Hélady Sanders Pinheiro

Early presence of calcium oxalate deposition in kidney graft biopsies is associated with poor long-term graft survival

Accumulated oxalate will be excreted after renal transplantation, creating an increased risk of tubular precipitation, especially in the presence of allograft dysfunction. We evaluated calcium oxalate (CaOx) deposition in renal allograft biopsies with early dysfunction, its association with acute tubular necrosis (ATN) and graft survival. We studied 97 renal transplant patients, submitted to a graft biopsy within 3 months post‐transplant, and reanalyzed them after 10 years. We analyzed renal tissue under polarized light and quantified CaOx deposits. CaOx deposits were detected in 52.6% of the patients; 26.8% were of mild and 25.8% of moderate intensity. The deposits were more frequent in biopsies performed within 3 weeks post‐transplant (82.4 vs. 63.0%, p < 0.05) and in allografts with more severe renal dysfunction (creatinine 5.6 mg/dL vs. 3.4 mg/dL, p < 0.001). ATN incidence was also higher in patients with CaOx deposits (47% vs. 24%, p < 0.001). Twelve‐year graft survival was strikingly worse in patients with CaOx deposits compared to those free of deposits (49.7 vs. 74.1%, p = 0.013). Our study shows a high incidence of CaOx deposits in kidney allografts with early dysfunction, implying an additional risk for acute tubular injury, with a negative impact on graft survival.

Influence of TH1/TH2 Switched Immune Response on Renal Ischemia-Reperfusion Injury

Background/Aims: Recent evidence shows a critical role of the CD4+ T cell with the Th1/Th2 paradigm as a possible effector mechanism in ischemia and reperfusion injury. We hypothesize that a polarized Th1 activation response may negatively influence the renal IRI through its relationship with chemokine production (MCP-1) and with a protective tissue response (HO-1). Methods: We subjected mice to renal ischemia for 45 min using IL-4 and IL-12 knockout C57BL/6. We then measured serum urea levels, performed histomorphometric analysis for tubular necrosis and regeneration, and evaluated the mRNA expression of HO-1, t-bet, Gata-3 and MCP-1 by real-time PCR at 24, 48 and 120 h after surgery. Results/Conclusions: The IL-4 knockout mice had a statistically significant rise in serum urea levels post IRI compared with control animals. The IL-12-deficient mice were not affected. The IL-4-deficient mice had a statistically significant increase in tubular injury and impairment in cell regeneration. The IRI in IL-4-deficient mice was accompanied by higher levels of HO-1, t-bet and later up-regulation of MCP-1. These findings suggest that the deleterious effects of the Th1 cell involve increased production of chemokines such as MCP-1.

Urinary Tract Infection Caused by Extended-Spectrum Beta-Lactamase-Producing Bacteria in Kidney Transplant Patients

Urinary tract infection (UTI) is a common complication among kidney transplant patients. UTI caused by multi-resistant extended-spectrum beta-lactamase producing bacteria (ESBL) have largely increased among the hospitalized patient population and especially kidney transplant recipients. We retrospectively studied 83 kidney transplant patients to evaluate the incidence and possible causative conditions of ESBL-related UTI over the last 6 years. ESBL production was determined by the antibiotic susceptibility profile of urine cultures. We compared the incidence in two 3-year periods, 2003-2005 (period 1) and 2006-2008 (period 2). An high incidence of ESBL-related UTI (16.8%) was observed in the posttransplant period performing 31% of the overall UTI incidence, with an increase over the last 3 years from 23.8% to 37.5%. ESBL-related UTI was related to previous episodes of UTI (78.6% vs 29.0%; P < .01) and reoperations (50.0% vs 12.9%; P < .05). We observed a progressively increasing incidence of 13%, 38%, and 45% of ESBL-related UTI among first, second, and third episodes, respectively. Age, gender, HLA mismatches, etiology of chronic kidney disease, diabetes mellitus, acute rejection, induction treatment, and type/level of immunosuppressants were similiar between the groups with or without ESBL-related UTI. We observed a high increased incidence of ESBL-related UTI among kidney transplant recipients, and particularly patients with recurrent UTI.

Contribution of CD4+ T cells to the early mechanisms of ischemia- reperfusion injury in a mouse model of acute renal failure

Renal ischemia-reperfusion (IR) injury is the major cause of acute renal failure in native and transplanted kidneys. Mononuclear leukocytes have been reported in renal tissue as part of the innate and adaptive responses triggered by IR. We investigated the participation of CD4+ T lymphocytes in the pathogenesis of renal IR injury. Male mice (C57BL/6, 8 to 12 weeks old) were submitted to 45 min of ischemia by renal pedicle clamping followed by reperfusion. We evaluated the role of CD4+ T cells using a monoclonal depleting antibody against CD4 (GK1.5, 50 micro, ip), and class II-major histocompatibility complex molecule knockout mice. Both CD4-depleted groups showed a marked improvement in renal function compared to the ischemic group, despite the fact that GK1.5 mAb treatment promoted a profound CD4 depletion (to less than 5% compared to normal controls) only within the first 24 h after IR. CD4-depleted groups presented a significant improvement in 5-day survival (84 vs 80 vs 39%; antibody treated, knockout mice and non-depleted groups, respectively) and also a significant reduction in the tubular necrosis area with an early tubular regeneration pattern. The peak of CD4-positive cell infiltration occurred on day 2, coinciding with the high expression of betaC mRNA and increased urea levels. CD4 depletion did not alter the CD11b infiltrate or the IFN-gamma and granzyme-B mRNA expression in renal tissue. These data indicate that a CD4+ subset of T lymphocytes may be implicated as key mediators of very early inflammatory responses after renal IR injury and that targeting CD4+ T lymphocytes may yield novel therapies.

Chronic kidney disease increases cardiovascular unfavourable outcomes in outpatients with heart failure.

BackgroundChronic heart failure (CHF) has a high morbidity and mortality. Chronic kidney disease (CKD) has consistently been found to be an independent risk factor for unfavorable cardiovascular (CV) outcomes. Early intervention on CKD reduces the progression of CHF, hospitalizations and mortality, yet there are very few studies about CKD as a risk factor in the early stages of CHF. The aims of our study were to assess the prevalence and the prognostic importance of CKD in patients with systolic CHF stages B and C.MethodsThis is a prospective cohort study, dealing with prognostic markers for CV endpoints in patients with systolic CHF (ejection fraction ≤ 45%).ResultsCKD was defined as estimated glomerular filtration rate <60 mL/min/1.73 m2 and CV endpoints as death or hospitalization due to CHF, in 12 months follow-up. Eighty three patients were studied, the mean age was 62.7 ± 12 years, and 56.6% were female. CKD was diagnosed in 49.4% of the patients, 33% of patients with CHF stage B and 67% in the stage C. Cardiovascular endpoints were observed in 26.5% of the patients. When the sample was stratified into stages B and C of CHF, the occurrence of CKD was associated with 100% and 64.7%, respectively, of unfavorable CV outcomes. After adjustments for all other prognostic factors at baseline, it was observed that the diagnosis of CKD increased in 3.6 times the possibility of CV outcomes (CI 95% 1.04-12.67, p = 0.04), whereas higher ejection fraction (R = 0.925, IC 95% 0.862-0.942, p = 0.03) and serum sodium (R = 0.807, IC 95% 0.862-0.992, p = 0.03) were protective.ConclusionIn this cohort of patients with CHF stages B and C, CKD was prevalent and independently associated with increased risk of hospitalization and death secondary to cardiac decompensation, especially in asymptomatic patients.

Standardization of renal function evaluation in Wistar rats (Rattus norvegicus) from the Federal University of Juiz de Fora's colony

INTRODUCTION There is great interest in the use of animal models in the study of renal pathophysiology requires standardization of parameters. OBJECTIVE Standardize assessment of renal function in rats from in the Center for Reproductive Biology of Federal University of Juiz de Foras colony. METHODS Thirty Wistar rats were used and performed measurements of creatinine (serum and urine), serum urea and proteinuria. Were evaluated: the urine collection interval in metabolic cages (24 hours or 12 hours), the need for 12-hour fast, the need of urine and serum deproteinization for creatinine measurement, need of serum deproteinization in animals with acute kidney injury to a spectrophotometer and ELISA, and the comparison of 24-hour proteinuria (PT 24 hours) with the protein/creatinine ratio (rP/C). Means were compared by the Students t test, Pearson correlation, Bland-Altman plot for agreement and linear regression model to estimate PT 24 hours from rP/C. RESULTS The 24 hours urine output was greater than 12 hours, interfering with the creatinine clearance calculation. In the fasting group showed less water intake and lower urinary creatinine. There was great variability for the deproteinized whey and readings performed in the two devices were similar. There was a strong correlation between PT 24 hours and rP/C and the equation was generated: PT 24 hours = (8.6113 x rP/C) + 1.0869. CONCLUSION Was standardized: 24-hour urine collection without fasting. The deproteinization showed no benefit. The measurements were performed with spectrophotometer reliability. It generated a practical formula for estimating PT 24 hours through rP/C.

Anemia crônica no pós-transplante renal: parvovirose B19

Anemia is frequent in kidney transplant patients, and its prevalence varies according to posttransplant time and the adopted diagnostic criteria. Parvovirus B19 (PV B19) infection is an underdiagnosed cause of anemia in this particular population. To illustrate epidemiologic and clinical data regarding it, we present a case of PV B19 infection complicated by pure red cell aplasia (PRCA), pointing out the pitfalls we encountered in diagnosis and treatment. The use of viral DNA detection by polymerase chain reaction (PCR), and correct interpretation of morphological features of bone marrow histology are particularly important for the diagnosis of this condition in kidney transplant patients, who fail to develop a proper humoral response against PV B19, thus importantly decreasing the sensitivity of serological methods in this setting.

Dissociation of antihypertensive and metabolic response to losartan and spironolactone in experimental rats with metabolic sindrome

INTRODUCTION The treatment of arterial hypertension (AH) in patients with metabolic syndrome (MS) is a challenge, since non drug therapies are difficult to implement and optimal pharmacological treatment is not fully established. OBJECTIVE To assess the blockade of the rennin angiotensin aldosterone system (RAAS) in blood pressure (BP) in renal function and morphology in an experimental model of MS induced by high fat diet. METHODS Wistar rats were fed on high fat diet from the fourth week of life, for 20 weeks. The groups received Losartan or Spironolactone from the eighth week of life. We weekly evaluated the body weight and BP by tail plethysmography. At the end of the experiment oral glucose tolerance, lipid profile, creatinine clearance tests, and the direct measurement of BP were performed. A morphometric kidney analysis was performed. RESULTS The administration of high-fat diet was associated with the development of MS, characterized by central fat accumulation, hypertension, hyperglycemia and hypertriglyceridemia. In this model there were no changes in renal histomorphometry. The blockade of angiotensin II (Ang II) receptor AT1 prevented the development of hypertension. The mineralocorticoid blockage did not have antihypertensive efficacy but was associated with reduction of abdominal fat. CONCLUSION The dissociation of the antihypertensive response to the blockades of Ang II receptors and mineralocorticoid indicates the involvement of Ang II in the pathogenesis of hypertension associated with obesity. Reduction of central obesity with Spironolactone suggests the presence of mineralocorticoid adipogenic effect.

Impact of social vulnerability on the outcomes of predialysis chronic kidney disease patients in an interdisciplinary center

INTRODUCTION Numerous studies examined the associations between socio-demographic, economic and individual factors and chronic kidney disease (CKD) outcomes and observed that the associations were complex and multifactorial. Socioeconomic factors can be evaluated by a model of social vulnerability (SV). OBJECTIVE To analyze the impact of SV on the outcomes of predialysis patients. METHODS Demographic, clinical and laboratory data were collected from a cohort of patients with predialysis stage 3 to 5 who were treated by an interdisciplinary team (January 2002 and December 2009) in Minas Gerais, Brazil. Factor, cluster and discriminant analysis were performed in sequence to identify the most important variables and develop a model of SV that allowed for classification of the patients as vulnerable or non-vulnerable. Cox regression was performed to examine the impact of SV on the outcomes of mortality and need for renal replacement therapy (RRT). RESULTS Of the 209 patients examined, 29.4% were classified as vulnerable. No significance difference was found between the vulnerable and non-vulnerable groups regarding either mortality (log rank: 0.23) or need for RRT (log rank: 0.17). In the Cox regression model, the hazard ratios (HRs) for the unadjusted and adjusted impact of SV on mortality were found to be 1.87 (confidence interval [CI]: 0.64-5.41) and 1.47 (CI: 0.35-6.0), respectively, and the unadjusted and adjusted impact of need for RRT to be 1.85 (CI: 0.71-4.8) and 2.19 (CI: 0.50-9.6), respectively. CONCLUSION These findings indicate that SV did not influence the outcomes of patients with predialysis CKD treated in an interdisciplinary center.

Severe sepsis from a Ciprofloxacin resistant salmonellosis in a kidney transplant recipient

INTRODUCTION Salmonellosis is a relatively rare complication in kidney transplant recipients that cannot be clinically distinguished from other forms of enteritis. Among kidney transplant patients, it varies broadly in intensity, and is highly associated with extra-intestinal disease, bacteremia, and, in this case, a high mortality rate. CASE REPORT Here we describe a clinical case of ciprofloxacin resistant salmonellosis in a kidney transplant patient. CONCLUSION This case illustrates how immunosuppressed patients can be exposed to rare forms of infection, often clinically difficult to identify, and possibly with severe clinical courses and poor outcomes despite evidence-based empiric antibiotic therapy.