The yield of bone marrow biopsy and culture compared with blood culture in the evaluation of HIV-infected patients for mycobacterial and fungal infections.

PURPOSE: To compare the clinical utility of bone marrow biopsy and culture specimens with blood cultures for mycobacterial and fungal infections among human immunodeficiency virus (HIV)-infected patients. PATIENTS AND METHODS: All bone marrow biopsies obtained from HIV-infected patients at the University of Alabama at Birmingham (UAB) Medical Center during 1993 to 1995 were blindly reviewed in a standardized format. Bone marrow culture results and blood culture results obtained within 6 weeks of each bone marrow study were compiled. Medical records were reviewed to determine indications for performing bone marrow biopsies, empiric or prophylactic antimicrobial therapies preceding the biopsy, and CD4 counts. RESULTS: Eighty-two bone marrow studies were obtained from 76 patients. Most were performed during the evaluation of fever, cytopenia, or weight loss. Of 55 bone marrow mycobacterial cultures, 13 yielded Mycobacterium avium complex (MAC) and 2 yielded M tuberculosis (MTB). Of 51 bone marrow fungal cultures performed, 2 yielded Cryptococcus neoformans and 1 Histoplasma capsulatum. All patients with a bone marrow culture positive for MAC had a CD4 count of 20 cells/mm3 or less. The mean CD4 count in this group (+/-95% confidence interval) (8+/-3 cells/mm3) was lower than that of culture-negative cases (41+/-25 cells/mm3); P <0.015). When bone marrow cultures and mycobacterial blood cultures were concurrently obtained, results were usually in agreement between the two sites. The mean time until the report of positive mycobacterial bone marrow cultures (22+/-5 days) was similar to that for blood cultures (24+/-3 days). Most (84%) patients with multiple mycobacterial cultures had completely concordant results (all positive or all negative). When blood or bone marrow culture yielded mycobacteria, only 29% of the corresponding bone marrow examinations revealed stainable acid-fast bacilli (AFB). In contrast, all 3 cases with positive fungal bone marrow cultures also had stainable organisms on histologic examination. CONCLUSIONS: The combined use of bone marrow biopsy and culture as well as blood cultures provide the maximum diagnostic yield when evaluating patients with AIDS for mycobacterial or fungal infections. However, when mycobacterial infections were diagnosed, bone marrow results seldom provided more immediate or specific information than lysis centrifugation blood cultures. A single lysis centrifugation blood culture should be the first step in the routine evaluation of HIV-infected patients when disseminated MAC infection is suspected.

Severe hyperglycemia in an HIV clinic: preexisting versus drug-associated diabetes mellitus.

We determined the frequency and clinical nature of severe hyperglycemia in a university clinic for HIV-1-infected patients. The medical records of 1392 adult HIV-infected patients were reviewed for cases of severe hyperglycemia, defined as two or more serum glucose values >250 mg/dl or diabetes treatment during clinic care. Demographic information, family histories of diabetes mellitus, body weights, CD4+ lymphocyte counts, and use of corticosteroids, megestrol acetate, pentamidine, or didanosine were recorded for subjects meeting the case definition. Comparisons were made between preexisting diabetic (group 1) and incident hyperglycemic cases (group 2). Less than 2% of the total clinic population experienced severe hyperglycemia: 12 in group 1 and 13 in group 2. Group 2 had lower body weights (mean, 70.6 kg versus 90.0 kg; p < 0.05) and more advanced HIV disease (mean CD4 count, 79/mm3 versus 550/mm3; p < 0.05) than group 1. Group 2 cases had evidence of drug-associated hyperglycemia; four cases demonstrated hyperglycemia coinciding with large fluctuations in weight during megestrol therapy. Among megestrol recipients, cases did not differ from noncases in demographics, weight, or CD4 count. Severe hyperglycemia is uncommon in adult HIV-infected patients. Approximately one half of these patients have preexisting diabetic conditions; many of the remainder may have drug-induced hyperglycemia, especially as a result of corticosteroids or megestrol acetate.

Effects of tapering doses of oral prednisone on viral load among HIV-infected patients with unexplained weight loss.

In an exploratory study of virologic and immunomodulatory effects of corticosteroid therapy for wasting syndrome, four HIV-infected adults with recent unexplained weight loss were given tapering doses of prednisone over a 2-month period. Serum neopterin and TNF receptor II levels decreased from baseline after 7 days. An antiretroviral effect was observed initially, peaking on days 14-21 (mean change in HIV-1 branched chain DNA assay on day 21 of -0.52 log10; mean change, from baseline to nadir for each individual, of -0.63 log10); subsequent bDNA levels returned toward baseline as prednisone was tapered. No patient lost weight and there was a mean weight gain of 3.5 kg. Anecdotal reports of corticosteroid benefits in the wasting syndrome may result in part from decreased T cell activation leading to decreased HIV replication, an effect that may be self-limited or that may occur only at higher prednisone doses. Studies involving more targeted immunomodulatory agents for wasting syndrome are warranted.