Study of Post-Kidney Transplantation Parietal Complications and Presarcopenia.

BACKGROUND: Sarcopenia is defined as a loss of muscle mass and strength. Its effects on postoperative outcomes in oncology and geriatrics have already been shown. Approximately 40% of patients in end-stage renal failure are affected with sarcopenia. A recent study suggests that sarcopenia could predict surgical complications after renal transplantation in obese patients. The aim of this study was to evaluate the effect of sarcopenia on parietal complications (eg, wound healing, lymphocele, hematoma). METHODS: Two indices of muscle fat infiltration (intra-muscular adipose content [IMAC], Hounsfield unit average calculation [HUAC]) and 3 of muscle mass index (total psoas index [TPI], visceral fat area/total abdominal muscle area [VFA/TAMA], and skeletal muscle mass index [SMMI]) were retrospectively measured on pretransplant computed tomography scans for patients undergoing kidney transplantation between 2007 and 2017. Patients were considered sarcopenic when the index was above the third quartile for muscle fat infiltration (IMAC, HUAC) and VFA/TAMA, and under the first quartile for muscle mass (TPI, SMMI). The occurrence of wound healing, collection (hematoma and lymphocele), and acute rejection were compared between sarcopenic and nonsarcopenic patients. RESULTS: Of 484 transplanted patients, 117 patients had a computed tomography scan before transplantation. Patients with a high HUAC had significantly more collections (P = .02) and total parietal complications (P = .09). Patients with a high IMAC had significantly more acute rejection (P = .001). CONCLUSIONS: Muscle fat infiltration appears to influence the outcome of renal transplantation. The management of sarcopenia in pretransplantation should be a subject of further research.

Renal biopsy in very elderly patients (over 80 years): clinical presentation, histological diagnosis, and long-term outcome.

PURPOSE: Data regarding the long-term outcome of very elderly (VE) patients undergoing renal biopsy (RB) are lacking. The objective of this study was to analyse the outcome of VE patients undergoing RB. METHODS: All patients over 65 years that underwent native RB between 2004 and 2016 in our center were included. Among the 206 included patients, those over 80 years (VE, 46 patients) were analysed and compared to those aged 65-80 years (160 patients). The outcomes of the VE group were analysed. RESULTS: Baseline characteristics, renal presentation, safety of RB and RB-related diagnosis were not different between VE patients and 65-80-year-old patients. Survival of VE patients was 73.1, 50.6 and 21.8% at 2, 4 and 6 years after RB, significantly poorer than those of 65-80-year-old group. Early death (< 1 year) occurred in 10 VE patients, was associated with a higher proteinuria-to-creatininuria ratio and tended to be associated with a more frequent dialysis need at RB. Of the 46 VE patients, 31 (67.4%) were diagnosed with a potentially reversible kidney disease, of whom 17 (40%) were started on immunosuppressive regimens. Survival of patients with a reversible kidney disease tended to be better than those with other diseases. CONCLUSION: RB appears as a safe and valuable procedure to assess diagnosis of kidney disease in VE patients. Our data suggest that RB is critical for the identification and treatment decision of patients with potentially reversible diseases and may translate in clinical improvement.

CD45RC Expression of Circulating CD8+ T Cells Predicts Acute Allograft Rejection: A Cohort Study of 128 Kidney Transplant Patients.

Predictive biomarkers of acute rejection (AR) are lacking. Pre-transplant expression of CD45RC on blood CD8+ T cells has been shown to predict AR in kidney transplant (KT) patients. The objective of the present study was to study CD45RC expression in a large cohort of KT recipients exposed to modern immunosuppressive regimens. CD45RC expression on T cells was analyzed in 128 KT patients, where 31 patients developed AR, of which 24 were found to be T-cell mediated (TCMR). Pre-transplant CD4+ and CD8+ CR45RChigh T cell proportions were significantly higher in patients with AR. The frequency of CD45RChigh T cells was significantly associated with age at transplantation but was not significantly different according to gender, history of transplantation, pre-transplant immunization, and de novo donor specific anti-Human Leucocyte Antigen (HLA) antibody. Survival-free AR was significantly better in patients with CD8+ CD45RChigh T cells below 58.4% (p = 0.0005), but not different according to CD4+ T cells (p = 0.073). According to multivariate analysis, CD8+ CD45RChigh T cells above 58.4% increased the risk of AR 4-fold (HR 3.96, p = 0.003). Thus, pre-transplant CD45RC expression on CD8+ T cells predicted AR, mainly TCMR, in KT patients under modern immunosuppressive therapies. We suggest that CD45RC expression should be evaluated in a prospective study to validate its usefulness to quantify the pre-transplant risk of AR.

Pre-transplant CD45RC expression on blood T cells differentiates patients with cancer and rejection after kidney transplantation.

BACKGROUND: Biological biomarkers to stratify cancer risk before kidney transplantation are lacking. Several data support that tumor development and growth is associated with a tolerant immune profile. T cells expressing low levels of CD45RC preferentially secrete regulatory cytokines and contain regulatory T cell subset. In contrast, T cells expressing high levels of CD45RC have been shown to secrete proinflammatory cytokines, to drive alloreactivity and to predict acute rejection (AR) in kidney transplant patients. In the present work, we evaluated whether pre-transplant CD45RClow T cell subset was predictive of post-transplant cancer occurrence. METHODS: We performed an observational cohort study of 89 consecutive first time kidney transplant patients whose CD45RC T cell expression was determined by flow cytometry before transplantation. Post-transplant events including cancer, AR, and death were assessed retrospectively. RESULTS: After a mean follow-up of 11.1±4.1 years, cancer occurred in 25 patients (28.1%) and was associated with a decreased pre-transplant proportion of CD4+CD45RChigh T cells, with a frequency below 51.9% conferring a 3.7-fold increased risk of post-transplant malignancy (HR 3.71 [1.24-11.1], p = 0.019). The sensibility, specificity, negative predictive and positive predictive values of CD4+CD45RChigh<51.9% were 84.0, 54.7, 89.8 and 42.0% respectively. Confirming our previous results, frequency of CD8+CD45RChigh T cells above 52.1% was associated with AR, conferring a 20-fold increased risk (HR 21.7 [2.67-176.2], p = 0.0004). The sensibility, specificity, negative predictive and positive predictive values of CD8+CD45RChigh>52.1% were 94.5, 68.0, 34.7 and 98.6% respectively. Frequency of CD4+CD45RChigh T cells was positively correlated with those of CD8+CD45RChigh (p<0.0001), suggesting that recipients with high AR risk display a low cancer risk. CONCLUSION: High frequency of CD45RChigh T cells was associated with AR, while low frequency was associated with cancer. Thus, CD45RC expression on T cells appears as a double-edged sword biomarker of promising interest to assess both cancer and AR risk before kidney transplantation.

Serum Magnesium after Kidney Transplantation: A Systematic Review.

Magnesium (Mg) status has recently drawn close attention in chronic kidney disease and in kidney transplant recipients. This review aims to evaluate the body of evidence linking hypomagnesemia to clinical consequences in these specific populations. After a brief summary of the main mechanisms involved in Mg regulation and of Mg status in end-stage renal disease, the review focuses on the relationship between hypomagnesemia and cardiovascular risk in kidney transplant recipients. A body of evidence in recent studies points to a negative impact of hypomagnesemia on post-transplant diabetes mellitus (PTDM) and cardiovascular risk, which currently represent the main threat for morbidity and mortality in kidney transplantation. Deleterious biological mechanisms induced by hypomagnesemia are also discussed. While data analysis enables us to conclude that hypomagnesemia is linked to the development of PTDM, studies prospectively evaluating the impact of hypomagnesemia correction after kidney transplantation are still lacking and needed.