1. Investigación

Chronic kidney disease (CKD) has been increasing over the last years, with a rate between 0.49% to 0.87% new cases per year. Currently, the number of affected people is around 850 million worldwide. CKD is a slowly progressive disease that leads to irreversible loss of kidney function, end-stage kidney disease, and premature death. Therefore, CKD is considered a global health problem, and this sets the alarm for necessary efficient prediction, management, and disease prevention. At present, modern computer analysis, such as in silico medicine (ISM), denotes an emergent data science that offers interesting promise in the nephrology field. ISM offers reliable computer predictions to suggest optimal treatments in a case-specific manner. In addition, ISM offers the potential to gain a better understanding of the kidney physiology and/or pathophysiology of many complex diseases, together with a multiscale disease modeling. Similarly, -omics platforms (including genomics, transcriptomics, metabolomics, and proteomics), can generate biological data to obtain information on gene expression and regulation, protein turnover, and biological pathway connections in renal diseases. In this sense, the novel patient-centered approach in CKD research is built upon the combination of ISM analysis of human data, the use of in vitro models, and in vivo validation. Thus, one of the main objectives of CKD research is to manage the disease by the identification of new disease drivers, which could be prevented and monitored. This review explores the wide-ranging application of computational medicine and the application of -omics strategies in evaluating and managing kidney diseases.

Introducción: PROGRESER es un estudio multicéntrico, prospectivo, observacional, con tres años de seguimiento, de una cohorte de pacientes con enfermedad renal crónica (ERC)-3 KDOQI, incluidos en servicios de Nefrología del Sistema Nacional de Salud en 14 comunidades autónomas de España. El objetivo primario fue analizar los factores de riesgo asociados con la progresión de la ERC, para identificar posibles diferencias entre pacientes con y sin diabetes mellitus (DM). El objetivo secundario fue investigar si los factores asociados con hospitalizaciones y mortalidad. Material y métodos: Se incluyeron 462 pacientes (342 hombres y 120 mujeres, con una edad media de 66,5 ± 11,5 añ os), reclutados en 25 centros. Se recogieron datos epidemiológicos, clínicos y analíticos cada seis meses, registrados en cuaderno electrónico. Se recogieron y congelaron muestras biológicas para biobanco basales y a 18 y 36 meses.Resultados: El filtrado glomerular estimado (FGe), calculado inicialmente mediante la ecuación Modification of Diet in Renal Disease (MDRD) y después recalculado mediante CKD-EPI fue de 43,9 ± 7,9 mL/min/1,73 m2 en el momento basal y de 29,9 ± 6,8 mL/min/1,73 m2 a los tres añ os de seguimiento. Dos tercios de los pacientes (66,2%) presentaron progresión del daño renal según criterio del estudio (descenso mayor del 15% del FGe sobre el valor basal). Un 38,7% presentaron una reducción del FGe ≥ 30%; un 20,3% tuvieron una reducción del FGe≥ 40%; un 10,4% tuvieron una reducción ≥ 50% y un 6,9%, una reducción ≥ 57%. De los 199 diabéticos, 134 (67,3%) presentaron progresión. De los 263 no diabéticos, 172 (65,3%) presentaron progresión (p = 0,456). El 27,3% de pacientes presentaban microalbuminuria y el 22,5%, proteinuria. El estudio mostró que la progresión de un estadio a otros más avanzados no fue superior en los pacientes con DM respecto a los no diabéticos. El análisis multivariante reveló que la presencia de hipertensión arterial (HTA) se aproximó a la significación estadística (p = 0,07) asociado a la progresión en los pacientes sin DM, y que en los pacientes con DM unos niveles basales de calcio más bajos y de PTH-i más elevados sobre el valor basal tuvieron significación estadística como factores de progresión de la ERC. Conclusión: Nuestro estudio no ha revelado nuevos factores de progresión de daño renal con relación a los factores clásicos ya conocidos. No hemos encontrado diferencias significativas en cuanto a la progresión en pacientes con y sin DM. La progresión del daño renal en pacientes con ERC-3 KDOQI debe interpretarse en un contexto multifactorial. Se precisa la búsqueda de nuevos biomarcadores, diferentes de los tradicionales, para establecer nuevas estrategias terapéuticas para prevenir la progresión de la ERC.

Bone strength is determined not only by bone quantity [bone mineral density (BMD)] but also by bone quality, including matrix composition, collagen fiber arrangement, microarchitecture, geometry, mineralization, and bone turnover, among others. These aspects influence elasticity, the load-bearing and repair capacity of bone, and microcrack propagation and are thus key to fractures and their avoidance. In chronic kidney disease (CKD)-associated osteoporosis, factors traditionally associated with a lower bone mass (advanced age or hypogonadism) often coexist with non-traditional factors specific to CKD (uremic toxins or renal osteodystrophy, among others), which will have an impact on bone quality. The gold standard for measuring BMD is dual-energy X-ray absorptiometry, which is widely accepted in the general population and is also capable of predicting fracture risk in CKD. Nevertheless, a significant number of fractures occur in the absence of densitometric World Health Organization (WHO) criteria for osteoporosis, suggesting that methods that also evaluate bone quality need to be considered in order to achieve a comprehensive assessment of fracture risk. The techniques for measuring bone quality are limited by their high cost or invasive nature, which has prevented their implementation in clinical practice. A bone biopsy, high-resolution peripheral quantitative computed tomography, and impact microindentation are some of the methods established to assess bone quality. Herein, we review the current evidence in the literature with the aim of exploring the factors that affect both bone quality and bone quantity in CKD and describing available techniques to assess them.

Aim: Sodium-glucose co-transporter 2 inhibitors and mineralocorticoid receptor antagonists reduce albuminuria and the risk of kidney failure. The aim of this study was to investigate the effects of both agents alone and in combination on markers of the glomerular endothelial glycocalyx and tubular function. Methods: This post-hoc analysis utilized data of the ROTATE-3 study, a randomized cross-over study in 46 adults with chronic kidney disease and urinary albumin excretion ≥100 mg/24 h, who were treated for 4 weeks with dapagliflozin, eplerenone or its combination. The effects of dapagliflozin, eplerenone and the combination on outcome measures such as heparan sulphate, neuro-hormonal markers and tubular sodium handling were assessed with mixed repeated measures models. Results: The mean percentage change from baseline in heparan sulphate after 4 weeks treatment with dapagliflozin, eplerenone or dapagliflozin-eplerenone was -34.8% (95% CI -52.2, -10.9), -5.9% (95% CI -32.5, 31.3) and -28.1% (95% CI -48.4, 0.1) respectively. The mean percentage change from baseline in plasma aldosterone was larger with eplerenone [38.9% (95% CI 2.8, 87.7)] and dapagliflozin-eplerenone [32.2% (95% CI -1.5, 77.4)], compared with dapagliflozin [-12.5% (95% CI -35.0, 17.8)], respectively. Mean percentage change from baseline in copeptin with dapagliflozin, eplerenone or dapagliflozin-eplerenone was 28.4% (95% CI 10.7, 49.0), 4.2% (95% CI -10.6, 21.4) and 23.8% (95% CI 6.6, 43.9) respectively. Dapagliflozin decreased proximal absolute sodium reabsorption rate by 455.9 mmol/min (95% CI -879.2, -32.6), while eplerenone decreased distal absolute sodium reabsorption rate by 523.1 mmol/min (95% CI -926.1, -120.0). Dapagliflozin-eplerenone decreased proximal absolute sodium reabsorption [-971.0 mmol/min (95% CI -1411.0, -531.0)], but did not affect distal absolute sodium reabsorption [-9.2 mmol/min (95% CI -402.0, 383.6)]. Conclusions: Dapagliflozin and eplerenone exert different effects on markers of glomerular and tubular function supporting the hypothesis that different mechanistic pathways may account for their kidney protective effects.

Background: Chronic kidney disease (CKD) is a common complication of a non-kidney solid organ transplant (NKSOT). Identifying predisposing factors is crucial for an early approach and correct referral to nephrology. Methods: This is a single-center retrospective observational study of a cohort of CKD patients under follow-up in the Nephrology Department between 2010 to 2020. Statistical analysis was performed between all the risk factors and four dependent variables: end-stage renal disease (ESKD); increased serum creatinine ≥50%; renal replacement therapy (RRT); and death in the pre-transplant, peri-transplant, and post-transplant periods. Results: 74 patients were studied (7 heart transplants, 34 liver transplants, and 33 lung transplants). Patients who were not followed-up by a nephrologist in the pre-transplant (p < 0.027) or peri-transplant (p < 0.046) periods and those who had the longest time until an outpatient clinic follow-up (HR 1.032) were associated with a higher risk of creatinine increase ≥50%. Receiving a lung transplant conferred a higher risk than a liver or heart transplant for developing a creatinine increase ≥50% and ESKD. Peri-transplant mechanical ventilation, peri-transplant and post-transplant anticalcineurin overdose, nephrotoxicity, and the number of hospital admissions were significantly associated with a creatinine increase ≥50% and developing ESKD. Conclusions: Early and close follow-up by a nephrologist was associated with a decrease in the worsening of renal function.

Although phosphorus is an essential element for life, it is not found in nature in its native state but rather combined in the form of inorganic phosphates (PO4 3−), with tightly regulated plasma levels that are associated with deleterious effects and mortality when these are out of bounds. The growing interest in the accumulation of PO4 3− in human pathophysiology originated in its attributed role in the pathogenesis of secondary hyperparathyroidism (SHPT) in chronic kidney disease. In this article, we review the mechanisms by which this effect was justified and we commemorate the important contribution of a Spanish group led by Dr. M. Rodríguez, just 25 years ago, when they first demonstrated the direct effect of PO4 3−on the regulation of the synthesis and secretion of parathyroid hormone by maintaining the structural integrity of the parathyroid glands in their original experimental model. In addition to demonstrating the importance of arachidonic acid (AA) and the phospholipase A2-AA pathway as a mediator of parathyroid gland response, these findings were predecessors of the recent description of the important role of PO4 3- on the activity of the calcium sensorreceptor, and also fueled various lines of research on the importance of PO4 3− overload not only for the pathophysiology of SHPT but also in its systemic pathogenic role.

Introduction: Secondary hyperparathyroidism (SHP) is frequent in patients with chronic kidney disease (CKD), particularly in those in dialysis. To treat this complication, the current options available include phosphorus restriction, phosphate binders, the inhibition of parathyroid hormone (PTH) synthesis and secretion by the supplementation of vitamin D or VDR activators, or the use of calcimimetics. Beyond the control of PTH, the effects of the treatment of SHP on other biomarkers of risk may represent an additional benefit for this population. In this study, we explore the benefits of current SHP treatment options, mainly paricalcitol and/or etelcalcetide in the inflammatory state of hemodialysis (HD) patients. Results: the study finally included 142 maintenance HD patients (5 patients were excluded) followed for 6 months (dialysis vintage 26 ± 30 months, mean age 70 years old, 73% women, 81% Spanish white, 47% diabetic). In this case, 52 patients were on regular treatment with paricalcitol for SHP and 25 patients were eligible to initiate etelcalcetide. The baseline serum levels of Ca, P, PTH, Ferritin, albumin, C-reactive protein (CRP), and other variables were measured. We found serum PTH levels showed an improvement after the treatment with etelcalcetide again paricalcitol and no treatment (p < 0.04). Of note, serum levels of CRP were significantly lower in a small group of patients (n = 11) receiving paricalcitol + etelcalcetide compared to paricalcitol or etelcalcetide alone. The proportion of patients with CRP within target ranges (≤1.0 mg/dL) increased significantly after combined treatment (p < 0.001). Conclusions: etelcalcetide proved to safely reduce the PTH levels without significant adverse events and the possibility of a synergic anti-inflammatory effect with the simultaneous use of Paricalcitol in HD patients.

Type 2 diabetes mellitus (T2DM) affects an estimated 463 million people worldwide, equivalent to 1 in 11 adults. Moreover, the rapid growth of this disease has resulted in a high incidence of diabetic kidney disease (DKD), which, together with hypertension, is the main cause of chronic kidney disease (CKD). Hyperglycaemia, low-grade inflammation, altered lipid metabolism and hyperactivation of the renin–angiotensin–aldosterone system (RAAS) seem to be interrelated mechanisms contributing to both T2DM and microvascular complications. The introduction of drugs such as sodium–glucose cotransporter 2 inhibitors and glucagon-like peptide 1 receptor agonists has improved the ability to slow the progression of DKD, and has also demonstrated benefits in cardiovascular disease. Beyond the effects of these novel antidiabetic drugs, a body of evidence suggests that the overactivation of the mineralocorticoid receptor also contributes to CKD progression. Moreover, new and ongoing trials have demonstrated that the selective nonsteroidal mineralocorticoid receptor antagonist (MRA) finerenone improves the risk of CKD progression and cardiovascular events in patients with CKD and T2DM and optimized RAAS blockade. We review the rationale for the development and use of MRA drugs to slow CKD progression in patients with DKD, as well as other pleiotropic effects, and highlight the warnings associated with these agents.

Background. Over the last few years, the use of sodium-glucose cotransporter 2 inhibitors (SGLT2i) and glucagon-like peptide 1 receptor agonists (GLP-1RA) has increased substantially in medical practice due to their documented benefits in cardiorenal and metabolic health. In this sense, and in addition to being used for glycemic control in diabetic patients, these drugs also have other favorable effects such as weight loss and lowering blood pressure, and more recently, they have been shown to have cardio and renoprotective effects with anti-inflammatory properties. Concerning the latter, the individual or associated use of these antihyperglycemic agents has been linked with a decrease in proinflammatory cytokines and with an improvement in the inflammatory profile in chronic endocrine-metabolic diseases. Hence, these drugs have been positioned as first-line therapy in the management of diabetes and its multiple comorbidities, such as obesity, which has been associated with persistent inflammatory states that induce dysfunction of the adipose tissue. Moreover, other frequent comorbidities in long-standing diabetic patients are chronic complications such as diabetic kidney disease, whose progression can be slowed by SGLT2i and/or GLP-1RA. The neuroendocrine and immunometabolism mechanisms underlying adipose tissue inflammation in individuals with diabetes and cardiometabolic and renal diseases are complex and not fully understood. Summary. This review intends to expose the probable molecular mechanisms and compile evidence of the synergistic or additive anti-inflammatory effects of SGLT2i and GLP-1RA and their potential impact on the management of patients with obesity and cardiorenal compromise.