Seroprevalence of Aspergillus-Specific IgG Antibody among Mozambican Tuberculosis Patients

Background: Chronic pulmonary aspergillosis (CPA) is a life-threatening sequel in patients with pulmonary tuberculosis (PTB). Aspergillus-specific IgG antibody is a useful diagnostic biomarker supporting CPA diagnosis, especially in countries with limited health recourses.

Methods: We conducted a prospective pilot study to assess the seroprevalence of Aspergillus-specific IgG antibodies among 61 Mozambican tuberculosis patients before, during, and after the end of TB treatment. Aspergillus-specific IgG antibody levels were measured using the ImmunoCAP^®.

Results: In this study, 3 out of 21 HIV-negative PTB patients had a positive Aspergillus-specific IgG antibody level before, during, and after the end of TB treatment. Antibody levels were 41.1, 45.5, and 174 mg/L at end of treatment (EOT), respectively. Additionally, two HIV-negative PTB patients with negative Aspergillus-specific IgG antibody levels at baseline became seropositive at EOT (41.9 and 158 mg/L, respectively). Interestingly, none of the HIV-positive PTB patients (40/61) had a positive Aspergillus-specific IgG antibody level at any time, neither at baseline nor at EOT. Probable CPA was diagnosed in one HIV-negative patient (5%; 1/20).

Conclusion: Seroprevalence of Aspergillus-specific IgG antibody may differ between HIV-negative and HIV-positive Mozambican PTB patients. Future studies evaluating post-tuberculosis lung disease should integrate CPA as a life-threatening sequel to PTB.