Acquired Fanconi syndrome in patients with Legionella pneumonia

BACKGROUND: Hyponatremia is often observed in patients with Legionella pneumonia. However, other electrolyte abnormalities are uncommon and the mechanism remains to be clarified. CASE PRESENTATION: We experienced two male cases of acquired Fanconi syndrome associated with Legionella pneumonia. The laboratory findings at admission showed hypophosphatemia, hypokalemia, hypouricemia and/or hyponatremia. In addition, they had the generalized dysfunction of the renal proximal tubules presenting decreased tubular reabsorption of phosphate (%TRP), increased fractional excretion of potassium (FEK) and uric acid (FEUA), low-molecular-weight proteinuria, panaminoaciduria and glycosuria. Therefore, they were diagnosed as Fanconi syndrome. Treatment for Legionella pneumonia with antibiotics resulted in the improvement of all serum electrolyte abnormalities and normalization of the %TRP, FEK, FEUA, low-molecular-weight proteinuria, panaminoaciduria and glycosuria, suggesting that Legionella pneumophila infection contributed to the pathophysiology of Fanconi syndrome. CONCLUSION: To the best of our knowledge, this is the first report demonstrating Fanconi syndrome associated with Legionella pneumonia.