Usefulness of bone marrow examination in the diagnosis of fever of unknownorigin in patients with human immunodeficiency virus infection

BACKGROUND: To analyze the usefulness of bone marrow (BM) study in the diag nosis of fever of unknown origin (FUO) in patients infected by the human im munodeficiency virus (HIV) in a single center during a period of 42 months. PATIENTS AND METHODS: 182 episodes of FUO in 162 patients with HIV infectio n were studied. Age, sex, risk factor for HIV infection, hemoglobin level, counts of leucocytes, neutrophils, lymphocytes, CD4 positive lymphocytes, p latelets and levels of hepatic enzymes, albumin and beta(2)-microglobulin w ere studied. BM aspirate was performed in all episodes for cytologic and mi crobiologic examination, and BM biopsy was done in 43. Analysis of factors related with the probability of diagnosis by BM examination was carried out . RESULTS: The median age was 33 years (range, 22-70), and 123 were males. Dr ug abuse was the most frequent risk factor for HIV infection (63%). One hun dred thirty patients had previous AIDS diagnosis before they were evaluated for unexplained fever. A specific diagnosis was achieved in 161 episodes ( 88%) and the most frequent diagnoses were Mycobacterium spp. (55%) and Leis hmania spp. (14%) infections. Fifty-four episodes (30%) were diagnosed by B M examination, and in 36 (20%) BM study was the only diagnostic tool. Exami nation of the BM aspirate yielded the diagnosis in 40 out of the 178 episod es (13%), whereas BM biopsy was a diagnostic tool in 8 (19%); in 9 addition al cases (21%) granulomas were observed. Microbiologic study of BM smears f or mycobacterial infections was positive in 28 of the 143 episodes (19%), a nd the culture for Leishmania was positive in 2 out of the 42 cases. The pr esence of thrombocytopenia (< 75 x 10(9)/l) and elevated serum levels of as partate-aminotransferase (AST) (> 100 U/l) were the factors associated with a high probability to obtain the diagnosis through BM study. CONCLUSIONS: In patients infected by the HIV and unexplained fever, BM exam ination is an useful procedure for the diagnosis, particularly in areas whe re infections by Mycobacterium spp. and Leishmania are prevalent. So that, in our setting, systematic use of this procedure is justified for diagnosis of FUO in those patients.