Detection of Mycobacterium avium-intracellulare complex in bone marrow specimens of patients with acquired immunodeficiency syndrome.

Thirty-seven bone marrow core biopsy specimens from 21 human immunodeficiency virus-infected patients with Mycobacterium avium-intracellulare complex bacteremia were stained using rabbit polyclonal antibodies against Mycobacterium bovis strain Bacillus-Calmette-Guerin (BCG) and Mycobacterium duvalii, as well as Kenyon and Fite stains, to compare sensitivities of these techniques and evaluate possible response to therapy. The patients in this study had participated in a phase I/II trial of liposome-encapsulated gentamicin therapy. Two biopsy specimens had inadequate tissue for evaluation. Thirty-two specimens demonstrated bacilli with anti-M duvalii, 33 with anti-BCG, 20 with Kenyon, and 23 with Fite. Two were negative with all stains. Fifteen biopsy specimens had epithelioid granulomas, 12 had histiocytic granulomas, and 1 had a granuloma of indeterminate type. The remaining seven biopsy specimens had no granulomas. Four of these seven demonstrated bacilli with anti-M duvalii, 5 with anti-BCG, 1 with Kenyon, and 2 with Fite. The number of M avium-intracellulare organisms per milliliter of blood decreased in 14 of 21 patients after liposome-encapsulated gentamicin therapy. However, none of the 11 patients whose pre- and post-therapy bone marrow core biopsy specimens were both evaluable demonstrated a reduction in the number of M avium-intracellulare organisms. The authors concluded that anti-M duvalii and anti-BCG are more sensitive than acid-fast stains for identifying M avium-intracellulare infection in bone marrow core biopsy specimens of patients who have acquired immunodeficiency syndrome (AIDS) with M avium-intracellulare bacteremia. Bone marrow core biopsy specimens may provide a perspective on M avium-intracellulare infection in AIDS patients that differs from the one provided by blood cultures.