Cyclosporine nephrotoxicity

CD44 expression in renal tubular epithelial cells in the kidneys of rats with cyclosporine-induced chronic kidney disease

Renal tubular epithelial cell (TEC) injury is the most common cause of drug-induced kidney injury (DIKI). Although TEC regeneration facilitates renal function and structural recovery following DIKI, maladaptive repair of TECs leads to irreversible fibrosis, resulting in chronic kidney disease (CKD). CD44 is specifically expressed in TECs during maladaptive repair in several types of rat CKD models. In this study, we investigated CD44 expression and its role in renal fibrogenesis in a cyclosporine (CyA) rat model of CKD. Seven-week-old male Sprague-Dawley rats fed a low-salt diet were subcutaneously administered CyA (0, 15, or 30 mg/kg) for 28 days. CD44 was expressed in atrophic, dilated, and hypertrophic TECs in the fibrotic lesions of the CyA groups. These TECs were collected by laser microdissection and evaluated by microarray analysis. Gene ontology analysis suggested that these TECs have a mesenchymal phenotype, and pathway analysis identified CD44 as an upstream regulator of fibrosis-related genes, including fibronectin 1 (Fn1). Immunohistochemistry revealed that epithelial and mesenchymal markers of TECs of fibrotic lesions were downregulated and upregulated, respectively, and that these TECs were surrounded by a thickened basement membrane. In situ hybridization revealed an increase in Fn1 mRNA in the cytoplasm of TECs of fibrotic lesions, whereas fibronectin protein was localized in the stroma surrounding these tubules. Enzyme-linked immunosorbent assay revealed increased serum CD44 levels in CyA-treated rats. Collectively, these findings suggest that CD44 contributes to renal fibrosis by inducing fibronectin secretion in TECs exhibiting partial epithelial-mesenchymal transition and highlight the potential of CD44 as a biomarker of renal fibrosis.

Differences in management approaches for lupus nephritis within the UK

Objectives

Outcomes of therapy for LN are often suboptimal. Guidelines offer varied options for treatment of LN and treatment strategies may differ between clinicians and regions. We aimed to assess variations in the usual practice of UK physicians who treat LN.

Methods

We conducted an online survey of simulated LN cases for UK rheumatologists and nephrologists to identify treatment preferences for class IV and class V LN.

Results

Of 77 respondents, 48 (62.3%) were rheumatologists and 29 (37.7%) were nephrologists. A total of 37 (48.0%) reported having a joint clinic between nephrologists and rheumatologists, 54 (70.0%) reported having a multidisciplinary team meeting for LN and 26 (33.7%) reported having a specialized lupus nurse. Of the respondents, 58 (75%) reported arranging a renal biopsy before starting the treatment. A total of 20 (69%) of the nephrologists, but only 13 (27%) rheumatologists, reported having a formal departmental protocol for treating patients with LN (P < 0.001). The first-choice treatment of class IV LN in pre-menopausal patients was MMF [41 (53.2%)], followed by CYC [15 (19.6%)], rituximab [RTX; 12 (12.5%)] or a combination of immunosuppressive drugs [9 (11.7%)] with differences between nephrologists' and rheumatologists' choices (P = 0.026). For class V LN, MMF was the preferred initial treatment, irrespective of whether proteinuria was in the nephrotic range or not. RTX was the preferred second-line therapy for non-responders.

Conclusion

There was variation in the use of protocols, specialist clinic service provision, biopsies and primary and secondary treatment choices for LN reported by nephrologists and rheumatologists in the UK.

Acute kidney injury after cardiac surgery

PURPOSE OF REVIEW

Patients undergoing cardiac surgery are at high risk to develop cardiac surgery-associated acute kidney injury (CS-AKI) postoperatively. CS-AKI is associated with an increased risk for persistent renal dysfunction, morbidity and mortality. This review summarizes the epidemiology and pathophysiology of CS-AKI, as well as current treatment and prevention strategies.

RECENT FINDINGS

As AKI is a syndrome with complex pathophysiology, no causative treatment strategies exist. Recent advances in the field of AKI biomarkers offer new perspectives on the issue and the implementation of biomarker-guided preventive strategies may reduce rates of CS-AKI. Finally, nephroprotective treatments and angiotensin II as a novel vasopressor may offer new opportunities for high-risk patients undergoing cardiac surgery.

SUMMARY

Based on the described novel approaches for early detection, prevention and management of CS-AKI, a precision-medicine approach should be implemented in order to prevent the development of AKI in patients undergoing cardiac surgery.

Next Generation PDE4 Inhibitors that Selectively Target PDE4B/D Subtypes: A Narrative Review

For decades, topical corticosteroids have been the mainstay of treatment for mild-to-moderate inflammatory skin diseases, even though only short-term use is approved for these agents and systemic inflammation is not addressed. Increased understanding of the immunopathogenesis of these conditions, especially for psoriasis and atopic dermatitis, has facilitated the development of antibody-based drugs that neutralize single key cytokines or their associated receptors, such as interleukin (IL)-17A/F, IL-23, and IL-17RA in psoriasis and IL-13 and IL-4Rα in atopic dermatitis. However, oral therapy is still preferred by many patients owing to the ease of use and needle-free administration. Phosphodiesterase 4 (PDE4) inhibitors have been approved for both oral and topical use for inflammatory skin diseases. In this review, we present a summary of an emerging class of selective PDE4B/D inhibitors under clinical development and compare the differences in selectivity of this new generation of PDE4 inhibitors with the less selective currently approved PDE4 inhibitors.

Chronic dehydration induces injury pathways in rats, but does not mimic histopathology of chronic interstitial nephritis in agricultural communities

CINAC-patients present renal proximal tubular cell lysosomal lesions which are also observed in patients experiencing calcineurin inhibitor (CNI) nephrotoxicity, suggesting that CINAC is a toxin-induced nephropathy. An alternative hypothesis advocates chronic dehydration as a major etiological factor for CINAC. Here, we evaluated histological and molecular changes in dehydrated versus toxin exposed rats. Wistar rats were divided in 3 groups. Group 1 (n = 6) had free access to drinking water (control group). Group 2 (n = 8) was water deprived for 10 h per 24 h, 5 days/week and placed in an incubator (37 °C) for 30 min/h during water deprivation. Group 3 (n = 8) underwent daily oral gavage with cyclosporine (40 mg/kg body weight). After 28 days, renal function, histopathology and proteomic signatures were analysed. Cyclosporine-treated rats developed focal regions of atrophic proximal tubules with associated tubulo-interstitial fibrosis. PASM staining revealed enlarged argyrophilic granules in affected proximal tubules, identified as lysosomes by immunofluorescent staining. Electron microscopy confirmed the enlarged and dysmorphic phenotype of the lysosomes. Overall, these kidney lesions resemble those that have been previously documented in farmers with CINAC. Dehydration resulted in none of the above histopathological features. Proteomic analysis revealed that dehydration and cyclosporine both induce injury pathways, yet of a clear distinct nature with a signature of toxicity only for the cyclosporine group. In conclusion, both cyclosporine and dehydration are injurious to the kidney. However, dehydration alone does not result in kidney histopathology as observed in CINAC patients, whereas cyclosporine administration does. The histopathological analogy between CINAC and calcineurin inhibitor nephrotoxicity in rats and humans supports the involvement of an as-yet-unidentified environmental toxin in CINAC etiology.

Impact of Abdominal Aortic Calcification on Chronic Kidney Disease After Liver Transplantation: A Retrospective Study

BACKGROUND

With improved graft and patient survival after liver transplantation (LT), the onset of late complications, such as renal dysfunction, has become a problem. In this study, we aimed to investigate abdominal aortic calcification (AAC), a potential indicator of systemic atherosclerosis, and evaluate the relationship between preoperative AAC and postoperative chronic kidney disease (CKD), as the latter might be a long-term complication after LT.

METHODS

Among the 184 LTs performed at our center between 2008 and 2021, 110 LTs with normal renal function (estimated glomerular filtration rate [eGFR] 60 mL/min per 1.73 m²) before surgery were included. These were divided into high- (≥100 mm³) and low-AAC groups (<100 mm³) consisting of 51 and 59 patients, respectively. The AAC volume was automatically calculated for calcifications located in the abdominal aorta using the Agatston method.

RESULTS

The high-AAC group was older, consisted of more men, and had lower preoperative creatinine and eGFR levels. No significant difference in the onset of postoperative CKD was found between the 2 groups. However, the cumulative incidence of postoperative CKD was significantly higher in the high-AAC group compared with the low-AAC group. Multivariate analysis of postoperative CKD using the Cox proportional hazards model showed significant differences in preoperative AAC ≥100 mm³, recipient age ≥50 years, and preoperative eGFR <75 mL/min per 1.73 m².

CONCLUSIONS

The development of postoperative CKD should be monitored in liver transplant recipients despite normal preoperative renal function. Our study suggests that preoperative AAC may influence postoperative renal dysfunction.

Is It Time for a Requiem for Creatine Supplementation-Induced Kidney Failure? A Narrative Review

Creatine has become one of the most popular dietary supplements among a wide range of healthy and clinical populations. However, its potential adverse effects on kidney health are still a matter of concern. This is a narrative review of the effects of creatine supplementation on kidney function. Despite a few case reports and animal studies suggesting that creatine may impair kidney function, clinical trials with controlled designs do not support this claim. Creatine supplementation may increase serum creatinine (Crn) concentration for some individuals, but it does not necessarily indicate kidney dysfunction, as creatine is spontaneously converted into Crn. Based on studies assessing kidney function using reliable methods, creatine supplements have been shown to be safe for human consumption. Further studies with people who have pre-existing kidney disease remain necessary.

Immunosuppression in Uterus Transplantation: Experience From the Dallas Uterus Transplant Study

BACKGROUND

Uterus transplantation is a temporary transplant allowing women with absolute uterine factor infertility to experience pregnancy and childbirth. The degree of immunosuppression (IS) required to prevent rejection while minimizing toxicity to the recipient and fetus remains an area of investigation.

METHODS

In this article, we describe immunosuppressive therapy, rejection episodes, infections, and adverse events in 14 uterus transplant recipients. Induction consisted of antithymocyte globulin and methylprednisolone. Ten recipients (71%) received no steroids postoperatively, and 4 (29%) had steroids tapered off at 42 d. All received oral tacrolimus, either immediate release (n = 2, 14%) or extended release (n = 12, 86%). Mycophenolate was used in 4 cases (29%), de novo azathioprine in 9 (64%), and de novo everolimus in 1 (7%).

RESULTS

Sixteen clinically silent, treatment-responsive rejection episodes occurred in 10 recipients. Five recipients (36%) experienced acute kidney injury. In 3 recipients, IS was discontinued due to renal dysfunction. Eleven infection episodes were noted in 7 recipients. No babies had congenital abnormalities.

CONCLUSIONS

Our experience demonstrates that safe IS regimens can be used for uterus transplant recipients before and during pregnancy.

Amelioration of Cyclosporine A-Induced Acute Nephrotoxicity by Cordyceps cicadae Mycelia via Mg+2 Reabsorption and the Inhibition of GRP78-IRE1-CHOP Pathway: In Vivo and In Vitro

Fruiting bodies of Cordyceps cicadae (CC) have been reported to have a therapeutic effect in chronic kidney disease. Due to the rare and expensive resources from natural habitats, artificially cultivated mycelia using submerged liquid cultivation of CC (CCM) have been recently developed as an alternative to scarce sources of CC. However, little is known regarding potential protective effects of CCM against cyclosporine A (CsA)-induced acute nephrotoxicity in vivo and in vitro. In this study, male Sprague-Dawley rats were divided into six groups: control, CCM (40 mg and 400 mg/kg, orally), CsA (10 mg/kg, oral gavage), and CsA + CCM (40 mg and 400 mg/kg, orally). At the end of the study on day 8, all rats were sacrificed, and the blood and kidneys retrieved. CsA-induced acute nephrotoxicity was evident by increased levels of blood urea nitrogen (BUN). Levels of the endoplasmic reticulum (ER) resident chaperone glucose regulated protein 78 (GRP 78) were increased significantly in rats with acute nephrotoxicity. BUN and GRP 78 were significantly ameliorated in synchronous oral groups of CCM (40 or 400 mg/kg) plus CsA. Examination of hematoxylin and eosin stained kidney tissues revealed that the combined treatment of CCM slightly improved vacuolization in renal tubules upon CsA-induced damage. CsA-induced down-regulation of protein expression of magnesium ion channel proteins and transient receptor potential melastatin 6 and 7 were abolished by the combined treatment of CCM. CCM has the potential to protect the kidney against CsA-induced nephrotoxicity by reducing magnesium ion wasting, tubular cell damage, and ER stress demonstrated further by human renal proximal tubular epithelial cell line HK-2. Our results contribute to the in-depth understanding of the role of polysaccharides and nucleobases as the main secondary metabolites of CCM in the defense system of renal functions in CsA-induced acute nephrotoxicity.

Nephroprotective effects of Candesartan Cilexetil against Cyclosporine A-induced nephrotoxicity in a rat model

Cyclosporine A (CsA), a well-known immunosuppressive drug, has been prescribed after organ transplantation and in a variety of disorders with an immunological origin. Nephrotoxicity is one of the most frequently stated problems associated with CsA, and therefore the treatment with CsA remains a big challenge. This study sets out to assess the ameliorative influences of Candesartan Cilexetil (CC) on oxidative stress and the nephrotoxic effect of CsA in a rat model. Twenty-four Wister Albino rats, 7-8-week-old, weighing 150-250g, were randomly categorized into three groups (eight animals in each group). These groups were the (1) CsA-treated group, (2) vehicle-treated group, and (3) CC-treated group. Bodyweights were assessed at the start and end of experiments. Renal function test and levels of glutathione peroxidase 1 catalase -CAT (Gpx1), catalase (CAT), superoxide dismutase (SOD), interleukin -2 (IL-2), and malondialdehyde (MDA) were investigated in renal tissues. Histological changes in kidneys were also evaluated. Data showed that levels of urea and creatinine in serum and levels of IL-2 and MDA in renal tissues were elevated in the CsA-treated group, with severe histological changes compared with the control group. Furthermore, tissue levels of Gpx1, CAT, and SOD were significantly decreased in CsA-treated in comparison with the control group. Treatment with CC for the rats subjected to CSA resulted in a marked reduction in levels of serum urea and creatinine and tissue levels of IL-2 and MDA. Levels of Gpx1, CAT, and SOD in renal tissues were greater in the CC-treatment group compared with the CsA-treated group. CC treatment reduced the deterioration of renal morphology compared with CsA treatment. The findings of this study suggest that CC could prevent CSA-induced nephrotoxicity through its anti-inflammatory and antioxidant influences. Considerably more work needs to be done to determine the mechanistic insight behind the ameliorative effect of CC.

Renal and Urological Disorders Associated With Inflammatory Bowel Disease

Renal and urinary tract complications related to inflammatory bowel disease (IBD) have been relatively understudied in the literature compared with other extraintestinal manifestations. Presentation of these renal manifestations can be subtle, and their detection is complicated by a lack of clarity regarding the optimal screening and routine monitoring of renal function in IBD patients. Urolithiasis is the most common manifestation. Penetrating Crohn's disease involving the genitourinary system as an extraintestinal complication is rare but associated with considerable morbidity. Some biologic agents used to treat IBD have been implicated in progressive renal impairment, although differentiating between drug-related side effects and deteriorating kidney function due to extraintestinal manifestations can be challenging. The most common findings on renal biopsy of IBD patients with renal injury are tubulointerstitial nephritis and IgA nephropathy, the former also being associated with drug-induced nephrotoxicity related to IBD medication. Amyloidosis, albeit rare, must be diagnosed early to reduce the chance of progression to renal failure. In this review, we evaluate the key literature relating to renal and urological involvement in IBD and emphasize the high index of suspicion required for the prompt diagnosis and treatment of these manifestations and complications, considering the potential severity and implications of acute or chronic loss of renal function. We also provide suggestions for future research priorities.

Ferulic acid prevents cyclosporine-induced nephrotoxicity in rats through exerting anti-oxidant and anti-inflammatory effects via activation of Nrf2/HO-1 signaling and suppression of NF-κB/TNF-α axis

Cyclosporine is one of the main immunosuppressive agents used in the treatment of autoimmune diseases or transplantation. Despite the favorable effects, cyclosporine-mediated nephrotoxicity critically restricts the clinical use of the agent. Given this, herein, we aimed to evaluate whether ferulic acid could prevent cyclosporine-mediated nephrotoxicity in rats. A total of 32 Wistar rats were chosen to be treated with cyclosporine, ferulic acid, and the combination of both agents for 21 days. To evaluate the nephron-protective mechanism of ferulic acid, the serum levels of biochemical parameters, as well as the tissue levels of several oxidative and anti-oxidative mediators, were examined. The expression and the tissue levels of nuclear factor (NF)-κB, tumor necrosis factor (TNF)-α, heme oxygenase (HO-1), and nuclear factor erythroid 2-related factor 2 (Nrf2) were evaluated using the qRT-PCR and ELISA, respectively. Our results showed while cyclosporine elevated the serum levels of renal-related markers in the rats, in the presence of ferulic acid, there was a significant reduction in the levels of urea, uric acid, creatinine, and sGOT. Moreover, we found that ferulic acid remarkably prevented cyclosporine-mediated nephrotoxicity by restoring the anti-oxidant system through activating the Nrf2/HO-1 axis. By halting the NF-κB-mediated upregulation of TNF-α, it also seems that ferulic acid prevented lymphocytes infiltration into kidney tissue and consequently suppressed inflammatory responses. Overall, the results of the present study suggest that due to the anti-oxidant and anti-inflammatory properties of ferulic acid, this agent could be used alongside cyclosporine to reduce its adverse effects on kidney tissue.

Typical and atypical properties of peripheral nerve allografts enable novel strategies to repair segmental-loss injuries

We review data showing that peripheral nerve injuries (PNIs) that involve the loss of a nerve segment are the most common type of traumatic injury to nervous systems. Segmental-loss PNIs have a poor prognosis compared to other injuries, especially when one or more mixed motor/sensory nerves are involved and are typically the major source of disability associated with extremities that have sustained other injuries. Relatively little progress has been made, since the treatment of segmental loss PNIs with cable autografts that are currently the gold standard for repair has slow and incomplete (often non-existent) functional recovery. Viable peripheral nerve allografts (PNAs) to repair segmental-loss PNIs have not been experimentally or clinically useful due to their immunological rejection, Wallerian degeneration (WD) of anucleate donor graft and distal host axons, and slow regeneration of host axons, leading to delayed re-innervation and producing atrophy or degeneration of distal target tissues. However, two significant advances have recently been made using viable PNAs to repair segmental-loss PNIs: (1) hydrogel release of Treg cells that reduce the immunological response and (2) PEG-fusion of donor PNAs that reduce the immune response, reduce and/or suppress much WD, immediately restore axonal conduction across the donor graft and re-innervate many target tissues, and restore much voluntary behavioral functions within weeks, sometimes to levels approaching that of uninjured nerves. We review the rather sparse cellular/biochemical data for rejection of conventional PNAs and their acceptance following Treg hydrogel and PEG-fusion of PNAs, as well as cellular and systemic data for their acceptance and remarkable behavioral recovery in the absence of tissue matching or immune suppression. We also review typical and atypical characteristics of PNAs compared with other types of tissue or organ allografts, problems and potential solutions for PNA use and storage, clinical implications and commercial availability of PNAs, and future possibilities for PNAs to repair segmental-loss PNIs.

Role of (Pro)Renin Receptor in Cyclosporin A-Induced Nephropathy

Calcineurin inhibitors (CNIs) such as cyclosporin A (CsA) have been widely used to improve graft survival following solid-organ transplantation. However, the clinical use of CsA is often limited by its nephrotoxicity. The present study tested the hypothesis that activation of (pro)renin receptor (PRR) contributes to CsA-induced nephropathy by activating the renin-angiotensin system (RAS). Renal injury in male Sprague-Dawley rats was induced by a low-salt diet combined with CsA as evidenced by elevated plasma creatinine and BUN levels, decreased creatinine clearance and induced renal inflammation, apoptosis as well as interstitial fibrosis, elevated urinary N-acetyl-β-D-glucosaminidase activity and urinary kidney injury molecular 1 content. Each index of renal injury was attenuated following a 2-wk treatment with a PRR decoy inhibitor PRO20. While CsA rats with kidney injury displayed increased renal sPRR abundance, plasma sPRR, renin activity, Ang II, and heightened urinary total prorenin/renin content; RAS activation was attenuated by PRO20. Exposure of cultured human renal proximal tubular HK-2 cells to CsA induced expression of fibronectin and sPRR production, but the fibrotic response was attenuated by PRO20 and siRNA-mediated PRR knockdown. These findings support the hypothesis that activation of PRR contributes to CsA-induced nephropathy by activating the RAS in rats. Of importance, we provide strong proof of concept that targeting PRR offers a novel therapeutic strategy to limit nephotoxic effects of immunosuppressant drugs.

MAGEH1 interacts with GADD45G and induces renal tubular cell apoptosis

Background

Melanoma-associated antigen H1 (MAGEH1) is a protein that belongs to melanoma-associated antigen (MAGE) superfamily. Growth arrest and DNA damage 45G (GADD45G) is a member of the DNA damage-inducible gene family which responds to environmental stresses. We have previously shown that GADD45G is a protein that promotes apoptosis of renal tubular cells in response to a nephrotoxic injury. In this study, we show evidence that MAGEH1 interacts with GADD45G and is involved in the induction of nephrotoxin-induced apoptosis of renal tubular cells.

Methods

Primary human renal tubular epithelial (HRE) cells and human kidney 2 (HK-2) cells were used in this study. To produce stable cell lines in which MAGEH1 expression was silenced, HRE cells were transduced with a lentiviral vector encoding a single guide RNA construct targeting the MAGEH1 gene. To knockdown GADD45G expression in HRE cells, a vector containing short hairpin RNA (shRNA) was used. We used short interfering RNAs (siRNA) to achieve transient silencing of genes in HK-2 cells. Recombinant adenoviruses were synthesized to overexpress MAGEH1 and GADD45G proteins. Human protein microarray was used to identify proteins that binds to GADD45G. Co-immunoprecipitation assays were then performed to confirm microarray results. Cell death was induced by cyclosporine A (CsA). Real-time quantitative PCR assay was used to evaluate gene expression levels. The degree of apoptosis and necrosis of cultured cells was evaluated by flow cytometry. Expression levels of caspases were examined using western blot analysis.

Results

We found that GADD45G bound to one protein spotted in the protein microarray, which was subsequently identified as MAGEH1. We confirmed the interaction between GADD45G and MAGEH1 protein using the co-immunoprecipitation assay. MAGEH1 gene expression was not altered by CsA-induced cytotoxic injury, whereas GADD45G gene expression was increased significantly upon CsA treatment. MAGEH1 expression was significantly downregulated in GADD45G knockdown HRE stable cells suggesting that MAGEH1 expression may be dependent on GADD45G expression. CsA-induced apoptosis was significantly reduced in MAGEH1 knockdown HRE stable cells which led to an increased survival of these cells. Similar results were observed in GADD45G knockdown HRE stable cells. Accordingly, CsA-induced apoptosis was significantly decreased in MAGEH1 siRNA and GADD45G siRNA transfected HK-2 cells. CsA-induced activation of caspase-7 and caspase-9 was inhibited in MAGEH1 knockdown HRE stable cells, and similarly in GADD45G knockdown HRE stable cells.

Conclusions

To the best of our knowledge, this is the first study to show that MAGEH1 interacts with GADD45G and that MAGEH1 is involved in caspase-dependent apoptosis of renal tubular cells induced by nephrotoxic drugs.

Protective effect of dapagliflozin against cyclosporine A-induced nephrotoxicity

This study aimed to reveal the possible protective effect of dapagliflozin (DAPA) against acute kidney damage due to cyclosporine A (CsA). Thirty-two mice with an eight-week-old Balb\c albino strain were divided into four groups: control group, CsA group, DAPA group, and CsA + DAPA group. On day 9 of treatment, the animals were decapitated, and bilateral nephrectomy was performed. Oxidative stress and apoptosis were evaluated with caspase-3 activity, total oxidant status (TOS), total antioxidant status (TAS), malondialdehyde (MDA), myeloperoxidase (MPO), B-cell lymphoma-2 (Bcl-2), and Bcl-2-associated X protein (Bax) in the right kidney resection material. The left kidney resection material was evaluated histopathologically. CsA increased caspase-3 activity, Bax, TOS, MDA, TAS, and MPO levels, and the administration of DAPA with CsA significantly reduced this increase in levels (p < 0.001, p < 0.001, p < 0.001, p < 0.001, p < 0.001, and p < 0.001, respectively). CsA decreased Bcl-2 levels, and administration of CsA + DAPA significantly increased Bcl-2 levels compared with only CsA administration (p < 0.001). Additionally, administration of DAPA significantly reduced the histopathological findings (parenchymal inflammation, hyaline cast formation, vacuolization, and lysis of renal tubular cells) caused by CsA. DAPA reduces oxidative stress, apoptosis, and histopathological damage caused by CsA in renal tissue.

Drug interaction profile of TKI alectinib allows effective and safe treatment of ALK+ lung cancer in the kidney transplant recipient

ALK targeting with tyrosine kinase inhibitors (TKIs) is a highly potent treatment option for the therapy of ALK positive non-small cell lung cancer (NSCLC). However, pharmacokinetics of TKIs leads to clinically significant drug interactions, and the interfering co-medication may hamper the anti-cancer therapeutic management. Here, we present for the first time a drug interaction profile of ALK-TKIs, crizotinib and alectinib, and immunosuppressive agent cyclosporine A in kidney transplant recipients diagnosed with ALK+ lung cancer. Based on therapeutic drug monitoring of cyclosporin A plasma level, the dose of cyclosporine A has been adjusted to achieve a safe and effective therapeutic level in terms of both cancer treatment and kidney transplant condition. Particularly, 15 years upon the kidney transplantation, the stage IV lung cancer patient was treated with the 1st-line chemotherapy, the 2nd-line ALK-TKI crizotinib followed by ALK-TKI alectinib. The successful therapy with ALK-TKIs has been continuing for more than 36 months, including the period when the patient was treated for COVID-19 bilateral pneumonia. Hence, the therapy of ALK+ NSCLC with ALK-TKIs in organ transplant recipients treated with cyclosporine A may be feasible and effective.

Calcineurin Inhibitor Toxicity in Solid Organ Transplantation

Calcineurin inhibitors (CNIs) have a substantial role in maintaining immunosuppression after solid organ transplantation (SOT). These drugs have a narrow therapeutic window, and individual doses and drug treatment monitoring are necessary. Still, a substantial proportion of patients suffer from short- or long-term calcineurin inhibitor toxicity (CNT), including kidney function impairment, hypertension, neurotoxicity, and metabolic disturbances. The authors discuss pathophysiology, clinical presentation, and histological features of CNT, with focus on renal manifestations. Furthermore, we elucidate recent and ongoing attempts to reduce the burden of CNT in SOT including CNI-sparing and CNI-free regimens.

Steroid resistant focal segmental glomerulosclerosis: effect of arterial hyalinosis on outcome: single center study

Background. Few data with adequate evidence exists as regards the effect of Cyclosporine (CsA) and mycophenolate mofetil (MMF) on pathological prognostic parameters in patients with steroid resistant focal segmental glomerulosclerosis (FSGS). The purpose of the present study is to compare the effect of cyclosporin and mycophenolate mofetil in addition to steroids on functional and histopathologic renal parameters in patients with steroid resistant FSGS one year after treatment.Material and methods. Thirty-seven adults with primary FSGS patients resistant to steroid therapy consecutively randomized to treatment with either MMF or cyclosporine. Low dose prednisolone added to both groups. Glomerular filtration rate (GFR) and blood pressure (BP) were determined at all examinations and a second renal biopsy was taken 12 months after treatment with either of cyclosporin and mycophenolate mofetil.Results. GFR significantly increased in MMF group p < 0.01 after 6 months and unchanged after 12 months. On the other hand, GFR significantly decrease in CsA group p < 0.001 after 6 months and reduced more after 12 months p < 0.001 compared to base line levels. There was a significant difference of GFR between the 2 groups at 6 months p < 0.001. The extent of proteinuria decreased significantly in CsA group after 12 months p < 0.001. The extent of arteriolar hyalinosis increased significantly in CsA group (0.78 to 1.81 score, p < 0.001) but was unchanged in MMF group (0.93 to 0.96 score), whereas interstitial fibrosis increased to same level in both groups (grade 3).Conclusion. Conversion to MMF in those patients may be superior to CsA as regards GFR after 12 months after treatment in spite of the presence of greater level of protein excretion. The increased arteriolar hyalinosis during CsA treatment most likely results in higher BP compared to MMF treatment in patients with FSGS resistant to steroids.

Economic burden of congenital athymia in the United States for patients receiving supportive care during the first 3 years of life

AIMS

Congenital athymia is an ultra-rare pediatric condition characterized by the lack of thymus in utero and the naïve T cells critical for infection defense and immune regulation. Patients with congenital athymia receive supportive care to minimize and treat infections, autoimmune phenomena, and autologous graft-versus-host disease (aGVHD) manifestations, but historically, die within the first 3 years of life with supportive care only. We estimated the healthcare resource utilization and economic burden of supportive care over patients' first 3 years of life in the United States.

METHODS

A medical chart audit by the treating physician was used to collect patient data from birth to age 3 on clinical manifestations associated with congenital athymia (clinical manifestations due to underlying syndromic conditions excluded). Using costs and charges from publicly available sources, the total economic burden of direct medical costs and charges for the first 3 years of life (considered "lifetime" for patients receiving supportive care) and differences in economic burden between patients with higher and lower inpatient hospitalization durations were estimated.

RESULTS

All patients (n = 10) experienced frequent infections and aGVHD manifestations; 40% experienced ≥1 episode of sepsis, and 20% had recurrent sepsis episodes annually. The estimated mean 3-year economic burden per patient was US$5,534,121 (2020 US dollars). The annual mean inpatient hospitalization duration was 150.6 days. Inpatient room charges accounted for 79% of the economic burden, reflecting the high costs of specialized care settings required to prevent infection, including isolation. Patients with high inpatient utilization (n = 5; annual mean inpatient hospitalization duration, 289.6 days) had an estimated 3-year economic burden of US$9,926,229.

LIMITATIONS

The total economic burden may not be adequately represented due to underestimation of some direct costs or overestimation of others.

CONCLUSIONS

Current treatment of patients with congenital athymia (supportive care) presents a high economic burden to the healthcare system.

Targeting Calcium Release-activated Calcium Channel Is Not Sufficient to Prevent Rejection in Nonhuman Primate Kidney Transplantation

BACKGROUND

Calcineurin inhibitors successfully control rejection of transplanted organs but also cause nephrotoxicity. This study, using a rhesus monkey renal transplantation model, sought to determine the applicability of a new immunomodulatory drug inhibiting the store-operated calcium release-activated calcium channel of lymphocytes to control transplant rejection without nephrotoxicity.

METHODS

Animals underwent kidney transplantation and were treated with tacrolimus alone (n = 3), a CRACM1 inhibitor (PRCL-02) (n = 6) alone, or with initial tacrolimus monotherapy followed by gradual conversion at 3 weeks to PRCL-02 alone (n = 3). PRCL-02 was administered via a surgically inserted gastrostomy tube BID.

RESULTS

Dose-related drug exposure in monkeys was established and renal transplants were then performed using PRCL-02 monotherapy. Oral dosing of PRCL-02 was well tolerated and resulted in suppressed T-cell proliferation in in vitro MLR comparable to animals in the tacrolimus control arm. Animals receiving tacrolimus monotherapy were e on day 100 without rejection. PRCL-02 monotherapy only marginally prolonged graft survival (MST = 13.16 d; group 2) compared with untreated controls. Animals treated initially with tacrolimus and converted to PRCL-02 monotherapy had a mean graft survival of 35.3 days which was prolonged compared with PRCL-02 monotherapy but not compared with the tacrolimus-treated group. Pharmacokinetic studies showed inconsistent drug exposures despite attempts to adjust dose and exposure which may have contributed to the rejections.

CONCLUSIONS

We conclude that, in this nonhuman primate model of kidney transplantation, PRCL-02 demonstrated evidence of in vivo immunosuppressive activity but was inferior to tacrolimus treatment with respect to suppressing immune transplant rejection.

The Management of Erythrodermic Psoriasis Complicated by Cyclosporine

We present a 64-year-old woman with past medical history of psoriasis and alcoholic liver cirrhosis who presented with a diffuse, erythematous, and scaly rash. Pertinent medications included topical triamcinolone 0.1% cream. She was started on oral prednisone 40 milligrams (mg) and oral cyclosporine 150 mg daily and was continued on topical triamcinolone. After the administration of two doses of this regimen, the serum creatinine increased to 1.76 mg/dL, and serum potassium increased to 6.7 mEq/L. The serum creatinine continued to uptrend to 2.42 mg/dL, and the glomerular filtration rate (GFR) decreased to 20 mL/min. The patient was emergently hemodialyzed. The patient was placed on an extended steroid taper, alleviating the psoriatic rash. However, the patient needed to be placed on a steroid-sparing regimen. Because of its rarity and ensuing complications, erythrodermic psoriasis must be identified and managed promptly. Cyclosporine is currently the first-line treatment. However, initiation of this therapy in our patient resulted in an acute kidney injury (AKI). Even though a steroid taper assisted in alleviating erythroderma, a steroid-sparing regimen needed to be started. This led to the consideration of alternate methods of therapy for further management of erythrodermic psoriasis with renal impairment.

Immunosuppression therapy is effective for both acquired tumor-associated and primary pure red cell aplasia: a match pair case-control study

No agreement had been reached on the treatment of patients with pure red cell aplasia (PRCA) secondary to indolent malignancies. Data was collected from patients with acquired PRCA from May, 2014 to May, 2018 in Peking Union Medical College Hospital. Tumor-associated PRCA and primary PRCA patients were matched at a ratio of 1:2 with compatible baseline characteristics. All patients had been treated with CsA or sirolimus for at least 6 months with the efficacy and adverse events recorded. Twelve tumor-associated PRCA patients (3 thymoma, 8 lymphoproliferative disorders, and 1 smoldering multiple myeloma) with stable underling disease and 24 acquired primary PRCA patients were selected. 83.3% tumor-associated PRCA patients and 100% primary PRCA patients (P = 0.436) responded to immunosuppression therapy (IST) at a median of 2.5 and 3.5 months (P = 0.137), respectively. No different was found in side effects. The ORR at the end of a median of 21.5-month follow-up was 75% and 70.8% (P = 0.795), respectively. No tumor progression was reported except one secondary patient had lymphoma relapse after 2 years of IST and was given chemotherapy again. These results suggested IST had similar effect, safety on patients with tumor-associated, and primary PRCA patients when the tumors were stable.

Apocynin and catalase prevent hypertension and kidney injury in Cyclosporine A-induced nephrotoxicity in rats

Oxidative stress is involved in the pathogenesis of a number of diseases including hypertension and renal failure. There is enhanced expression of nicotinamide adenine dinucleotide (NADPH oxidase) and therefore production of hydrogen peroxide (H2O2) during renal disease progression. This study investigated the effect of apocynin, an NADPH oxidase inhibitor and catalase, an H2O2 scavenger on Cyclosporine A (CsA) nephrotoxicity in Wistar-Kyoto rats. Rats received CsA (25mg/kg/day via gavage) and were assigned to vehicle, apocynin (2.5mmol/L p.o.), catalase (10,000U/kg/day i.p.) or apocynin plus catalase for 14 days. Renal functional and hemodynamic parameters were measured every week, and kidneys were harvested at the end of the study for histological and NADPH oxidase 4 (NOX4) assessment. Oxidative stress markers and blood urea nitrogen (BUN) were measured. CsA rats had higher plasma malondialdehyde (by 340%) and BUN (by 125%), but lower superoxide dismutase and total antioxidant capacity (by 40%, all P<0.05) compared to control. CsA increased blood pressure (by 46mmHg) and decreased creatinine clearance (by 49%, all P<0.05). Treatment of CsA rats with apocynin, catalase, and their combination decreased blood pressure to near control values (all P<0.05). NOX4 mRNA activity was higher in the renal tissue of CsA rats by approximately 63% (P<0.05) compared to controls but was reduced in apocynin (by 64%), catalase (by 33%) and combined treatment with apocynin and catalase (by 84%) compared to untreated CsA rats. Treatment of CsA rats with apocynin, catalase, and their combination prevented hypertension and restored renal functional parameters and tissue Nox4 expression in this model. NADPH inhibition and H2O2 scavenging is an important therapeutic strategy during CsA nephrotoxicity and hypertension.

Successful sirolimus treatment of patients with pure red cell aplasia complicated with renal insufficiency

For patients with pure red cell aplasia (PRCA), cyclosporine (CsA) is the first line therapy. Occasionally, some patients who suffer from renal insufficiency cannot tolerate CsA. To explore the efficacy and tolerance of sirolimus treatment for those patients, twelve PRCA patients with renal insufficiency from May 2014 to May 2018 in Peking Union Medical College Hospital were enrolled, treated with sirolimus, and followed up at the median time of 16 (10-50) months. Eleven patients (91.7%) responded to sirolimus, with 58.3% complete response (CR) and 41.7% partial response (PR). The median time to achieve the optimum effect was 4 (1-7) months. The serum creatinine level remained stable or even reduced during the treatment period for eleven patients. Seven patients (58.3%) reported adverse events during sirolimus therapy, including increased blood glucose, infection, skin rash, elevated triglyceride or total cholesterol, and elevated serum creatinine compared with baseline. No treatment-related death was noticed during the follow-up time. Three patients relapsed with an overall response rate of 75.0% at 1 year. These results suggested that sirolimus was effective and tolerable for patients with PRCA complicated with renal insufficiency.

Delineating a role for the mitochondrial permeability transition pore in diabetic kidney disease by targeting cyclophilin D

Mitochondrial stress has been widely observed in diabetic kidney disease (DKD). Cyclophilin D (CypD) is a functional component of the mitochondrial permeability transition pore (mPTP) which allows the exchange of ions and solutes between the mitochondrial matrix to induce mitochondrial swelling and activation of cell death pathways. CypD has been successfully targeted in other disease contexts to improve mitochondrial function and reduced pathology. Two approaches were used to elucidate the role of CypD and the mPTP in DKD. Firstly, mice with a deletion of the gene encoding CypD (Ppif-/-) were rendered diabetic with streptozotocin (STZ) and followed for 24 weeks. Secondly, Alisporivir, a CypD inhibitor was administered to the db/db mouse model (5 mg/kg/day oral gavage for 16 weeks). Ppif-/- mice were not protected against diabetes-induced albuminuria and had greater glomerulosclerosis than their WT diabetic littermates. Renal hyperfiltration was lower in diabetic Ppif-/- as compared with WT mice. Similarly, Alisporivir did not improve renal function nor pathology in db/db mice as assessed by no change in albuminuria, KIM-1 excretion and glomerulosclerosis. Db/db mice exhibited changes in mitochondrial function, including elevated respiratory control ratio (RCR), reduced mitochondrial H2O2 generation and increased proximal tubular mitochondrial volume, but these were unaffected by Alisporivir treatment. Taken together, these studies indicate that CypD has a complex role in DKD and direct targeting of this component of the mPTP will likely not improve renal outcomes.

Safety of systemic therapy for noninfectious uveitis

Introduction: The treatment strategies for noninfectious uveitis (NIU) aim to achieve disease remission, prevention of recurrences, and preserving vision, while minimizing the side effects associated with the therapies used.Areas covered: The index review aims to provide a detailed overview of the adverse events and safety parameters associated with the systemic therapies for the management of the NIU.Expert opinion: Despite being the cornerstone of management of acute cases of NIU, long-term corticosteroid use is associated with multi-system side effects, requiring the use of steroid-sparing agents. Adalimumab was recently approved by the FDA for the management of NIU based on the results of VISUAL studies. Similarly, newer drugs targeting various aspects of the inflammatory cascade are being developed. However, until we completely understand the molecular pathways of the inflammatory diseases, the therapeutic profile of these newer agents needs to be broad enough to suppress inflammatory cascade and narrow enough to spare normal cellular processes. Another strategy that has shown some potential in decreasing the systemic side effects is to provide local drug delivery. Therefore, the future of management of NIU is very bright with many novel therapeutic agents and strategies of drug delivery on the horizon.

Melatonin ameliorates the drug induced nephrotoxicity: Molecular insights

BACKGROUND

Drug-induced nephrotoxicity is a frequent adverse event that can lead to acute or chronic kidney disease and increase the healthcare expenditure. It has high morbidity and mortality incidence in 40-70% of renal injuries and accounts for 66% cases of renal failure in elderly population.

OBJECTIVE

Amelioration of drug-induced nephrotoxicity has been long soughed to improve the effectiveness of therapeutic drugs. This study was conducted to review the melatonin potential to prevent the pathogenesis of nephrotoxicity induced by important nephrotoxic drugs.

METHODS

We analyzed the relevant studies indexed in Pubmed, Medline, Scielo and Web of science to explain the molecular improvements following melatonin co-administration with special attention to oxidative stress, inflammation and apoptosis as key players of drug-induced nephrotoxicity.

RESULTS

A robust consensus among researchers of these studies suggested that melatonin efficiently eradicate the chain reaction of free radical production and induced the endogenous antioxidant enzymes which attenuate the lipid peroxidation of cellular membranes and subcellular oxidative stress in drug-induced nephrotoxicity. This agreement was further supported by the melatonin role in disintegration of inflammatory process through inhibition of principle pro-inflammatory or apoptotic cytokines such as TNF-α and NF-κB. These studies highlighted that alleviation of drug-induced renal toxicity is a function of melatonin potential to down regulate the cellular inflammatory and oxidative injury process and to stimulate the cellular repair or defensive mechanisms.

CONCLUSION

The comprehensive nephroprotection and safer profile suggests the melatonin to be a useful adjunct to improve the safety of nephrotoxic drugs.

Impact of calcineurin inhibitors on rat glioma cells viability

Background

Although kidney transplantation outcomes have improved dramatically after using calcineurin inhibitors (CNIs), CNI toxicity continues to be reported and the mechanism remains uncertain. Here, we investigated the neurotoxicity of CNIs by focusing on the viability of glioma cells.

Methods

Glioma cells were treated with several concentrations of CNIs for 24 hours at 37℃ and their cell viability was evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay.

Results

Exposure to 0, 0.25, 0.5, 2.5, 5.0, and 10.0 mM concentrations respectively showed 100%, 64.3%, 61.3%, 68.1%, 62.4%, and 68.6% cell viability for cyclosporine and 100%, 38.6%, 40.8%, 43.7%, 37.8%, and 43.0% for tacrolimus. The direct toxic effect of tacrolimus on glioma cell viability was stronger than that of cyclosporine at the same concentration.

Conclusion

CNIs can cause neurological side effects by directly exerting cytotoxic effects on brain cells. Therefore, we should carefully monitor the neurologic symptoms and level of CNIs in kidney transplant patients.

Antitumor pharmacotherapy of colorectal cancer in kidney transplant recipients

Renal transplantation has become the sole most preferred therapy modality for end-stage renal disease patients. The growing tendency for renal transplants, and prolonged survival of renal recipients, have resulted in a certain number of post-transplant colorectal cancer patients. Antitumor pharmacotherapy in these patients is a dilemma. Substantial impediments such as carcinogenesis of immunosuppressive drugs (ISDs), drug interaction between ISDs and anticancer drugs, and toxicity of anticancer drugs exist. However, experience of antitumor pharmacotherapy in these patients is limited, and the potential risks and benefits have not been reviewed systematically. This review evaluates the potential impediments, summarizes current experience, and provides potential antitumor strategies, including adjuvant, palliative, and subsequent regimens. Moreover, special pharmaceutical care, such as ISDs therapeutic drug monitoring, metabolic enzymes genotype, and drug interaction, are also highlighted.

Tacrolimus: 20 years of use in adult kidney transplantation. What we should know about its nephrotoxicity

Tacrolimus (or FK506), a calcineurin inhibitor (CNI) introduced in field of transplantation in the 1990s, is the cornerstone of most immunosuppressive regimens in solid organ transplantation. Its use has revolutionized the future of kidney transplantation (KT) and has been associated with better graft survival, a lower incidence of rejection, and improved drug tolerance with fewer side effects compared to cyclosporine. However, its monitoring remains complicated and underexposure increases the risk of rejection, whereas overexposure increases the risk of adverse effects, primarily nephrotoxicity, neurotoxicity, infections, malignancies, diabetes, and gastrointestinal complaints. Tacrolimus nephrotoxicity can be nonreversible and can lead to kidney graft loss, and its diagnosis is therefore best made with reference to the clinical context and after exclusion of other causes of graft dysfunction. Many factors contribute to its development including: systemic levels of tacrolimus; local renal exposure to tacrolimus; exposure to metabolites of tacrolimus; local susceptibility factors for CNI nephrotoxicity independent of systemic or local tacrolimus levels, such as the age of a kidney; local renal P-glycoprotein, local intestinal and hepatic cytochrome P450A3, and renin angiotensin system activation. The aim of this review is to describe the pharmacokinetics, pharmacodynamics, and mechanisms of acute and chronic tacrolimus nephrotoxicity in adult KT.

Timing of quality of life improvements in psoriatic patients treated with different systemic therapies

Psoriasis impacts the quality of life (QoL) by disrupting overall health and social life. Thus, the use of a QoL evaluation item is crucial in assessing a therapeutic regimen. Also, faster improvements in QoL lead to better patient compliance, but very few studies compare psoriasis traditional and biologic therapies timing. To evaluate how much different systemic therapies improve disease severity and QoL, a retrospective analysis was performed on 56 patients. Subjects were administered different drugs and their vital statistics, psoriasis area severity index (PASI) and PSOdisk were collected at baseline and after 30 days. We found a moderate correlation between PASI and PSOdisk score with (r): .62. In terms of clinical scores improvement after 30 days, Ustekinumab turned out to be the fastest therapy available, while cyclosporine, among the systemic therapies available, appeared as highly competitive if not better than other biologic therapies.

[Renal and Urinary Manifestations of Inflammatory Bowel Disease]

The incidence of inflammatory bowel disease (IBD) is increasing rapidly and extra-intestinal manifestations in IBD are also increasing. The prevalence of renal and urinary involvement in IBD ranges from 4-23%. Nephrolithiasis is the most common urinary complication in IBD patients. Parenchymal renal disease is rare but has been well documented and presents most commonly as glomerulonephritis or tubulointerstitial nephritis. The overall morbidity of IBD-related renal manifestations is significant. Therefore, a high index of clinical suspicion and optimal monitoring of the renal function are needed for the early diagnosis and prevention of IBD-related renal manifestations and complications.

Prevention of complications from use of conventional immunosuppressants: a critical review

Synthetic immunosuppressive drugs are largely used in immune-related renal diseases and in kidney transplantation. Most of these drugs have a low therapeutic index (the ratio that compares the blood concentration at which a drug becomes toxic and the concentration at which the drug is effective), which means that the drug should be dosed carefully and the patient monitored frequently. In this review, we consider the categories of synthetic immunosuppressive agents more frequently and conventionally used in clinical nephrology: glucocorticoids, Aalkylating agents (cyclophosphamide, chlorambucil), purine synthesis inhibitors (azathioprine, mycophenolate salts) and calcineurin inhibitors (cyclosporine, tacrolimus). For each category the possible side effects will be reviewed, the general and specific measures to prevent or treat the adverse events will be suggested, and the more common mistakes that may increase the risk of toxicity will be described. However, the efficacy and safety of immunosuppressive agents depend not only on the pharmacologic characteristics of single drugs but can be influenced also by the clinical condition and genetic characteristics of the patient, by the typology and severity of the underlying disease and by the interaction with other concomitantly used drugs.

Growth arrest and DNA damage 45γ is required for caspase-dependent renal tubular cell apoptosis

BACKGROUND

Growth Arrest and DNA Damage 45γ (GADD45γ) is a member of the DNA damage-inducible gene family which responds to environmental stresses. Apoptosis is a critical mode of renal tubular cell death in nephrotoxin-induced acute kidney injury. In this study, we investigated the role of GADD45γ in renal tubular cell apoptosis induced by nephrotoxic drugs.

METHODS

Primary human renal tubular epithelial (HRE) cells were used in this study. To derive stable cell lines in which GADD45γ expression was silenced, HRE cells were transduced with a plasmid encoding GADD45γ-specific shRNA. The recombinant adenovirus containing the GADD45γ gene was synthesized to overexpress GADD45γ protein. Cell death was induced by cisplatin and cyclosporine A (CsA). To prevent apoptotic cell death, pan-caspase inhibitor ZVAD-FMK was used. To prevent non-apoptotic cell death, necrostatin-1 and ferrostatin-1 were used. The degree of apoptosis and necrosis of cultured cells were evaluated by flow cytometry.

RESULTS

Expression of the GADD45γ gene was significantly upregulated in response to treatment with CsA and cisplatin. Apoptosis and necrosis induced by these drugs were significantly reduced by silencing of GADD45γ, and significantly augmented by the overexpression of GADD45γ. The activation of caspase-3 and caspase-7 as well as caspase-9 induced by cisplatin or CsA was reduced by silencing of GADD45γ, and was augmented by the overexpression of GADD45γ, indicating that caspase activation is dependent on the expression of GADD45γ. ZVAD-FMK significantly inhibited apoptosis induced by cisplatin or CsA, indicating a role of caspases in mediating apoptotic cell death. ZVAD-FMK was effective to prevent necrosis as well, indicating that the observed necrosis was a secondary event following apoptosis at least in part.

CONCLUSIONS

To our knowledge, this is the first study to show that GADD45γ is required for the caspase-dependent apoptosis of renal tubular cells induced by nephrotoxic drugs.

Biomarkers for individualized dosage adjustments in immunosuppressive therapy using calcineurin inhibitors after organ transplantation

Calcineurin inhibitors (CNIs), such as cyclosporine A and tacrolimus, are widely used immunosuppressive agents for the prevention of post-transplantation rejection and have improved 1-year graft survival rates by up to 90%. However, CNIs can induce severe reactions, such as acute or chronic allograft nephropathy, hypertension, and neurotoxicity. Because CNIs have varied bioavailabilities, narrow therapeutic ranges, and individual propensities for toxic effects, therapeutic drug monitoring is necessary for all CNIs. Identifying the genetic polymorphisms in drug-metabolizing enzymes will help to determine personalized dosage regimens for CNIs, as CNIs are substrates for CYP3A5 and P-glycoprotein (P-gp, MDR1). CNIs are often concomitantly administered with voriconazole or proton pump inhibitors (PPIs), giving rise to drug interaction problems. Voriconazole and PPIs can increase the blood concentrations of CNIs, and both are primarily metabolized by CYP2C19. Thus, it is expected that interactions between CNIs and voriconazole or PPI would be affected by CYP2C19 and CYP3A5 polymorphisms. CNI-induced acute kidney injury (AKI) is a serious complication of transplantations. Neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule 1 (KIM-1) are noninvasive urinary biomarkers that are believed to be highly sensitive to CNI-induced AKI. In this article, we review the adverse events and pharmacokinetics of CNIs and the biomarkers related to CNIs, including CYP3A5, CYP2C19, MDR1, NGAL, and KIM-1. We hope that these data will help to identify the optimal biomarkers for monitoring CNI-based immunosuppressive therapy after organ transplantation.

Simultaneous Determination of Tacrolimus and Cyclosporine A in Whole Blood by Ultrafast LC-MS/MS

Numerous methods for the measurement of tacrolimus and cyclosporine A involving traditional liquid chromatography tandem mass spectrometry (LC-MS/MS) have previously been described. The majority of these methods use solid-phase extraction, liquid-liquid extraction, or protein precipitation extraction with instrument run times greater than 15 s per sample. Continued demands in clinical labs for greater efficiency and throughput have put increased stress on traditional technologies such as high-performance liquid chromatography-ultraviolet detection (HPLC-UV) and traditional LC-MS/MS. As an improvement to the existing methods, we describe a sensitive ultrafast LC-MS/MS with run times of less than 15 s per sample.

The TWEAK/Fn14 pathway is required for calcineurin inhibitor toxicity of the kidneys

Calcineurin inhibitor toxicity (CNT) is a frequent occurrence in transplanted renal grafts and autochthone kidneys from patients undergoing long-term treatment with calcineurin inhibitors, notably cyclosporin A (CsA) and tacrolimus. Here, we show an indispensable role of the tumor necrosis factor superfamily (TNFS) molecule TNF-related weak inducer of apoptosis (TWEAK) (TNFSF12) in the pathogenesis of acute CNT lesions in mice. A deficiency in TWEAK resulted in limited tubulotoxicity after CsA exposure, which correlated with diminished expression of inflammatory cytokines and reduced intraparenchymal infiltration with immune cells. We further identified tubular epithelial cells of the kidney as major targets of CsA activity and found that Fn14 (tumor necrosis factor receptor superfamily 12A), the receptor for TWEAK, is a highly CsA-inducible gene in these cells. Correlating with this, CsA pretreatment sensitized tubular epithelial cells specifically to the pro-inflammatory activities of recombinant TWEAK in vitro. Moreover, injection of rTWEAK alone into mice induced moderate disease similar to CsA, and rTWEAK combined with CsA resulted in synergistic nephrotoxicity. These findings support the importance of tubular epithelial cells as cellular targets of CsA toxicity and introduce TWEAK as a critical contributor to CNT pathogenesis.

Reduced Tacrolimus Trough Level Is Reflected by Estimated Glomerular Filtration Rate (eGFR) Changes in Stable Renal Transplantation Recipients: Results of the OPTIMUM Phase 3 Randomized Controlled Study

Background

Minimizing the tacrolimus dosage in patients with stable allograft function needs further investigation.

Material/Methods

We performed an open-label, randomized, controlled study from 2010 to 2016 in 7 tertiary teaching hospitals in Korea and enrolled 345 kidney transplant recipients with a stable graft status. The study group received reduced-dose tacrolimus, 1080–1440 mg/day of enteric-coated mycophenolate sodium (EC-MPS), and corticosteroids. The control group received the standard tacrolimus dosage and 540–720 mg/day of EC-MPS with steroids. The primary endpoint was the mean estimated glomerular filtration rate (eGFR) and change in the eGFR at 12 months after randomization.

Results

The mean tacrolimus trough level of the study group was 4.51±1.62 ng/mL, which was lower than that of the control group, at 6.75±2.82 ng/mL (P<0.001). The primary endpoint was better in the study group in terms of change in eGFR (P<0.001). The month 12 eGFRs were 73.6±28.4 and 68.3±18.1 mL/min/1.73 m² in the study and the control groups, respectively, but the difference did not reach statistical significance (P=0.07). The incidence of adverse events was similar between the study and the control groups.

Conclusions

Minimizing tacrolimus to a trough level below 5 ng/mL combined with conventional EC-MPS can be considered in patients with a steady follow-up, as it was associated with small benefits in the changes of the eGFR (Clinicaltrials.gov number: NCT01159080).

Molecular basis of the counteraction by calcium channel blockers of cyclosporine nephrotoxicity

Nephrotoxicity is a serious side effect for the immunosuppressant drug cyclosporine A(CSA). In this study, we tested the hypothesis that administration of calcium channel blockers such as verapamil or nifedipine ameliorates renal CSA-induced renal dysfunction. Furthermore, our study investigates the roles of inflammatory, oxidative, and fibrotic pathways in CSA-induced renal dysfunction. Six groups of male rats ( n = 6/group) were used and received one of the following treatments for seven consecutive days: vehicle (Cremophor EL ip), CSA (25 mg·kg^-1·day^-1 ip), verapamil (2 mg·kg^-1·day^-1 ip), nifedipine (3 mg·kg^-1·day^-1 ip), CSA in the presence or absence of either verapamil, or nifedipine. Biochemical and histomorphometric analyses showed that rats treated with CSA exhibited clear signs of nephrotoxicity that included 1) proteinuria and elevations in serum creatinine and blood urea nitrogen, 2) mesangial expansion, 3) increases in glomerular and tubular type IV collagen expression, and 4) increases in the glomerulosclerosis and tubulointerstitial fibrosis indices. Although the single administration of nifedipine or verapamil had no significant effect on renal pathology, or its biochemical and physiological function, the concurrent use of either calcium channel blockers significantly and equipotently ameliorated the biochemical, morphological, and functional derangements caused by CSA. More importantly, we report that the oxidative (reactive oxygen species production, NADPH-oxidase activity, and dual oxidase 1/2 levels), fibrotic (transforming growth factor-β1 expression), and inflammatory (NF-κB expression) manifestations of renal toxicity induced by CSA were significantly reversed upon administration of nifedipine or verapamil. Together, these results highlight the efficacy of calcium channel-blocking agents in attenuating CSA-induced nephrotoxicity and predisposing biochemical and molecular machineries.

Possible protective effect of the algae spirulina against nephrotoxicity induced by cyclosporine A and/or gamma radiation in rats

The present study was conducted to evaluate the possible protective role of the algae spirulina (Sp) against nephrotoxicity and oxidative stress which are the main secondary effects induced by the immunosuppressant drug CSA and/or ionizing radiation. In this study, male rats were given Sp (1 g/kg) either for 15 days before irradiation (6.5 Gy) or 5 days before and 10 days concomitant with CSA (25 mg/kg). Markers used to assess renal injury included serum creatinine, urea, glucose, albumin, protein, and lipid profile as well as kidney content of reduced glutathione (GSH); lipid peroxidation (thiobarbituric acid reactive substances (TBARS)); nitrite and superoxide dismutase (SOD) activity. In addition, some trace elements (Zn and Mg) were estimated in kidney. Apoptosis was assessed by immunohistochemical estimation of caspase-3 expression in addition to histopathological examination. Results revealed that gamma radiation and/or CSA induced elevation in urea, creatinine, lipids, and glucose while decreasing albumin and protein levels. There was a noticeable increase in kidney content of GSH, TBARS, and nitrite. Meanwhile, profound decrease in kidney SOD activity was observed. Treatment with Sp significantly reversed the changes induced by CSA and/or gamma radiation in renal function tests. Spirulina also ameliorated kidney oxidative stress through decreasing GSH, TBARS, and nitrite kidney content while increasing SOD activity. Histopathological examination further confirmed Sp protective efficacy. Moreover, kidney caspase-3 expression that was triggered by CSA and/or gamma radiation was decreased. In conclusion, spirulina can be regarded as a promising renoprotective natural agent against renal injury induced by CSA and/or gamma radiation.

Risk factors for calcineurin inhibitor nephrotoxicity after renal transplantation: a systematic review and meta-analysis

Background

Nephrotoxicity of calcineurin inhibitors (CNIs) is the major concern for long-term allograft survival despite its predominant role in current immunosuppressive regime after renal transplantation. CNI nephrotoxicity is multifactorial with demographic, environmental, and pharmacogenetic flexibility, whereas studies indicating risk factors for CNI nephrotoxicity obtained incomplete or conflicting results.

Methods

A systematic review and meta-analysis of risk factors for CNI nephrotoxicity was performed on all retrieved studies through a comprehensive research of network database. Data were analyzed by Review Manager 5.2 with heterogeneity assessed using the Cochrane Q and I² tests. CNI nephrotoxicity was primarily indicated with protocol biopsy or index-based clinical diagnosis, and the secondary outcome was defined as delayed graft function.

Results

Twelve observational studies containing a total of 2,849 cases were identified. Donor age (odds ratio [OR], 1.01; 95% CI, 1.01-1.03; p=0.02), recipient zero-time arteriosclerosis (OR, 1.44; 95% CI, 1.04-1.99; p=0.03), and CYP3A5*3/*3 genotype (OR, 2.80; 95% CI, 2.63-2.98; p=0.00) were confirmed as risk factors for CNI nephrotoxicity. Subgroup and sensitivity analysis claimed donor age as a significant contributor in Asian and Caucasian areas.

Conclusion

Older donor age, recipient zero-time arteriosclerosis, and CYP3A5*3/*3 genotype might add up the risk for CNI nephrotoxicity, which could be interpreted into a robust biomarker system.