Tuberculosis in HIV-Associated Cryptococcal Meningitis is Associated with an Increased Risk of Death

Abstract

Tuberculosis (TB) and cryptococcal meningitis are leading causes of morbidity and mortality in advanced HIV disease. Data are limited on TB co-infection among individuals with cryptococcal meningitis. We performed a retrospective analysis of HIV-infected participants with cryptococcal meningitis from 2010-2017. Baseline demographics were compared between three groups: 'prevalent TB' if TB treated >14 days prior to cryptococcal meningitis diagnosis, 'concurrent TB' if TB treated ± 14 days from diagnosis, or 'No TB at baseline'. We used time-updated proportional-hazards regression models to assess TB diagnosis as a risk for death. Of 870 participants with cryptococcal meningitis, 50 (6%) had prevalent TB, 67 (8%) had concurrent TB, and 753 (86%) had no baseline TB. Among participants without baseline TB, 67 (9%) were diagnosed with incident TB (after >14 days), with a median time to TB incidence of 41 days (IQR, 22-69). The 18-week mortality was 50% (25/50) in prevalent TB, 46% (31/67) in concurrent TB, and 45% (341/753) in the no TB group (p = 0.81). However, TB co-infection was associated with an increased hazard of death (HR = 1.75; 95% CI, 1.33-2.32; p < 0.001) in a time-updated model. TB is commonly diagnosed in cryptococcal meningitis, and the increased mortality associated with co-infection is a public health concern.

Keywords: AIDS-related opportunistic infections; Cryptococcus; HIV; Tuberculosis; co-infection; cryptococcal meningitis.

Figure 1

Classification of study participants. Patients with cryptococcal meningitis were classified at baseline (± 14 days of cryptococcal meningitis diagnosis) as ‘TB prevalent’, ‘concurrent TB’, or ‘no TB’. Those developing TB during study follow-up period were classified as ‘subsequent TB’. Incident TB included those with concurrent or subsequent TB. Abbreviations: CM, cryptococcal meningitis; TB, tuberculosis.