Time to Change Our Viewpoints to Assess Renal Risks in Patients with Solitary Kidneys beyond Traditional Approaches?

Solitary functioning kidney (SFK) can be defined as the absence or hypofunction of a kidney due to acquired or congenital reasons. A congenital solitary functioning kidney (cSFK) is more common than is an acquired one (aSFK) and is characterized by the anatomical absence (agenesis) or hypofunction (hypoplasia; hypodysplasia) of one kidney from birth. Among the acquired causes, the most important is nephrectomy (Nx) (due to the donor, trauma or mass resection). Patients with SFK are at risk for the development of chronic kidney disease (CKD) in the long term. This risk potential is also significantly affected by hypertension. The relationship between hypertension and subclinical chronic inflammation is a connection that has not yet been fully clarified pathogenetically, but there are many studies highlighting this association. In recent years, studies examining different fibrosis and inflammation biomarkers in terms of the evaluation and prediction of renal risks have become increasingly popular in the literature. Oxidative stress is known to play an important role in homocysteine-induced endothelial dysfunction and has been associated with hypertension. In our study, we aimed to investigate the relationship between ambulatory blood pressure monitoring (ABPM) and urinary/serum fibrosis and inflammatory markers in patients with SFK. We prospectively investigated the relationship between ABPM results and soluble urokinase plasminogen activator receptor (suPAR), procollagen type III N-terminal peptide (PIIINP), homocysteine and other variables in 85 patients with SFK and compared them between cSFK and aSFK groups. In the etiology of SFK, a congenital or acquired origin may differ in terms of the significance of biomarkers. In particular, the serum homocysteine level may be associated with different clinical outcomes in patients with cSFK and aSFK.

The effects of tacrolimus and mycophenolate mofetil on regression of encapsulating peritoneal sclerosis in a rat model / Efectos del tacrolimus y el micofenolato mofetil en la regresión de la esclerosis peritoneal encapsulante en ratas

ABSTRACT Objective: Encapsulating peritoneal sclerosis (EPS) is a rare, but potentially fatal complication of peritoneal dialysis. Currently, treatment of peritoneal fibrosis is not fully possible yet. In this study, we aimed to demonstrate the effects of tacrolimus therapy on peritoneal fibrosis and inflammation when administered alone or with mycophenolate mofetil (MMF) in the EPS model induced in rats. Methods: Thirty six Wistar albino rats were separated into six equal groups. Group I was the control group. Group II-VI were administered intraperitoneal chlorhexidine (CH) for induced EPS model in rats. Group II, IV, V, VI were administered isotonic liquid, tacrolimus, tacrolimus and concurrently with CH, tacrolimus and MMF together, respectively. Group III was not administered any drug. All peritoneal samples were stained immunohistochemically with matrix metalloproteinase-2 (MMP-2) antibody. Thickness of peritoneal fibrosis, subserosal large collagen fibers, subserosal fibroblast proliferation and subserosal fibrotic matrix deposition were evaluated. Results: Comparing the experimentally induced EPS groups, the best histopathological results and the largest staining with MMP-2 were achieved in Group VI. Furthermore, in all treatment groups (IV, V, VI) more staining with MMP-2 was detected compared to non-treatment groups (I, II, III) but no statistically significant differences were found among all groups. A statistically significant remission was observed in all histopathological parameters, primarily peritoneal thickness in rats that were administered MMF with tacrolimus, compared to rats which were administered tacrolimus only. Conclusion: Concurrent use of tacrolimus and MMF in the treatment of EPS may be a promising approach.

RESUMEN Objetivos: La esclerosis peritoneal encapsulante (EPE) es una complicación rara, peropotencialmente fatal de la diálisis peritoneal. Actualmente, el tratamiento de la fibrosis peritoneal aún no es posible. En este estudio, apuntamos a demostrar los efectos de la terapia con tacrolimus en la fibrosis peritoneal y la inflamación cuando se administran solos o con micofenolato de mofetilo (MMF) en el modelo EPE inducido en ratas. Métodos: Treinta y seis ratas Wistar albinas se separaron en seis grupos iguales. El Grupo I era el grupo de control. En los grupos II-VI se administró clorhexidina intraperitoneal (CH) para el modelo EPE inducido en ratas. En los Grupos II, IV, V, VI se administró respectivamente líquido isotónico, tacrolimus, tacrolimus y CH y finalmente tacrolimus y MMF juntos. El grupo III no recibió ningún medicamento. Todas las muestras peritoneales se tiñeron inmunohistoquímicamente con el anticuerpo Matrix Metaloproteinasa-2 (MMP- 2). Se evaluó el grosor de la fibrosis peritoneal, se evaluaron las fibras de colágeno grandes subserosas, la proliferación de fibroblastos subserosa y la deposición de la matriz fibrótica subserosa. Resultados: Comparando los grupos de EPE inducidos experimentalmente, los mejores resultados histopatológicos y la tinción con MMP- 2 más extensa se lograron en el Grupo VI. Además, en todos los grupos de tratamiento (IV, V, VI) se detectó más tinción con MMP-2 en comparación con los grupos de no tratamiento (I, II, III), pero no se encontraron diferencias estadísticamente significativas entre todos los grupos. Se observó una remisión estadísticamente significativa en todos los parámetros histopatológicos, principalmente el espesor peritoneal en ratas que recibieron MMF con tacrolimus, en comparación con las ratas que recibieron solo tacrolimus. Conclusión: El uso concurrente de tacrolimus y MMF en el tratamiento de EPS puede ser una aplicación prometedora.

Characteristics and outcomes of acute kidney injury in hospitalized COVID-19 patients: A multicenter study by the Turkish society of nephrology.

BACKGROUND: Acute kidney injury (AKI) is common in coronavirus disease-2019 (COVID-19) and the severity of AKI is linked to adverse outcomes. In this study, we investigated the factors associated with in-hospital outcomes among hospitalized patients with COVID-19 and AKI. METHODS: In this multicenter retrospective observational study, we evaluated the characteristics and in-hospital renal and patient outcomes of 578 patients with confirmed COVID-19 and AKI. Data were collected from 34 hospitals in Turkey from March 11 to June 30, 2020. AKI definition and staging were based on the Kidney Disease Improving Global Outcomes criteria. Patients with end-stage kidney disease or with a kidney transplant were excluded. Renal outcomes were identified only in discharged patients. RESULTS: The median age of the patients was 69 years, and 60.9% were males. The most frequent comorbid conditions were hypertension (70.5%), diabetes mellitus (43.8%), and chronic kidney disease (CKD) (37.6%). The proportions of AKI stages 1, 2, and 3 were 54.0%, 24.7%, and 21.3%, respectively. 291 patients (50.3%) were admitted to the intensive care unit. Renal improvement was complete in 81.7% and partial in 17.2% of the patients who were discharged. Renal outcomes were worse in patients with AKI stage 3 or baseline CKD. The overall in-hospital mortality in patients with AKI was 38.9%. In-hospital mortality rate was not different in patients with preexisting non-dialysis CKD compared to patients without CKD (34.4 versus 34.0%, p = 0.924). By multivariate Cox regression analysis, age (hazard ratio [HR] [95% confidence interval (95%CI)]: 1.01 [1.0-1.03], p = 0.035], male gender (HR [95%CI]: 1.47 [1.04-2.09], p = 0.029), diabetes mellitus (HR [95%CI]: 1.51 [1.06-2.17], p = 0.022) and cerebrovascular disease (HR [95%CI]: 1.82 [1.08-3.07], p = 0.023), serum lactate dehydrogenase (greater than two-fold increase) (HR [95%CI]: 1.55 [1.05-2.30], p = 0.027) and AKI stage 2 (HR [95%CI]: 1.98 [1.25-3.14], p = 0.003) and stage 3 (HR [95%CI]: 2.25 [1.44-3.51], p = 0.0001) were independent predictors of in-hospital mortality. CONCLUSIONS: Advanced-stage AKI is associated with extremely high mortality among hospitalized COVID-19 patients. Age, male gender, comorbidities, which are risk factors for mortality in patients with COVID-19 in the general population, are also related to in-hospital mortality in patients with AKI. However, preexisting non-dialysis CKD did not increase in-hospital mortality rate among AKI patients. Renal problems continue in a significant portion of the patients who were discharged.

Mortality analysis of COVID-19 infection in chronic kidney disease, haemodialysis and renal transplant patients compared with patients without kidney disease: a nationwide analysis from Turkey.

BACKGROUND: Chronic kidney disease (CKD) and immunosuppression, such as in renal transplantation (RT), stand as one of the established potential risk factors for severe coronavirus disease 2019 (COVID-19). Case morbidity and mortality rates for any type of infection have always been much higher in CKD, haemodialysis (HD) and RT patients than in the general population. A large study comparing COVID-19 outcome in moderate to advanced CKD (Stages 3-5), HD and RT patients with a control group of patients is still lacking. METHODS: We conducted a multicentre, retrospective, observational study, involving hospitalized adult patients with COVID-19 from 47 centres in Turkey. Patients with CKD Stages 3-5, chronic HD and RT were compared with patients who had COVID-19 but no kidney disease. Demographics, comorbidities, medications, laboratory tests, COVID-19 treatments and outcome [in-hospital mortality and combined in-hospital outcome mortality or admission to the intensive care unit (ICU)] were compared. RESULTS: A total of 1210 patients were included [median age, 61 (quartile 1-quartile 3 48-71) years, female 551 (45.5%)] composed of four groups: control (n = 450), HD (n = 390), RT (n = 81) and CKD (n = 289). The ICU admission rate was 266/1210 (22.0%). A total of 172/1210 (14.2%) patients died. The ICU admission and in-hospital mortality rates in the CKD group [114/289 (39.4%); 95% confidence interval (CI) 33.9-45.2; and 82/289 (28.4%); 95% CI 23.9-34.5)] were significantly higher than the other groups: HD = 99/390 (25.4%; 95% CI 21.3-29.9; P < 0.001) and 63/390 (16.2%; 95% CI 13.0-20.4; P < 0.001); RT = 17/81 (21.0%; 95% CI 13.2-30.8; P = 0.002) and 9/81 (11.1%; 95% CI 5.7-19.5; P = 0.001); and control = 36/450 (8.0%; 95% CI 5.8-10.8; P < 0.001) and 18/450 (4%; 95% CI 2.5-6.2; P < 0.001). Adjusted mortality and adjusted combined outcomes in CKD group and HD groups were significantly higher than the control group [hazard ratio (HR) (95% CI) CKD: 2.88 (1.52-5.44); P = 0.001; 2.44 (1.35-4.40); P = 0.003; HD: 2.32 (1.21-4.46); P = 0.011; 2.25 (1.23-4.12); P = 0.008), respectively], but these were not significantly different in the RT from in the control group [HR (95% CI) 1.89 (0.76-4.72); P = 0.169; 1.87 (0.81-4.28); P = 0.138, respectively]. CONCLUSIONS: Hospitalized COVID-19 patients with CKDs, including Stages 3-5 CKD, HD and RT, have significantly higher mortality than patients without kidney disease. Stages 3-5 CKD patients have an in-hospital mortality rate as much as HD patients, which may be in part because of similar age and comorbidity burden. We were unable to assess if RT patients were or were not at increased risk for in-hospital mortality because of the relatively small sample size of the RT patients in this study.