The gut microbiome in end-stage lung disease and lung transplantation.

Gut dysbiosis has been associated with impaired outcomes in liver and kidney transplant recipients, but the gut microbiome of lung transplant recipients has not been extensively explored. We assessed the gut microbiome in 64 fecal samples from end-stage lung disease patients before transplantation and 219 samples from lung transplant recipients after transplantation using metagenomic sequencing. To identify dysbiotic microbial signatures, we analyzed 243 fecal samples from age-, sex-, and BMI-matched healthy controls. By unsupervised clustering, we identified five groups of lung transplant recipients using different combinations of immunosuppressants and antibiotics and analyzed them in relation to the gut microbiome. Finally, we investigated the gut microbiome of lung transplant recipients in different chronic lung allograft dysfunction (CLAD) stages and longitudinal gut microbiome changes after transplantation. We found 108 species (58.1%) in end-stage lung disease patients and 139 species (74.7%) in lung transplant recipients that were differentially abundant compared with healthy controls, with several species exhibiting sharp longitudinal increases from before to after transplantation. Different combinations of immunosuppressants and antibiotics were associated with specific gut microbial signatures. We found that the gut microbiome of lung transplant recipients in CLAD stage 0 was more similar to healthy controls compared to those in CLAD stage 1. Finally, the gut microbial diversity of lung transplant recipients remained lower than the average gut microbial diversity of healthy controls up to more than 20 years post-transplantation. Gut dysbiosis, already present before lung transplantation was exacerbated following lung transplantation.IMPORTANCEThis study provides extensive insights into the gut microbiome of end-stage lung disease patients and lung transplant recipients, which warrants further investigation before the gut microbiome can be used for microbiome-targeted interventions that could improve the outcome of lung transplantation.

Tacrolimus Variability and Clinical Outcomes in the Early Post-lung Transplantation Period: Oral Versus Continuous Intravenous Administration.

BACKGROUND AND OBJECTIVE: High variability in tacrolimus pharmacokinetics directly after lung transplantation (LuTx) may increase the risk for acute kidney injury (AKI) and transplant rejection. The primary objective was to compare pharmacokinetic variability in patients receiving tacrolimus orally versus intravenously early after LuTx. METHODS: Pharmacokinetic and clinical data from 522 LuTx patients transplanted between 2010 and 2020 in two university hospitals were collected to compare orally administered tacrolimus to intravenous tacrolimus early post-transplantation. Tacrolimus blood concentration variability, measured as intrapatient variability (IPV%) and  percentage of time within the therapeutic range (TTR%), was analyzed within the first 14 days after LuTx. Secondary outcomes were AKI, acute rejection, length of stay in the intensive care unit (ICU), and mortality in the ICU and during hospital admission. RESULTS: We included 224 patients in the oral and 298 in the intravenous group. The mean adjusted IPV% was 10.8% (95% confidence interval [CI] 6.9-14.6; p < 0.001) higher in the oral group (27.2%) than the intravenous group (16.4%). The mean TTR% was 7.3% (95% CI - 11.3 to - 3.4; p < 0.001) lower in the oral group (39.6%) than in the intravenous group (46.9%). The incidence of AKI was 46.0% for oral and 42.6% for intravenous administration (adjusted odds ratio [OR] 1.2; 95% CI 0.8-1.8; p = 0.451). The frequencies of clinically diagnosed acute rejection in the oral and intravenous groups were nonsignificant (24.6% vs 17.8%; OR 1.5 [95% CI 1.0-2.3; p = 0.059]). ICU and hospital mortality rate and ICU length of stay were similar. CONCLUSIONS: Administering tacrolimus orally directly after LuTx leads to a higher variability in blood concentrations compared to intravenous administration. There was no difference in the occurrence of AKI or transplant rejection.

Management of infectious disease syndromes in thoracic organ transplants and mechanical circulatory device recipients: a Delphi panel.

PURPOSE: Antimicrobial misuse contributes to antimicrobial resistance in thoracic transplant (TTx) and mechanical circulatory support (MCS) recipients. This study uses a modified Delphi method to define the expected appropriate antimicrobial prescribing for the common clinical scenarios encountered in TTx and MCS recipients. METHODS: An online questionnaire on managing 10 common infectious disease syndromes was submitted to a multidisciplinary Delphi panel of 25 experts from various disciplines. Consensus was predefined as 80% agreement for each question. Questions where consensus was not achieved were discussed during live virtual live sessions adapted by an independent process expert. RESULTS: An online survey of 62 questions related to 10 infectious disease syndromes was submitted to the Delphi panel. In the first round of the online questionnaire, consensus on antimicrobial management was reached by 6.5% (4/62). In Round 2 online live discussion, the remaining 58 questions were discussed among the Delphi Panel members using a virtual meeting platform. Consensus was reached among 62% (36/58) of questions. Agreement was not reached regarding the antimicrobial management of the following six clinical syndromes: (1) Burkholderia cepacia pneumonia (duration of therapy); (2) Mycobacterium abscessus (intra-operative antimicrobials); (3) invasive aspergillosis (treatment of culture-negative but positive BAL galactomannan) (duration of therapy); (4) respiratory syncytial virus (duration of antiviral therapy); (5) left ventricular assist device deep infection (initial empirical antimicrobial coverage) and (6) CMV (duration of secondary prophylaxis). CONCLUSION: This Delphi panel developed consensus-based recommendations for 10 infectious clinical syndromes seen in TTx and MCS recipients.

Non-tuberculous mycobacteria disease pre-lung transplantation: A systematic review of the treatment regimens and duration pre- and post-transplant.

BACKGROUND: There is lack of consensus on non-tuberculous mycobacteria pulmonary disease (NTM-PD) treatment regimen and duration in patient listed for lung transplantation (LTx). We conducted a systematic review on treatment regimen and duration pre- and directly post-LTx, for patients with known NTM-PD pre-LTx. Additionally, we searched for risk factors for NTM disease development post-LTx and for mortality. METHODS: Literature was reviewed on PubMed, Embase and the Cochrane Library, for articles published from inception to January 2022. Individual patient data were sought. RESULTS: Sixteen studies were included reporting 92 patients. Most frequent used agents were aminoglycosides and macrolides for Mycobacterium abscessus (M. abscessus) and macrolides and tuberculostatic agents for Mycobacterium avium complex (M. avium complex). The median treatment duration pre-LTx was 10 months (IQR 6-17) and 2 months (IQR 2-8) directly post-LTx. Longer treatment duration pre-LTx was observed in children and in patients with M. abscessus. 46% of the patients with NTM-PD pre-LTx developed NTM disease post-LTx, related mortality rate was 10%. Longer treatment duration pre-LTx (p < 0.001) and sputum non-conversion pre-LTx (p = 0.003) were significantly associated with development of NTM-disease post-LTx. Longer treatment duration pre-LTx (p = 0.004), younger age (p < 0.001) and sputum non-conversion (p = 0.044) were risk factors for NTM related death. CONCLUSIONS: The median treatment duration pre-LTx was 10 months (IQR 6-17) and 2 months (IQR 2-8) directly post-LTx. Patients with longer treatment duration for NTM-PD pre-LTx and with sputum non-conversion are at risk for NTM disease post-LTx and for NTM-related death. Children were particularly at risk for NTM related death.

Genomic profiling of post-transplant lymphoproliferative disorders using cell-free DNA.

Diagnosing post-transplant lymphoproliferative disorder (PTLD) is challenging and often requires invasive procedures. Analyses of cell-free DNA (cfDNA) isolated from plasma is minimally invasive and highly effective for genomic profiling of tumors. We studied the feasibility of using cfDNA to profile PTLD and explore its potential to serve as a screening tool. We included seventeen patients with monomorphic PTLD after solid organ transplantation in this multi-center observational cohort study. We used low-coverage whole genome sequencing (lcWGS) to detect copy number variations (CNVs) and targeted next-generation sequencing (NGS) to identify Epstein-Barr virus (EBV) DNA load and somatic single nucleotide variants (SNVs) in cfDNA from plasma. Seven out of seventeen (41%) patients had EBV-positive tumors, and 13/17 (76%) had stage IV disease. Nine out of seventeen (56%) patients showed CNVs in cfDNA, with more CNVs in EBV-negative cases. Recurrent gains were detected for 3q, 11q, and 18q. Recurrent losses were observed at 6q. The fraction of EBV reads in cfDNA from EBV-positive patients was 3-log higher compared to controls and EBV-negative patients. 289 SNVs were identified, with a median of 19 per sample. SNV burden correlated significantly with lactate dehydrogenase levels. Similar SNV burdens were observed in EBV-negative and EBV-positive PTLD. The most commonly mutated genes were TP53 and KMT2D (41%), followed by SPEN, TET2 (35%), and ARID1A, IGLL5, and PIM1 (29%), indicating DNA damage response, epigenetic regulation, and B-cell signaling/NFkB pathways as drivers of PTLD. Overall, CNVs were more prevalent in EBV-negative lymphoma, while no difference was observed in the number of SNVs. Our data indicated the potential of analyzing cfDNA as a tool for PTLD screening and response monitoring.

A Joint Pharmacokinetic Model for the Simultaneous Description of Plasma and Whole Blood Tacrolimus Concentrations in Kidney and Lung Transplant Recipients.

BACKGROUND AND OBJECTIVE: Historically, dosing of tacrolimus is guided by therapeutic drug monitoring (TDM) of the whole blood concentration, which is strongly influenced by haematocrit. The therapeutic and adverse effects are however expected to be driven by the unbound exposure, which could be better represented by measuring plasma concentrations. OBJECTIVE: We aimed to establish plasma concentration ranges reflecting whole blood concentrations within currently used target ranges. METHODS: Plasma and whole blood tacrolimus concentrations were determined in samples of transplant recipients included in the TransplantLines Biobank and Cohort Study. Targeted whole blood trough concentrations are 4-6 ng/mL and 7-10 ng/mL for kidney and lung transplant recipients, respectively. A population pharmacokinetic model was developed using non-linear mixed-effects modelling. Simulations were performed to infer plasma concentration ranges corresponding to whole blood target ranges. RESULTS: Plasma (n = 1973) and whole blood (n = 1961) tacrolimus concentrations were determined in 1060 transplant recipients. A one-compartment model with fixed first-order absorption and estimated first-order elimination characterised observed plasma concentrations. Plasma was linked to whole blood using a saturable binding equation (maximum binding 35.7 ng/mL, 95% confidence interval (CI) 31.0-40.4 ng/mL; dissociation constant 0.24 ng/mL, 95% CI 0.19-0.29 ng/mL). Model simulations indicate that patients within the whole blood target range are expected to have plasma concentrations (95% prediction interval) of 0.06-0.26 ng/mL and 0.10-0.93 ng/mL for kidney and lung transplant recipients, respectively. CONCLUSION: Whole blood tacrolimus target ranges, currently used to guide TDM, were translated to plasma concentration ranges of 0.06-0.26 ng/mL and 0.10-0.93 ng/mL for kidney and lung transplant recipients, respectively.

Humoral and cellular immune responses after COVID-19 vaccination of lung transplant recipients and patients on the waiting list: a 6-month follow-up.

Background: Data on cellular response and the decay of antibodies and T cells in time are scarce in lung transplant recipients (LTRs). Additionally, the development and durability of humoral and cellular immune responses have not been investigated in patients on the waitlist for lung transplantation (WLs). Here, we report our 6-month follow-up of humoral and cellular immune responses of LTRs and WLs, compared with controls. Methods: Humoral responses to two doses of the mRNA-1273 vaccination were assessed by determining spike (S)-specific IgG antibodies and neutralizing antibodies. Cellular responses were investigated by interferon gamma (IFN-γ) release assay (IGRA) and IFN-γ ELISpot assay at 28 days and 6 months after the second vaccination. Results: In LTRs, the level of antibodies and T-cell responses was significantly lower at 28 days after the second vaccination. Also, WLs had lower antibody titers and lower T-cell responses compared with controls. Six months after the second vaccination, all groups showed a decrease in antibody titers and T-cell responses. In WLs, the rate of decline of neutralizing antibodies and T-cell responses was significantly higher than in controls. Conclusion: Our results show that humoral and cellular responses in LTRs, if they develop, decrease at rates comparable with controls. In contrast, the inferior cellular responses and the rapid decay of both humoral and cellular responses in the WL groups imply that WLs may not be protected adequately by two vaccinations and repeat boostering may be necessary to induce protection that lasts beyond the months immediately post-transplantation.

Chronic kidney disease after lung transplantation in a changing era.

Lung transplant (LTx) physicians are responsible for highly complex post-LTx care, including monitoring of kidney function and responding to kidney function loss. Better survival of the LTx population and changing patient characteristics, including older age and increased comorbidity, result in growing numbers of LTx patients with chronic kidney disease (CKD). CKD after LTx is correlated with worse survival, decreased quality of life and high costs. Challenges lie in different aspects of post-LTx renal care. First, serum creatinine form the basis for estimating renal function, under the assumption that patients have stable muscle mass. Low or changes in muscle mass is frequent in the LTx population and may lead to misclassification of CKD. Second, standardizing post-LTx monitoring of kidney function and renal care might contribute to slow down CKD progression. Third, new treatment options for CKD risk factors, such as diabetes mellitus, proteinuria and heart failure, have entered clinical practice. These new treatments have not been studied in LTx yet but are of interest for future use. In this review we will address the difficult aspects of post-LTx renal care and evaluate new and promising future approaches to slow down CKD progression.

The effect of COVID-19 on transplant function and development of CLAD in lung transplant patients: A multicenter experience.

BACKGROUND: Concerns have been raised on the impact of coronavirus disease (COVID-19) on lung transplant (LTx) patients. The aim of this study was to evaluate the transplant function pre- and post-COVID-19 in LTx patients. METHODS: Data were retrospectively collected from LTx patients with confirmed COVID-19 from all 3 Dutch transplant centers, between February 2020 and September 2021. Spirometry results were collected pre-COVID-19, 3- and 6-months post infection. RESULTS: Seventy-four LTx patients were included. Forty-two (57%) patients were admitted, 19 (26%) to the intensive care unit (ICU). The in-hospital mortality was 20%. Twelve out of 19 ICU patients died (63%), a further 3 died on general wards. Patients with available spirometry (78% at 3 months, 65% at 6 months) showed a significant decline in mean forced expiratory volume in 1 second (FEV1) (ΔFEV1 138 ± 39 ml, p = 0.001), and forced vital capacity (FVC) (ΔFVC 233 ±74 ml, p = 0.000) 3 months post infection. Lung function improved slightly from 3 to 6 months after COVID-19 (ΔFEV1 24 ± 38 ml; ΔFVC 100 ± 46 ml), but remained significantly lower than pre-COVID-19 values (ΔFEV1 86 ml ± 36 ml, p = 0.021; ΔFVC 117 ± 35 ml, p = 0.012). FEV1/FVC was > 0.70. CONCLUSIONS: In LTx patients COVID-19 results in high mortality in hospitalized patients. Lung function declined 3 months after infection and gradually improved at 6 months, but remained significantly lower compared to pre-COVID-19 values. The more significant decline in FVC than in FEV1 and FEV1/FVC > 70%, suggested a more restrictive pattern.

Impact of COVID-19 social distancing measures on lung transplant recipients: decline in overall respiratory virus infections is associated with stabilisation of lung function.

BACKGROUND: Coronavirus disease 2019 (COVID-19) social distancing measures led to a dramatic decline in non-COVID-19 respiratory virus infections, providing a unique opportunity to study their impact on annual forced expiratory volume in 1 s (FEV1) decline, episodes of temporary drop in lung function (TDLF) suggestive of infection and chronic lung allograft dysfunction (CLAD) in lung transplant recipients (LTRs). METHODS: All FEV1 values of LTRs transplanted between 2009 and April 2020 at the University Medical Center Groningen (Groningen, The Netherlands) were included. Annual FEV1 change was estimated with separate estimates for pre-social distancing (2009-2020) and the year with social distancing measures (2020-2021). Patients were grouped by individual TDLF frequency (frequent/infrequent). Respiratory virus circulation was derived from weekly hospital-wide respiratory virus infection rates. Effect modification by TDLF frequency and respiratory virus circulation was assessed. CLAD and TDLF rates were analysed over time. RESULTS: 479 LTRs (12 775 FEV1 values) were included. Pre-social distancing annual change in FEV1 was -114 (95% CI -133- -94) mL, while during social distancing FEV1 did not decline: 5 (95% CI -38-48) mL (difference pre-social distancing versus during social distancing: p<0.001). The frequent TDLF subgroup showed faster annual FEV1 decline compared with the infrequent TDLF subgroup (-150 (95% CI -181- -120) versus -90 (95% CI -115- -65) mL; p=0.003). During social distancing, we found significantly lower odds for any TDLF (OR 0.53, 95% CI 0.33-0.85; p=0.008) and severe TDLF (OR 0.34, 0.16-0.71; p=0.005) as well as lower CLAD incidence (OR 0.53, 95% CI 0.27-1.02; p=0.060). Effect modification by respiratory virus circulation indicated a significant association between TDLF/CLAD and respiratory viruses. CONCLUSIONS: During COVID-19 social distancing the strong reduction in respiratory virus circulation coincided with markedly less FEV1 decline, fewer episodes of TDLF and possibly less CLAD. Effect modification by respiratory virus circulation suggests an important role for respiratory viruses in lung function decline in LTRs.

Biological Characteristics of HLA-G and Its Role in Solid Organ Transplantation.

Organ transplantation is a lifesaving option for patients with advanced diseases. Rejection is regarded as one of the most severe risk factors post-transplantation. A molecule that contributes to immune tolerance and resisting rejection is human leukocyte antigen (HLA)-G, which belongs to the non-classical major histocompatibility complex class (MHC) I family. HLA-G was originally found to play a role during pregnancy to maintain immune tolerance between mother and child. It is expressed in the placenta and detected in several body fluids as soluble factor as well as different membrane isoforms on cells. Recent findings on HLA-G show that it can also play multifaceted roles during transplantation. This review will explain the general characteristics and biological function of HLA-G and summarize the views supporting the tolerogenic and other roles of HLA-G to better understand its role in solid organ transplantation (SOT) and its complications. Finally, we will discuss potential future research on the role of HLA-G in prevention, diagnosis, and treatment in SOT.

Long-term outcome and bridging success of patients evaluated and bridged to lung transplantation on the ICU.

BACKGROUND: Evaluating and bridging patients to lung transplantation (LTx) on the intensive care unit (ICU) remains controversial, especially without a previous waitlist status. Long term outcome data after LTx from ICU remains scarce. We compared long-term survival and development of chronic lung allograft dysfunction (CLAD) in elective and LTx from ICU, with or without previous waitlist status. METHODS: Patients transplanted between 2004 and 2018 in 2 large academic Dutch institutes were included. Long-term survival and development of CLAD was compared in patients who received an elective LTx (ELTx), those bridged and transplanted from the ICU with a previous listing status (BTT), and in patients urgently evaluated and bridged on ICU (EBTT). RESULTS: A total of 582 patients underwent a LTx, 70 (12%) from ICU, 39 BTT and 31 EBTT. Patients transplanted from ICU were younger than ELTx (46 vs 51 years) and were bridged with mechanical ventilation (n = 42 (60%)), extra corporeal membrane oxygenation (n = 28 (40%)), or both (n = 21/28). Bridging success was 48% in the BTT group and 72% in the EBTT group. Patients bridged to LTx on ICU had similar 1 and 5 year survival (86.8% and 78.4%) compared to elective LTx (86.8% and 71.9%). This was not different between the BTT and EBTT group. 5 year CLAD free survival was not different in patients transplanted from ICU vs ELTx. CONCLUSION: Patients bridged to LTx on the ICU with and without prior listing status had excellent short and long-term patient and graft outcomes, and was similar to patients electively transplanted.

Lung transplantation for acute respiratory distress syndrome: A multicenter experience.

Acute respiratory distress syndrome (ARDS) is a rapidly progressive lung disease with a high mortality rate. Although lung transplantation (LTx) is a well-established treatment for a variety of chronic pulmonary diseases, LTx for acute lung failure (due to ARDS) remains controversial. We reviewed posttransplant outcome of ARDS patients from three high-volume European transplant centers. Demographics and clinical data were collected and analyzed. Viral infection was the main reason for ARDS (n = 7/13, 53.8%). All patients were admitted to ICU and required mechanical ventilation, 11/13 were supported with ECMO at the time of listing. They were granted a median LAS of 76 (IQR 50-85) and waited for a median of 3 days (IQR 1.5-14). Postoperatively, median length of mechanical ventilation was 33 days (IQR 17-52.5), median length of ICU and hospital stay were 39 days (IQR 19.5-58.5) and 54 days (IQR 43.5-127). Prolongation of peripheral postoperative ECMO was required in 7/13 (53.8%) patients with a median duration of 2 days (IQR 2-7). 30-day mortality was 7.7%, 1 and 5-year survival rates were calculated as 71.6% and 54.2%, respectively. Given the lack of alternative treatment options, the herein presented results support the concept of offering live-saving LTx to carefully selected ARDS patients.

A translational rat model for ex vivo lung perfusion of pre-injured lungs after brain death.

The process of brain death (BD) detrimentally affects donor lung quality. Ex vivo lung perfusion (EVLP) is a technique originally designed to evaluate marginal donor lungs. Nowadays, its potential as a treatment platform to repair damaged donor lungs is increasingly studied in experimental models. Rat models for EVLP have been described in literature before, yet the pathophysiology of BD was not included in these protocols and prolonged perfusion over 3 hours without anti-inflammatory additives was not achieved. We aimed to establish a model for prolonged EVLP of rat lungs from brain-dead donors, to provide a reliable platform for future experimental studies. Rat lungs were randomly assigned to one of four experimental groups (n = 7/group): 1) healthy, directly procured lungs, 2) lungs procured from rats subjected to 3 hours of BD and 1 hour cold storage (CS), 3) healthy, directly procured lungs subjected to 6 hours EVLP and 4), lungs procured from rats subjected to 3 hours of BD, 1 hour CS and 6 hours EVLP. Lungs from brain-dead rats showed deteriorated ventilation parameters and augmented lung damage when compared to healthy controls, in accordance with the pathophysiology of BD. Subsequent ex vivo perfusion for 6 hours was achieved, both for lungs of healthy donor rats as for pre-injured donor lungs from brain-dead rats. The worsened quality of lungs from brain-dead donors was evident during EVLP as well, as corroborated by deteriorated ventilation performance, increased lactate production and augmented inflammatory status during EVLP. In conclusion, we established a stable model for prolonged EVLP of pre-injured lungs from brain-dead donor rats. In this report we describe tips and pitfalls in the establishment of the rat EVLP model, to enhance reproducibility by other researchers.

Waiting List Dynamics and Lung Transplantation Outcomes After Introduction of the Lung Allocation Score in The Netherlands.

The Netherlands was the third country to adopt the lung allocation score (LAS) for national allocation of donor lungs in April 2014. Evaluations of the introduction of the LAS in the United States and Germany showed mainly beneficial effects, including increased survival after transplantation. METHODS: Data for transplant candidates from 2010 to 2019 were retrieved from the Dutch Transplant Foundation database. Diagnosis categories and outcomes were compared between the periods before and after the introduction of the LAS. Time-dependent Cox regression and Fine-Gray analyses were performed to compare the chance for transplantation before and after introduction of the LAS. RESULTS: The cohort comprised 1276 patients. After introduction of the LAS, the annual number of transplantations and waiting list mortality did not change. The proportion of patients on the waiting list and transplanted patients with pulmonary fibrosis increased (25%-37%, P < 0.001; 22%-39%, P < 0.001). The chance of transplantation increased significantly for patients with pulmonary fibrosis after introduction of the LAS (hazard ratio 1.9 [95% confidence interval 1.4-2.9]). Patients who died on the waiting list had an increased LAS compared to the time of placement on the waiting list, reflecting clinical deterioration. This was not the case in patients with chronic obstructive pulmonary disease (P < 0.001). Overall survival was similar after introduction of the LAS (5-y survival 68%, compared to 74% [P = 0.171]). CONCLUSIONS: After the introduction of the LAS in The Netherlands, an increased proportion of transplantations was performed for patients with pulmonary fibrosis. Overall survival after transplantation did not change.

Machine Perfusion of Donation After Circulatory Death Liver and Lungs Before Combined Liver-lung Transplantation.

Shortage of deceased donor organs for transplantation has led to the increased use of organs from donation after circulatory death (DCD) donors. There are currently no reports describing outcomes after multiorgan transplantation with DCD livers. The use of DCD organs for multiorgan transplantation can be enhanced if the detrimental effects of prolonged cold ischemia and subsequent ischemia-reperfusion injury are overcome. We present a case in which the liver and lungs of a DCD donor were preserved using ex situ machine perfusion for combined liver-lung transplantation. The recipient was a 19-year-old male patient requiring bilateral lung transplantation for severe progressive pleural parenchymal fibroelastosis and portal hypertension with portal vein thrombosis. The donor liver was preserved with dual hypothermic oxygenated machine perfusion, whereas the lungs were perfused using ex vivo lung perfusion. With ex vivo lung perfusion, total preservation time of right and left lung reached 17 and 21 h, respectively. Now, 2 y after transplantation, liver function is normal and lung function is improving. To conclude, we suggest that combined transplantation of DCD liver and lungs is feasible when cold ischemia is reduced with ex situ machine perfusion preservation.

Ganciclovir therapeutic drug monitoring in transplant recipients.

BACKGROUND: The use of (val)ganciclovir is complicated by toxicity, slow response to treatment and acquired resistance. OBJECTIVES: To evaluate a routine therapeutic drug monitoring (TDM) programme for ganciclovir in a transplant patient population. METHODS: An observational study was performed in transplant recipients from June 2018 to February 2020. Dose adjustments were advised by the TDM pharmacist as part of clinical care. For prophylaxis, a trough concentration (Cmin) of 1-2 mg/L and an AUC24h of >50 mg·h/L were aimed for. For treatment, a Cmin of 2-4 mg/L and an AUC24h of 80-120 mg·h/L were aimed for. RESULTS: Ninety-five solid organ and stem cell transplant patients were enrolled. Overall, 450 serum concentrations were measured; with a median of 3 (IQR = 2-6) per patient. The median Cmin and AUC24h in the treatment and prophylaxis groups were 2.0 mg/L and 90 mg·h/L and 0.9 mg/L and 67 mg·h/L, respectively. Significant intra- and inter-patient patient variability was observed. The majority of patients with an estimated glomerular filtration rate of more than 120 mL/min/1.73 m2 and patients on continuous veno-venous haemofiltration showed underexposure. The highest Cmin and AUC24h values were associated with the increase in liver function markers and decline in WBC count as compared with baseline. CONCLUSIONS: This study revealed that a standard weight and kidney function-based dosing regimen resulted in highly variable ganciclovir Cmin and under- and over-exposure were observed in patients on dialysis and in patients with increased renal function. Clearly there is a need to explore the impact of concentration-guided dose adjustments in a prospective study.

Ageing of Immune System and Response to a Live-Attenuated Herpes Zoster Vaccine in Lung Transplant Candidates.

The mean age of lung transplant recipients has significantly increased in recent decades. Elderly recipients have a higher risk of developing herpes zoster (HZ), and they have in general a worse response to vaccination than younger persons do. We investigated the relationship between the humoral and cellular immune response to a live-attenuated HZ vaccine (Zostavax®, Merck Sharp and Dohme) and the frequencies of T and B cell subsets, especially aged cell subsets (CD28-T cells and age associated B cells, ABCs). In total, 37 patients awaiting lung transplantation received one dose of Zostavax®, and peripheral blood was collected before and within 6 months after vaccination. We observed a robust immune response after vaccination. The frequencies of CD28-T cells before vaccination had no impact on the subsequent immune response to HZ vaccination. However, a higher frequency of ABCs before vaccination correlated with a lower immune response especially regarding the cellular immune response. Cytomegalovirus seropositivity was associated with increased frequencies of CD28-T cells but not with frequencies of ABCs in the patients. In conclusion, increased levels of ABCs might disturb the cellular immune response to HZ vaccination, which could lower the efficacy of such vaccination in elderly transplant recipients.