Classification of death causes after transplantation (CLASS): Evaluation of methodology and initial results

Trends in underlying causes of death in allogeneic hematopoietic cell transplant recipients over the last decade

OBJECTIVES

Improved survival after hematopoietic cell transplantation (HCT) and an increasingly comorbid transplant population may give rise to new trends in the causes of death.

METHODS

This study includes all adult allogeneic HCT recipients transplanted at Rigshospitalet between January 1, 2010 and December 31, 2019. Underlying causes of death were determined using the Classification of Death Causes after Transplantation (CLASS) method.

RESULTS

Among 802 HCT recipients, 289 died during the study period. The main causes of death were relapse (N = 133, 46.0%), graft-versus-host disease (GvHD) (N = 64, 22.1%) and infections (N = 35, 12.1%). Multivariable analyses showed that with increasing transplant calendar year, a decreased risk of all-cause mortality (HR 0.92, 95% CI 0.87-0.97) and death from GvHD (HR 0.87, 95% CI 0.78-0.97) was identified, but not for other specific causes. Standardized mortality ratios (SMRs) for all-cause mortality decreased from 23.8 (95% CI 19.1-28.5) to 18.4 (95% CI 15.0-21.9) for patients transplanted in 2010-2014 versus 2015-2019, while SMR for patients who died from GvHD decreased from 8.19 (95% CI 5.43-10.94) to 3.65 (95% CI 2.13-5.18).

CONCLUSIONS

As risk of all-cause mortality and death from GvHD decreases, death from relapse remains the greatest obstacle in further improvement of survival after HCT.

Prognostic factors and predictive scores for 6-months mortality of hematopoietic stem cell transplantation recipients admitted to the pediatric intensive care unit

Objective

Despite advances in hematopoietic stem cell transplantation (HSCT), a considerable number of pediatric HSCT patients develops post-transplant complications requiring admission to the pediatric intensive care unit (PICU). The objective of this study was to evaluate clinical findings, PICU supportive therapy and outcome as well as predictive factors for 6-months survival after discharge of HSCT patients from PICU.

Study design

This retrospective single-center analysis investigated patient characteristics, microbiological findings, reasons for admission and death of 54 cases accounting for 94 admissions to the PICU of the University Children's Hospital Tuebingen from 2002 to 2017. We compared clinical characteristics between children with and without 6-months survival after discharge from PICU following HSCT. Finally, we assessed the potential prognostic value of the oncological Pediatric Risk of Mortality Score (O-PRISM), the Pediatric Sequential Organ Failure Assessment Score (pSOFA) and the pRIFLE Criteria for Acute Kidney Injury for 6-months survival using Generalized Estimating Equations (GEE) and Receiver Operating Characteristic curves.

Results

Respiratory insufficiency, gastroenterological problems and sepsis were the most common reasons for PICU admission. Out of 54 patients, 38 (70%) died during or after their last PICU admission, 30% survived for at least six months. When considering only first PICU admissions, we could not determine prognostic factors for 6-months mortality. In contrast, under consideration of all PICU admissions in the GEE model, ventilation (p=0.03) and dialysis (p=0.007) were prognostic factors for 6-months mortality. Furthermore, pSOFA (p=0.04) and O-PRISM (p=0.02) were independent risk factors for 6-months mortality considering all PICU admissions.

Conclusion

Admission of HSCT patients to PICU is still associated with poor outcome and 69% of patients died within 6 months. Need for respiratory support and dialysis are associated with poor outcome. Prediction of 6-months survival is difficult, especially during a first PICU admission. However, on subsequent PICU admissions pSOFA and O-PRISM scores might be useful to predict mortality. These scores should be prospectively evaluated in further studies to verify whether they can identify pediatric HSCT recipients profiting most from transferal to the PICU.

Recipient and Center Factors Associated With Immunosuppression Practice Beyond the First Year After Liver Transplantation and Impact on Outcomes

BACKGROUND

Immunosuppression is a critical aspect of post-transplant management, yet practices at intermediate and late time points after liver transplantation (LT) are poorly characterized.

METHODS

A retrospective cohort of 11 326 adult first LT alone recipients between 2007 and 2016 was identified by linking United Network for Organ Sharing transplant data to Medicare administrative claims. The immunosuppression regimen was obtained from Medicare billing claims. Factors associated with calcineurin inhibitor (CNI) monotherapy at 1-, 3-, and 5-y post-LT were investigated using mixed-effects logistic regression. Center practice heterogeneity was evaluated. The association of immunosuppression regimen (time-updating) with patient and graft survival was studied.

RESULTS

CNI monotherapy was used in 51.9% at 1-y post-LT and 68.6% at 5-y post-LT. Center-specific rates ranged from 20.0%-79.9% to 15.4%-95.2%, respectively. CNI monotherapy at 1- and 3-y post-LT was less likely among Black recipients ( P = 0.027 and P = 0.015 versus White, respectively). CNI plus antimetabolite was associated with improved adjusted patient (hazard ratio, 0.59; P < 0.001) and graft (hazard ratio, 0.62; P < 0.001) survival versus CNI monotherapy. The benefit of CNI plus antimetabolite on patient and graft survival increased with older age.

CONCLUSIONS

In this first longitudinal analysis of LT immunosuppression practices among Medicare beneficiaries, a CNI plus antimetabolite approach led to improved outcomes. Significant center heterogeneity in practice was observed.

Validation of cause of death classification after heart transplantation and cause-specific life expectancy compared to the general population

BACKGROUND

Post heart-transplant survival has increased, but information is lacking on specific causes of death and life expectancy. We aimed to assess cause-specific loss of life-years compared to the general population, evaluate classification for cause of death after heart transplantation, and assess validity of cause of death data from the International Society of Heart and Lung Transplant (ISHLT) registry.

METHODS

In this single center study, we included 239 heart recipients transplanted between 1988 and 2019 in Lund, Sweden (n = 239, 50% of the transplanted population where the cause of death was available). Two cardiologists retrospectively assigned causes of death according to a published classification (CLASS) in the 91 recipients who died during follow-up. Life expectancy was compared to data from the general population.

RESULTS

Compared to the average Swedish population, life expectancy for heart transplant recipients was 20 years shorter (IQR 12.9-27.2). The largest number of life-years lost were for deaths due to acute (49 years) and chronic rejection (27 years). Primary graft dysfunction (24 years) accounted for 24% of deaths, followed by malignancy (20 years) and infection (17 years), each accounting for ∼20% of deaths. Use of CLASS revealed moderate inter-rater agreement (56%) and moderate agreement with the ISHLT registry (62%).

CONCLUSIONS

Survival after heart transplantation was 20 years lower than in the general population. In the young, more life-years were lost due to acute graft rejection, whereas chronic graft rejection and primary graft failure were more important causes of death in older patients. Agreement was moderate between CLASS and the ISHLT registry classifications.

Trends in underlying causes of death in solid organ transplant recipients between 2010 and 2020: Using the CLASS method for determining specific causes of death

Monitoring specific underlying causes of death in solid organ transplant (SOT) recipients is important in order to identify emerging trends and health challenges. This retrospective cohort study includes all SOT recipients transplanted at Rigshospitalet between January 1st, 2010 and December 31st, 2019. The underlying cause of death was determined using the newly developed Classification of Death Causes after Transplantation (CLASS) method. Cox regression analyses assessed risk factors for all-cause and cause-specific mortality. Of the 1774 SOT recipients included, 299 patients died during a total of 7511 person-years of follow-up (PYFU) with cancer (N = 57, 19%), graft rejection (N = 55, 18%) and infections (N = 52, 17%) being the most frequent causes of death. We observed a lower risk of all-cause death with increasing transplant calendar year (HR 0.91, 95% CI 0.86–0.96 per 1-year increase), alongside death from graft rejection (HR 0.84 per year, 95% CI 0.74–0.95) and death from infections (HR 0.86 per year, 95% CI 0.77–0.97). Further, there was a trend towards lower cumulative incidence of death from cardiovascular disease, graft failure and cancer in more recent years, while death from other organ specific and non-organ specific causes did not decrease. All-cause mortality among SOT recipients has decreased over the past decade, mainly due to a decrease in graft rejection- and infection-related deaths. Conversely, deaths from a broad range of other causes have remained unchanged, suggesting that cause of death among SOT recipients is increasingly diverse and warrants a multidisciplinary effort and attention in the future.

Early- and late onset post-transplant lymphoproliferative disorders (PTLD) among adult kidney and liver transplant recipients

OBJECTIVES

Post-transplant lymphoproliferative disorder (PTLD) in solid organ transplant recipients has a high mortality and may present early (<2 years) or late (≥ 2 years) post-transplantation. We investigated the clinical characteristics of early and late PTLD among kidney and liver transplant recipients.

METHODS

Recipients, transplanted at Rigshospitalet, with PTLD development as adults from January 2010 to August 2020, were included. Clinical characteristics, laboratory parameters, and pathology of early and late PTLD were compared.

RESULTS

Thirty-one PTLD cases were detected where 10 (32%) were early and 21 (68%) were late PTLD. EBV DNA in plasma was detected in 78% vs 28% in early and late PTLD (p = 0.037). None of the recipients with early PTLD and 9 recipients with late PTLD (47%) had Ann Arbor stage IV at the time of their diagnosis (p = 0.006). Cyclophosphamid-Hydroxyrubicin-Oncovin-Prednisolon (CHOP) was used for treatment in 10 (48%) recipients with late PTLD (p = 0.032) only. There was no difference in mortality between the two groups.

CONCLUSIONS

Recipients with late PTLD had a lower prevalence of detectable EBV DNA in plasma, were diagnosed with more advanced disease, and were more frequently treated with chemotherapy compared to recipients with early PTLD. This article is protected by copyright. All rights reserved.

Posttransplantation Diabetes Mellitus Among Solid Organ Recipients in a Danish Cohort

Post-transplant diabetes mellitus (PTDM) is associated with a higher risk of adverse outcomes. We aimed to describe the proportion of patients with diabetes prior to solid organ transplantation (SOT) and post-transplant diabetes mellitus (PTDM) in three time periods (early-likely PTDM: 0–45 days; 46–365 days and >365 days) post-transplant and to estimate possible risk factors associated with PTDM in each time-period. Additionally, we compared the risk of death and causes of death in patients with diabetes prior to transplant, PTDM, and non-diabetes patients. A total of 959 SOT recipients (heart, lung, liver, and kidney) transplanted at University Hospital of Copenhagen between 2010 and 2015 were included. The highest PTDM incidence was observed at 46–365 days after transplant in all SOT recipients. Age and the Charlson Comorbidity Index (CCI Score) in all time periods were the two most important risk factors for PTDM. Compared to non-diabetes patients, SOT recipients with pre-transplant diabetes and PTDM patients had a higher risk of all-cause mortality death (aHR: 1.77, 95% CI: 1.16–2.69 and aHR: 1.89, 95% CI: 1.17–3.06 respectively). Pre-transplant diabetes and PTDM patients had a higher risk of death due to cardiovascular diseases and cancer, respectively, when compared to non-diabetes patients.

Achromobacter spp. in a Cohort of Non-Selected Pre- and Post-Lung Transplant Recipients

Achromobacter is an opportunistic pathogen that mainly causes chronic lung infections in cystic fibrosis (CF) patients and is associated with increased mortality. Little is known about Achromobacter spp. in the lung transplant recipient (LTXr) population. We aimed at describing rates of Achromobacter spp. infection in LTXr prior to, in relation to, and after transplantation, as well as all-cause mortality proportion in infected and uninfected LTXr. We included 288 adult LTXr who underwent lung transplantation (LTX) between 1 January 2010 and 31 December 2019 in Denmark. Bronchoalveolar lavage was performed at regular intervals starting two weeks after transplantation. Positive cultures of Achromobacter spp. were identified in nationwide microbiology registries, and infections were categorized as persistent or transient, according to the proportion of positive cultures. A total of 11 of the 288 LTXr had transient (n = 7) or persistent (n = 4) Achromobacter spp. infection after LTX; CF was the underlying disease in 9 out of 11 LTXr. Three out of the four patients, with persistent infection after LTX, also had persistent infection before LTX. The cumulative incidence of the first episode of infection one year after LTX was 3.8% (95% CI: 1.6–6.0). The incidence rates of transient and persistent infection in the first year after LTX were 27 (12–53) and 15 (5–37) per 1000 person-years of follow-up, respectively. The all-cause mortality proportion one year after LTX was 27% in the Achromobacter spp. infected patients and 12% in the uninfected patients (p = 0.114). Achromobacter spp. mainly affected LTXr with CF as the underlying disease and was rare in non-CF LTXr. Larger studies are needed to assess long-term outcomes of Achromobacter spp. in LTXr.

The HLA-DR4-DQ8 phenotype of the recipient is associated with increased mortality after kidney transplantation

The importance of the human leukocyte antigen (HLA) system in kidney transplantation is well-known, but it remains unexplored if patient HLA antigens constitute independent risk factors in complications after transplantation. We hypothesized that specific HLA class II phenotypes associated with immune-mediated disease (HLA-IMD) predispose to immunological activity and/or complications after kidney transplantation. Based on the literature we defined HLA-DR2-DQ6; -DR3-DQ2 and -DR4-DQ8 as HLA-IMD phenotypes. We investigated associations between HLA-IMD phenotypes in patients, biomarkers of systemic chronic inflammation at the time of transplantation, and the outcome after kidney transplantation in a retrospective cohort study of 611 kidney transplanted patients. The HLA-IMD phenotypes were associated with higher levels of biomarkers of systemic inflammation. The HLA-DR4-DQ8 phenotype was associated with mortality after transplantation in Cox analyses with adjustments for confounders. Data support the hypothesis that specific HLA class II phenotypes affects immunological pathways that determine the midterm clinical outcome of kidney transplantation.

Sport and Exercise in Improving Outcomes After Solid Organ Transplantation: Overview From a UK Meeting. Transplantation. 2019;103:S1-S11. [PMID: 31259878 DOI: 10.1097/tp.0000000000002710]

Outcomes after solid organ transplantation continue to improve, but premature loss of life remains a major concern, with death from cerebrovascular disease and cardiovascular disease accounting for around 20% late deaths. There are multiple contributory factors including preexisting, and the posttransplant development of, cardiometabolic conditions (such as hypertension, diabetes mellitus, hyperlipidemia, and obesity). There is accumulating evidence that the regular engagement in exercise is an important factor affecting outcomes before, during, and after transplantation; yet most waitlist candidates and recipients have reduced levels of physical activity. The mechanisms whereby physical activity is associated with better outcomes and a reduction in risk factors for cardiovascular disease are incompletely understood. Attempts to increase physical activity in the transplant population, as in the general population, have had limited success. Use of concepts from Nudge theory provides an evidence-based approach that may help increase physical activity and so reduce premature mortality. Both National and International Transplant Games provide a vehicle for increasing physical activity in this population and may also help to reduce premature death by providing a forum for mutual support for recipients and their families as well as an excellent forum for highlighting the success and impact of organ donation.

"Risk of de novo or secondary cancer after solid organ or allogeneic haematopoietic stem cell transplantation"

PURPOSE

Solid organ (SOT) and allogeneic haematopoietic stem cell (HSCT) transplant recipients have elevated risks of de novo or secondary cancer. We explored risk factors hereof.

METHODS

Among SOT and HSCT between January 2004 and December 2014, standardised incidence ratio (SIR) of de novo/secondary cancer compared with the Danish population was determined and risk factors were identified using Poisson regression.

RESULTS

During a median of 3.4 (IQR 1.3-6.4) and 2.6 (0.8-5.4) person-years (PY) after SOT and HSCT, a total of 212/1656 (13%) and 75/992 (8%) persons developed cancer; SIR 3.61 (3.0-4.3) and 2.2 (1.6-3.0), resp.). SIR correlated with younger age and was highest for skin and haematological cancers for both types of transplantation. Within the cohort, cancer was associated with older age (adjusted incidence rate ratio > 50 vs ≤ 19 years, among SOT and HSCT: 9.4 (3.4-25.7) and 25.4 (5.1-126.0), resp.) and current elevated C-reactive protein (CRP) (≥ 10 vs < 10 mg/L: 2.5 (1.8-3.4) and 2.3 (1.4-3.9), resp.), but neither with prior cancer nor type of immunosuppressants.

CONCLUSION

Rates of de novo or secondary cancers are elevated in both SOT and HSCT compared with the general population and mainly for skin and haematological cancers. Among transplant recipients, older age and current elevated CRP are risk factors.

Immune function as predictor of infectious complications and clinical outcome in patients undergoing solid organ transplantation (the ImmuneMo:SOT study): a prospective non-interventional observational trial

Background

Solid organ transplantation (SOT) is a well-established and life-saving treatment for patients with end-stage organ failure. Organ rejection and infections are among the main complications to SOT and largely determines the clinical outcome. The correct level of immunosuppression is of major importance to prevent these complications. However, it is a consistent observation that in recipients on the same immunosuppressive regimens the clinical outcome varies, and no reliable marker exists to monitor immune function.

Methods

In a prospective, observational study, we plan to enroll 630 adult patients with a planned organ transplantation at Rigshospitalet, University of Copenhagen, Denmark. Prior to and on different time points up to two years after transplantation we will perform a complete immunological profile on the recipients. This profile will consist of classical descriptive immune phenotyping (flow cytometry and circulating biomarkers) and the functional assay TruCulture®. In TruCulture® whole blood is incubated ex vivo with stimulants imitating bacterial, viral and fungal infections, where after a panel of selected cytokines is quantified. Clinical data from electronic health records will be obtained from the PERSIMUNE (Centre of Excellence for Personalized Medicine of Infections Complications in Immune Deficiency at Rigshospitalet, Copenhagen) data repository, a warehouse of data generated as part of routine care including vital signs, biochemistry, microbiology, pathology as well as medication, demographics, diagnoses, hospital contacts, surgical procedures and mortality.

Discussion

This will be the first large scale study to determine several aspects of immune function and perform a complete immunological profiling in SOT recipients. It is expected that knowledge generated will provide information to generate prediction models identifying patients at increased risk of infection and/or rejection. If the study is successful, we will subsequently use the generated prediction models to propose personalized immunosuppressive regimens to be tested in future randomized controlled trials.

Trial registration

This study has been approved by the Regional ethical committee (H-17024315), the Danish Data Protection Agency (RH-2016-47, RH-2015-04, I-Suite 03605) and the Danish National board of Health (3–3013-1060/1). The trial is retrospectively registered at clinicaltrials.gov (NCT03847285) the 20th February 2019.

Sepsis: Personalized Medicine Utilizing 'Omic' Technologies-A Paradigm Shift?

Sepsis has over the years proven a considerable challenge to physicians and researchers. Numerous pharmacological and non-pharmacological interventions have been tested in trials, but have unfortunately failed to improve the general prognosis. This has led to the speculation that the sepsis population may be too heterogeneous to be targeted with the traditional one treatment suits all’ approach. Recent advances in genetic and biochemical analyses now allow genotyping and biochemical characterisation of large groups of patients via the ‘omics’ technologies. These new opportunities could lead to a paradigm shift in the approach to sepsis towards personalised treatments with interventions targeted towards specific pathophysiological mechanisms activated in the patient. In this article, we review the potentials and pitfalls of using new advanced technologies to deepen our understanding of the clinical syndrome of sepsis.