A Nephrologist Perspective on Obesity: From Kidney Injury to Clinical Management

Malaltia renal crònica; Obesitat; Trasplantament de ronyóEnfermedad renal crónica; Obesidad; Trasplante de riñónChronic kidney disease; Obesity; Kidney transplantationObesity is one of the epidemics of our era. Its prevalence is higher than 30% in the U.S. and it is estimated to increase by 50% in 2030. Obesity is associated with a higher risk of all-cause mortality and it is known to be a cause of chronic kidney disease (CKD). Typically, obesity-related glomerulopathy (ORG) is ascribed to renal hemodynamic changes that lead to hyperfiltration, albuminuria and, finally, impairment in glomerular filtration rate due to glomerulosclerosis. Though not only hemodynamics are responsible for ORG: adipokines could cause local effects on mesangial and tubular cells and podocytes promoting maladaptive responses to hyperfiltration. Furthermore, hypertension and type 2 diabetes mellitus, two conditions generally associated with obesity, are both amplifiers of obesity injury in the renal parenchyma, as well as complications of overweight. As in the native kidney, obesity is also related to worse outcomes in kidney transplantation. Despite its impact in CKD and cardiovascular morbility and mortality, therapeutic strategies to fight against obesity-related CKD were limited for decades to renin-angiotensin blockade and bariatric surgery for patients who accomplished very restrictive criteria. Last years, different drugs have been approved or are under study for the treatment of obesity. Glucagon-like peptide-1 receptor agonists are promising in obesity-related CKD since they have shown benefits in terms of losing weight in obese patients, as well as preventing the onset of macroalbuminuria and slowing the decline of eGFR in type 2 diabetes. These new families of glucose-lowering drugs are a new frontier to be crossed by nephrologists to stop obesity-related CKD progression

Kidney transplantation and COVID-19 renal and patient prognosis

Coronavirus SARS-CoV-2; COVID-19; 2019-nCoV; Síndrome de dificultat respiratòria aguda; Trasplantament renalCoronavirus SARS-CoV-2; COVID-19; 2019-nCoV; Síndrome de dificultad respiratoria aguda; Trasplante renalCoronavirus SARS-CoV-2; COVID-19; 2019-nCoV; Acute respiratory distress syndrome; Renal transplantationCoronavirus disease 2019 (COVD-19) emerged as a pandemic in December 2019. Infection has spread quickly and renal transplant recipients receiving chronic immunosuppression have been considered a population at high risk of infection, complications and infection-related death. During this year a large amount of information from nationwide registries, multicentre and single-centre studies have been reported. The number of renal transplant patients diagnosed with COVID-19 was higher than in the general population, but the lower threshold for testing may have contributed to its better identification. Major complications such as acute kidney injury and acute respiratory distress syndrome were very frequent in renal transplant patients, with a high comorbidity burden, but further studies are needed to support that organ transplant recipients receiving chronic immunosuppression are more prone to develop these complications than the general population. Kidney transplant recipients experience a high mortality rate compared with the general population, especially during the very early post-transplant period. Despite the fact that some studies report more favourable outcomes in patients with a kidney transplant than in patients on the kidney waiting list, the higher mortality described in the very early post-transplant period would advise against performing a kidney transplant in areas where the spread of infection is high, especially in recipients >60 years of age. Management of transplant recipients has been challenging for clinicians and strategies such as less use of lymphocyte-depleting agents for new transplants or anti-metabolite withdrawal and calcineurin inhibitor reduction for transplant patients with COVID-19 are not based on high-quality evidence.The authors received grants from Red de Investigación Renal (REDinREN RD16/0009/0030) and Fondo de Investigación Sanitaria del Instituto de Salud Carlos III (PI 18/01704, PI 18/01382). B.C. is supported by a Vall d’Hebron Institute of Research grant. This article is part of a supplement supported by Fresenius Medical Care without any influence on its content

On the relevance of thrombomodulin variants in atypical hemolytic uremic syndrome

Atypical hemolytic uremic syndrome; Genetic analysis; ThrombomodulinSíndrome hemolítica urèmica atípica; Anàlisi genètica; TrombomodulinaSíndrome hemolítico urémico atípico; Análisis genético; TrombomodulinaThis project was funded by the Instituto de Salud Carlos III: REDinREN (RD016/009/009) and Instituto de Investigacion Puerta de Hierro-Segovia Arana (IDIPHISA) to AH and by grants from the Spanish Ministerio de Economía y Competitividad–FEDER (European Regional Development Fund) (PID2019-104912RB-I00) and the Autonomous Region of Madrid (S2017/BMD-3673 and S2022/BMD-7278) to SRdC. TC was supported by a grant from National Health Institute Carlos III (RETIC ISCIII RD21/0005; RICORS), This work was developed under the supervision of the Spanish Registry of the Atypical Hemolytic Uremic Syndrome and C3 Glomerulopathy (aHUS/C3G) registry

Progression of Interstitial Fibrosis and Tubular Atrophy in Low Immunological Risk Renal Transplants Monitored by Sequential Surveillance Biopsies: The Influence of TAC Exposure and Metabolism

Coeficient de variació; Biòpsies de protocol; Trasplantament renalCoeficiente de variación; Biopsias de protocolo; Trasplante renalCoefficient of variation; Protocol biopsies; Renal transplantationThe combination of tacrolimus (TAC) and mycophenolate is the most widely employed maintenance immunosuppression in renal transplants. Different surrogates of tacrolimus exposure or metabolism such as tacrolimus trough levels (TAC-C0), coefficient of variation of tacrolimus (CV-TAC-C0), time in therapeutic range (TTR), and tacrolimus concentration dose ratio (C/D) have been associated with graft outcomes. We explore in a cohort of low immunological risk renal transplants (n = 85) treated with TAC, mycophenolate mofetil (MMF), and steroids and then monitored by paired surveillance biopsies the association between histological lesions and TAC-C0 at the time of biopsy as well as CV-TAC-C0, TTR, and C/D during follow up. Interstitial inflammation (i-Banff score ≥ 1) in the first surveillance biopsy was associated with TAC-C0 (odds ratio (OR): 0.69, 95% confidence interval (CI): 0.50–0.96; p = 0.027). In the second surveillance biopsy, inflammation was associated with time below the therapeutic range (OR: 1.05 and 95% CI: 1.01–1.10; p = 0.023). Interstitial inflammation in scarred areas (i-IFTA score ≥ 1) was not associated with surrogates of TAC exposure/metabolism. Progression of interstitial fibrosis/tubular atrophy (IF/TA) was observed in 35 cases (41.2%). Multivariate regression logistic analysis showed that mean C/D (OR: 0.48; 95% CI: 0.25–0.92; p = 0.026) and IF/TA in the first biopsy (OR: 0.43, 95% CI: 0.24–0.77, p = 0.005) were associated with IF/TA progression between biopsies. A low C/D ratio is associated with IF/TA progression, suggesting that TAC nephrotoxicity may contribute to fibrosis progression in well immunosuppressed patients. Our data support that TAC exposure is associated with inflammation in healthy kidney areas but not in scarred tissue.The authors received grants from Red de Investigación Renal (REDinREN RD16/0009/0030), Fondo de Investigación Sanitaria del Instituto de Salud Carlos III (PI 18/01704, PI 18/01382), the Spanish Society of Transplantation and a Diaverum Spain restricted grant. Betty Chamoun has been supported by a VHIR (Vall Hebron Institute Research) grant