Evaluation of urinary N-acetyl-beta-D-glucosaminidase as a marker of early renal damage in patients with type 2 diabetes mellitus / Avaliação da N-acetil-beta-D-glucosaminidase urinária como marcador de dano renal precoce em pacientes com diabetes melito tipo 2

Objective To evaluate the clinical usefulness of urinary N-acetyl-beta-D-glucosaminidase (NAG) excretion for the detection of early tubular damage in type 2 diabetes mellitus (T2DM). Subjects and methods Thirty six patients with T2DM were divided into two groups based on urinary albumin to creatinine ratio (ACR): normoalbuminuria (ACR <30 mg/g; n=19) and microalbuminuria (ACR =30‐300 mg/g; n=17). The following parameters were determined in both groups: urinary NAG and albumin, serum and urine creatinine, fasting plasma glucose and glycated hemoglobin (HbA1c). Results Urinary NAG levels [Units/g creatinine; median (range)] were significantly increased in microalbuminuria group [17.0 (5.9 - 23.3)] compared to normoalbuminuria group [4.4 (1.5 - 9.2)] (P<0.001). No differences between groups were observed in fasting glucose, HbA1c, serum creatinine levels and estimated glomerular filtration rates (eGFR). Urinary NAG positively correlated with ACR (r=0.628; p<0.0001), while no significant association was observed between NAG and glycemia, HbA1c, serum creatinine and eGFR. Conclusions The increase of urinary NAG at the microalbuminuria stage of diabetic nephropathy (DN) suggests that tubular dysfunction is already present in this period. The significant positive association between urinary NAG excretion and ACR indicates the possible clinical application of urinary NAG as a complementary marker for early detection of DN in T2DM. .

Objetivo Avaliar a utilidade clínica da excreção urinária da N-acetil-beta-D-glucosaminidase (NAG) para a detecção de dano tubular precoce no diabetes melito tipo 2 (DM2). Sujeitos e métodos Foram estudados trinta e seis pacientes com DM2 que se dividiram em dois grupos com base na excreção urinária de albumina (EUA): normoalbuminúrico (EUA <30 mg/g de creatinina; n=19) e microalbuminúrico (EUA =30‐300 mg/g de creatinina; n=17). Em ambos os grupos foram determinados os seguintes parâmetros: NAG e albumina urinária, creatinina sérica e urinária, glicemia de jejum e hemoglobina glicada (HbA1c). Resultados Os níveis de NAG urinária [unidades/g de creatinina; mediana (intervalo interquartílico)] foram significativamente maiores no grupo microalbuminúrico [17,0 (5,9 - 23,3)] em comparação com o grupo normoalbuminúrico [4,4 (1,5 - 9,2)] (p<0,001). Não se observaram diferenças significativas entre os dois grupos nos níveis de glicemia de jejum, HbA1c, creatinina sérica e taxa de filtração glomerular estimada (TFGe). A NAG urinária se correlacionou positivamente com o EUA (r=0,628, p<0,0001), não sendo observada associação significativa da NAG com glicemia, HbA1c, creatinina sérica e TFGe. Conclusões O aumento da NAG urinária na fase de microalbuminúria da nefropatia diabética (ND) sugere que a disfunção tubular já está presente nesse período. A associação positiva significativa entre a excreção urinária da NAG e EUA indica a possível aplicação clínica da NAG urinária como marcador complementar para a detecção precoce da ND no DM2. .

Predicción de sobrevida del injerto a corto y largo plazo mediante el uso de índices gamagráficos en receptores de trasplante renal / Prediction of short and long term graft survival by 99mTc-MAG3 scintigraphy after renal transplantation

Background: 99Tcm-MAG3 is a non-invasive method for the evaluation of renal transplants, giving information about allograft function and short- and long-term allograft survival. However, few studies have validated this observation. Objetive: To determine the predictive power of different scintigraphic parameters on graft survival at 6 -12 months after renal transplantation. Methods: Between 1996-2007, receptors with varying degrees of kidney dysfunction were studied with 99mTc-MAG3 scintigraphy within 14 days after transplantation. Tubular injury score (TISS) ranging I-VI according to severity and renal extraction index (R20/3) were calculated. Survival analysis and Cox regression were used for analysis. Results: Three-hundred and four renograms were performed in 146 allografts (143 receptors, mean age 38.9 +/- 17 years, 81.5 percent from cadaveric donor). Mean follow-up time was 44 months. There was graft loss (GL) in 32 percent renal trasplants. According to severity range, graft survival at 6 and 12 months was: TISS I-II 85.23 percent and 81.17 percent; TISS III-IV 82.43 percent and 80.56 percent, and TISS V-VI 32 percent and 2.,43 percent respectively. TISS score of V-VI score was an independent predictor for GL (HR = 6.3 CI 95 percent 2.9–13; p<0.0001). R20/3 index was not a good predictor of GL. Conclusions: TISS score was an independent predictor of short- and long-term allograft survival using 99mTc-MAG3 scintigraphy performed early after kidney transplantation in patients with suspected patients renal dysfunction. TISS V-VI had a greater discriminatory power. R20/3 index individually did not present a good prognostic performance.

Correlación entre el daño tubulointersticial y vascular en la nefritis lúpica con algunas variables clínicas / Correlation between the tubulointerstitial and vascular damage in lupus nephritis with some clinical variables

Las lesiones tubulointersticiales (TI) y vasculares (VS) son frecuentes en la nefritis lúpica (NL) a pesar de no ser consideradas en la clasificación de la OMS de 1995. Se revisaron 339 biopsias renales para correlacionar ciertas variables clínicas con las lesiones del TI y los vasos y saber la frecuencia con la que se producen. Se determinó la frecuencia del daño TI 101/29,8 por ciento y VS 65/19,2 por ciento. Se tuvo en cuenta además la incidencia de las lesiones TI en los distintos tipos de glomerulonefritis lúpica: 0 en la tipo I; 7/9,8 por ciento en la II; 8/15,7 por ciento en la III; 65/50 por ciento en la IV; 2/6,3 por ciento en la V y 16/100 por ciento en la VI. Quedó evidenciado que el daño TI y VS fue expresión de severidad clínica, pues se acompañó de mayor frecuencia de hipertensión 83/82 por ciento y 64/97 por ciento, que cuando no existieron estas lesiones 128/58 por ciento, mayor tiempo medio de evolución de la enfermedad: 3,4; 2,8 y 1,89 años y cifras de creatinina plasmática 189,1; 172,1 y 134,5 mmol/L para el daño TI, VS y la ausencia de estos, respectivamente. La proteinuria fue mayor en presencia de lesión TI, 3,4 g/L y menor en los pacientes con daño VS, 1,89, lo contrario a la incidencia de hematuria, 65/100 por ciento VS y 48/47,5 por ciento TI. En los pacientes sin lesión en estas estructuras los resultados fueron: 2,02 g/L para la proteinuria y 143/61 por ciento para la hematuria

Antioxidative effects of melatonin in protection against renal tubular damage caused by fumonisin [histological, histochemical and electronmicroscopical studies]

Melatonin is the chief secretory product of the pineal gland and has a very potent antioxidant activity. This study was designed to evaluate the effects of the mycotoxin fumonisin on renal tubular damage and protective role of melatonin to reduce this effect. A total of 48 female albino rats weighing [100-140 g] were used in this study. The animals were divided into six groups, each group contained 8 rats. The first group served as control. The animals of the second group were fed ration contaminated with fumonisin [100 mg/kg diet]. The third group of rats were fed ration contaminated with fumonisin [200 mg/ kg diet]. The fourth group was given daily interperitoneal injection of 10 mg/ kg melatonin and fed ration contaminated with fumonism [100 mg/ Kg diet]. The fifth group was given daily interperitoneal injection of 10 mg/kg melatonin and fed ration contaminated with fumonisin [200 mg/kg diet]. The sixth group was given melatonin only at a dose level of 10 mg /kg. The rats were treated for one month Histological effects in kidney were demonstrated in the form of vacuolar degeneration in tubular epithelial cells with degenerated and pyknotic nuclei in animals fed ration contaminated with fumonisin [100 mg/kg diet], markedly degenerated tubules and glomerular degeneration were noticed in group of rats treated with fumonisin [200 mg/kg diet]. Histochemical results showed marked diminution of protein content, mucopolysaccharides and increase in alkaline phosphatase activity. Quantitative DNA image analysis [Leica image] showed that the kidney contained 12.15% aneuploid cells in the group of rats fed fumonisine at dose level of 200 mg/kg diet. No pathological, histochemical or ultrastructural changes could be noticed in rats treated with melatonin only. Ultrastructural changes were observed in animals fed ration contaminated with fumonisin in the form of shrinkage and degeneration of nuclei. The mitochondria were condensed, fragmented and variable in size and shape. The endoplasmic reticulum was fragmented. The treatment of rats with melatonin along with fumonisin resulted in an improvement in histolgical picture as well as histochemical parameters and ultrastructural changes