[Association of hypercalcemia, elevated levels of calcitriol and tuberculosis in patients on hemodialysis]. / Asociación de hipercalcemia, niveles elevados de calcitriol y tuberculosis en hemodiálisis.

ABSTRACT

Hypercalcemia is associated with numerous chronic granulomatous processes and chronic infections. Increased production of calcitriol by activated macrophages has been shown to be the cause in most cases. In this article, we describe three cases of hypercalcemia associated with inappropriately elevated calcitriol levels and suppressed PTH in hemodialysis. In addition to conventional techniques for tuberculosis diagnosis we used Ligase Chain Reaction (LCR) to detect mycobacterial DNA in pleural effusion with acid-fast stain and culture negativity. Antituberculous therapy was associated with a decrease in the levels of calcium, as well as in serum calcitriol concentrations, and a substantial increase in the levels of iPTH. The serum levels of 25(OH)D3 remained unchanged. These findings suggested ectopic production of calcitriol. The discussion reviews the previously reported cases of hypercalcemia and tuberculosis that occurred during hemodialysis, and concludes that ectopic production of calcitriol by tuberculous granulomas is extremely unusual and its demonstration requires a high index of suspicion. Molecular techniques are a potentially useful approach for early and rapid diagnosis of tuberculous infection in dialysis patients.