Sj gren's syndrome associated with voltage defect distal renal tubular acidosis and nephrogenic diabetes insipidus / 대한내과학회지

ABSTRACT

Distal renal tubular acidosis is a condition characterized by an inability of the distal nephron to acidify urine, causing hyperchloremic metabolic acidosis. Distal renal tubular acidosis is classified as proton secretory defect, permeability defect and voltage defect based on its pathophysiology. In the former two, serum level of potassium decreases due to increased excretion of potassium. But in the latter (voltage defect), hyperkalemia is characteristic by impaired the generation of an optimal electrical gradient for hydrogen ion and potassium secretion. We experienced a case of Sj gren's syndrome associated with both voltage defect distal renal tubular acidosis and nephrogenic diabetes insipidus. The patient was a 58- year-old woman who complained of general weakness, nausea and xerostomia. Laboratory analysis showed metabolic acidosis with alkaline urine and hyperkalemia. Anti-nuclear antibody and anti-ds DNA antibody were positive. She presented with polyuria, low urine osmolarity and inadequate response to DDAVP. The response to Shirmer test was decreased. Salivary scintigraphy showed decrease of uptake in the parotid and submandibular salivary glands. We believe this is the first case report in which Sj gren's syndrome is associated with both voltage defect distal renal tubular acidosis and nephrogenic diabetes insipidus.