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.