Organ Transplant Rejection Research Articles

Prescription Patterns of Mycophenolate Mofetil in a Group of Patients from Colombia

Background: Mycophenolate mofetil is used for the prevention of solid organ transplant rejection and for other indications, such as systemic lupus erythematosus (SLE). Objective: To determine the prescription patterns of mycophenolate mofetil in a group of Colombian patients. Methods: This was a cross-sectional study of patients receiving mycophenolate mofetil between 2021 and 2022. The data were obtained from a drug dispensing database. Sociodemographic, clinical (diagnostic), and pharmacological variables were identified. Results: A total of 979 patients who underwent treatment were identified; their mean age was 45.9 ± 17.1 years, and 87.4% were women. The main diagnosis associated with the use of mycophenolate mofetil was SLE (39.1%), followed by other rheumatic diseases (8.5%), nephrotic syndrome (7.5%), and solid organ transplantation (6.4%). The relationship between the mean dose and the defined daily dose was 0.75. Ten percent of patients received mycophenolate alone, whereas 32.9% received mycophenolate in combination therapy with conventional disease-modifying antirheumatic drugs and glucocorticoids. A total of 76.2% had polypharmacy (five or more drugs). Conclusions: Mycophenolate mofetil is used mainly in combination therapy for patients with SLE and other rheumatological diseases and for solid organ transplants at doses lower than those recommended.

Human OX40L-CAR-Tregs target activated antigen-presenting cells and control T cell alloreactivity.

Regulatory T cells (Tregs) make major contributions to immune homeostasis. Because Treg dysfunction can lead to both allo- and autoimmunity, there is interest in correcting these disorders through Treg adoptive transfer. Two of the central challenges in clinically deploying Treg cellular therapies are ensuring phenotypic stability and maximizing potency. Here, we describe an approach to address both issues through the creation of OX40 ligand (OX40L)-specific chimeric antigen receptor (CAR)-Tregs under the control of a synthetic forkhead box P3 (FOXP3) promoter. The creation of these CAR-Tregs enabled selective Treg stimulation by engagement of OX40L, a key activation antigen in alloimmunity, including both graft-versus-host disease and solid organ transplant rejection, and autoimmunity, including rheumatoid arthritis, systemic sclerosis, and systemic lupus erythematosus. We demonstrated that OX40L-CAR-Tregs were robustly activated in the presence of OX40L-expressing cells, leading to up-regulation of Treg suppressive proteins without induction of proinflammatory cytokine production. Compared with control Tregs, OX40L-CAR-Tregs more potently suppressed alloreactive T cell proliferation in vitro and were directly inhibitory toward activated monocyte-derived dendritic cells (DCs). We identified trogocytosis as one of the central mechanisms by which these CAR-Tregs effectively decrease extracellular display of OX40L, resulting in decreased DC stimulatory capacity. OX40L-CAR-Tregs demonstrated an enhanced ability to control xenogeneic graft-versus-host disease compared with control Tregs without abolishing the graft-versus-leukemia effect. These results suggest that OX40L-CAR-Tregs may have wide applicability as a potent cellular therapy to control both allo- and autoimmune diseases.

Successful use of therapeutic plasma exchange for the management of acute lung transplant rejection secondary to immune checkpoint inhibitor therapy

The use of immune checkpoint inhibitors (ICIs) in individuals with a history of solid organ transplantation is fraught with the emergence of solid organ transplantation rejection (SOTR). The current recommendations for the management of SOTRs secondary to ICI include the use of high-dose steroids along with the escalation of immunosuppressive therapy. Therapeutic Plasma Exchange (TPE) has been described to be effective in managing various immune-related toxicities, however, the data for using TPE in the setting of acute SOTRs induced by ICIs are limited. Herein, we describe the successful use of TPE in a patient with a history of bilateral lung transplantation who developed an episode of mixed acute cellular and antibody-mediated lung transplant rejection after a single dose of PD-1 inhibitor Pembrolizumab for the treatment of underlying melanoma.

The Angiotensin Type 1 Receptor: A Drug Target to Reduce the Risk of Organ Transplant Rejection

: Allograft rejection is one of the main problems that must be overcome. Evidence suggests a role of the local renin-angiotensin system (RAS) in the progress of chronic allograft injury. Angiotensin II, generated by the renin-angiotensin system, is well-known as a major regulator molecule to control the blood pressure and fluid system. Evidence suggests that this bioactive molecule and its receptor increase the risk of tissue injuries and organ transplant rejection through different molecular mechanisms such as activation of innate and cellular immunity, upregulation of inflammatory pathways, and accumulation of extracellular matrix by expression pro-fibrotic molecules like transforming growth factor β (TGF-β) to increase the risk of fibrosis. Based on these findings, AT1R antagonists might have therapeutic potential to prevent the risk of tissue injuries and allograft rejection by regulating immune response, inflammation pathway, and fibrogenesis to improve organ functions.

Gene expression–based molecular scoring of pancreas transplant rejection for a quantitative assessment of rejection severity and resistance to treatment

Pancreas transplantation improves glycemic control and mortality in patients with diabetes but requires aggressive immunosuppression to control the alloimmune and autoimmune response. Recent developments in “omics” methods have provided gene transcript-based biomarkers for organ transplant rejection. The tissue Common Response Module (tCRM) score is developed to identify the severity of rejection in kidney, heart, liver, and lung transplants. Still, it has not yet been validated in pancreas transplants (PT). We evaluated the tCRM score’s relevance in PT and additional markers of acute cellular rejection (ACR) for PT. An analysis of 51 pancreas biopsies with ACR identified 37 genes and 56 genes significantly upregulated in the case of grade 3 and grade 2 ACR, respectively (P < .05). Significant differences were seen with higher grades of rejection among several transcripts. Of the 22 genes differentially expressed in grade 3 ACR, 18 were also differentially expressed in grade 2 ACR. The rejection signal was attributable to activated leukocytes’ infiltration. Significantly higher tCRM scores were found in grade 3 ACR (P = .007) and grade 2 ACR (P = .004), compared to normal samples. The tCRM score was able to distinguish treatment-resistant cases from those successfully treated for rejection.

Pharmacogenetic analysis of interleukin-10 variants and tacrolimus metabolism in kidney transplant patients from Pakistani population.

End stage renal disease (ESRD) occurs when the kidneys are unable to filter the waste products and excessive fluids from the blood that results into the accumulation of toxins and fluid in the body. Tacrolimus is commonly used immunosuppressant while sirolimus and cyclosporin are rarely used drugs to stop solid organ transplant rejection. The host's immunological response following transplantation produces interleukin-10 (IL-10), which influences the varied CYP3A-dependent drug disposition of tacrolimus. The aim of this study was to determine the genetic polymorphisms of IL-10 (rs1800871, rs1800872 and rs1800896) gene associated with tacrolimus metabolism in kidney transplant patients from Lahore Punjab, Pakistan. The study collected blood samples of 103 healthy individuals and 137 kidney transplant patients as control and treatment groups, respectively. We employed Tetra ARMS PCR for the genotype analysis of extracted DNA. The alleles were called on 2% agarose gel. Moreover, the study utilized SPSS software to analyze statistical significance of polymorphism. It was found that genotypic frequencies of IL-10 (rs1800871), IL-10 (rs1800872), and IL-10 (rs1800896) were (TT: 66.4%; TC: 31.4%; CC: 2.2%), (AA: 27.7%; AC: 54%; CC: 18.2%), (AA: 64.2%; GA: 17.5%; GG: 18.3%), respectively among kidney transplant patients. All parameters show significant association at different points after transplantation. Genetic analysis showed that TC and CC genotypes in rs1800871 (OR (95%CI) = 5.721 (3.231-10.131), P < 0.001; OR (95%CI) = 3.370 (0.642-17.672), P = 0.150), AC and CC genotypes in rs1800872 (OR (95%CI) = 1.294 (0.695-2.410), P = 0.415; OR (95%CI) = 1.453 (0.671-3.147), P = 0.342), GA and GG genotypes in rs1800896 (OR (95%CI) = 42.952 (17.566-105.021), P = 0.001; OR (95%CI) = 7.040 (2.563-19.333), P = 0.342) was associated with risk of renal rejection in kidney transplant patients. Besides, genetic models showed that TT in rs1800871, AA genotypes in rs1800872 and rs1800892 were associated with risk of renal rejection under dominant model when compared to controls (OR (95%CI) = 5.721 (3.231-10.131), P < 0.001; OR (95%CI) = 1.335 (0.735-9.290), P < 0.341; OR (95%CI) = 24.629 (10.599-57.230), P < 0.001), respectively. From the results, it is concluded that genetic polymorphism of IL-10 (rs1800871, rs1800872 and rs1800896) has a highly significant association with risk of renal rejection in Pakistani kidney transplant patients.

Alloreactive memory CD4 T cells promote transplant rejection by engaging DCs to induce innate inflammation and CD8 T cell priming

Alloreactive memory T cells have been implicated as central drivers of transplant rejection. Perplexingly, innate cytokines, such as IL-6, IL-1β, and IL-12, are also associated with rejection of organ transplants. However, the pathways of innate immune activation in allogeneic transplantation are unclear. While the role of microbial and cell death products has been previously described, we identified alloreactive memory CD4 T cells as the primary triggers of innate inflammation. Memory CD4 T cells engaged MHC II-mismatched dendritic cells (DCs), leading to the production of innate inflammatory cytokines. This innate inflammation was independent of several pattern recognition receptors and was primarily driven by TNF superfamily ligands expressed by alloreactive memory CD4 T cells. Blocking of CD40L and TNFα resulted in dampened inflammation, and mice genetically deficient in these molecules exhibited prolonged survival of cardiac allografts. Furthermore, myeloid cell and CD8 T cell infiltration into cardiac transplants was compromised in both CD40L- and TNFα-deficient recipients. Strikingly, we found that priming of naive alloreactive CD8 T cells was dependent on licensing of DCs by memory CD4 T cells. This study unravels the key mechanisms by which alloreactive memory CD4 T cells contribute to destructive pathology and transplant rejection.

Understanding and Therapeutic Application of Immune Response in Major Histocompatibility Complex (MHC) Diversity Using Multimodal Artificial Intelligence

Human Leukocyte Antigen (HLA) is like a device that monitors the internal environment of the body. T lymphocytes immediately recognize the HLA molecules that are expressed on the surface of the cells of the different individual, attacking it defeats microorganisms that is one of the causes of rejection in organ transplants performed between people with unmatched HLA types. Over 2850 and 3580 different polymorphisms have been reported for HLA-A and HLA-B respectively, around the world. HLA genes are associated with the risk of developing a variety of diseases, including autoimmune diseases, and play an important role in pathological conditions. By using a deep learning method called multi-task learning to simultaneously predict the gene sequences of multiple HLA genes, it is possible to improve accuracy and shorten execution time. Some new systems use a model called convolutional neural network (CNNs) in deep learning, which uses neural networks consisting of many layers and can learn complex correlations between SNP information and HLA gene sequences based on reference data for HLA imputation, which serves as training data. The learned model can output predicted values of HLA gene sequences with high accuracy using SNP information as input. To investigate which part of the input information surrounding the HLA gene is used to make learning predictions, predictions were made using not only a small number of nearby SNP information but also many SNP information distributed over a wider area by visualizing the learning information of the model. While conventional methods are strong at learning using nearly SNP information and not good at learning using SNP information located at distant locations, some new systems are thought that prediction accuracy may have improved because this problem was overcome. HLA genes are involved in the onset of a variety of diseases and are attracting attention. As an important area from the perspective of elucidating pathological conditions and realizing personalized medicine. The applied multi-task learning to two different HLA imputation reference panels—a Japanese panel (n = 1118) and type I diabetes genetics consortium panel (n = 5122). Through 10-fold cross-validation on these panels, the multi-task learning achieved higher imputation accuracy than conventional methods, especially for imputing low-frequency and rare HLA alleles. The increased prediction accuracy of HLA gene sequences is expected to increase the reliability of HLA analysis, including integrated analysis between different racial populations, and is expected to greatly contribute to the identification of HLA gene sequences associated with diseases and further elucidation of pathological conditions.

Deficiency in the mitophagy mediator Parkin accelerates murine skin allograft rejection

Alterations in mitochondrial function and associated quality control programs, including mitochondrial-specific autophagy, termed mitophagy, are gaining increasing recognition in the context of disease. However, the role of mitophagy in organ transplant rejection remains poorly understood. Using mice deficient in Parkin, a ubiquitin ligase that tags damaged or dysfunctional mitochondria for autophagic clearance, we assessed the impact of Parkin-dependent mitophagy on skin-graft rejection. We observed accelerated graft loss in Parkin-deficient mice across multiple skin graft models. Immune cell distributions posttransplant were largely unperturbed compared to wild-type; however, the CD8+ T cells of Parkin-deficient mice expressed more T-bet, IFNγ, and Ki67, indicating greater priming toward effector function. This was accompanied by increased circulating levels of IL-12p70 in Parkin-deficient mice. Using a mixed leukocyte reaction, we demonstrated that naïve Parkin-deficient CD4+ and CD8+ T cells exhibit enhanced activation marker expression and proliferative responses to alloantigen, which were attenuated with administration of a pharmacological mitophagy inducer (p62-mediated mitophagy inducer), known to increase mitophagy in the absence of a functional PINK1-Parkin pathway. These findings indicate a role for Parkin-dependent mitophagy in curtailing skin-graft rejection.

The evolution of cyclosporine treatments for treatment of ocular surface diseases.

Cyclosporine is a versatile immunomodulatory drug commonly employed in modern medicine. Although cyclosporine was initially used to prevent solid organ transplant rejection, its indications have extended to treat many inflammatory or autoimmune diseases. Cyclosporin is available for use in oral, intravenous, and topical forms, including eye drops to treat corneal and ocular surface conditions. It is naturally advantageous to administer cyclosporin directly into the eye, avoiding potential and dose limiting systemic adverse effects. However, the transition from systemic to topical administration has been a challenging one. This report reviews the evolution of ophthalmic cyclosporine treatment and explores its clinical impacts and future research directions. Latest advancements in formulations - from oil-based solutions to nanomicelle and gel systems and waterless formulations - have improved the therapeutic efficacy and tolerability of topically applied cyclosporine, demonstrating greater effectiveness in treating ocular surface parameters compared to oil-based solution. Cyclosporine continues to be a safe and effective immunomodulatory drug in the field of ophthalmology to treat various chronic inflammatory ocular surface diseases and dry eye. Currently, there are several commercially available topical preparations available for ophthalmic use each with unique formulation and clinical outcomes.

Hemorrhagic events associated with tacrolimus: a real-world pharmacovigilance study

ABSTRACT Background Tacrolimus is a potent macrolide immunosuppressant frequently used to prevent graft rejection in organ transplantation. Despite the known side effect of hemorrhage, there are no extensive descriptive series of patients who experience hemorrhage events associated with tacrolimus. We sought to review and describe tacrolimus-related hemorrhage events reported by healthcare professionals to the United States Food and Drug Association Adverse Event Reporting System (FAERS) database. Methods The FAERS database (2004q1-2022q4) was retrospectively analyzed to characterize reporting of hemorrhage adverse events (AEs) with tacrolimus. Subgroup analysis was completed on the hemorrhage. Results A total of 75,310 tacrolimus-associated AEs were identified, of which 1,511 cases met specific inclusion/exclusion criteria with most occurring in the gastrointestinal tract (422 cases, 27.93% of all included cases). Death was reported in 558 patients (36.93% of hemorrhage cases), the most of which occurred in cases of brain hemorrhage (219 cases, 39.25% of death cases). Among definitive organ transplants, renal transplant was the most common indication for tacrolimus (62 cases, 4.10%) followed by bone marrow transplant (44 cases, 2.91%) and liver transplant (30 cases, 1.99%). Conclusions This study presents the largest collective description of tacrolimus-related hemorrhage events. We additionally described a number of previously unreported tacrolimus-related hemorrhage events.

CLINICAL CASE OF THE FIRST KIDNEY TRANSPLANTATION IN UKRAINE TO A SERVICEMAN OF THE ARMED FORCES OF UKRAINE WHO RECEIVEDWITH MINES BLAST TRAUMA(MВT) AS A RESULT OF THE ARMED AGGRESSION OF THE RUSSIAN FEDERATION AGAINST UKRAINE

Kidney injury is one of the most common parenchymal organ injuries in military personnel because of military actions. This pathology requires a comprehensive approach to diagnosis (both instrumental and laboratory) and surgical and conservative treatment. One of the effective methods of surgical treatment is kidney transplantation. This surgical intervention is a method of renal replacement therapy in end-stage renal disease. The outcome is influenced by many factors: the age and weight of the donor and recipient, the presence of cardiovascular complications, and others. Patients are also assessed for the risk of acute organ rejection. This operation is the simplest and at the same time the most complex in transplantology. Such patients require special care and monitoring by qualified specialists.

Comparison of whole-blood sirolimus concentrations measured by EMIT-based Siemens Viva-ProE® System and LC-MS/MS in Chinese transplant patients

Sirolimus (SRL) is commonly used in transplant patients to prevent organ transplant rejection. The current guidelines recommend to perform SRL therapeutic drug monitoring regularly to improve treatment outcomes and avoid adverse effects. Consequently, a precise and accurate method for determining SRL is crucial in clinical practice. Currently, liquid chromatography–tandem mass spectrometry (LC-MS/MS) and immunoassays have been widely adopted for determining SRL concentrations. However, previous studies have shown that immunoassays exhibit a positive bias compared to LC-MS/MS. As the new updated version of the EMIT-based Viva-E® System (SVPS), this study aims to compare SRL blood concentrations measured by the SVPS and LC-MS/MS. The residual whole-blood samples obtained from transplant patients were simultaneously analyzed using the SVPS and LC-MS/MS, respectively. The correlation between the two assays was analyzed using the linear regression analysis and Deming linear regression. The Pearson correlation coefficient and Intraclass correlation coefficient (ICC) analysis were executed. The Paired Wilcoxon test and Bland-Altman analysis were performed to assess the concordance between the two methods. The SVPS considerably increased SRL concentration value by 46.62 % as compared to the LC-MS/MS method. When SRL concentrations measured by the SVPS were above 4.0 ng/mL, there was no significant difference between the corrected SVPS concentrations after using the Deming linear regression equation, indicating their interchangeability. Given the significant disparities observed between EMIT and LC-MS/MS, it is crucial to indicate the methodology and instruments in both TDM reports and future clinical guidelines. Our study also provides the conversion formulas between the SVPS and LC-MS/MS, which can be applied as a reference for different clinical centers.

Management of paediatric monomorphic post-transplant lymphoproliferative disorders with low-intensity treatment: A multicentre international experience.

Monomorphic post-transplant lymphoproliferative disorder (mPTLD) is a major cause of morbidity/mortality following solid organ transplant (SOT), with infection, mPTLD progression and organ rejection presenting equal risks. Balancing these risks is challenging, and the intensity of therapy required by individual patients is not defined. Although an increasing body of evidence supports the use of a stepwise escalation of therapy through reduction in immunosuppression (RIS) to rituximab monotherapy and low-dose chemo-immunotherapy, many centres still use B-cell non-Hodgkin lymphoma (B-NHL) protocols, especially when managing Burkitt/Burkitt-like (BL) PTLD. This study sought to define outcomes for children managed in the UK or Spanish centres using low-intensity first-line treatments. Retrospective data were anonymously collected on patients younger than 18years of age, with post-SOT mPTLD diagnosed between 2000 and 2020. Only patients given low-intensity treatment at initial diagnosis were included. Fifty-six patients were identified. Age range was 0.9-18years (median 10.7). Most (62.5%) had early-onset PTLD. Haematopathological analysis showed 75% were diffuse large B-cell like, 14.3% were BL and nine of 33 (27%) harboured a MYC-rearrangement. Stage III-IV disease was present in 78.6%. All but one had RIS, 26 received rituximab monotherapy and 24 low-dose chemo-immunotherapy, mostly R-COP. Intensified B-NHL chemotherapy was required in 10/56 (17.9%). There were a total of 13 deaths in this cohort, three related to PTLD progression. The 1-year overall survival (OS), event-free survival (EFS) and progression-free survival (PFS) were 92.8%, 78.6% and 80.2%, respectively. R-COP provides an effective low-dose chemotherapy option. Escalation to more intensive therapies in the minority of inadequately controlled patients is an effective strategy.

Does Uromodulin Play a Role in Tacrolimus-Mediated Upregulation of the Sodium Chloride Cotransporter?

Background: Tacrolimus, a calcineurin inhibitor (CNI), is a medication commonly prescribed to prevent organ transplant rejection. However, chronic CNI use has several adverse effects, including hypertension. Recent studies have revealed that the renal sodium chloride cotransporter (NCC) mediates tacrolimus-induced hypertension. However, the mechanisms underlying NCC upregulation are not fully understood. Previous studies indicate that uromodulin plays a key role in renal ion channel regulation. As such, we hypothesize that uromodulin mediates tacrolimus induced NCC upregulation. Experimental Design: To test this hypothesis, male C57BL/6 mice received tacrolimus (10 mg/kg/day) or vehicle (ethanol/DMSO/saline) for 21 consecutive days via intraperitoneal injection. The impact of tacrolimus on systolic blood pressure (BP) was monitored by tail-cuff plethysmography. To examine uromodulin and NCC expression, kidneys were harvested and processed for immunohistochemistry. Results: Compared to the BP of vehicle-treated mice (120 mm Hg ± 4.252), mice administered tacrolimus had significant increases in BP (170 mm Hg ± 3.528). Furthermore, tacrolimus treatment increased phosphorylated NCC (pNCC) and uromodulin expression. Conclusions: These results indicate that tacrolimus-induced hypertension is accompanied by pNCC and uromodulin upregulation in distal convoluted tubules. Significance: Overall, these findings highlight uromodulin as a possible regulator of NCC. Funding: R21 DK119879, R01 DK-133698, R25DK07838. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

The immunosuppressive drug cyclosporin A has an immunostimulatory function in CD8+ T cells.

Cyclosporin A is a well-established immunosuppressive drug used to treat or prevent graft-versus-host disease, the rejection of organ transplants, autoimmune disorders, and leukemia. It exerts its immunosuppressive effects by inhibiting calcineurin-mediated dephosphorylation of the nuclear factor of activated T cells (NFAT), thus preventing its nuclear entry and suppressing T cell activation. Here we report an unexpected immunostimulatory effect of cyclosporin A in activating the mammalian target of rapamycin complex 1 (mTORC1), a crucial metabolic hub required for T cell activation. Through screening a panel of tool compounds known to regulate mTORC1 activation, we found that cyclosporin A activated mTORC1 in CD8+ T cells in a 3-phosphoinositide-dependent protein kinase 1 (PDK1) and protein kinase B (PKB/AKT)-dependent manner. Mechanistically, cyclosporin A inhibited the calcineurin-mediated AKT dephosphorylation, thereby stabilizing mTORC1 signaling. Cyclosporin A synergized with mTORC1 pathway inhibitors, leading to potent suppression of proliferation and cytokine production in CD8+ T cells and an increase in the killing of acute T cell leukemia cells. Consequently, relying solely on CsA is insufficient to achieve optimal therapeutic outcomes. It is necessary to simultaneously target both the calcineurin-NFAT pathway and the mTORC1 pathway to maximize therapeutic efficacy.

Disulfiram treatment suppresses antibody-producing reactions by inhibiting macrophage activation and B cell pyrimidine metabolism

AbstractAntibody responses, involving B cells, CD4 + T cells, and macrophages, are implicated in autoimmune diseases and organ transplant rejection. We have previously shown that inhibiting FROUNT with disulfiram (DSF) suppresses macrophage activation and migration, effectively treating inflammatory diseases. In this study, we investigated the effectiveness of DSF in antibody-producing reactions. Using a heart transplantation mouse model with antibody-mediated rejection, we administered anti-CD8 antibody to exclude cellular rejection. DSF directly inhibited B cell responses in vitro and significantly reduced plasma donor-specific antibodies and graft antibody deposition in vivo, resulting in prolonged survival of the heart graft. DSF also mediated various effects, including decreased macrophage infiltration and increased Foxp3+ regulatory T-cells in the grafts. Additionally, DSF inhibited pyrimidine metabolism-related gene expression induced by B-cell stimulation. These findings demonstrate that DSF modulates antibody production in the immune response complexity by regulating B-cell and macrophage responses.

Impact of Blood Products Transfusion on Patients in the Immediate Post-Lung Transplant Period: A Cohort Study.

BACKGROUND Anemia is common in post-transplant patients. Blood product transfusion is associated with mortality and rejection in solid organ transplants. In lung transplant recipients, transfusion predisposes to primary graft dysfunction (PGD). The adverse effects and associated mortality of perioperative transfusions in lung transplant recipients have not been evaluated. This study examined the effects of perioperative blood transfusions in lung transplant recipients. MATERIAL AND METHODS We conducted a retrospective study of the effects of blood product transfusions in patients who received single- or double-lung transplantation at Houston Methodist Hospital between August 2017 and September 2019. Univariable and multiple logistic regression modeling were used to determine the characteristics associated with single events as well as a composite outcome within 30 days (including mortality, acute myocardial infarction, acute stroke, lower respiratory tract infection, urinary tract infection, surgical site infections, or PGD). RESULTS A total of 232 patients received lung transplants between December 2015 and September 2019 at our center. Univariable analysis revealed an increased risk of PGD (P<0.001), more mechanical ventilation days (P<0.001), more ICU days post-transplant (P<0.001), and greater need for ECMO support (P=0.001) in patients who received blood product transfusions. In univariate analysis, the composite outcome was also more common (P=0.01) in patients who received any transfusion perioperatively. A total of 7 patients died within 30 days from transplant, and they were all in the transfused group. CONCLUSIONS Among lung transplant recipients, PGD, ICU days, need for mechanical ventilation and ECMO support, and total composite events were significantly greater in patients who received blood transfusion perioperatively.

Does Lymphovenous Anastomosis Effect Mammalian Target of Rapamycin Inhibitor-associated Lymphedema Patients?

The mammalian target of rapamycin (mTOR) inhibitors are used to prevent organ transplant rejection and are preferred over other immunosuppressants due to its low nephrotoxicity. However, mTOR inhibitors have been associated with various adverse effects including lymphedema. Although rare in incidence, previously known treatments for mTOR inhibitor-induced lymphedema were limited to discontinuation of related drugs and complex disruptive therapy with variable results. In this article, three patients who developed lymphedema in their lower limbs after using mTOR inhibitors, including two bilateral and one unilateral case, were treated with physiologic surgery methods such as lymphovenous anastomosis (LVA) and lymph node transfer. The efficacy of the treatment was evaluated. In the three cases described, cessation of the drug did not lead to any reduction in edema. The use of LVA and lymph node transfer resulted in early reductions in volume but failed to sustain over time. All patients underwent secondary nonphysiologic surgery such as liposuction resulting in sustained improvement. This series presents the first physiologic approach to mTOR inhibitor-induced lymphedema. Although further study is warranted, the physiologic surgical options may have limited success and nonphysiologic options may offer better sustainable results.

Conversion from twice-daily everolimus to once-daily sirolimus in long-term stable liver transplant recipients

BackgroundAfter organ transplantation, strategies for simplifying the therapeutic regimen may improve adherence and prevent acute organ rejection and/or late graft loss. The present study aimed to evaluate the safety and efficacy of conversion from everolimus (EVR) twice daily to sirolimus (SIR) once daily in a large cohort of liver transplantation (LT) patients. MethodsWe included 108 LT patients with at least 12 months of post-transplant follow-up and no rejection episodes in the last year. Conversion was based on a 1:1 ratio (but eventually adapted to available formulations of SIR). ResultsThe median age at the time of conversion was 68.9 years (range: 26.1–83.6); 75.0% were men. The main indications for mTOR inhibitor use were renal failure (38.9%) and/or a history of malignancy (37.0%). Median conversion time after LT was 14.8 years (range: 2.3–31.5). The median dose of EVR and SIR (initially) was 1.50 mg/day (range: 0.5–4.5). The mean follow-up after conversion was 15.8±4.4 months. Median serum EVR/SIR trough levels before/after conversion were 3.85 ng/mL vs. 6.32 ng/mL (p < 0.05), i.e. a 1:1.64 ratio. At the end of follow-up after conversion, the median dose of SIR was 1.25 mg/day (range: 0.5–3.5), and the mean serum SIR trough level was 5.23 ng/mL; 9 patients (8.3%) had returned to EVR, because of side effects (mainly digestive), that resolved thereafter. No biopsy-proven acute rejection episode was observed. Finally, 87.1% of patients considered the conversion beneficial and the cost was reduced by 50.3%. ConclusionThe results of our study indicate that conversion from once-daily EVR to once-daily SIR in stable LT patients is safe, but needs dose adaptations and careful monitoring.