PCR use in miliary tuberculosis presenting with acute respiratory distress syndrome

A 30-year-old pregnant woman admitted to the hospital for rapidly progressive dyspnoea, non-productive cough and altered general status evolving over 1-month period. Her vital signs showed a low blood pressure 90/60 mm Hg, pulse rate 100 beats/min, respiratory rate 32 breaths/min and oxygen saturation on room air of 88%. Laboratory findings showed haemoglobin 9.7 g/dl, white blood cells 15 000/mm(3) (neutrophils 82%), C reactive protein 74 mg/l, alkaline phosphatase 320 U/l, alanine aminotransferase 62 IU/l, aspartate aminotransferase 120 IU/l, γ glutamyl transpeptidase 125 U/l; brain natriuretic peptide 25.4 pg/ml, procalcitonine >2, lactate dehydrogenase 1618 U/l. Chest radiographics showed diffuse bilateral micronodular pulmonary infiltrates and CT of the chest confirmed 1-3 mm diffuse bilateral micronodular infiltrates with ground glass opacities. Complete investigation including bronchoalveolar lavage (BAL) for any viral, bacteriologic, acid-fast bacilli and full serum antibodies panel were all negative. DNA amplification for mycobacterium using PCR on the BAL rapidly rectified the diagnosis of tuberculosis.