Natriuretic Peptides as Predictors of Protein-Energy Wasting in Hemodialysis Population.

OBJECTIVE: Imbalance between anabolism and catabolism is linked to cachexia and protein-energy wasting (PEW), especially in frail populations such as patients with chronic kidney disease. PEW is responsible of poor outcomes with increased morbidity and mortality. Several causes are involved in PEW such as insulin resistance, acidosis, or hyperparathyroidism. Natriuretic peptides (NPs) have recently been described as activators of resting energy expenditure through the induction of browning of white adipose tissue in rodents with chronic kidney disease. The present study was therefore implemented to investigate whether NPs could be associated with PEW criteria and predict clinical outcomes. METHODS: We quantified serum N-terminal pro-B-type natriuretic peptide (NT-proBNP) in a prospective cohort of 231 patients undergoing maintenance hemodialysis and atrial natriuretic peptide in a subgroup of 35 patients. Body composition parameters were measured with bioimpedance spectroscopy. RESULTS: NT-proBNP was inversely associated with serum albumin, prealbumin, and body mass index and, conversely, positively associated with age and C-reactive protein. NT-proBNP as well as atrial natriuretic peptide were significantly higher in patients with PEW criteria. NT-proBNP was negatively associated with body fat mass. In multiple linear regression, NT-proBNP remained associated with body mass index. Kaplan-Meier analysis revealed a significant correlation between serum NT-proBNP concentrations and all-cause mortality and cardiovascular events. This association remained significant after multivariable Cox regression models adjusted for demographic factors and cardiovascular risk factors. CONCLUSION: Accumulation of NPs seems to be associated with poor nutritional status and reduced survival among hemodialysis patients. Further studies are needed to confirm this association using resting energy expenditure measurement and adipose tissue biopsy.

Accumulation of natriuretic peptides is associated with protein energy wasting and activation of browning in white adipose tissue in chronic kidney disease.

Protein energy wasting is a common feature of patients with chronic kidney disease (CKD) and is associated with poor outcomes. Protein energy wasting and cachexia, a severe form of protein energy wasting, are characterized by increased resting energy expenditure but the underlying mechanisms are unclear. Browning corresponds to the activation of inducible brown adipocytes in white adipose tissue and occurs in states of cachexia associated with hypermetabolic disease such as cancer. Here we tested the hypothesis that CKD-associated protein energy wasting could result from browning activation as a direct effect of the uremic environment on adipocytes. In a murine model of CKD (5/6 nephrectomy), there was increased resting energy expenditure, expression of uncoupling protein 1 (a thermogenic protein uncoupling oxidative phosphorylation in mitochondria) and citrate synthase activity (a proxy of mitochondrial density in white adipose tissue). Mice with CKD also exhibited increased levels of atrial natriuretic peptide, a well known activator of browning. The incubation of primary adipose cells with plasma from patients receiving dialysis treatment and having signs of protein energy wasting led to an increased synthesis of uncoupling protein 1. Similarly, primary adipose cells exposed to atrial natriuretic peptide at concentrations relevant of CKD led to a significant increase of uncoupling protein 1 content. Thus, accumulation of cardiac natriuretic peptides during CKD could contribute to the browning of white adipose tissue and protein energy wasting.

A reverse transcription-nested PCR assay for HHV-6 mRNA early transcript detection after transplantation.

Monitoring of human herpesvirus-6 (HHV-6) reactivation is important, especially in immunocompromised patients such as transplant recipients. Reverse transcription PCR (RT-PCR) is a useful method to distinguish between latent and active infection. Here, a RT-nested PCR coupled with a colorimetric plate hybridization assay was established to detect HHV-6 types A and B U79/80 mRNAs. After confirming the reliability of the assay on HHV-6 cultures, it was applied to the detection of HHV-6 reactivation after renal (27 patients), bone marrow (14 patients) or heart (7 patients) transplantation. A total of 206 blood samples were tested from renal (137), bone marrow (58) and heart (11) transplant recipients. U79/80 mRNAs were found in 32 samples that were considered as indicative of HHV-6 reactivation: 15, 13 and 5 from kidney, bone marrow and heart transplant recipients, respectively. Finally, U79/80 mRNA detection was correlated with clinical manifestations including leucopenia, skin rash, graft rejection or dysfunction and diarrhoea.

Intracranial granuloma and skull osteolysis: complication of a primary cutaneous cryptococcosis in a kidney transplant recipient.

Cryptococcosis is the third most common invasive fungal infection in organ transplant recipients after candidiasis and aspergillosis. It occurs almost exclusively in the late posttransplantation period (>6 months after the initiation of immunosuppression). Subclinical onset of meningitis is the usual clinical presentation. Despite initiation of therapy, the mortality rate associated with this infection in this patient population remains high. To the best of our knowledge, this report describes one of the first cases of a rare entity: a primary cutaneous cryptococcosis in a renal transplant recipient disclosed by skull osteomyelitis and pseudotumoral intracranial extension. Surgical debridement and azole antifungal therapy were performed. Ten months after the onset of treatment, the patient feels good, clinical examination findings are normal, and no sign of evolutive cryptococcosis is noted.