Pulmonary tuberculosis in HIV infection: radiographic appearance is related to CD4+ T-lymphocyte count.

Setting: An adult HIV outpatient clinic in Cape Town, South Africa.

Objective: To investigate the relationship between the radiographic appearance of pulmonary tuberculosis (PTB) in HIV infected patients and CD4+ T-lymphocyte count.

Design: Pretreatment radiographs of 150 patients with newly diagnosed PTB were reviewed. CD4+ T-lymphocyte count was used as a marker of HIV disease progression.

Results: Upper zone infiltrate typical of PTB reactivation was present in 18 patients. This pattern was associated with early HIV infection (mean CD4+ T-cell count 389) and had 78% positive predictive value for identifying patients with > 200 CD4+ T-lymphocytes/microL. Pleural effusion was present in 32 patients and occurred over a wide intermediate range of CD4+ T-cell counts (mean 185). Lower or midzone infiltrates, adenopathy, interstitial pattern or normal radiograph occurred in 136 patients and were associated with advanced HIV disease (mean CD4+ T-cell count 105). These patterns had 84%, 89%, 89% and 100% positive predictive value, respectively, for identifying patients with < 200 CD4+ T-cell/microL.

Conclusion: Pulmonary tuberculosis in African HIV-positive patients presents with a spectrum of radiographic abnormalities predictive of stage of HIV disease progression. In patients dually infected with HIV and PTB, chest radiographs are a useful adjunct to clinical staging.