Márcio Dantas

Renal and extrarenal manifestations of autosomal dominant polycystic kidney disease

The objective of the present study was to determine the frequency of the most common clinical features in patients with autosomal dominant polycystic kidney disease in a sample of the Brazilian population. The medical records of 92 patients with autosomal dominant polycystic kidney disease attended during the period from 1985 to 2003 were reviewed. The following data were recorded: age at diagnosis, gender, associated clinical manifestations, occurrence of stroke, age at loss of renal function (beginning of dialysis), and presence of a family history. The involvement of abdominal viscera was investigated by ultrasonography. Intracranial alterations were prospectively investigated by magnetic resonance angiography in 42 asymptomatic patients, and complemented with digital subtraction arteriography when indicated. Mean age at diagnosis was 35.1 +/- 14.9 years, and mean serum creatinine at referral was 2.4 +/- 2.8 mg/dL. The most frequent clinical manifestations during the disease were arterial hypertension (63.3%), lumbar pain (55.4%), an abdominal mass (47.8%), and urinary infection (35.8%). Loss of renal function occurred in 27 patients (mean age: 45.4 +/- 9.5 years). The liver was the second organ most frequently affected (39.1%). Stroke occurred in 7.6% of the patients. Asymptomatic intracranial aneurysm was detected in 3 patients and arachnoid cysts in 3 other patients. In conclusion, the most common clinical features were lumbar pain, arterial hypertension, abdominal mass, and urinary infection, and the most serious complications were chronic renal failure and stroke. Both intracranial aneurysms and arachnoid cysts occurred in asymptomatic patients at a frequency of 7.14%.

Acute Renal Failure and Hypercalcemia

Hypercalcemia can result from excessive bone resorption, renal calcium retention, excessive intestinal calcium absorption, or a combination of these conditions. Hypercalcemia may also provoke acute renal failure (ARF) or hypertension, or aggravate the tubular necrosis that is frequently found in cases of ARF. The association of ARF and hypercalcemia was studied retrospectively in eight patients based in the data in their charts. Data are expressed as median and percentile (25th; 75th). Our results show that ARF associated with hypercalcemia was related with comorbidity in all cases (cancer, multiple myeloma, hyperparathyroidism, sarcoidosis, vitamin D intoxication, and leprosy). Maximum median serum creatinine levels were 3.3 mg/dL (2.7, 3.8 mg/dL) before treatment and 1.1 mg/dL (0.9, 1.3 mg/dL) after treatment. Maximum total median serum calcium was 15.9 mg/dL (13.5, 19.8 mg/dL) before treatment and 9.1 mg/dL (8.4, 9.7 mg/dL) after treatment. Maximum median ionized serum calcium was 2.1 mmol/L (1.8, 2.2 mmol/L) before treatment and 1.1 mmol/L (1.0, 1.2 mmol/L) after treatment. Different kinds of treatment induced a rapid fall in serum calcium concentration. All patients were treated with hydration and diuretics, and three patients also received calcitonin. Serum creatinine concentration always fell simultaneously with the decrease in serum calcium in all cases. All patients progressed with nonoliguric renal failure. In conclusion, in ARF, patients are frequently hypocalcemic. Usually, the presence of hypercalcemia associated with ARF is indicative of the presence of comorbidity, as observed in all eight patients studied here. There was an improvement of renal function in all cases as serum calcium levels decreased.

Facial leontiasis ossea : a rare presentation of hyperparathyroidism secondary to chronic renal insufficiency

The term renal osteodystrophy is often used in a generic sense to include skeletal disorders of patients with chronic renal failure due to secondary hyperparathyroidism. The prevalence of this condition among patients on hemodialysis is considerably high. However, extreme forms such as facial leontiasis ossea are very rare, only 2 well-characterized cases having been reported thus far in the literature. In the present article we report the case of a female patient who developed hyperparathyroidism secondary to end-stage renal disease which was manifested as facial leontiasis ossea and culminated in dysphagia and respiratory difficulties caused by excess bone tissue growth.

Star fruit: simultaneous neurotoxic and nephrotoxic effects in people with previously normal renal function

Patients with renal failure not yet on dialysis (stages 3–5) or on dialysis treatment are susceptible to intoxication from eating star fruit (Figure ​(Figure1).1). In these patients, star fruit may cause mild to severe neurotoxicity including hiccups, vomiting, asthenia, mental confusion, seizures, coma and death [1–3]. However, there are anecdotal reports of individuals with normal renal function who became intoxicated as a result of eating or drinking a large amount of star fruit, and intractable and persistent hiccups are usually the main symptom. Fig. 1 Star fruit (Averrhoa carambola) or carambola has been cultivated in Malaysia, Southern China, Taiwan, India and Brazil. It is rather popular in the Philippines and Queensland, Australia and moderately so in some of the South Pacific Islands, particularly ... Star fruit nephrotoxicity in people with normal renal function is rarely reported and it is never associated with signs of neurotoxicity. There is only prior one study of such cases, which reported on two cases of acute renal failure (ARF) due to acute oxalate nephropathy in patients with previous normal renal function [4]. In the current study, we present five patients with previously normal renal function who became intoxicated from eating star fruit or drinking star fruit juice and presented simultaneously nephrotoxic and neurotoxic effects.

Renal Changes Induced by Envenomation with Africanized Bee Venom in Female Wistar Rats

Human envenomation caused by bee or wasp stings has been reported to cause acute renal failure (ARF), usually due to acute tubular necrosis (ATN), as a frequent complication. The pathogenetic mechanisms of ATN occurring in these accidents are still unclear. In the present study, female Wistar rats weighing 150-200 g were injected intravenously with Africanized bee venom at a dose of 0.4 microl/100 g body weight and used in functional and light microscopy studies. The animals were divided into two groups: the early group was studied 3-8 h after inoculation, and the late group was studied 24-30 h thereafter. The animals showed ARF characterized by reduction of glomerular filtration rate with increasing levels of plasma creatinine. They also showed increased fractional sodium and potassium excretions, suggesting changes in the proximal portion of the nephron. The water transport through collecting tubules was reduced, with consequent diuresis, indicating functional changes in the distal portion of the nephron. These functional changes were more marked in the early group, with recovery tending to occur after 24 h. Albuminuria was also observed in this group. Light microscopy showed ATN mainly in cortex and outer medulla, with isolated necrosis in cells or small groups of cells and cast formation in the distal and collecting tubules. After 24 h frequent mitotic figures were found in the tubular epithelium. The observed ARF was due to ATN which in turn was probably caused by multiple effects, mainly hemodynamic changes secondary to cardiotoxicity and systemic vasodilation caused by the venom, myohemoglobinuria, and the direct action of the venom on tubular cells.

Elucidating the Neurotoxicity of the Star Fruit

Caramboxin: Patients suffering from chronic kidney disease are frequently intoxicated after ingesting star fruit. The main symptoms of this intoxication are named in the picture. Bioguided chemical procedures resulted in the discovery of caramboxin, which is a phenylalanine-like molecule that is responsible for intoxication. Functional experiments in vivo and in vitro point towards the glutamatergic ionotropic molecular actions of caramboxin, which explains its convulsant and neurodegenerative properties.

alpha-Smooth muscle actin and proliferating cell nuclear antigen expression in focal segmental glomerulosclerosis: functional and structural parameters of renal disease progression

The aim of the present study was to investigate the expression of alpha-smooth muscle actin (alpha-SM-actin) and proliferating cell nuclear antigen (PCNA) in renal cortex from patients with focal segmental glomerulosclerosis (FSGS) and their correlations with parameters of renal disease progression. We analyzed renal biopsies from 41 patients with idiopathic FSGS and from 14 control individuals. The alpha-SM-actin immunoreaction was evaluated using a score that reflected the changes in the extent and intensity of staining in the glomerular or cortical area. The PCNA reaction was quantified by counting the labeled cells of the glomeruli or renal cortex. The results, reported as median +/- percentile (25th; 75th), showed that the alpha-SM-actin scores in the glomeruli and tubulointerstitium from the renal cortex were 2.0 (2.0; 4.0) and 3.0 (3.0; 4.0), respectively, in patients with FSGS, and 0.5 (0.0; 1.0) and 0.0 (0.0; 0.5) in the controls. The number of PCNA-positive cells per glomerulus and graded field of tubulointerstitium from the renal cortex was 0.2 (0.0; 0.4) and 1.1 (0.3; 2.2), respectively, for patients with FSGS, and 0.0 (0.0; 0.5) and 0.0 (0.0; 0.0) for controls. The present data showed an increase of alpha-SM-actin and PCNA expression in glomeruli and renal cortex from FSGS patients. The extent of immunoreaction for alpha-SM-actin in the tubulointerstitial area was correlated with the intensity of proteinuria. However, there was no correlation between the kidney expression of these proteins and the reciprocal of plasma creatinine level or renal fibrosis. These findings suggest that the immunohistochemical alterations may be reversible.

Insuficiência renal aguda associada ao uso de aciclovir endovenoso

OBJECTIVE The aim of this study was to evaluate the incidence and outcome of acute renal failure (ARF) in patients submitted to intravenous (IV) acyclovir treatment. METHODS All patients over 13 years of age that used intravenous acyclovir for 5 or more days were retrospectively analyzed. When serum creatinine levels, previously in the normal range, increased above 2 mg/dl, the case was considered an ARF. Treatment and outcome of patients that developed ARF were analyzed. RESULTS Eighty-five patients received IV acyclovir during the study period. Forty-one patients were included in the study. ARF developed in 8 out of 41 patients (19.5%). In the ARF cases, after beginning of treatment, the average time for increase of the serum creatinine levels was 4.2 days. Creatinine levels reached their peak in a mean time of 7.1 days (ranging from 3 to 14 days). Recovery of the renal function, evaluated by decrease of the creatinine level, varied from 1 to 7 days (mean of 3.6 days). ARF had a good outcome with hydration, lengthening of drug infusion time and adjustment of the drug dosage. CONCLUSION Acyclovir induced ARF in 19.5% of the patients. All patients had a positive response with return to a normal renal function after hydration, lengthening of drug infusion time and adjustment of the drug dosage. None of the patients required treatment with hemodialysis. Acyclovir is a safe drug when administered with certain preventive measures.

Mast cells, TGF-β1 and myofibroblasts expression in lupus nephritis outcome

Renal biopsies of 69 patients with lupus nephritis were studied according to the WHO classification. The aim of the present study was to correlate the interstitial tryptase-positive mast cells with the interstitial TGF-β1 and α-SM actin expression and clinical outcome of lupus nephritis, and identify the pathological role of the interstitial tryptase-positive mast cells in lupus nephritis. The mean follow-up time was 70.7 ± 54.4 months. Eight patients were grouped as WHO class II lupus nephritis, 15 patients as class III, 28 patients as class IV and 18 patients as class V. Interstitial tryptase-positive mast cells were not correlated with clinical outcome and interstitial TGF-β1 expression in lupus nephritis. Interstitial tryptase-positive mast cells were correlated with tubulo-interstitial α-SM actin expression for WHO class V lupus nephritis, but not to the other classes. In conclusion, in spite of interstitial tryptase-positive mast cells being related to renal interstitial fibrosis process, their expression according to the clinical outcome of lupus nephritis was not significant.

Classes, activity and chronicity indices, and α-smooth muscle actin expression as prognostic parameters in lupus nephritis outcome

Renal biopsies of 86 patients with lupus nephritis were assessed according to the WHO classification, and according to activity and chronicity indices. The aim of the present study was to correlate clinical, and histological features (WHO class, activity and chronicity indices, and a-SM actin expression)with the progression of lupus nephritis, and identify the pathologicalrole of a-SM actin in lupus nephritis. The median follow-up time was 75.5§ 57.3 months. Two patients were grouped as WHO class IIa lupus nephritis, eight patients as class IIb, 16 patients as class III, 25 patients as class IV, 15 patients as class V, and 19 patients as mixed pattern lupus nephritis. Sex, age, race, and the a-SM actin expression in glomeruli and tubulo-interstitialarea in WHO class III and IV showed no correlation with clinical follow-up outcome of lupus nephritis. Unfavorable clinical outcome of lupus nephritis was correlated with WHO class IV compared to the other classes, and with the chronicity index in WHO class III patients.