eLife (May 2023)

Tryptophan metabolism determines outcome in tuberculous meningitis: a targeted metabolomic analysis

  • Edwin Ardiansyah,
  • Julian Avila-Pacheco,
  • Le Thanh Hoang Nhat,
  • Sofiati Dian,
  • Dao Nguyen Vinh,
  • Hoang Thanh Hai,
  • Kevin Bullock,
  • Bachti Alisjahbana,
  • Mihai G Netea,
  • Riwanti Estiasari,
  • Trinh Thi Bich Tram,
  • Joseph Donovan,
  • Dorothee Heemskerk,
  • Tran Thi Hong Chau,
  • Nguyen Duc Bang,
  • Ahmad Rizal Ganiem,
  • Rovina Ruslami,
  • Valerie ACM Koeken,
  • Raph L Hamers,
  • Darma Imran,
  • Kartika Maharani,
  • Vinod Kumar,
  • Clary B Clish,
  • Reinout van Crevel,
  • Guy Thwaites,
  • Arjan van Laarhoven,
  • Nguyen Thuy Thuong Thuong

DOI
https://doi.org/10.7554/eLife.85307
Journal volume & issue
Vol. 12

Abstract

Read online

Background: Cellular metabolism is critical for the host immune function against pathogens, and metabolomic analysis may help understand the characteristic immunopathology of tuberculosis. We performed targeted metabolomic analyses in a large cohort of patients with tuberculous meningitis (TBM), the most severe manifestation of tuberculosis, focusing on tryptophan metabolism. Methods: We studied 1069 Indonesian and Vietnamese adults with TBM (26.6% HIV-positive), 54 non-infectious controls, 50 with bacterial meningitis, and 60 with cryptococcal meningitis. Tryptophan and downstream metabolites were measured in cerebrospinal fluid (CSF) and plasma using targeted liquid chromatography–mass spectrometry. Individual metabolite levels were associated with survival, clinical parameters, CSF bacterial load and 92 CSF inflammatory proteins. Results: CSF tryptophan was associated with 60-day mortality from TBM (hazard ratio [HR] = 1.16, 95% confidence interval [CI] = 1.10–1.24, for each doubling in CSF tryptophan) both in HIV-negative and -positive patients. CSF tryptophan concentrations did not correlate with CSF bacterial load nor CSF inflammation but were negatively correlated with CSF interferon-gamma concentrations. Unlike tryptophan, CSF concentrations of an intercorrelating cluster of downstream kynurenine metabolites did not predict mortality. These CSF kynurenine metabolites did however correlate with CSF inflammation and markers of blood–CSF leakage, and plasma kynurenine predicted death (HR 1.54, 95% CI = 1.22–1.93). These findings were mostly specific for TBM, although high CSF tryptophan was also associated with mortality from cryptococcal meningitis. Conclusions: TBM patients with a high baseline CSF tryptophan or high systemic (plasma) kynurenine are at increased risk of death. These findings may reveal new targets for host-directed therapy. Funding: This study was supported by National Institutes of Health (R01AI145781) and the Wellcome Trust (110179/Z/15/Z and 206724/Z/17/Z).

Keywords