Low parathormone levels and hypercalcaemia in patients with pulmonary tuberculosis: relation to radiological extent of disease and tuberculin skin test.

Aim: We hypothesised that serum calcium (Ca) and parathormone (PTH) levels correlate with radiological extent and that there may also be a relationship between the tuberculin skin test (TST), serum Ca and PTH levels in patients with pulmonary tuberculosis (PTB).

Materials And Methods: Forty-four patients with active PTB and 33 healthy subjects were enrolled in the study. Serum Ca, PTH, magnesium and phosphate levels were measured in patients and controls and compared. Correlations were also investigated for TST values, erythrocyte sedimentation rate (ESR), the degree of radiological involvement, serum PTH and corrected Ca levels.

Results: There was a significant difference between the two groups for mean serum PTH and corrected Ca levels. Significant correlations were detected between radiological extent of disease and serum PTH levels, between TST values and serum PTH levels and between ESR and serum PTH levels. We suggest that abnormal Ca metabolism in PTB patients is related to the radiological extent of disease. Factors determining the radiological extent of disease, predominantly the patient's immune status, may have an important role in modulating Ca metabolism in PTB patients.