Clinical Features and Serum β₂-Microglobulin Levels in HIV-1 Positive and Negative Tanzanian Patients with Tuberculosis

Serum β₂-microglobulin (β₂M) rises in the later stages of HIV disease and has therefore been used to monitor progression to AIDS. However, little work has been done on patients co-infected with HIV and tuberculosis. We studied clinical features and serum β₂-M in 35 Tanzanian patients treated for pulmonary tuberculosis (9 HIV-positive, 26 HIV-negative). The provisional WHO clinical definition of AIDS for use in Africa was fulfilled by 89% of the HIV-positive and 65% of the HIV-negative patients. Median serum β₂-M on admission was slightly higher in HIV-positive (3.17 mg/l) than in HIV-negative (2.85 mg/1) patients. Serum β₂-M fell during treatment in 17/24 (71%) of HIV-negative and 3/7 (43%) HIV-positive patients followed up for 6 months. We conclude that serum β₂-M is frequently raised in active tuberculosis, and is therefore an unreliable indicator of the stage of HIV disease in co-infected patients. The WHO clinical definition of AIDS also proved unreliable in patients with tuberculosis.