The immunodeficiency caused by human immunodeficiency virus (HIV) infection may be related to loss of diversity in the T cell receptor (TCR) repertoire. A cross-sectional study of the CD4 TCR ...repertoire was done for patients at various stages of HIV infection. Semiquantitative polymerase chain reaction was used to study the relative usage of the variable chain β (BV) subfamilies and the size distributions of transcripts (CDR3 size analysis) within these subfamilies. The relative usage of the TCRBV subfamilies of patients and controls was not significantly different. The proportion of subfamilies with abnormal CDR3 size patterns was higher in the HIV-infected patients (25%, 95% confidence interval CI, 17%-33%) than in the controls (7.2%, 95%c CI, 2.3%-12.1%; P < .001), with a significant negative correlation between the number of CD4 cells and the percentage of abnormal TCRBV subfamilies. These results indicate that progressive loss of CD4 T cells is accompanied by increasing disruptions within the T cell receptor repertoire.
To determine the incidence of Mycobacterium tuberculosis bacteremia in a general hospital and to describe the clinical characteristics, therapy, and outcome of patients with bacteremic tuberculosis.
...Clinical charts of all patients in whom M tuberculosis was isolated from blood cultures during a 5-year period were reviewed. Mycobacterium tuberculosis was detected by means of a nonradiometric blood culture system.
Of 285 patients with culture-proved tuberculosis in whom blood cultures were obtained, 50 (14%) had M tuberculosis bacteremia. Of 42 patients analyzed, 34 (81%) were infected with human immunodeficiency virus (HIV) and eight (19%) were not infected with HIV. Blood was the only or the first positive specimen in 14 patients (33%). Most HIV-infected patients (79%) were intravenous drug users, and 40 (88%) had clinical and/or radiologic evidence of involvement of one or more organs. Lungs were affected in 71% of the patients. In-hospital mortality was 18% in HIV-infected patients with mycobacteremia. Among eight non-HIV-infected patients, four had an underlying disease, and none was immunosuppressed. Disseminated disease was diagnosed in three patients. Two patients died as a consequence of tuberculosis in this group.
Mycobacterium tuberculosis bacteremia is common in HIV-infected patients and is possible in nonimmunosuppressed subjects. Blood cultures are helpful in making the diagnosis of tuberculosis and can help establish a diagnosis of disseminated infection.
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