Programmed death ligand 1 is over-expressed by neutrophils in the blood of patients with active tuberculosis

2011

Neutrophils and PD-L1 in Active Tuberculosis

Sample size: 7 publication 10 minutes Evidence: moderate

Author Information

Author(s): Finlay W McNab, Matthew P R Berry, Christine M Graham, Susannah A A Bloch, Tolu Oni, Katalin A Wilkinson, Robert J Wilkinson, Onn M Kon, Jacques Banchereau, Damien Chaussabel, Anne O'Garra

Primary Institution: MRC National Institute for Medical Research

Hypothesis

The expression of programmed death ligand 1 (PD-L1) is increased in whole blood from active tuberculosis patients compared to healthy controls.

Conclusion

PD-L1 is over-represented in the blood of patients with active tuberculosis, primarily due to neutrophil expression, and this over-representation decreases with successful treatment.

Supporting Evidence

PD-L1 was significantly over-represented in whole blood from active TB patients compared with healthy controls.
Neutrophils were identified as the predominant cell type expressing PD-L1 in active TB patients.
PD-L1 levels decreased significantly with anti-mycobacterial treatment.

Takeaway

In people with active tuberculosis, a protein called PD-L1 is found in higher amounts in their blood, mostly from a type of white blood cell called neutrophils, and this goes down when they get treated.

Methodology

The study involved analyzing blood samples from active TB patients, latent TB patients, and healthy controls for PD-L1 expression using microarray and flow cytometry techniques.