Wander Barros do Carmo

Associação entre fatores de risco clínicos e laboratoriais e progressão da doença renal crônica pré-dialítica

INTRODUCTION Chronic kidney disease (CKD) is a very common condition that has become a public health issue. Knowing more about risk factors associated with the progression of CKD allows therapeutic interventions that may change the natural course of the disease. OBJECTIVE To evaluate the impact of clinical and laboratory variables at admission on the outcomes death and need for renal replacement therapy (RRT). METHODS A retrospective cohort study comprised of 211 adult patients with stages 3-5 CKD, followed-up for 56.6 ± 34.5 months. RESULTS Mean age of patients was 65.4 ± 15.1 years and 63.5% were > 60 years. The main causes of CKD were hypertensive nephrosclerosis (29%) and diabetic kidney disease (DKD) (17%). Most patients (47.3%) were on stage 4 CKD. The mean annual loss of glomerular filtration rate (GFR) was 0.6 ± 2.5 mL/min/1.73 m² (median 0.77 mL/min/1.73 m²) After the adjustments for demographic, clinical and laboratory variables, DKD [relative risk (RR) 4.4; 95% confidence interval (CI), 1.47 to 13.2; p = 0.008] was predictive of RRT; age (RR 1.09; 95% CI, 1.04 to 1.15; p < 0.0001) and the non-treatment with angiotensin receptor blocker (ARB) (RR 4.18, 95% CI, 1.34 to 12.9; p = 0.01) were predictors of death. Renal and patient survival rates were 70.9% and 68.6%, respectively. CONCLUSION In this study, patients with stage 3-5 CKD treated conservatively showed stabilization of renal function and low mortality, which were impacted by DKD, age and to not using ARB, respectively.

Achados histopatológicos renais em idosos

INTRODUCTION The elderly population has significantly increased worldwide and recent studies have evidenced a 10-year increase in Brazilian life expectancy. Similarly to other comorbidities, glomerular diseases are also observed in the elderly, and, in that age group, kidney biopsy emerges as a fundamental diagnostic tool to help disease management, preventing unnecessary therapies. OBJECTIVE To establish the frequency of histological diagnoses in the elderly undergoing kidney biopsy, with an emphasis on glomerulopathies (GPs), at two Brazilian universities. METHODS Retrospective assessment of kidney biopsy reports of the Department of Pathology of UNIFESP (patients aged 60 years or above, from 01/01/1996 to 12/31/2003) and of the outpatient clinic of GPs of NIEPEN. The studies of transplanted kidneys and nephrectomies were excluded. The following data were analyzed: age; sex; clinical syndrome at presentation; and histological diagnosis (light microscopy and immunofluorescence). Nephropathies were classified as primary GPs, secondary kidney diseases, nonglomerular diseases, and others. RESULTS One hundred and thirteen biopsies were assessed, the mean age of patients was 66.0 ± 6.0 years, and the male sex prevailed (54.8%). The most common clinical presentation was nephrotic syndrome (32.7%), followed by acute and chronic kidney failure (18.6%, each). Glomerular diseases were as follows: membranous nephropathy (MN), 15%; hypertensive nephrosclerosis, 11.5%; focal segmental glomerulosclerosis and vasculitis/crescentic GN, 9.7% each; amyloidosis, chronic glomerulonephritis, and minimal change disease, 7.1% each; diffuse proliferative GN, 4.4%; IgA nephropathy and lupus nephritis, 2.7% each. Primary GPs predominated (45.2%) as compared with other nephropathies. CONCLUSION Nephrotic syndrome was the major indication for kidney biopsy. Regarding the kidney histological diagnoses, glomerular diseases predominated, in particular MN and hypertensive nephrosclerosis, findings compatible with previous studies in the area, but rarely assessed among us. It is clear that the diversity of diagnoses and differentiated treatments justify kidney biopsy for decision making in that group of patients.

Effect of cross-linked chitosan iron (III) on vascular calcification in uremic rats

Cross-linked chitosan iron (III) is a chitin-derived polymer with a chelating effect on phosphorus, but it is untested in vascular calcification. We evaluated this compounds ability to reduce hyperphosphatemia and its effect on vascular calcification in uremic rats using an adenine-based, phosphorus-rich diet for seven weeks. We used a control group to characterize the uremia. Uremic rats were divided according the treatment into chronic kidney disease, CKD-Ch-Fe(III)CL (CKD-Ch), CKD-calcium carbonate, or CKD-sevelamer groups. We measured creatinine, phosphorus, calcium, alkaline phosphatase, phosphorus excretion fraction, parathyroid hormone, and fibroblast growth factor 23. Vascular calcification was assessed using the aortic calcium content, and a semi-quantitative analysis was performed using Von Kossa and hematoxylin–eosin staining. At week seven, rats in the chronic kidney disease group had higher creatinine, phosphorus, phosphorus excretion fraction, calcium, alkaline phosphatase, fibroblast growth factor 23, and aortic calcium content than those in the Control group. Treatments with cross-linked chitosan iron (III) and calcium carbonate prevented phosphorus increase (20%–30% reduction). The aortic calcium content was lowered by 88% and 85% in the CKD-Ch and CKD-sevelamer groups, respectively. The prevalence of vascular changes was higher in the chronic kidney disease and CKD-calcium carbonate (62.5%) groups than in the CKD-Ch group (37.5%). In conclusion, cross-linked chitosan iron (III) had a phosphorus chelating effect similar to calcium carbonate already available for clinical use, and prevented calcium accumulation in the aorta. Impact statement Vascular calcification (VC) is a common complication due to CKD-related bone and mineral disorder (BMD) and is characterized by deposition of calcium in vessels. Effective therapies are not yet available but new phosphorus chelators can prevent complications from CV. We tested the effect of chitosan, a new phosphorus chelator, on the VC of uremic animals. It has recently been proposed that chitosan treatment may be effective in the treatment of hyperphosphataemia. However, its action on vascular calcification has not been investigated yet. In this study, we demonstrated that chitosan reduced the calcium content in the aorta, suggesting that this may be a therapeutic approach in the treatment of hyperphosphatemia by preventing CV.

Chitosan-Fe (III) Complex as a Phosphate Chelator in Uraemic Rats: A Novel Treatment Option

Phosphate retention and hyperphosphataemia are associated with increased mortality in patients with chronic kidney disease (CKD). We tested the use of cross‐linked iron chitosan III (CH‐FeCl) as a potential phosphate chelator in rats with CKD. We evaluated 96 animals, divided equally into four groups (control, CKD, CH‐FeCl and CKD/CH‐FeCl), over 7 weeks. We induced CKD by feeding animals an adenine‐enriched diet (0.75% in the first 4 weeks and 0.1% in the following 3 weeks). We administered 30 mg/kg daily of the test polymer, by gavage, from the third week until the end of the study. All animals received a diet supplemented with 1% phosphorus. Uraemia was confirmed by the increase in serum creatinine in week 4 (36.24 ± 18.56 versus 144.98 ± 22.1 μmol/L; p = 0.0001) and week 7 (41.55 ± 22.1 versus 83.98 ± 18.56 μmol/L; p = 0.001) in CKD animals. Rats from the CKD group treated with CH‐FeCl had a 54.5% reduction in serum phosphate (6.10 ± 2.23 versus 2.78 ± 0.55 mmol/L) compared to a reduction of 25.6% in the untreated CKD group (4.75 ± 1.45 versus 3.52 ± 0.74 mmol/L, p = 0.021), between week 4 and week 7. At week 7, renal function in both CKD groups was similar (serum creatinine: 83.98 ± 18.56 versus 83.10 ± 23.87 μmol/L, p = 0.888); however, the CH‐FeCl‐treated rats had a reduction in phosphate overload measured by fractional phosphate excretion (FEPi) (0.71 ± 0.2 versus 0.4 ± 0.16, p = 0.006) compared to the untreated CKD group. Our study demonstrated that CH‐FeCl had an efficient chelating action on phosphate.

Point of care kidney ultrasonography and its role in the diagnosis ofurinary obstruction: a case report

INTRODUCTION Ultrasonography (US) is a rapid, non-invasive and safe procedure that allows the nephrologist to obtain vital information to the bedside, as well as allows to guide the procedures for nephrology practice. CASE REPORT Male patient, elderly with hypertension, diabetes mellitus and chronic kidney disease presents with infraumbilical protrusion that the Point of Care US (POCUS), performed by the nephrologist, proved to be a large bladder with a diverticulum. In addition, the US enabled the nephrologist to diagnose bilateral hydronephrosis, preservation of the cortico-medullary differentiation and echotexture of the right kidney, post-voiding urinary retention, urinary catheter placement and functional and morphological monitoring of the urinary tract after surgical correction of the infravesical obstruction. CONCLUSION POCUS assessment of the renal tract may become the new standard of care among nephrologists by enabling the expansion of clinical information in a timely fashion, allowing faster resolution of cases and permitting the monitoring of the treatment done.