METABOLIC IMPLICATIONS OF PERITONEAL DIALYSIS IN PATIENTS WITH ACUTE KIDNEY INJURY

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

The long-term outcome after acute kidney injury: a narrative review

This review will focus on long-term outcomes after acute kidney injury (AKI). Surviving AKI patients have a higher late mortality compared with those admitted without AKI. Recent studies have claimed that long-term mortality in patients after AKI varied from 15% to 74% and older age, presence of previous co-morbidities, and the incomplete recovery of renal function have been identified as risk factors for reduced survival. AKI is also associated with progression to chronic kidney (CKD) disease and the decline of renal function at hospital discharge and the number and severity of AKI episodes have been associated with progression to CKD. IN the most studies, recovery of renal function is defined as non-dependence on renal replacement therapy which is probably too simplistic and it is expected in 60-70% of survivors by 90 days. Further studies are needed to explore the long-term prognosis of AKI patients.

Peritoneal dialysis in acute kidney injury: trends in the outcome across time periods

Peritoneal dialysis (PD) should be considered a suitable method of renal replacement therapy in acute kidney injury (AKI) patients. This study is the largest cohort providing patient characteristics, clinical practice, patterns and their relationship to outcomes in a developing country. Its objective was to describe the main determinants of patient and technique survival, including trends over time of PD treatment in AKI patients. This was a Brazilian prospective cohort study in which all adult AKI patients on PD were studied from January/2004 to January/2014. For comparison purposes, patients were divided into 2 groups according to the year of treatment: 2004-2008 and 2009-2014. Patient survival and technique failure (TF) were analyzed using the competing risk model of Fine and Gray. A total of 301 patients were included, 51 were transferred to hemodialysis (16.9%) during the study period. The main cause of TF was mechanical complication (47%) followed by peritonitis (41.2%). There was change in TF during the study period: compared to 2004-2008, patients treated at 2009-2014 had relative risk (RR) reduction of 0.86 (95% CI 0.77-0.96) and three independent risk factors were identified: period of treatment at 2009 and 2014, sepsis and age>65 years. There were 180 deaths (59.8%) during the study. Death was the leading cause of dropout (77.9% of all cases) mainly by sepsis (58.3%), followed cardiovascular disease (36.1%). The overall patient survival was 41% at 30 days. Patient survival improved along study periods: compared to 2004-2008, patients treated at 2009-2014 had a RR reduction of 0.87 (95% CI 0.79-0.98). The independent risk factors for mortality were sepsis, age>70 years, ATN-ISS > 0.65 and positive fluid balance. As conclusion, we observed an improvement in patient survival and TF along the years even after correction for several confounders and using a competing risk approach.

Lycopene supplementation reduces TNF-alpha via RAGE in the kidney of obese rats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Proteinuria predicts relapse in adolescent and adult minimal change disease

OBJECTIVE: This study sought to outline the clinical and laboratory characteristics of minimal change disease in adolescents and adults and establish the clinical and laboratory characteristics of relapsing and non-relapsing patients. METHODS: We retrospectively evaluated patients with confirmed diagnoses of minimal change disease by renal biopsy from 1979 to 2009; the patients were aged >13 years and had minimum 1-year follow-ups. RESULTS: Sixty-three patients with a median age (at diagnosis) of 34 (23-49) years were studied, including 23 males and 40 females. At diagnosis, eight (12.7%) patients presented with microscopic hematuria, 17 (27%) with hypertension and 17 (27%) with acute kidney injury. After the initial treatment, 55 (87.3%) patients showed complete remission, six (9.5%) showed partial remission and two (3.1%) were nonresponders. Disease relapse was observed in 34 (54%) patients who were initial responders (n = 61). In a comparison between the relapsing patients (n = 34) and the non-relapsing patients (n = 27), only proteinuria at diagnosis showed any significant difference (8.8 (7.1-12.0) vs. 6.0 (3.6-7.3) g/day, respectively, p = 0.001). Proteinuria greater than 7 g/day at the initial screening was associated with relapsing disease. CONCLUSIONS: In conclusion, minimal change disease in adults may sometimes present concurrently with hematuria, hypertension, and acute kidney injury. The relapsing pattern in our patients was associated with basal proteinuria over 7 g/day.

Oxidative Stress and Modification of Renal Vascular Permeability Are Associated with Acute Kidney Injury during P. berghei ANKA Infection

Malaria associated-acute kidney injury (AKI) is associated with 45% of mortality in adult patients hospitalized with severe form of the disease. However, the causes that lead to a framework of malaria-associated AKI are still poorly characterized. Some clinical studies speculate that oxidative stress products, a characteristic of Plasmodium infection, as well as proinflammatory response induced by the parasite are involved in its pathophysiology. Therefore, we aimed to investigate the development of malaria-associated AKI during infection by P. berghei ANKA, with special attention to the role played by the inflammatory response and the involvement of oxidative stress. For that, we took advantage of an experimental model of severe malaria that showed significant changes in the renal pathophysiology to investigate the role of malaria infection in the renal microvascular permeability and tissue injury. Therefore, BALB/c mice were infected with P. berghei ANKA. To assess renal function, creatinine, blood urea nitrogen, and ratio of proteinuria and creatininuria were evaluated. The products of oxidative stress, as well as cytokine profile were quantified in plasma and renal tissue. The change of renal microvascular permeability, tissue hypoxia and cellular apoptosis were also evaluated. Parasite infection resulted in renal dysfunction. Furthermore, we observed increased expression of adhesion molecule, proinflammatory cytokines and products of oxidative stress, associated with a decrease mRNA expression of HO-1 in kidney tissue of infected mice. The measurement of lipoprotein oxidizability also showed a significant increase in plasma of infected animals. Together, our findings support the idea that products of oxidative stress, as well as the immune response against the parasite are crucial to changes in kidney architecture and microvascular endothelial permeability of BALB/c mice infected with P. berghei ANKA.

Long-Term Follow-Up of Patients after Acute Kidney Injury: Patterns of Renal Functional Recovery

Background and Objectives: Patients who survive acute kidney injury (AKI), especially those with partial renal recovery, present a higher long-term mortality risk. However, there is no consensus on the best time to assess renal function after an episode of acute kidney injury or agreement on the definition of renal recovery. In addition, only limited data regarding predictors of recovery are available. Design, Setting, Participants, & Measurements: From 1984 to 2009, 84 adult survivors of acute kidney injury were followed by the same nephrologist (RCRMA) for a median time of 4.1 years. Patients were seen at least once each year after discharge until end stage renal disease (ESRD) or death. In each consultation serum creatinine was measured and glomerular filtration rate estimated. Renal recovery was defined as a glomerular filtration rate value >= 60 mL/min/1.73 m2. A multiple logistic regression was performed to evaluate factors independently associated with renal recovery. Results: The median length of follow-up was 50 months (30-90 months). All patients had stabilized their glomerular filtration rates by 18 months and 83% of them stabilized earlier: up to 12 months. Renal recovery occurred in 16 patients (19%) at discharge and in 54 (64%) by 18 months. Six patients died and four patients progressed to ESRD during the follow up period. Age (OR 1.09, p < 0.0001) and serum creatinine at hospital discharge (OR 2.48, p = 0.007) were independent factors associated with non renal recovery. The acute kidney injury severity, evaluated by peak serum creatinine and need for dialysis, was not associated with non renal recovery. Conclusions: Renal recovery must be evaluated no earlier than one year after an acute kidney injury episode. Nephrology referral should be considered mainly for older patients and those with elevated serum creatinine at hospital discharge.

Renal Function at Hospital Admission and Mortality Due to Acute Kidney Injury after Myocardial Infarction

Background: The role of an impaired estimated glomerular filtration rate (eGFR) at hospital admission in the outcome of acute kidney injury (AKI) after acute myocardial infarction (AMI) has been underreported. The aim of this study was to assess the influence of an admission eGFR<60 mL/min/1.73 m(2) on the incidence and early and late mortality of AMI-associated AKI. Methods: A prospective study of 828 AMI patients was performed. AKI was defined as a serum creatinine increase of >= 50% from the time of admission (RIFLE criteria) in the first 7 days of hospitalization. Patients were divided into subgroups according to their eGFR upon hospital admission (MDRD formula, mL/min/1.73 m(2)) and the development of AKI: eGFR >= 60 without AKI, eGFR<60 without AKI, eGFR >= 60 with AKI and eGFR<60 with AKI. Results: Overall, 14.6% of the patients in this study developed AKI. The admission eGFR had no impact on the incidence of AKI. However, the admission eGFR was associated with the outcome of AMI-associated AKI. The adjusted hazard ratios (AHR, Cox multivariate analysis) for 30-day mortality were 2.00 (95% CI 1.11-3.61) for eGFR, 60 without AKI, 4.76 (95% CI 2.45-9.26) for eGFR >= 60 with AKI and 6.27 (95% CI 3.20-12.29) for eGFR, 60 with AKI. Only an admission eGFR of <60 with AKI was significantly associated with a 30-day to 1-year mortality hazard (AHR 3.05, 95% CI 1.50-6.19). Conclusions: AKI development was associated with an increased early mortality hazard in AMI patients with either preserved or impaired admission eGFR. Only the association of impaired admission eGFR and AKI was associated with an increased hazard for late mortality among these patients.

Minimal change disease associated with type 1 and type 2 diabetes mellitus

A 19-year-old female with type 1 diabetes for four years, and a 73-year-old female with type 2 diabetes for twenty years developed sudden-onset nephrotic syndrome. Examination by light microscopy, immunofluorescence, and electron microscopy (in one case) identified minimal change disease (MCD) in both cases. There was a potential causative drug (meloxicam) for the 73-year-old patient. Both patients were treated with prednisone and responded with complete remission. The patient with type 1 diabetes showed complete remission without relapse, and the patient with type 2 diabetes had two relapses; complete remission was sustained after associated treatment with cyclophosphamide and prednisone. Both patients had two years of follow-up evaluation after remission. We discuss the outcomes of both patients and emphasize the role of kidney biopsy in diabetic patients with an atypical proteinuric clinical course, because patients with MCD clearly respond to corticotherapy alone or in conjunction with other immunosuppressive agents. Arq Bras Endocrinol Metab. 2012;56(5):331-5

Lithiasis in 1,313 Kidney Transplants: Incidence, Diagnosis, and Management

Background. Renal transplantation remains the optimal treatment of patients with end-stage renal disease. Urinary lithiasis represents an unusual urologic complication in renal transplantation, with an incidence of <1%. Today, recipients of kidneys from deceased donors are more likely to receive grafts with undiagnosed lithiasis, which does not occur in patients from living donors, owing to screening with computerized tomography. Objective. The aim of this study was to evaluate the incidence, diagnosis, and therapeutic management of renal lithiasis in transplanted kidneys at a single institution. Methods. We reviewed the medical records for 1,313 patients who underwent kidney transplantation from February 1968 to February 2011. Results. Among the grafts, 17 patients (1.29%) had nephrolithiasis: 9 women and 8 men. Ages ranged from 32 to 63 years (mean = 45.6 years). Fifteen patients received kidneys from cadaveric and only 2 from living related donors. Two stones, both located inside the ureter, were identified during transplant surgery (11.7%). Three instances of lithiasis were incidentally diagnosed by ultrasound during graft evaluation, within 7 days after surgery (17.6%); all 3 were in the calyces. The 12 remaining patients had the stones diagnosed later (70.58%): 6 in the calyces, 3 in the renal pelvis, and 3 inside the ureter. Conclusions. Urinary lithiasis is a rare complication in renal transplantation. In most patients the condition occurs without pain. The diagnosis and treatment options for graft urolithiasis are similar to those patients with nephrofithiasis in the general population. Extracorporeal shock wave lithotripsy (ESWL) was the most common treatment method.

Autoimmune disease and multiple autoantibodies in 42 patients with RASopathies

The association of RASopathies [Noonan syndrome (NS) and Noonan-related syndromes] and autoimmune disorders has been reported sporadically. However, a concomitant evaluation of autoimmune diseases and an assessment of multiple autoantibodies in a large population of patients with molecularly confirmed RASopathy have not been performed. The clinical and laboratory features were analyzed in 42 RASopathy patients, the majority of whom had NS and five individuals had Noonan-related disorders. The following autoantibodies were measured: Anti-nuclear antibodies, anti-double stranded DNA, anti-SS-A/Ro, anti-SS-B/La, anti-Sm, anti-RNP, anti-Scl-70, anti-Jo-1, anti-ribosomal P, IgG and IgM anticardiolipin (aCL), thyroid, anti-smooth muscle, anti-endomysial (AE), anti-liver cytosolic protein type 1 (LC1), anti-parietal cell (APC), anti-mitochondrial (AM) antibodies, anti-liver-kidney microsome type 1 antibodies (LKM-1), and lupus anticoagulant. Six patients (14%) fulfilled the clinical criteria for autoimmune diseases [systemic lupus erythematous, polyendocrinopathy (autoimmune thyroiditis and celiac disease), primary antiphospholipid syndrome (PAPS), autoimmune hepatitis, vitiligo, and autoimmune thyroiditis]. Autoimmune antibodies were observed in 52% of the patients. Remarkably, three (7%) of the patients had specific gastrointestinal and liver autoantibodies without clinical findings. Autoimmune diseases and autoantibodies were frequently present in patients with RASopathies. Until a final conclusion of the real incidence of autoimmunity in Rasopathy is drawn, the physicians should be alerted to the possibility of this association and the need for a fast diagnosis, proper referral to a specialist and ultimately, adequate treatment. (c) 2012 Wiley Periodicals, Inc.

De Novo Thrombotic Microangiopathy After Kidney Transplantation: Clinical Features, Treatment, and Long-Term Patient and Graft Survival

Introduction. Posttransplant thrombotic microangiopathy (TMA)/hemolytic uremic syndrome (HUS) can occur as a recurrent or de novo disease. Methods. A retrospective single-center observational study was applied in order to examine the incidence and outcomes of de novo TMA/HUS among transplantations performed between 2000 and 2010. Recurrent HUS or antibody-mediated rejections were excluded. Results. Seventeen (1.1%) among 1549 kidney transplant recipients fulfilled criteria for de novo TMA. The mean follow-up was 572 days (range, 69-1769). Maintenance immunosuppression was prednisone, tacrolimus (TAC), and mycophenolic acid in 14 (82%) patients. Mean age at onset was 40 +/- 15 years, and serum creatinine was 6.1 +/- 4.1 mg/dL. TMA occurred at a median of 25 days (range, 1-1755) after transplantation. Nine (53%) patients developed TMA within 1 month of transplantation and only 12% after 1 year. Clinical features were anemia (hemoglobin < 10 g/dL) in 9 (53%) patients, thrombocytopenia in 7 (41%), and increased lactate dehydrogenase in 12 (70%). Decreased haptoglobin was observed in 64% and schistocytes in 35%. Calcineurin inhibitor (CM) withdrawal or reduction was the first step in the management of 10/15 (66%) patients, and 6 (35%) received fresh frozen plasma (FFP) and/or plasmapheresis. TAC was successfully reintroduced in six patients after a median of 17 days. Eight (47%) patients needed dialytic support after TMA diagnosis and 75% remained on dialysis. At 4 years of follow-up, death-censored graft survival was worse for TMA group (43.0% versus 85.6%, log-rank = 0.001; hazard ratio = 3.74) and there was no difference in patient survival (53.1% versus 82.2%, log-rank = 0.24). Conclusion. De novo TMA after kidney transplantation is a rare but severe condition with poor graft outcomes. This syndrome may not be fully manifested, and clinical suspicion is essential for early diagnosis and treatment, based mainly in CM withdrawal and FFP infusions and/or plasmapheresis.

Adipose Tissue-Derived Stem Cell Treatment Prevents Renal Disease Progression

Adipose tissue-derived stem cells (ASCs) are an attractive source of stem cells with regenerative properties that are similar to those of bone marrow stem cells. Here, we analyze the role of ASCs in reducing the progression of kidney fibrosis. Progressive renal fibrosis was achieved by unilateral clamping of the renal pedicle in mice for 1 h; after that, the kidney was reperfused immediately. Four hours after the surgery, 2 x 10(5) ASCs were intraperitoneally administered, and mice were followed for 24 h posttreatment and then at some other time interval for the next 6 weeks. Also, animals were treated with 2 x 10(5) ASCs at 6 weeks after reperfusion and sacrificed 4 weeks later to study their effect when interstitial fibrosis is already present. At 24 h after reperfusion, ASC-treated animals showed reduced renal dysfunction and enhanced regenerative tubular processes. Renal mRNA expression of IL-6 and TNF was decreased in ASC-treated animals, whereas IL-4. IL-10, and HO-1 expression increased despite a lack of ASCs in the kidneys as determined by SRY analysis. As expected, untreated kidneys shrank at 6 weeks, whereas the kidneys of ASC-treated animals remained normal in size, showed less collagen deposition, and decreased staining for FSP-1, type I collagen, and Hypoxyprobe. The renal protection seen in ASC-treated animals was followed by reduced serum levels of TNF-alpha, KC, RANTES, and IL-1 alpha. Surprisingly, treatment with ASCs at 6 weeks, when animals already showed installed fibrosis, demonstrated amelioration of functional parameters, with less tissue fibrosis observed and reduced mRNA expression of type I collagen and vimentin. ASC therapy can improve functional parameters and reduce progression of renal fibrosis at early and later times after injury, mostly due to early modulation of the inflammatory response and to less hypoxia, thereby reducing the epithelial-mesenchymal transition.

The perception of sleep quality in kidney transplant patients during the first year of transplantation

OBJECTIVE: Poor sleep quality is one of the factors that adversely affects patient quality of life after kidney transplantation, and sleep disorders represent a significant cardiovascular risk factor. The objective of this study was to investigate the prevalence of changes in sleep quality and their outcomes in kidney transplant recipients and analyze the variables affecting sleep quality in the first years after renal transplantation. METHODS: Kidney transplant recipients were evaluated at two time points after a successful transplantation: between three and six months (Phase 1) and between 12 and 15 months (Phase 2). The following tools were used for assessment: the Pittsburgh Sleep Quality Index; the quality of life questionnaire Short-Form-36; the Hospital Anxiety and Depression scale; the Karnofsky scale; and assessments of social and demographic data. The prevalence of poor sleep was 36.7% in Phase 1 and 38.3% in Phase 2 of the study. RESULTS: There were no significant differences between patients with and without changes in sleep quality between the two phases. We found no changes in sleep patterns throughout the study. Both the physical and mental health scores worsened from Phase 1 to Phase 2. CONCLUSION: Sleep quality in kidney transplant recipients did not change during the first year after a successful renal transplantation.

The Real Importance of Pre-Existing Comorbidities on Long-Term Mortality after Acute Kidney Injury

Background: The causes of death on long-term mortality after acute kidney injury (AKI) have not been well studied. The purpose of the study was to evaluate the role of comorbidities and the causes of death on the long-term mortality after AKI. Methodology/Principal Findings: We retrospectively studied 507 patients who experienced AKI in 2005-2006 and were discharged free from dialysis. In June 2008 (median: 21 months after AKI), we found that 193 (38%) patients had died. This mortality is much higher than the mortality of the population of Sao Paulo City, even after adjustment for age. A multiple survival analysis was performed using Cox proportional hazards regression model and showed that death was associated with Khan's index indicating high risk [adjusted hazard ratio 2.54 (1.38-4.66)], chronic liver disease [1.93 (1.15-3.22)], admission to non-surgical ward [1.85 (1.30-2.61)] and a second AKI episode during the same hospitalization [1.74 (1.12-2.71)]. The AKI severity evaluated either by the worst stage reached during AKI (P=0.20) or by the need for dialysis (P=0.12) was not associated with death. The causes of death were identified by a death certificate in 85% of the non-survivors. Among those who died from circulatory system diseases (the main cause of death), 59% had already suffered from hypertension, 34% from diabetes, 47% from heart failure, 38% from coronary disease, and 66% had a glomerular filtration rate <60 previous to the AKI episode. Among those who died from neoplasms, 79% already had the disease previously. Conclusions: Among AKI survivors who were discharged free from dialysis the increased long-term mortality was associated with their pre-existing chronic conditions and not with the severity of the AKI episode. These findings suggest that these survivors should have a medical follow-up after hospital discharge and that all efforts should be made to control their comorbidities.