The Impact of Obesity and Associated Comorbidities on the Outcomes after Renal Transplantation with a Living Donor vs. Deceased Donor Grafts

Pre-Transplant Dual-Energy X-ray Absorptiometry (DXA)-Derived Body Composition Measures as Predictors of Treatment Outcomes and Early Post-Transplant Complications in Patients with Multiple Myeloma (MM) Treated with Autologous Hematopoietic Stem Cell Transplantation (AutoHSCT)

Background/Objectives: Changes in muscle mass and bone density are common in multiple myeloma (MM) patients. Dual-energy X-ray absorptiometry (DXA) offers precise, non-invasive insights into a patient's physical condition before autologous stem cell transplantation (autoHSCT). This study examines how pre-transplant body composition impacts treatment outcomes and early complications in MM patients undergoing autoHSCT. Methods: This study is a single-center, retrospective analysis of patients with MM who were treated with first or second autoHSCT and underwent DXA pre-transplant between 11 August 2019 and 12 June 2024. Results: We conducted a study of pre-transplant body composition in 127 patients with MM. Among them, 108 (85%) qualified for first autoHSCT, while 19 (15%) qualified for a second. The median age of the patients was 64 years (range 50-73). In the Cox proportional hazards regression conducted in the group of women, Total Body %Fat was a statistically significant predictor for progression-free survival (PFS) (HR = 0.07, 95% CI = 0.01,0.6, p = 0.0157). In the Mann-Whitney U test conducted on males, Lean Mass/Height2 and Appen. Lean Height2 were statistically significant predictors of early infections after autoHSCT (Z = 1.98, p = 0.0473 and Z = 2.32, p = 0.0204, respectively). In males, Fat Mass/Height2 was a significant predictor of non-infectious toxicity related to treatment (Z = -1.98, p = 0.0476). Conclusions: In women, higher levels of adipose tissue initially appear to exert a protective effect; however, this benefit diminishes over time, with greater fat mass eventually correlating with an increased risk of disease progression. In men, muscle mass has been identified as a significant predictor of early infection risk post-autoHSCT. Furthermore, our findings indicate that an increased amount of adipose tissue in men is statistically associated with a higher risk of non-infectious treatment-related toxicity. These conclusions highlight the critical need for further investigation into the role of body composition.

Obesity-associated Inflammation and Alloimmunity

Obesity is a worldwide health problem with a rapidly rising incidence. In organ transplantation, increasing numbers of patients with obesity accumulate on waiting lists and undergo surgery. Obesity is in general conceptualized as a chronic inflammatory disease, potentially impacting alloimmune response and graft function. Here, we summarize our current understanding of cellular and molecular mechanisms that control obesity-associated adipose tissue inflammation and provide insights into mechanisms affecting transplant outcomes, emphasizing on the beneficial effects of weight loss on alloimmune responses.

Impact of Recipient and Donor Body Mass Index on Survival Outcomes After Intestinal Transplantation: A United Network for Organ Sharing Database Analysis

BACKGROUND Long-term patient survival after intestinal transplantation (IT) remains low compared with other organ transplants despite years of advancement in clinical experience. While patients with extremely high or low body mass index (BMI) are often considered ineligible for IT, the impact of BMI on post-transplant IT survival remains understudied. MATERIAL AND METHODS Using the United Network for Organ Sharing Standard Transplant database, we conducted a retrospective cohort study on patients who underwent IT between April 11, 1994, and September 29, 2021. We assessed the association of recipient and donor BMI at transplant with post-transplant mortality using Kaplan-Meier survival curves and univariate and multivariate Cox regression analyses. RESULTS A total of 1541 patients were included in our final sample. Of these patients, 806 were females (52.5%) and most were in the normal-weight BMI subgroup (54.2%). Obese class II (mean; 36.8±10.92 years) and underweight patients (mean; 37.6±13.37 years) were significantly younger than patients in other BMI categories. The adjusted multivariate model demonstrated an increased risk of mortality in underweight IT recipients compared to normal-weight IT recipients (aHR=1.25, 95% confidence interval [CI], 1.02-1.54; P=0.032).There was no significant association between donor BMI categories and survival in IT recipients. CONCLUSIONS Recipient BMI below normal is associated with an increased risk of mortality after intestinal transplantation and represents a potentially modifiable patient characteristic to improve survival outcomes.

A World Update of Progress in Lower Extremity Transplantation: What's Hot and What's Not

ABSTRACT

The field of vascularized composite allotransplantation (VCA) is the new frontier of solid organ transplantation (SOT). VCA spans life-enhancing/life-changing procedures such as upper extremity, craniofacial (including eye), laryngeal, tracheal, abdominal wall, penis, and lower extremity transplants. VCAs such as uterus transplants are life giving unlike any other SOT. Of all VCAs that have shown successful intermediate- to long-term graft survival with functional and immunologic outcomes, lower extremity VCAs have remained largely underexplored. Lower extremity transplantation (LET) can offer patients with improved function compared to the use of conventional prostheses, reducing concerns of phantom limb pain and stump complications, and offer an option for eligible amputees that either fail prosthetic rehabilitation or do not adapt to prosthetics. Nevertheless, these benefits must be carefully weighed against the risks of VCA, which are not trivial, including the adverse effects of lifelong immunosuppression, extremely challenging perioperative care, and delayed nerve regeneration. There have been 5 lower extremity transplants to date, ranging from unilateral or bilateral to quadrimembral, progressively increasing in risk that resulted in fatalities in 3 of the 5 cases, emphasizing the inherent risks. The advantages of LET over prosthetics must be carefully weighed, demanding rigorous candidate selection for optimal outcomes.

Weight loss with GLP-1 analogues in preparation for transplantation

This case describes a woman in her 20s with a 6-month history of progressive exertional dyspnoea and cough. Examination revealed hypoxia on room air, sinus tachycardia, finger clubbing and bibasal inspiratory crackles. Inflammatory markers were mildly elevated and empirical antimicrobial therapy was commenced. A multidisciplinary discussion consensus diagnosis of acute interstitial pneumonitis was made based on the findings of high-resolution CT of the chest, macrophage predominant bronchoalveolar lavage cell differential and surgical lung biopsy. There was clinical and radiological deterioration despite glucocorticoids and antifibrotic therapy. A body mass index of 37.5 kg/m2 precluded her from lung transplant assessment and consideration. Following consultation with the weight management service, she was commenced on glucagon-like peptide 1 (GLP-1) analogue therapy. She had a remarkable response within 6 months, was listed for lung transplantation, and within 18 months of her initial presentation, a double lung transplantation was performed.

Effect of Recipient Body Mass Index on Kidney Transplantation Outcomes: A Systematic Review and Meta-analysis by the Transplant Committee from the French Association of Urology

CONTEXT

The impact of recipient obesity on kidney transplantation (KT) outcomes remains unclear.

OBJECTIVE

The aim of this study was to perform a systematic review and meta-analysis to appraise all available evidence on the outcomes of KT in obese patients (body mass index [BMI] ≥30 kg/m2) versus nonobese patients (BMI <30 kg/m2).

EVIDENCE ACQUISITION

A systematic review and meta-analysis was performed. Search was conducted in the MEDLINE OvidSP, Web of Science, Google Scholar, Embase, and Cochrane databases to identify all studies reporting the outcomes of KT in obese versus nonobese recipients.

EVIDENCE SYNTHESIS

Fifty-two articles met the inclusion criteria. Delayed graft function and surgical complications were significantly higher in obese recipients (delayed graft function: relative risk [RR]: 1.44, 95% confidence interval [CI]: 1.32-1.57, p < 0.01; surgical complications: RR: 1.74, 95% CI: 1.36-2.22, p < 0.0001). Five-year patient survival (RR: 0.96, 95% CI: 0.92-1.00, p = 0.01), 10-yr patient survival (RR: 0.90, 95% CI: 0.84-0.97, p = 0.006), and 10-yr graft survival (RR: 0.87, 95% CI: 0.79-0.96, p = 0.01) were significantly inferior in the obese group.

CONCLUSIONS

KT in obese recipients was associated with lower patient and graft survival, and higher delayed graft function, acute rejection, and medical and surgical complications than nonobese recipients. In the current situation of organ shortage and increasing prevalence of obesity, ways to optimize KT in this setting should be investigated.

PATIENT SUMMARY

Compared with nonobese population, kidney transplantation in obese recipients has inferior patient and graft survival, and higher medical and surgical complications.

Protective Effect of Subcutaneous Drains on Wound Infections in Kidney Transplantation

BACKGROUND

Wound infections following kidney transplantation are common, with a reported incidence of 5%-19%. In the first few days after surgery, these patients receive extremely high doses of immunosuppression and high volumes of intravenous fluids, and they represent a specific subgroup of surgical patients that may benefit from using prophylactic subcutaneous drains.

METHODS

We analyzed a nonrandomized series of 112 consecutive kidney transplants between January 2017 and December 2019: those who received a subcutaneous drain in addition to the standard retroperitoneal drain (SQ drain group) vs those with a retroperitoneal drain alone (standard group).

RESULTS

The SQ drain group had a significantly higher median BMI (31.2 vs 25.8, P < .0001) and a trend towards more patients having diabetes and receiving thymoglobulin on induction. Nonetheless, 1/36 (3%) of patients in the SQ drain group had a documented wound infection requiring packing compared to the standard group 13/73 (17%) (P = .032). When multivariate regression analysis accounted for the potential confounders BMI, thymoglobulin use, and diabetes, the protective effect of the SQ drain was more significant (P = .001).

CONCLUSIONS

An SQ drain may be a simple and inexpensive method to reduce the rate of wound complications in kidney transplant recipients; prospective studies are warranted.

The Impact and Effectiveness of Weight Loss on Kidney Transplant Outcomes: A Narrative Review

Obesity is a worldwide epidemic that leads to several non-communicable illnesses, including chronic kidney disease (CKD). Diet and lifestyle modifications have shown a limited impact in the treatment of obesity. Because the group of end-stage renal disease (ESRD) patients examined in this study had limited access to kidney transplantation (KT), patients with obesity were thought to be at an increased risk of intraoperative and postoperative KT complications. Although bariatric surgery (BS) is now recognized as the gold standard treatment for morbid obesity, its role in ESRD or kidney transplant patients remains unknown. It is critical to know the correlation between weight loss and complications before and after KT, the impact of the overall graft, and patients' survival. Hence, this narrative review aims to present updated reports addressing when to perform surgery (before or after a KT), which surgical procedure to perform, and again, if strategies to avoid weight regain must be specific for these patients. It also analyzes the metabolic alterations produced by BS and studies its cost-effectiveness pre- and post-transplantation. Due to the better outcomes found in KT recipients, the authors consider it more convenient to perform BS before KT. However, more multicenter trials are required to provide a solid foundation for these recommendations in ERSD patients with obesity.

Abdominal Organ Transplantation: Noteworthy Literature in 2022

This review highlights noteworthy literature published in 2022 pertinent to anesthesiologists and critical care physicians caring for patients undergoing abdominal organ transplantation. We begin by exploring the impacts that the COVID-19 pandemic has had across the field of abdominal organ transplantation, including the successful use of grafts procured from COVID-19-infected donors. In pancreatic transplantation, we highlight several studies on dexmedetomidine and ischemia-reperfusion injury, equity in transplantation, and medical management, as well as studies comparing pancreatic transplantation to islet cell transplantation. In our section on intestinal transplantation, we explore donor selection. Kidney transplantation topics include cardiovascular risk management, obesity, and intraoperative management, including fluid resuscitation, dexmedetomidine, and sugammadex. The liver transplantation section focuses on clinical trials, systematic reviews, and meta-analyses published in 2022 and covers a wide range of topics, including machine perfusion, cardiovascular issues, renal issues, and coagulation/transfusion.

Obesity and kidney transplantation

PURPOSE OF REVIEW

Obesity has reached epidemic proportions in the United States. It is a risk factor for developing, among others, heart disease, stroke, type 2 diabetes, and chronic kidney disease (CKD), and thus a major public health concern and driver of healthcare costs. Although the prevalence of obesity in the CKD/end-stage kidney disease population is increasing, many obese patients are excluded from the benefit of kidney transplant based on their BMI alone. For this reason, we sought to review the experience thus far with kidney transplantation in obese patients and associated outcomes.

RECENT FINDINGS

Obesity is associated with a lower rate of referral and waitlisting, and lower likelihood of kidney transplantation. Despite increased risk for early surgical complications and delayed graft function, experience from multiple centers demonstrate a clear survival benefit of transplantation over dialysis in most obese patients, and comparable graft and patient survival rates to nonobese recipients.

SUMMARY

Data suggest that long-term transplant outcomes among obese recipients are similar to those among nonobese. Strategies to achieve pretransplant weight reduction and minimally invasive surgical techniques may further improve results of kidney transplantation in obese recipients.

Changes in serum pigment epithelium-derived factor levels after kidney transplantation in patients with end-stage renal disease

Background

Pigment epithelium-derived factor (PEDF) is a serin protease inhibitor and a potent inhibitor of angiogenesis. Its serum level has significant associations with metabolic parameters. However, little is known about the association between PEDF levels and lipid parameters in renal transplanted (TX) patients. Therefore, our aim was to investigate the relationship between PEDF level and lipid parameters in TX patients.

Methods

Seventy TX patients (47 males, 23 females, mean age 51.7 ± 12.4 years) and 34 healthy controls were enrolled. We examined the serum creatinine, C-reactive protein, fasting glucose and lipid parameters right before, then 1 and 6 months after TX. High-density lipoprotein (HDL)-associated paraoxonase-1 (PON1) activities were measured spectrophotometrically. Lipoprotein subfractions were determined by Lipoprint. PEDF and oxidized low-density liporotein (oxLDL) levels were measured by ELISA.

Results

Before transplantation, patients had had a significantly higher PEDF level compared to control subjects (p < 0.001). One month after transplantation, their PEDF level decreased significantly reaching the healthy controls’ level, and this lower level was maintained during the 6 months follow-up period as well. The initial oxLDL level was significantly higher, while PON1 activities were significantly lower in the patient group compared to the control group. We found a significant positive correlation between PEDF and total cholesterol, low-density lipoprotein (LDL)-cholesterol, triglyceride, oxLDL and small HDL subfraction; while negative correlations were found between PEDF and mean LDL size and large HDL subfraction during the entire follow-up period.

Conclusion

PEDF may play an important role in the increased oxidative stress and enhanced atherogenesis in renal transplant patients.