PTH and hypophosphatemia: Laboratory investigation revealed a rheumatoid factor of 227.0 IU/ml (normal range, <19.5 IU/ml), hypophosphatemia with serum phosphate levels ranging from 0.46 to 0.52 mmol/L (normal range, 0.85- 1.51 mmol/L), elevated ALP levels ranging from 229 to 328 U/L (normal range, 30- 120 U/L), PTH at 92.88 pg/mL (normal range, 15- 65 pg/mL), and high-sensitivity C-reactive protein levels ranging from 12.7 to 17.6 mg/L (normal range, < 5 mg/L).