From water to aquaretics: a legendary route.

Man is water. When life appeared on earth, the primordial cell had a simple structure and could immediately ascertain from the surrounding aquatic environment the substances for nutrition and oxygen, without any need for structural complexity. As part of evolution, during the transition from aquatic to terrestrial life, vertebrates had to fight against dehydration as well as fish in the sea. In this complex mechanism of osmoregulation, the structure and function of some osmoregulatory hormones have been maintained during the evolution of species, from fish to man. Within the homeostatic mechanism, the renin-angiotensin-aldosterone system (RAAS) is crucial in the regulation of renal reasorption of water and sodium. It is also involved in the regulation of renal plasma flux, blood volume and blood pressure. Vasopressin plays a hormonal function in the mechanisms of water homeostasis acting through Aquaporins (AQP), channel-proteins that allow bi-directional water transport across cell membranes.

Mental health, COVID-19 burden and quality of life of kidney transplant recipients two years after the COVID-19 pandemic.

Introduction: Few studies have evaluated the psychological distress of COVID-19 in kidney transplantation and the psychological impact that the COVID-19 pandemic has had on kidney transplant recipients is not yet well understood. The present study aimed to investigate the change in symptom burden and health-related quality of life in the two years after initial assessment, by outlining the change over time of symptoms at 12 and 24 months of follow-up. Methods: This is a follow-up study. We performed a study published in 2021 (phase 1 of COVID-19); of the 89 kidney transplant recipients evaluated in this study, 60 completed the 12 months follow-up (March 2021 June 2021, phase 2 of COVID-19) and 57 completed the 24 months follow-up (March 2022 June 2022, post COVID-19). The same tools as in previous study were administered: the ad hoc questionnaire on emotional state and psychophysical well-being during COVID-19, the Middlesex Hospital Questionnaire (MHQ) to provide a simple and rapid quantification of the psychological and somatic symptoms and the Short Form Health Survey 36 (SF-36) was used to assess health-related quality of life. Results: Compared to the first and second phase of COVID-19, the mean score of quality of life variables were higher in the post COVID-19 phase; thus the recipients physical health, mental health and their perception of their general health improved. Regarding the psychopathology variables the levels of Anxiety, Depression and Phobia in the Post COVID-19 phase decreased, while the Somatization score was higher. Lastly, burden of COVID-19 scores in the third phase, significantly decreased. Discussion: Our study highlights a significant association between mental health and the burden of COVID-19 pandemic in kidney transplant recipients. This study showed, a significant worsening, over time, of some specific symptoms, such as somatization and phobias. However, the results showed that depressive symptoms improved during the study period. Long-term monitoring of kidney transplant recipients therefore remains fundamental. These results confirmed the need to provide integrated multidisciplinary services to adequately address the long-term effects of the COVID-19 pandemic on the mental health of the most vulnerable subjects.

Apelin, plasmatic osmolality and hypotension in dialyzed patients.

BACKGROUND/AIMS: To evaluate the balance between arginine-vasopressin (AVP) and apelin during hemodialysis and its role in hypotension onset and in the inflammation status. METHODS: We enrolled 50 patients chronically treated with hemodialysis. We assessed plasmatic osmolality, AVP, apelin, mean blood pressure (BP), high-sensitivity C-reactive protein (hsCRP) and ß(2)-microglobulin. RESULTS: Apelin rises during dialytic treatment (from 0.68 ± 0.34 to 1.89 ± 0.56 pg/ml, p < 0.0001), while plasmatic osmolality (from 325 ± 4.54 to 311 ± 1.20 mosm/kg H(2)O, p < 0.0001), AVP (from 4.28 ± 1.12 to 2.48 ± 0.50 pg/ml, p < 0.0001) and mean BP (from 124 ± 6 to 110 ± 7 mm Hg, p < 0.0001) decrease. At multivariate regression with respect to apelin, only mean BP remains (r = -0.95, p < 0.0001). We also correlated the AVP/apelin ratio with BP. Moreover, apelin is inversely related to hsCRP (r = -0.79, p < 0.0001). CONCLUSIONS: The AVP/apelin balance changes with plasmatic osmolality variations induced by hemodialytic sessions and could represent a physiopathological marker of arterial hypo- and hypertension. Finally, apelin appears inversely related to inflammation markers.

Apelin beyond kidney failure and hyponatremia: a useful biomarker for cancer disease progression evaluation.

Apelin regulates angiogenesis, stimulating endothelial cell proliferation and migration. It is upregulated during tumor angiogenesis, and its overexpression was reported to increase tumor growth. Furthermore, apelin controls vasopressin release and body fluid homeostasis. The aim of this study was to examine the correlations between apelin expression and clinical outcomes in oncologic patients, such as cancer disease progression and patient's survival. Apelin levels were evaluated in a cohort of 95 patients affected by different varieties of cancer. Partial remission and stable disease were assigned to the 'no progression' group, comparing it with the progressor group. Patients were followed up for 2 years. Receiver operating characteristics analysis was employed for identifying the progression of the oncologic disease and Kaplan-Meier curves assessed the survival. Adjusted risk estimates for progression endpoint were calculated using Cox proportional hazard regression analysis. Oncologic patients had higher apelin levels compared with healthy subjects, and apelin was closely related to the stages of the disease. In the hyponatremia group, apelin values were significantly higher than patients with eunatremia. After the follow-up of 24 months, 41 patients (43%) reached the endpoint. Progressor subjects presented significantly increased apelin values at baseline compared with non-progressor. Univariate followed by multivariate Cox proportional hazard regression analysis showed that apelin predicted cancer progression independently of other potential confounders. In patients with cancer, apelin closely reflects the stage of the disease and represents a strong and independent risk marker for cancer progression.

New therapeutic strategies under development to halt the progression of renal failure.

INTRODUCTION: Chronic kidney disease (CKD) is a pathological condition associated with high morbidity and mortality. Accordingly, prevention of CKD onset and progression is mandatory. As pharmacological agents already used in clinical practice are not yet able to halt the progression of renal damage, new therapeutic strategies are being explored. AREAS COVERED: The authors carried out a systematic review on completed and ongoing Phase I and II clinical trials with an aim to evaluate the safety and efficacy of novel therapeutic approaches to CKD. The data in this manuscript was retrieved from the currently available scientific literature as well as from the ClinicalTrials.gov website. EXPERT OPINION: Several drugs are currently under investigation due to their supposed antiproteinuric action, such as selective endothelin-A receptor antagonists and vitamin D analogues. Other drugs could be used in CKD because of their antifibrotic, anti-inflammatory and antioxidative properties or due to the hypothetical ability to repair damaged podocytes. A fascinating therapeutic approach involves the use of progenitor/stem cells. There is still some way to go in the use of stem cells in clinical practice but remarkable progress has been made. This is especially true in terms of the understanding of their biology and behaviour, as well as in the procedures required to mobilize and activate endogenous stem cells in damaged kidneys or simply introducing them.