PLoS ONE (Jan 2012)

Prospective monitoring reveals dynamic levels of T cell immunity to Mycobacterium tuberculosis in HIV infected individuals.

  • Jessica E Mitchell,
  • Shivan Chetty,
  • Pamla Govender,
  • Mona Pillay,
  • Manjeetha Jaggernath,
  • Anne Kasmar,
  • Thumbi Ndung'u,
  • Paul Klenerman,
  • Bruce D Walker,
  • Victoria O Kasprowicz

DOI
https://doi.org/10.1371/journal.pone.0037920
Journal volume & issue
Vol. 7, no. 6
p. e37920

Abstract

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Monitoring of latent Mycobacterium tuberculosis infection may prevent disease. We tested an ESAT-6 and CFP-10-specific IFN-γ Elispot assay (RD1-Elispot) on 163 HIV-infected individuals living in a TB-endemic setting. An RD1-Elispot was performed every 3 months for a period of 3-21 months. 62% of RD1-Elispot negative individuals were positive by cultured Elispot. Fluctuations in T cell response were observed with rates of change ranging from -150 to +153 spot-forming cells (SFC)/200,000 PBMC in a 3-month period. To validate these responses we used an RD1-specific real time quantitative PCR assay for monokine-induced by IFN-γ (MIG) and IFN-γ inducible protein-10 (IP10) (MIG: r=0.6527, p=0.0114; IP-10: r=0.6967, p=0.0056; IP-10+MIG: r=0.7055, p=0.0048). During follow-up 30 individuals were placed on ARVs and 4 progressed to active TB. Fluctuations in SFC did not correlate with CD4 count, viral load, treatment initiation, or progression to active TB. The RD1-Elispot appears to have limited value in this setting.