[Abnormal synthesis of 1,25-dihydroxyvitamin D and hypercalcemia in children with tuberculosis].
Three children with tuberculosis and hypercalcemia are reported. Before antitubercular treatment 1,25-dihydroxyvitamin D serum levels and urinary calcium excretion were elevated for age in all patients; vitamin D and 25-hydroxyvitamin D were in normal range whereas serum intact parathyroid hormone concentrations were suppressed. Low calcium diet and antitubercular treatment caused a normalization of serum calcium levels and urinary calcium excretion; 1,25-dihydroxyvitamin D concentrations returned in normal range after three months of antituberculosis therapy. When 1,25-dihydroxyvitamin D was normal, a reintroduction of a diet with normal calcium content did not determine new hypercalcemic episodes. These data suggest that an abnormal 1,25-dihydroxyvitamin D production sustains the hypercalcemia of children with tuberculosis. An ectopic and unregulated synthesis of 1,25-dihydroxyvitamin D by macrophages of granulomatous tissue is proposed.
Saggese
G
G
Laboratorio di Vitamina D, Università di Pisa, Italia.
Bertelloni
S
S
Baroncelli
G I
GI
Fusaro
C
C
Gualtieri
M
M
D002118:Calcium / Q000097:blood / Q000378:metabolism* / Q000652:urine; D002648:Child; D002675:Child, Preschool; D004100:Dihydroxycholecalciferols / Q000378:metabolism*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006934:Hypercalcemia / Q000378:metabolism*; D008297:Male; D014397:Tuberculosis, Pulmonary / Q000378:metabolism*
D004100:Dihydroxycholecalciferols; D002118:Calcium
Abnorme sintesi di 1,25-diidrossivitamina D ed ipercalcemia in bambini con tubercolosi.