Dialysis encephalopathy secondary to aluminum toxicity, diagnosed by bone biopsy.

showed serum creatinine (sCr) 7.5mg/dl, urea 280mg/dl, sodium 139mEq/l, potassium 6.8mEq/l, calcium 0.98mmol/l, phosphorus 8.6mg/dl and creatine kinase 602 234 IU/l. Haematological examination showed the presence of leukocytosis (16.7 10/l) only, with no anaemia (haemoglobin 13.7mg/dl) or thrombocytopaenia (456 10/l). Fractional excretion of sodium was 0.8% and the urinary excretion of potassium was 630mmol/day. The patient needed dialysis support for 2 weeks (eight sessions) and evolved with a decrease in creatine-kinase levels and complete recovery of renal function (sCr, 1.2mg/dl). Urine output was maintained during the entire hospital stay, with a mean output of 2.050ml/day. Leptospirosis diagnosis was confirmed by positive serologic tests (ELISA IgM and microscopic agglutination test). Investigation for other infectious diseases (HIV, cytomegalovirus, toxoplasmosis and Coxsackie) was negative. The pathophysiology of renal failure in leptospirosis involves proximal tubular dysfunction, augmenting distal sodium delivery and, consequently, potassium excretion by the intact distal tubule [2]. In the presented case, the presence of hyperkalaemia is explained by the rhabdomyolysis. However, the low fractional excretion of sodium and urinary potassium of the patient described is dissimilar to the findings described by Covic et al. [3]. These authors demonstrated, in a large series of ARF due to leptospirosis, a high fractional excretion of sodium (>1%) in all patients, even in those with volume depletion. Moreover, in the same series, 20/22 patients with hypokalaemia had a urinary excretion >1000mmol/day. On the other hand, the low urinary excretion of sodium and potassium observed in this case is in agreement with ARF due to rhabdomyolysis [4]. In conclusion, the absence of jaundice, normal platelet value and low renal excretion of sodium and potassium allowed us to conclude that the major renal lesion in this case was due to rhabdomyolysis, with no or minimal involvement of leptospirosis.