Calcineurin Inhibitors Research Articles

Treatment with mTOR Inhibitors as primary immunosuppression after combined heart and kidney transplantation

Abstract Background It has been hypothesized that combined heart and kidney transplantation (HKT) may lead to immune modulation and attenuation of cardiac allograft vasculopathy (CAV) progression. Sirolimus (SRL) has been shown to mitigate the progression of CAV and confer renal protection. With the increasing use of SRL as primary immunosuppression in heart transplant (HT) recipients, the effect of HKT on CAV progression compared to HT-only remains undetermined. Purpose We sought to investigate the patterns of conversion from calcineurin inhibitors (CNI) to SRL, and its impact on CAV progression and outcomes in HKT compared to HT-only in a cohort with frequent use of SRL as primary immunosuppression. Methods A cohort of 302 patients who underwent either HT only (n=262) or combined HKT (n=40) was analyzed. CAV progression was assessed by measuring the delta (Δ) annual change in plaque volume (PV) normalized to vessel length (PV/VL in mm3/mm) and plaque index (PI) (%) (calculated as the PV to VV ratio) between baseline and last follow-up coronary intravenous ultrasound (IVUS). Clinical adverse outcomes included all-cause death and CAV-associated events. Secondary outcomes included differences in renal function and incidence of SRL-associated proteinuria (defined as Δ urine protein ≥300 mg/24 h at 1 year after conversion to SRL) between HT-only and HKT recipients. Results Overall, 217 (72%) patients were converted from CNI to SRL as primary immunosuppression. HT recipients were more likely to be converted to SRL than combined HKT recipients (74% vs. 55%, P=0.01). HKT was associated with significantly higher ΔPV/VL (P=0.01) and a trend toward a higher ΔPI (P=0.06) than HT-only, but this association was markedly attenuated after adjustment to SRL conversion. HKT was associated with similar risk of death (adjusted hazard ratio [HR] 0.69, 95%CI: 0.28-1.71, P=0.43) and CAV-related events (adjusted HR 0.83, 95% CI: 0.30-2.31, P=0.72). Conversion to SRL was significantly associated with decreased risk of death and CAV-related events in the overall cohort. This association was not modified by the type of organ transplantation (Pinteraction=NS), and without a significant effect on estimated glomerular filtration rate (eGFR) or proteinuria. Conclusions HKT recipients compared to HT-only were less likely to be converted from CNI to SRL-based immunosuppression and had a greater CAV progression but without significant differences in all-cause mortality or CAV-related events. The clinical benefit and safety of conversion to SRL appeared similar in the HKT and isolated HT cohorts.

Optimization and Protection of Kidney Health in Liver Transplant Recipients: Intra- and Postoperative Approaches.

Postoperative acute kidney injury after liver transplant (LT) has long-term implications for kidney health. LT recipients are at risk of acute kidney injury due to a number of factors related to the donor liver, intraoperative factors including surgical technique, as well as recipient factors, such as pre-LT kidney function and postoperative complications. This review discusses these factors in detail and their impact on posttransplant kidney function. Long-term risk factors such as calcineurin inhibitors have also been discussed. Additionally, the impact of liver allocation policies on pre- and post-LT kidney health is discussed.

Psoriasis: Sind Geschlechtsunterschiede bedeutsam?

Background: Psoriasis is a common chronic inflammatory skin disease with an exceptionally high burden for women. Objective: Sex-dependent differences in disease manifestation, severity, treatment choices, subjective disease perception, and the impact on quality of life and risk factors are described and comprehensively discussed. Methods: A literature search was conducted using MEDLINE (PubMed) and the Cochrane Library for systematic reviews to investigate the challenges in treating women with psoriasis. Results and conclusions: : The incidence, prevalence, and manifestation of psoriasis of the skin are similar between different sexes. Genetic and environmental factors such as obesity and metabolic syndrome are risk factors and are not equally relevant or pronounced in women and men. Overall, women have a lower disease severity measured by the Psoriasis Area Severity Index, which is associated with a higher impairment of their life quality measured by the Dermatology Life Quality Index compared with men. In addition, women with psoriasis are more likely to have depression than men. Hormonal factors affect psoriasis, with a correlation of high estrogen levels and improvement of psoriasis. Data regarding differences in prescribing patterns of systemic treatments and the severity of psoriasis are not entirely consistent. Registry studies show that men tend to have more severe psoriasis and, in some cases, are prescribed systemic therapies more frequently. Women tend to respond better to systemic treatments and to experience more adverse events. Treatment options are the same for both sexes, except during pregnancy and lactation. Various treatment options are contraindicated due to fear of fetal or neonate harm and lack of data. Topical steroids can be prescribed with a high degree of safety during pregnancy. For other topical therapies (calcineurin inhibitors and vitamin D analogs), no studies of adverse effects in pregnancy are available, and safety data mainly stem from studies examining effects after systemic administration. Antitumor necrosis factor monoclonal antibodies (except for certolizumab pegol) have been associated with a possible increased risk of preterm birth, low gestational age, and cesarean deliveries. Prospective data on the safety of biologics other than antitumor necrosis factor-alpha antibodies to accurately assess whether novel biologics (eg, anti-interleukin 17, 12/23, 23) can be used for systemic therapy in pregnancy are lacking or currently being conducted. © 2022 The Authors. Published by Wolters Kluwer Health, Inc. on behalf of Women’s Dermatologic Society.

Decreasing IV magnesium infusion time to improve delivery of patient care.

Hypomagnesemia is a common issue in patients with cancer due to magnesium wasting drugs like calcineurin inhibitors, chemotherapy sides effects such as diarrhea, and poor oral intake. Historically, magnesium has been given over prolonged infusions due to concern for rapid elimination of magnesium when large doses are administered. At UW Health, magnesium was given at a rate of 1g/60 min. A prolonged infusion rate often creates logistical issues including limited IV access, incompatibility concerns and increased chair time. The purpose of this project is to increase the infusion rate of IV magnesium without compromising therapeutic repletion, benefit, and safety. The magnesium infusion rate was increased to the following rates: 4g/60 min, 2g/30 min, 1g/15 min. The primary outcome is the grams of IV magnesium replaced per outpatient visit between the pre-intervention (prolonged) and post-intervention (rapid) groups. Secondary outcomes include assessment of differences in chair time between groups and total incidence of critical magnesium lab values. There was no statistically significant difference in magnesium requirements per outpatient visit between a prolonged and rapid magnesium infusion rate (2.18g vs 2.15g; p = 0.49). Additionally, there was no difference in number of outpatient visits (3 vs 3; p = 1). The average chair time was decreased by 110 min per outpatient encounter between the prolonged and rapid magnesium infusion rate, which was determined to be clinically and statistically significant. This study suggests that there is no difference in magnesium requirements between a rapid or prolonged magnesium infusion in both solid and liquid tumor patients.

Treatment Modalities for Genital Lichen Sclerosus: A Systematic Review

Background: Lichen sclerosus (LS) is a chronic, inflammatory dermatosis that affects both genital and extragenital sites. It is often difficult to treat and may lead to a variety of complications if not adequately treated. The mainstay of therapy involves topical corticosteroids, topical calcineurin inhibitors, and systemic immunomodulators. Although a variety of topical, oral, and procedural therapies are available, a review comparing relative efficacy is lacking. To this end, this systematic review aimed to summarize the literature regarding treatment modalities and their respective response rates in patients with genital LS. Methods: A literature search was conducted in accordance with PRISMA guidelines. Results: This review qualitatively summarizes information from 31 randomized controlled trials, encapsulating a total of 1507 patients with LS, the majority of which were female (n = 1374, 91%). Topical corticosteroids, the mainstay of therapy for LS, were discussed throughout the literature, and proved to be more efficient than topical calcineurin inhibitors, topical hormonal therapy, topical vitamin E oil and cold cream. However, other treatment modalities proved to be more efficient than topical corticosteroids, including CO2 and Nd:YAG laser therapies, and the addition of polydeoxyribonucleotide intradermal injections, to steroid therapy. Finally, other modalities that proved to be efficient in the treatment of LS included silk undergarments, human fibroblast lysate cream, platelet-rich plasma, acitretin, and surgical intervention. The risk of bias was assessed using the Cochrane risk-of-bias tool for randomized trials. Limitations included the inclusion of only randomized controlled trials, moderate or high risk of bias, and heterogeneity in treatment regimens, among others. Conclusion: Although high-potency topical corticosteroids have validated efficacy in the management of LS, other treatment modalities, including steroid-sparing agents and/or procedural adjuncts, have been demonstrated to have a beneficial role in the treatment of LS.

Safety and Efficacy of Sodium-Glucose Transport Protein 2 Inhibitors and Glucagon-like Peptide-1 Receptor Agonists in Diabetic Kidney Transplant Recipients: Synthesis of Evidence.

Background: This systematic review and meta-analysis aimed to evaluate the efficacy and safety of novel antidiabetics, namely, sodium-glucose transport protein 2 inhibitors (SGLT2-i) and glucagon-like peptide-1 receptor agonists (GLP1-RA), in diabetic kidney transplant recipients. Methods: Medline, Scopus, Web of Science, CENTRAL, and Clinicaltrials.gov were systematically searched from inception until 25 August 2024. Pooled estimates were obtained by applying random-effects models. Results: Overall, 18 studies (17 observational studies and one randomized controlled trial) were included. GLP1-RA were administered to 270 and SGLT2-i to 1003 patients. After GLP1-RA therapy, patients presented significantly lower glycated hemoglobin [mean difference (MD): -0.61%; 95% confidence interval (CI): -0.99; -0.23] and body weight (MD: -3.32 kg; 95% CI: -5.04; -1.59) but a similar estimated glomerular filtration rate (eGFR) and systolic blood pressure. After SGLT2-i therapy, patients had significantly lower glycated hemoglobin (MD: -0.40%, 95% CI: -0.57; -0.23) and body weight (MD: -2.21 kg, 95% CI: -2.74; -1.67), while no difference was noted in eGFR or systolic blood pressure. Preliminary data have shown an association between SGLT2-i use and a reduced risk of cardiovascular events, graft loss, and mortality. Evidence regarding the association between GLP1-RA and SGLT2-i and proteinuria was mixed. No significant effects on calcineurin inhibitor levels were observed. The risk of urinary tract infections was similar among patients treated with SGLT2-i or placebo (odds ratio: 0.84, 95% CI: 0.43; 1.64). Conclusions: Observational data suggest that GLP1-RA and SGLT2-i administration in diabetic kidney transplant recipients may be associated with better glycemic control and reduced body weight, presenting an acceptable safety profile.

Calcineurin inhibitor blocks tolerance by suppressing donor T cell terminal exhaustion after allogeneic hematopoietic cell transplantation.

Calcineurin inhibitor blocks tolerance by suppressing donor T cell terminal exhaustion after allogeneic hematopoietic cell transplantation.

Obinutuzumab versus rituximab for the treatment of refractory primary membranous nephropathy.

Rituximab has been shown effective in patients with primary membranous nephropathy refractory to glucocorticoids plus cyclophosphamide (GC+CTX) or calcineurin inhibitors (CNIs), but the response rates remain limited. Compared with rituximab, obinutuzumab is a humanized anti-CD20 monoclonal antibody with greater B-cell depletion capacity. This study was performed to investigate the effectiveness of obinutuzumab compared to rituximab in treating patients with refractory primary membranous nephropathy. A retrospective study was conducted at Huashan Hospital, Fudan University between January 1, 2015 and July 31, 2024, and included adult patients with primary membranous nephropathy who met the following criteria, 1) resistance to GC+CTX and/or calcineurin inhibitor (CNI) regimens, 2) dependence on CNIs, or 3) relapse within 1 year after CTX discontinuation. The patients subsequently received either obinutuzumab or rituximab. The primary endpoint was treatment response, which was defined as overall remission of nephrotic syndrome with no need for rescue therapy after obinutuzumab versus rituximab treatment. The secondary measures included immunological remission and safety profiles. Among the 51 participants, 20 received obinutuzumab and 31 received rituximab. The response rate was significantly greater in patients receiving obinutuzumab than in those receiving patients (90.0% vs. 38.7%, p<0.001) during a follow-up period of 24 (IQR, 10-34) months. Cox proportional hazards survival regression analysis also revealed the superior effectiveness of obinutuzumab (p<0.001). Immunological remission rates were higher in patients receiving obinutuzumab at both 3 months (75.0% vs. 20.0%, p<0.001) and 6 months (87.5% vs. 21.4%, p<0.001). The safety profiles of the two treatments were comparable. Among the 19 nonresponders treated with rituximab, 10 subsequently received obinutuzumab, and 8 achieved remission during a follow-up period of 20.0 (IQR, 18.5-22.3) months. This retrospective study suggests that obinutuzumab is an effective treatment option for patients with primary membranous nephropathy refractory to GC+CTX, CNI, and rituximab regimens.

Use of Nuclear Factor of Activated T Cell-Regulated Gene Expression for Monitoring Immunosuppression with Extended-Release Tacrolimus after Liver Transplantation-A Proof of Concept.

There is a narrow therapeutic window for immunosuppression using calcineurin inhibitors. Drug trough levels do not reflect immunosuppression and should be replaced by pharmacodynamic monitoring. This prospective cohort study was designed to evaluate the effect of an extended-release formulation of tacrolimus (LCP Tac) on the nuclear factor of activated T cell-regulated gene expression (NFAT-RGE). The expression of interleukin-2, interferon-γ, granulocyte-macrophage colony-stimulating factor, and three reference genes was measured. Samples from 23 patients at defined time points in the first year after liver transplantation were analyzed using a droplet digital polymerase chain reaction. All samples were within the targeted trough levels of LCP Tac, and their LCP Tac peak levels and residual NFAT-RGE showed a strong inverse correlation (r = -0.8). Most importantly, there was an individual immunosuppressive response to the LCP Tac. The mean individual trough effect of LCP Tac on the three target genes when all time points were pooled was 33% (26-56%) in patients without infection and 81% (53-95%) in those with infection (p < 0.011). The mean individual peak effect was 48% (44-64%) in patients without infection and 91% (90-94%) in those with infection (p < 0.001). Thus, tailored immunosuppression based on residual NFAT-RGE could prevent infections associated with over-immunosuppression early after liver transplantation.

Negative cell cycle regulation by calcineurin is necessary for proper beta cell regeneration in zebrafish.

Stimulation of pancreatic beta cell regeneration could be a therapeutic lead to treat diabetes. Unlike humans, the zebrafish can efficiently regenerate beta cells, notably from ductal pancreatic progenitors. To gain insight into the molecular pathways involved in this process, we established the transcriptomic profile of the ductal cells after beta cell ablation in the adult zebrafish. These data highlighted the protein phosphatase calcineurin (CaN) as a new potential modulator of beta cell regeneration. We showed that CaN overexpression abolished the regenerative response, leading to glycemia dysregulation. On the opposite, CaN inhibition increased ductal cell proliferation and subsequent beta cell regeneration. Interestingly, the enhanced proliferation of the progenitors was paradoxically coupled with their exhaustion. This suggests that the proliferating progenitors are next entering in differentiation. CaN appears as a guardian which prevents an excessive progenitor proliferation to preserve the pool of progenitors. Altogether, our findings reveal CaN as a key player in the balance between proliferation and differentiation to enable a proper beta cell regeneration.

Negative cell cycle regulation by calcineurin is necessary for proper beta cell regeneration in zebrafish

Stimulation of pancreatic beta cell regeneration could be a therapeutic lead to treat diabetes. Unlike humans, the zebrafish can efficiently regenerate beta cells, notably from ductal pancreatic progenitors. To gain insight into the molecular pathways involved in this process, we established the transcriptomic profile of the ductal cells after beta cell ablation in the adult zebrafish. These data highlighted the protein phosphatase calcineurin (CaN) as a new potential modulator of beta cell regeneration. We showed that CaN overexpression abolished the regenerative response, leading to glycemia dysregulation. On the opposite, CaN inhibition increased ductal cell proliferation and subsequent beta cell regeneration. Interestingly, the enhanced proliferation of the progenitors was paradoxically coupled with their exhaustion. This suggests that the proliferating progenitors are next entering in differentiation. CaN appears as a guardian which prevents an excessive progenitor proliferation to preserve the pool of progenitors. Altogether, our findings reveal CaN as a key player in the balance between proliferation and differentiation to enable a proper beta cell regeneration.

Inflammation Decreases Ciclosporin Metabolism in Allogeneic Hematopoietic Stem Cell Transplantation Recipients.

Graft-versus-host disease (GVHd) remains a significant challenge following allogeneic hematopoietic stem cell transplantation (HSCT). Prevention of GVHd relies mainly on the use of calcineurin inhibitors, notably ciclosporin that exhibits complex pharmacokinetics influenced by many factors including drug-drug interactions (DDIs). Due to the downregulation of drug metabolizing enzymes and transporters, it has been postulated that inflammation may be a contributing factor to the variability observed in ciclosporin pharmacokinetics. This study aimed to assess the impact of inflammation, as indicated by C-reactive protein (CRP) levels, on the metabolism of ciclosporin in adult allogeneic HSCT recipients. A retrospective observational study was conducted at Rennes University Hospital involving 71 adult HSCT patients. The relationship between the intensity of inflammation (no-to-mild, moderate, and severe), and the metabolism of ciclosporin (estimated by the concentration/dose ratio) was assessed. Severe inflammation significantly decreased the metabolism of ciclosporin, as evidenced by higher concentration/dose ratios. Thanks to the daily dose adjustment, inflammation did not influence the blood levels of ciclosporin. Interestingly, DDIs did not emerge as a significant covariate in influencing ciclosporin metabolism. This is likely because the CYP3A4 inhibitory potential of interacting drugs may be masked in HSCT patients where metabolism is already upstream downregulated by inflammation. The study highlights the intricate relationship between inflammation and ciclosporin pharmacokinetics in HSCT patients. This underscores the necessity for therapeutic monitoring and the potential adjustment of dosage strategies based on the inflammatory status. These insights could contribute to the development of more personalized, optimized, and effective management strategies for HSCT recipients.

Challenges in Diagnosis and Management of SLE in Africa: An Online Survey.

We surveyed African physicians about challenges in diagnosis and management of systemic lupus erythematosus (SLE). We used a cross-sectional, online questionnaire-based survey of African specialist physicians on availability of laboratory tests, medications, and specialized services for the diagnosis of SLE. Our 226 respondents from 31 countries were dermatologists (38%), rheumatologists (28%), and nephrologists (23%), the majority practicing at university/state-funded hospitals (80.8%), but over half of patients (59.6%) were self-funded for laboratory tests and medications. Antinuclear antibody (ANA), antiphospholipid antibody, and complement tests were available to 79.4%, 67.6%, and 62.3% of respondents, respectively, but fewer in the East and West African regions. Median turnaround time for the ANA test was within two weeks but more than four weeks for 5.6% of respondents, and longer in West Africa compared with other regions (P = 0.0002). Availability of urine protein-to-creatinine test, skin and renal histopathology was 82%, 82.5%, and 76.2%, respectively. Median turnaround times were within one to two weeks, but more than four weeks for 13.8% of respondents for skin histology results and usually within four weeks but more than four weeks for 24.5% of respondents for renal histology. Glucocorticoids and antimalarials were readily available across all regions, with variable availability of immunosuppressants from 93.7% for methotrexate to 65% for calcineurin inhibitors and only 58.4% for the biologic rituximab. Intensive care units/high care facilities, hemodialysis, and renal transplantation were available to 69.8%, 91.9%, and 56.5% of respondents, respectively. Variable availability of laboratory tests, medications, and supportive services coupled with cost constraints are major impediments to early diagnosis and optimal management of SLE in most of Africa and are likely factors contributing to underreporting and poor prognosis of SLE in Africa.

Role of SARS-CoV-2-specific memory B cells promoting immune protection after booster vaccination in solid organ transplantation.

Solid organ transplant (SOT) recipients display weak seroconversion and neutralizing antibody (NAb) responses after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination and remain at risk of severe coronavirus disease 2019 (COVID-19). While B-cell memory is the hallmark of serological immunity, its role in driving successful vaccine responses and providing immune protection in SOT patients remains unclear. We investigated the function and interplay of SARS-CoV-2-specific memory B cells (mBc), different cytokineproducing T cells, and cross-reactive NAb in driving seroconversion and protection against COVID-19 in two cohorts. First, we studied a large cohort of 148 SOT recipients and 32 immunocompetent individuals who underwent several vaccinations. Subsequently, we assessed 25 SOT patients participating in a randomized controlled trial to compare two different immunosuppressive strategies for allowing successful seroconversion and memory-cell responses after booster vaccination. We corroborate previous findings that B- and T-cell memory responses are weaker and more delayed in SOT patients than in immunocompetent (IC) individuals; however, within the SOT cohort, we found that these responses are relatively stronger and more robust in patients not receiving mycophenolate mofetil (MMF)-based therapies. Anti- spike IgG titers strongly correlated with RBD-specific IgG-producing mBc, with both displaying broad viral cross reactivity. Prebooster SARS-CoV-2-specific mBc and IL-2- producing T cells accurately predicted Nab seroconversion (AUC, 0.828) and protection against severe COVID-19. While switching unresponsive SOT patients from calcineurin inhibitors (CNI)/MMF to a low-exposure CNI/mTOR-i regimen favored wider SARS-CoV-2-specific immune responses after a fourth booster vaccination, preformed RBD-specific mBc predicted NAb seroconversion. Our study adds new insights into the pathobiology of immune memory and highlights the pivotal role of SARS-CoV-2-specific mBc in promoting immune protection inSOT patients.

Efficacy and Safety of Ruxolitinib Cream in Atopic Dermatitis Based on Previous Medication History.

For some patients with atopic dermatitis (AD), topical corticosteroids (TCS), topical calcineurin inhibitors (TCI), and systemic therapies are inadequate to control disease or are associated with adverse events (AEs). Ruxolitinib cream monotherapy demonstrated anti-inflammatory and anti-pruritic effects among patients enrolled in two pivotal phase 3 studies (TRuE-AD1/TRuE-AD2); most patients had long-term disease control with as-needed use during the 44-week long-term safety (LTS) period. This post hoc analysis explored efficacy and safety of 1.5% ruxolitinib cream by previous medication use. Patients aged ≥ 12years enrolled in TRuE-AD1/TRuE-AD2 were randomized 2:2:1 to twice-daily 0.75% or 1.5% ruxolitinib cream or vehicle cream for 8 weeks, followed by a 44-week LTS period; patients initially on vehicle were re-randomized 1:1 to either ruxolitinib cream strength. Within 12months of enrollment (N = 1249), previous AD therapies were used by 89.4% of efficacy-evaluable patients applying vehicle or ruxolitinib cream (n = 725); of these, 80.4% received TCS (n = 583), 22.2% TCI (n = 161), 20.3% TCS + TCI (n = 147), and 18.9% systemic therapies (n = 137). Across previous medication subgroups, achievement of Investigator's Global Assessment (IGA)-treatment success (IGA 0/1 with ≥ 2-grade improvement from baseline), ≥ 75% improvement in Eczema Area and Severity Index from baseline, and ≥ 4-point improvement in Itch numerical rating scale score from baseline at Week 8 did not substantially differ among patients who applied ruxolitinib cream. Outcomes were similar to those in the overall study population. At all study visits during the LTS period, > 70% of patients in each subgroup had IGA 0/1 and a low percentage (generally < 3%) of affected body surface area. Treatment-related AEs across subgroups were reported in 7.3% (n = 35/481)to17.4% (n = 19/109) of patients. Continuous-use ruxolitinib cream monotherapy for 8weeks followed by as-needed use was effective and well tolerated, regardless of previous topical or systemic therapy, with outcomes similar to those achieved in the overall study population. ClinicalTrials.gov Identifier, NCT03745638/NCT03745651.

Pityriasis rubra pilaris: A review

Pityriasis rubra pilaris (PRP, syn.: Devergie's disease) is a rare idiopathic papulo-squamous inflammatory skin disease characterized by follicular papules, palmar-plantar keratoderma, scaling plaques of orange-red color with characteristic foci of unaffected skin. Histologically, the alternating pattern of orthokeratosis and parakeratosis is considered a distinctive feature of PRP (staggered hyperkeratosis). A violation of the regulation of innate immunity is a component of the pathogenesis of PRP. Congenital mutations of CARD 14 or concomitant antigens, which can take the form of iatrogenic lesions, infections or malignant neoplasms, can be the initial triggers of the disease, although the etiology is often idiopathic. There are classically five subtypes of the disease, depending on the age of onset and clinical picture. Type VI PRP is associated with infection caused by the human immunodeficiency virus. CARD 14-associated papulosquamous rash and discoid dermatitis of the face represent new clinical phenotypes of PRP. Devergie's disease has a pronounced negative impact on the quality of life, and those who become ill are at increased risk of depression and suicide. Ixekizumab, methotrexate and secukinumab can be considered as systemic drugs of the first choice. If there is a contraindication to immunosuppressive therapy, high doses of isotretinoin are recommended. Topical agents, including calcipotriene, calcineurin inhibitors, emollients and topical corticosteroids, are used as additional therapy.

Defining the Etiology of Renal Allograft Dysfunction Using Banff 2019 Classification: Correlation with Post-Transplant Duration and Creatinine Levels-A Comprehensive Analysis of 200 Renal Biopsies at a Tertiary Care Medical Center Hospital.

Chronic kidney disease is a growing global health issue, contributing significantly to morbidity and mortality. The incidence of end-stage renal disease (ESRD) is approximately 100 per million population. Renal transplantation remains the cornerstone treatment for ESRD, with a projected 20-year survival rate of 60%. We aim to define the etiology of renal allograft dysfunction using the Banff 2019 classification by analyzing 200 renal allograft biopsies in correlation with creatinine levels across post-transplant time frames. 200 renal allograft biopsies are analyzed using the recent Banff 2019 classification with creatinine levels and post-transplant duration correlation. The study included 150 (75%) male patients and 50 (25%) female patients, with the majority 78 (39%) representing the age group of 16-30 years. 36 (18%) biopsies were within 3-month post-transplant, while 92 (46%) were 2-year post-transplant. According to the Banff 2019 classification, 92 (46.0%) transplant rejection biopsies were identified, with most 54 (27%) exhibiting antibody-mediated rejection (Category 2), including 40 (20%) active acute antibody-mediated rejection (ABMR) and 14 (7.0%) chronic active ABMR. T-cell-mediated rejection (TCMR; Category 4) represented 12 (6%) biopsies, including 10 (5%) acute TCMR and 2 (1%) chronic active TCMR. Category 5, the miscellaneous group, represented 100 (50%) biopsies, out of which 32 (16%) exhibited calcineurin inhibitor (CNI) toxicity, 38 (19%) acute tubular necrosis, and 8 (4%) thrombotic microangiopathy. A notable variation in the dysfunction distribution across different post-transplant time frames indicated a temporal evolution in the underlying causes of allograft dysfunction. Specific Banff categories showed a robust association with renal dysfunction, potentially contributing to the elevation of creatinine levels and renal function deterioration. Our study highlights the intricate pathophysiology of renal allograft dysfunction. Most biopsies were attributed to ABMR whereas one-third of biopsies exhibited mixed lesions (ABMR and TCMR or ABMR and calcineurin inhibitor toxicity (CNIT)). Additionally, this study suggests that renal allograft rejection remains a significant contributor to graft dysfunction. A complex interplay between histological findings, Banff classification, and renal function is noted. A significant difference in the distribution of dysfunction across post-transplant time frames is noted suggesting a temporal evolution in the etiology of allograft dysfunction. Certain Banff categories demonstrate a stronger association with renal dysfunction that may influence creatinine level increase and renal function deterioration. In correspondence to the recent Banff 2019 guidelines for diagnosing ABMR, we emphasize the role of C4d staining on immunofluorescence or immunohistochemistry in allograft biopsies as imperative for timely diagnosis and immunosuppressant therapy adjustment, ultimately enhancing graft survival. Further research is needed to elucidate the underlying mechanisms driving renal dysfunction in different Banff categories, ultimately informing personalized management strategies for patients with renal allograft dysfunction. In line with the Banff 2019 guidelines for diagnosing ABMR, this study highlights the critical role of C4d staining through immunofluorescence or immunohistochemistry in allograft biopsies for early diagnosis and timely adjustment of immunosuppressive therapy, ultimately improving graft survival.

Calcineurin-mediated dephosphorylation stabilizes E2F1 protein by suppressing binding of the FBXW7 ubiquitin ligase subunit

The transcription factor E2F1 serves as a regulator of the cell cycle and promotes cell proliferation. It is highly expressed in cancer tissues and contributes to their malignant transformation. Degradation by the ubiquitin-proteasome system may help to prevent such overexpression of E2F1 and thereby to suppress carcinogenesis. A detailed understanding of the mechanisms underlying E2F1 degradation may therefore inform the development of new cancer treatments. We here identified SCFFBXW7 as a ubiquitin ligase for E2F1 by comprehensive analysis. We found that phosphorylation of E2F1 at serine-403 promotes its binding to FBXW7 (F-box/WD repeat-containing protein 7) followed by its ubiquitination and degradation. Furthermore, calcineurin, a Ca2+/calmodulin-dependent serine-threonine phosphatase, was shown to stabilize E2F1 by mediating its dephosphorylation at serine-403 and thereby preventing FBXW7 binding. Treatment of cells with Ca2+ channel blockers resulted in downregulation of both E2F1 protein and the expression of E2F1 target genes, whereas treatment with the Ca2+ ionophore ionomycin induced upregulation of E2F1. Finally, the calcineurin inhibitor FK506 attenuated xenograft tumor growth in mice in association with downregulation of E2F1 in the tumor tissue. Impairment of the balance between the opposing actions of FBXW7 and calcineurin in the regulation of E2F1 abundance may therefore play an important role in carcinogenesis.

B-297 Tacrolimus Concentrations in Envarsus vs Prograf Patients: An Evaluation of the Clinical Impact of LC-MS/MS and Immunoassay Methods on Tacrolimus measurement

Abstract Background Tacrolimus is a calcineurin inhibitor used as part of an immunosuppressive regimen in kidney and liver transplant patients to prevent graft-versus-host disease (GvHD) and requires therapeutic drug monitoring due to its narrow therapeutic index. Tacrolimus levels are commonly measured using two different methodologies - immunoassay and liquid chromatography tandem mass spectrometry (LC-MS/MS). A global proficiency study to assess and compare the measurement of trough levels by these two methodologies noted a positive bias with the ARCHITECT immunoassay which is likely due to the presence of tacrolimus metabolites. The aim of our study is to assess the impact of two different formulations of tacrolimus on the accuracy of its analytical measurement. While differences between immunoassay and LC-MS/MS results have been evaluated for immediate-release tacrolimus (Prograf), it has yet to be characterized for extended-release formulations such as Envarsus. The discrepancy between immunoassay and LC-MS/MS has clinical implications, as dosage modifications are based on measured concentrations, analytical variation may cause intervals of subtherapeutic or supratherapeutic exposure, increasing the risk of graft rejection or toxicity. Methods Development of an LC-MS/MS method for the simultaneous quantification of tacrolimus and its major metabolite, desmethyl tacrolimus, was performed in whole blood. Traceable calibrators and quality control material for tacrolimus and specimens supplemented with desmethyl tacrolimus were used to determine accuracy and precision. Tacrolimus concentrations were measured by LC-MS/MS and ARCHITECT immunoassay methods in excess whole blood specimens from patients treated with either Prograf or Envarsus. Measurement biases between LC-MS/MS and immunoassay methodologies were determined for both formulations of tacrolimus. Results External calibration curves for both tacrolimus and desmethyl tacrolimus were linear (R2&amp;gt;0.995), and the analytical measurement range (AMR) for tacrolimus spanned from 1.1 - 31.6 ng/ml. Calibrator and Quality control (QC) biases were within 15% of their target values throughout the AMR and within-run imprecision was less than 10% (n=25) for all calibrators and QCs. Between-run imprecision for Low, Mid, and High QC levels over a period of 2 weeks (n=5 days) was less than 10%. Comparative bias of tacrolimus concentrations between immunoassay and LC-MS/MS was significantly lower (P value=0.0074) for Envarsus (n=20 specimens) relative to Prograf (n=32 specimens). Conclusions The differential bias between immunoassay and LC-MS/MS in the measurement of tacrolimus in patients dosed with immediate-release versus extended-release formulations suggests that their distinct pharmacokinetic profile may impact the accuracy of the measurement. Therefore, applying observed measurement biases from different assays derived from Prograf patients to Envarsus patients and vice versa may result in erroneous estimation of tacrolimus concentrations.

Early CYP3A5 Genotype-Based Adjustment of Tacrolimus Dosage Reduces Risk of De Novo Donor-Specific HLA Antibodies and Rejection among CYP3A5-Expressing Renal Transplant Patients.

Our previous retrospective single-center cohort study found, at 3-year follow-up, a trend toward low tacrolimus trough levels and an increased risk of de novo donor-specific anti-HLA antibodies (DSAs) and of antibody-mediated rejection (ABMR) in CYP3A5-expressing patients. Determining CYP3A5-expression status immediately after renal transplant would allow early genotype-based dosage adjustment of tacrolimus and might prevent the occurrence of de novo DSAs and ABMR, improving transplant outcome. 160 renal allograft recipients who underwent renal transplant at the University Hospital Essen between May 2019 and May 2022 were genotyped for the CYP3A5 rs776746 polymorphism within the first two weeks after transplant, and genotype-based dose adjustment of tacrolimus was performed for the follow-up of 2 years. CYP3A5 expression was detected in 33 (21%) of the 160 patients. Tacrolimus trough levels were similar in CYP3A5 expressers and nonexpressers over the entire 2-year follow-up period. However, we observed a trend toward slightly higher tacrolimus trough levels in CYP3A5 expressers, who, as expected, required tacrolimus dosages twice as high as did nonexpressers during follow-up. Calcineurin inhibitor (CNI) nephrotoxicity-free survival rates were comparable between CYP3A5 expressers and nonexpressers (p = 0.49). Rejection-free survival rates (p = 0.89), de novo anti-HLA antibody-free survival rates (p = 0.57) and de novo DSA-free survival rates (p = 0.61) did not differ between the two groups. Early detection of CYP3A5-expression status and resultant genotype-based adjustment of tacrolimus dosage after renal transplant protected patients from transplant rejection and de novo DSA formation and was not associated with increased incidence of CNI toxicity among CYP3A5 expressers.