life. Their early recognition and treatment are essential in reducing morbidity and mortality. The cutaneous manifestations can be divided into two main categories: nonspecific and specific. The nonspecific manifestations are commonly seen and include skin color changes, xerosis, half-and-half nails, and pruritus. The specific disorders include acquired perforating dermatosis, bullous dermatoses, metastatic calcification, and nephrogenic systemic fibrosis. This review article describes these conditions and considers the underlying pathophysiology, clinical presentations, diagnosis, and treatment options.

Rapamycin inhibits transforming growth factor β1-induced fibrogenesis in primary human lung fibroblasts

PURPOSE

The present study was designed to determine whether rapamycin could inhibit transforming growth factor β1 (TGF-β1)-induced fibrogenesis in primary lung fibroblasts, and whether the effect of inhibition would occur through the mammalian target of rapamycin (mTOR) and its downstream p70S6K pathway.

MATERIALS AND METHODS

Primary normal human lung fibroblasts were obtained from histological normal lung tissue of 3 patients with primary spontaneous pneumothorax. Growth arrested, synchronized fibroblasts were treated with TGF-β1 (10 ng/mL) and different concentrations of rapamycin (0.01, 0.1, 1, 10 ng/mL) for 24 h. We assessed m-TOR, p-mTOR, S6K1, p-S6K1 by Western blot analysis, detected type III collagen and fibronectin secreting by ELISA assay, and determined type III collagen and fibronectin mRNA levels by real-time PCR assay.

RESULTS

Rapamycin significantly reduced TGF-β1-induced type III collagen and fibronectin levels, as well as type III collagen and fibronectin mRNA levels. Furthermore, we also found that TGF-β1-induced mTOR and p70S6K phosphorylation were significantly down-regulated by rapamycin. The mTOR/p70S6K pathway was activated through the TGF-β1-mediated fibrogenic response in primary human lung fibroblasts.

CONCLUSION

These results indicate that rapamycin effectively suppresses TGF-β1-induced type III collagen and fibronectin levels in primary human lung fibroblasts partly through the mTOR/p70S6K pathway. Rapamycin has a potential value in the treatment of pulmonary fibrosis.

Minimizing risk of nephrogenic systemic fibrosis in cardiovascular magnetic resonance

Nephrogenic Systemic Fibrosis is a rare condition appearing only in patients with severe renal impairment or failure and presents with dermal lesions and involvement of internal organs. Although many cases are mild, an estimated 5% have a progressive debilitating course. To date, there is no known effective treatment thus stressing the necessity of ample prevention measures. An association with the use of Gadolinium based contrast agents (GBCA) makes Nephrogenic Systemic Fibrosis a potential side effect of contrast enhanced magnetic resonance imaging and offers the opportunity for prevention by limiting use of gadolinium based contrast agents in renal failure patients. In itself toxic, Gadolinium is embedded into chelates that allow its safe use as a contrast agent. One NSF theory is that Gadolinium chelates distribute into the extracellular fluid compartment and set Gadolinium ions free, depending on multiple factors among which the duration of chelates exposure is directly related to the renal function. Major medical societies both in Europe and in North America have developed guidelines for the usage of GBCA. Since the establishment of these guidelines and the increased general awareness of this condition, the occurrence of NSF has been nearly eliminated. Giving an overview over the current knowledge of NSF pathobiochemistry, pathogenesis and treatment options this review focuses on the guidelines of the European Medicines Agency, the European Society of Urogenital Radiology, the FDA and the American College of Radiology from 2008 up to 2011 and the transfer of this knowledge into every day practice.

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.

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.

Integrin-mediated signaling contributes to gadolinium-containing-particle-promoted cell survival and G₁ to S phase cell cycle transition by enhancing focal adhesion formation

We previously reported that Gd-containing particles formed under physiological conditions act as active entities to enhance cell survival and promote S phase entry via activation of both mitogen-activated protein kinase/extracellular-signal-regulated protein kinase (ERK) and phosphatidylinositol 3-kinase/Akt signaling pathways. However, how they transduce the extracellular signal inside the cell remains unclear. The present study demonstrates that Gd-containing particles can alleviate serum-deprivation-induced cell death and promote G₁ to S phase cell cycle progression by enhancing cell adhesion to the extracellular matrix. As an indicator of adhesion, the vinculin distribution was detected by confocal laser scanning microscopy. The control cells exhibited fewer and less typical focal adhesions. After treatment with Gd-containing particles, a large number of vinculin-containing focal adhesions were maintained. In the presence of integrin antagonists, the percentage of S phase entry induced by Gd-containing particles was decreased and the enhancement of cell viability was also attenuated, along with a decrease in both cyclin D expression and ERK phosphorylation. In summary, the present results suggest that the integrin-mediated signaling pathway plays an important role in cell survival and G₁ to S phase transition promoted by Gd-containing particles by enhancing focal adhesion formation. The results presented here provide novel evidence to advance knowledge leading to further understanding of the mechanisms of both cell proliferation and cell survival promoted by Gd and may be helpful for developing effective measures to prevent or treat nephrogenic systemic fibrosis.

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.

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.

Nephrogenic systemic fibrosis and gadolinium-based contrast agents

The strong association between nephrogenic systemic fibrosis (NSF) and exposure to gadolinium-based contrast agents (GBCAs) has greatly affected the care of patients with kidney disease. NSF has been reported in patients with ESRD, CKD, and acute kidney injury (AKI). The majority of cases have occurred in patients with ESRD, but about 20% have been reported in patients with AKI or CKD stages 4 and 5. There is also a risk difference among GBCAs, with the Food and Drug Administration contraindicating 3 linear agents in patients at risk. Given the significant morbidity and mortality of NSF, it is imperative to identify individuals at risk. Although there are no data to support a role for hemodialysis (HD) in reducing the risk for NSF after administration of GBCAs, immediate HD is still recommended within 2 hours. Patients maintained on peritoneal dialysis seem to be at high risk and immediate HD is also recommended. However, this is not the current recommendation for CKD stages 4 and 5, especially with suspected lower risk of noncontraindicated agents. Individualized assessment is important and especially in those patients close to dialysis initiation. Instituting policies is important to address the imaging needs of patients with CKD and AKI while ensuring a balance between benefits and risks.

The pathogenesis of systemic sclerosis

Systemic sclerosis (SSc), also known as scleroderma, is a rare connective tissue disease characterized by vascular and immune dysfunction, leading to fibrosis that can damage multiple organs. Its pathogenesis is complex and poorly understood. Two major clinical subtypes are the limited and diffuse forms. Research into SSc has been hampered by its rarity, its clinical heterogeneity, and the lack of mouse models that accurately recapitulate the disease. Clinical and basic studies have yielded some mechanistic clues regarding pathogenesis. Recent insights gained through the use of microarrays have revealed distinctive subsets of SSc within and beyond the limited and diffuse subsets. In this review, we discuss potential mechanisms underlying the vascular, autoimmune, and fibrotic points of dysregulation. Proper categorization of SSc patients for research studies by use of microarrays or other biomarkers is critical, as disease heterogeneity may explain some of the inconsistencies of prior studies.