Background. Clinical symptoms and outcomes of uraemic patients ingesting star fruit are quite variable and may progress to death. The purpose of the present report was to discuss the neurotoxic effects of star fruit intoxication in uraemic patients and to present the efficacy of different therapeutic approaches. Methods. We studied a total of 32 uraemic patients who had ingested star fruit. Before the intoxication episodes, 20 patients were on regular haemodialysis, eight were on peritoneal dialysis and four were not yet undergoing dialysis. Two patients were analysed retrospectively from their charts, 17 were directly monitored by our clinic and 13 were referred by physicians from many areas throughout the country, allowing us to follow their outcome from a distance. Intoxicated patients were given different therapeutic approaches (haemodialysis, peritoneal dialysis and supportive treatment), and their outcomes were analysed. Results. The most common symptoms were persistent and intractable hiccups in 30 patients (93.75%), vomiting in 22 (68.7%), variable degrees of disturbed consciousness (mental confusion, psychomotor agitation) in 21 (65.6%), decreased muscle power, limb numbness, paresis, insomnia and paresthesias in 13 (40.6%) and seizures in seven (21.8%). Patients who were promptly treated with haemodialysis, including those with severe intoxication, recovered without sequelae. Patients with severe intoxication who were not treated or treated with peritoneal dialysis did not survive. Conclusions. Haemodialysis, especially on a daily basis, is the ideal treatment for star fruit intoxication. In severe cases, continuous methods of replacement therapy may provide a superior initial procedure, since rebound effects are a common event. Peritoneal dialysis is of no use as a treatment, especially when consciousness disorders ensue.

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.

We observed six cases of patients in a dialysis programme who were apparently intoxicated by ingestion of star fruit. After ingestion of 2-3 fruits or 150-200 ml of the fruit juice, the six patients, who had previously been stable in a regular dialysis programme, developed a variety of symptoms ranging from insomnia and hiccups to agitation, mental confusion and (in one case) death. In preliminary investigations to characterize the hypothetical neurotoxin in the fruit, an extract, when injected intraperitoneally or intracerebroventricularly in rats, provoked persistent convulsions of the tonic-clonic type. It appears that star fruit (Averrhoa carambola) contains an excitatory neurotoxin. Patients with renal failure on conservative or dialysis treatment should be dissuaded from ingestion of the fruit.

Membranous nephropathy is a glomerulopathy, which main affected target is the podocyte, and has consequences on the glomerular basement membrane. It is more common in adults, especially over 50 years of age. The clinical presentation is nephrotic syndrome, but many cases can evolve with asymptomatic non-nephrotic proteinuria. The mechanism consists of the deposition of immune complexes in the subepithelial space of the glomerular capillary loop with subsequent activation of the complement system. Great advances in the identification of potential target antigens have occurred in the last twenty years, and the main one is the protein “M-type phospholipase-A2 receptor” (PLA2R) with the circulating anti-PLA2R antibody, which makes it possible to evaluate the activity and prognosis of this nephropathy. This route of injury corresponds to approximately 70% to 80% of cases of membranous nephropathy characterized as primary. In the last 10 years, several other potential target antigens have been identified. This review proposes to present clinical, etiopathogenic and therapeutic aspects of membranous nephropathy in a didactic manner, including cases that occur during kidney transplantation.