Two Cases of Hypophosphatemia with Increased Renal Phosphate Excretion in Legionella Pneumonia

We encountered 2 cases of hypophosphatemia due to Legionella pneumonia. Both cases showed increased urinary phosphate excretion and renal tubular dysfunction, which ameliorated with recovery from Legionella pneumonia. Serum fibroblast growth factor-23 level was suppressed, whereas serum 1,25(OH)2 vitamin D and parathyroid hormone levels were normal. Delayed elevation of serum 1,25(OH)2 vitamin D levels was observed with improvement in renal tubular function. These findings suggested hypophosphatemia might be mediated by renal tubular dysfunction.