High ratio of 1,25-dihydroxyvitamin D3 to parathyroid hormone in serum of tuberculous patients with end-stage renal disease.
OBJECTIVE
Diagnosis of tuberculosis is sometimes difficult because of the low specificity of diagnostic procedures especially in patients on end-stage renal disease (ESRD). As abnormal vitamin D metabolism has been reported in tuberculosis, the aim of the present study was to determine whether serum concentration of 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) may be a useful diagnostic indicator of tuberculosis in patients with ESRD.


METHODS
Serum concentrations of 1,25-(OH)2D3, parathyroid hormone (PTH), and calcium were compared in 6 patients with ESRD and active tuberculosis (ESRD-TB group) and 110 patients with ESRD and no tuberculosis (ESRD group). These parameters were compared before and after treatment for tuberculosis in patients of ESRD-TB group.


RESULTS
Hypercalcemia was observed in all 6 patients in the ESRD-TB group. Both higher serum concentration of 1,25-(OH)2D3 and lower serum concentration of PTH were observed in the ESRD-TB group relative to the ESRD group, suggesting enhanced extrarenal production of 1,25-(OH)2D3 and suppressed secretion of PTH by hypercalcemia in the ESRD-TB group. However, these parameters could not be used to distinguish the ESRD-TB group from the ESRD group. The ratio of 1,25-(OH)2D3 to PTH in serum was above 0.9 in the ESRD-TB group and below 0.9 in the ESRD group. Antituberculous treatment reduced this ratio to the range observed in the ESRD group.


CONCLUSIONS
High ratio of 1,25-(OH)2D3 to PTH in serum is noted in active tuberculous patients with ESRD because of enhanced extrarenal production of 1,25-(OH)2D3.
Hemodialysis Unit, Hamamatsu University School of Medicine, Hamamatsu, Japan. katsuh@hama-med.ac.jp
K
K
Yonemura
T
T
Ohtake
H
H
Matsushima
Y
Y
Fujigaki
A
A
Hishida
D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood*; D002117:Calcitriol / Q000097:blood*; D002118:Calcium / Q000097:blood; D005260:Female; D006801:Humans; D006934:Hypercalcemia / Q000097:blood; D007676:Kidney Failure, Chronic / Q000150:complications*; D008297:Male; D010281:Parathyroid Hormone / Q000097:blood*; D014376:Tuberculosis / Q000097:blood / Q000175:diagnosis*
D015415:Biomarkers; D010281:Parathyroid Hormone; D002117:Calcitriol; D002118:Calcium