[Severe consciousness disturbance after cord blood transplantation for relapsed T lymphoblastic lymphoma]

T-lymphoblastic leukemia/lymphoma (T-ALL/LBL) has a poor prognosis. Nelarabine has recently shown relatively good results in patients with relapsed or refractory T-ALL/LBL, but requires careful monitoring for neurological complications. A 50-year-old man with early recurrence of T-LBL after allogenic peripheral blood stem cell transplantation received nelarabine monotherapy and achieved complete remission after 1 cycle. He then received umbilical cord blood transplantation, and experienced sustained disturbance of consciousness. He later died of multiple organ failure, and autopsy suggested that nelarabine-induced leukoencephalopathy had caused the disturbance of consciousness. This case suggests that physicians should carefully monitor patients for neurological complications and consider imaging follow-up and consultation with a neurologist.

Survival prediction models since liver transplantation - comparisons between Cox models and machine learning techniques

BACKGROUND

Predicting survival of recipients after liver transplantation is regarded as one of the most important challenges in contemporary medicine. Hence, improving on current prediction models is of great interest.Nowadays, there is a strong discussion in the medical field about machine learning (ML) and whether it has greater potential than traditional regression models when dealing with complex data. Criticism to ML is related to unsuitable performance measures and lack of interpretability which is important for clinicians.

METHODS

In this paper, ML techniques such as random forests and neural networks are applied to large data of 62294 patients from the United States with 97 predictors selected on clinical/statistical grounds, over more than 600, to predict survival from transplantation. Of particular interest is also the identification of potential risk factors. A comparison is performed between 3 different Cox models (with all variables, backward selection and LASSO) and 3 machine learning techniques: a random survival forest and 2 partial logistic artificial neural networks (PLANNs). For PLANNs, novel extensions to their original specification are tested. Emphasis is given on the advantages and pitfalls of each method and on the interpretability of the ML techniques.

RESULTS

Well-established predictive measures are employed from the survival field (C-index, Brier score and Integrated Brier Score) and the strongest prognostic factors are identified for each model. Clinical endpoint is overall graft-survival defined as the time between transplantation and the date of graft-failure or death. The random survival forest shows slightly better predictive performance than Cox models based on the C-index. Neural networks show better performance than both Cox models and random survival forest based on the Integrated Brier Score at 10 years.

CONCLUSION

In this work, it is shown that machine learning techniques can be a useful tool for both prediction and interpretation in the survival context. From the ML techniques examined here, PLANN with 1 hidden layer predicts survival probabilities the most accurately, being as calibrated as the Cox model with all variables.

TRIAL REGISTRATION

Retrospective data were provided by the Scientific Registry of Transplant Recipients under Data Use Agreement number 9477 for analysis of risk factors after liver transplantation.

Post-Transplantation Diabetes Mellitus

Solid organ transplantation (SOT) is an established therapeutic option for chronic disease resulting from end-stage organ dysfunction. Long-term use of immunosuppression is associated with post-transplantation diabetes mellitus (PTDM), placing patients at increased risk of infections, cardiovascular disease and mortality. The incidence rates for PTDM have varied from 10 to 40% between different studies. Diagnostic criteria have evolved over the years, as a greater understating of PTDM has been reached. There are differences in pathophysiology and clinical course of type 2 diabetes and PTDM. Hence, managing this condition can be a challenge for a diabetes physician, as there are several factors to consider when tailoring therapy for post-transplant patients to achieve better glycaemic as well as long-term transplant outcomes. This article is a detailed review of PTDM, examining the pathogenesis, diagnostic criteria and management in light of the current evidence. The therapeutic options are discussed in the context of their safety and potential drug-drug interactions with immunosuppressive agents.

Ofatumumab rescue treatment in post-transplant recurrence of focal segmental glomerulosclerosis

BACKGROUND

Treatment of post-transplant focal segmental glomerulosclerosis (FSGS) recurrence is still debated. The use of the fully human anti-CD20 monoclonal antibody ofatumumab has been suggested.

CASE-DIAGNOSIS/TREATMENT

Two boys with FSGS received a kidney transplantation at the age of 15 years from a deceased and a living donor. Maintenance therapy consisted of calcineurin inhibitors, antiproliferative agents, and prednisone. Early post-transplant FSGS recurrence was observed after 2 and 3 days. Rituximab infusion and plasmapheresis sessions were performed with transient clinical improvement in the first patient, and no apparent response in the second patient. Both patients were treated with two ofatumumab infusions, which induced in patient #1 a complete and stable remission for more than 12 months and in patient #2 a partial remission with a progressive reduction of proteinuria and normalization of serum protein levels.

CONCLUSIONS

Ofatumumab may be a therapeutic option for post-transplant FSGS recurrence in patients who respond poorly to rituximab.

Prognostic value of myocardial perfusion imaging performed pre-renal transplantation: post-transplantation follow-up and outcomes

PURPOSE

Noninvasive stress testing is commonly performed as part of pre-renal transplantation (RT) evaluation. We evaluated the prognostic value of myocardial perfusion imaging (MPI)-myocardial perfusion, left ventricular ejection fraction (LVEF) and heart rate response (HRR)-post-RT.

METHODS

Consecutive RT recipients were identified at our institution. MPI was considered abnormal when there was a perfusion defect or reduced ejection fraction. HRR to vasodilator stress was calculated as percentage change from baseline. The primary outcome was a composite of cardiovascular (CV) death, myocardial infarction (MI) and coronary revascularization (CR) post-RT; all-cause mortality was the secondary endpoint.

RESULTS

Among 1189 RT recipients, 819 (69%) underwent MPI. Of those, 182 (22%) had abnormal MPI, and 31 (4%) underwent CR pre-RT. During a median follow-up of 56 months post-RT, the annual CV event and mortality rates for patients who had no MPI, normal MPI and abnormal MPI were 1.5%, 3.1% and 4.3% (p < 0.001), and 1.8%, 2.6% and 3.6% (p = 0.016), respectively. After multivariate adjustment, compared to patients without MPI, the hazard ratios (HRs) for CV events for normal and abnormal MPI were 1.47 ([0.93-2.33], p = 0.1) and 1.78 ([1.03-3.06], p = 0.04). Blunted HRR was an independent predictor of CV events (HR = 1.73 [1.04-2.86], p = 0.034) and all-cause death (HR = 2.26 [1.28-3.98], p = 0.005) after adjusting for abnormal MPI. Patients with abnormal MPI who underwent CR pre-RT had annual mortality rates similar to those with no or normal MPI (1.9% vs. 1.7-2.6%, p = 0.2), while those who did not undergo CR had higher annual mortality (4% vs. 1.7-2.6%, p = 0.003).

CONCLUSIONS

One in five RT recipients who underwent screening MPI had an abnormal study, an independent predictor of CV events. A blunted HRR to vasodilator stress was associated with increased risk of CV events and death, even after adjusting for abnormal MPI. Patients with abnormal MPI who underwent CR were at low risk of mortality following RT. MPI is a useful tool to aid in risk stratification pre-RT.

Post-transplantation Development of Food Allergies

PURPOSE OF REVIEW

The development of food allergies is increasingly being recognized as a post-solid organ transplant complication. In this article, we review the spectrum of post-transplant food allergy development and the proposed mechanisms for de novo food allergies and the clinical significance they pose.

RECENT FINDINGS

The development of new food allergies is disproportionately associated with pediatric liver transplants, where it occurs in up to 38% of select populations. The mechanism of food allergy development is not completely understood; however, it is likely promoted by unbalanced immune suppression. De novo food allergy development is a common complication of solid organ transplants with the highest risk occurring in pediatric liver transplant recipients. There are likely multiple mechanisms for food allergy development including passive transfer of membrane-bound IgE and lymphocytes from donor to recipient, as well as loss of food tolerance and active development of new food allergies. The optimal management of food allergies following organ transplants has not been well researched but may include changing the immune suppression regimen if the food allergy does not resolve without intervention.

Pediatric post-tonsillectomy hemorrhage in the setting of post-transplantation immunosuppression

INTRODUCTION

Long-term immunosuppressants form an integral part of therapy for post-transplantation patients. Immunosuppressants may also have an anticoagulant effect, and little is known about their effects on bleeding risk after adenotonsillectomy. Our objective was to investigate whether there is an increased observed rate of post-tonsillectomy hemorrhage in a population of pediatric patients on long-term immunosuppressants after solid organ transplantation, compared to healthy controls.

METHODS

This was a retrospective chart review of pediatric patients with a history of renal or heart transplant undergoing adenotonsillectomy at our institution between 2000 and 2014. All patients underwent tonsillectomy with monopolar electrocautery. Retrieved data included perioperative medications, occurrence of post-operative bleeding and associated treatment. For comparison, we obtained a population of age-matched controls with no history of immunosuppression who underwent the same procedure.

RESULTS

A total of 34 patients meeting criteria were identified, of which 3 (8.82%) suffered a postoperative bleed. Forty-seven controls were obtained, with a total of 2 (4.26%) postoperative hemorrhages (p = 0.65). Two of the post-transplantation patients who bled postoperatively required cauterization in the operating room. None of the controls required surgical treatment. The incidences of postoperative bleeding requiring surgical treatment were 5.88% and 0%, respectively (p = 0.17).

CONCLUSION

We failed to demonstrate an increased risk of bleeding after undergoing adenotonsillectomy in our cohort of post-transplantation pediatric patients on chronic immunosuppression. Future research, likely requiring a multi-institutional effort, could stratify by immunosuppressive agent to elucidate bleeding risk with specific medications.

Sexually-transmitted seronegative HCV infection in an HIV-positive post-liver transplant recipient. Case report and review of the literature

We report an HIV-positive patient post liver transplant for non-alcoholic steatohepatitis. Posttransplant liver enzymes became persistently elevated, however HCV antibody was repeatedly negative. Nucleic acid testing subsequently revealed ongoing HCV viremia. Exposure to HCV was on the basis of sexual transmission. The patient was subsequently successfully treated with sofosbuvir/ledipasvir.