Natural killer cells and their function in Takayasu's arteritis.

Area of Science:

• Immunology
• Rheumatology
• Vascular Biology

Background:

• Takayasu's arteritis (TAK) is a chronic, large vessel vasculitis.
• The role of immune cells, particularly natural killer (NK) cells, in TAK pathogenesis is not fully understood.
• Investigating NK cell involvement may reveal novel therapeutic targets for TAK.

Purpose of the Study:

• To investigate the role of peripheral blood NK cells in the pathogenesis of Takayasu's arteritis.
• To compare NK cell populations and functions between TAK patients and healthy controls.

Main Methods:

• Phenotyping of peripheral blood NK cells and their subsets (CD56Bright/CD56Dim) using CD3 and CD56 markers in 47 TAK patients and 27 healthy controls.
• Assessment of NK cell functional potential through granzyme B, perforin, and interferon-gamma (IFN-γ) production.
• Comparison of NK cell characteristics between active and inactive TAK disease states.

Main Results:

• TAK patients exhibited significantly decreased numbers of peripheral blood NK cells compared to healthy controls.
• Reduced percentages of both CD56Bright and CD56Dim NK cell subsets were observed in TAK patients.
• Lower expression of cytotoxic molecules Granzyme B and Perforin in NK cells of TAK patients; no difference in IFN-γ production.
• While NK cell numbers and subsets did not differ between active and inactive TAK, granzyme B expression was lower in active TAK.

Conclusions:

• Peripheral blood NK cell numbers and cytotoxic potential are diminished in patients with Takayasu's arteritis.
• These findings suggest a potential role for NK cell dysfunction in TAK pathogenesis.
• Reduced granzyme B expression in active TAK warrants further investigation into NK cell function during disease flares.