Expression of CD64 on neutrophils as a marker for detection of infection in rheumatoid arthritis patients

Abstract EN

Objective : The utility of CD64 (Fcy R1) expressed on peripheral blood neutrophils was examined as a marker for distinguishing infection from a flare up of disease in rheumatoid arthritis (RA).

Methodology : The level of CD64 expression on peripheral blood neutrophils was measured quantitatively with flow cytometry in 16 samples from active RA patients who experienced no infection, 14 RA patients with various types of infection and 15 samples from apparently healthy controls.

Results : There was a highly significant increase in the mean+ SD of CD64 expression on neutrophils among RA patients with infection (40.77 + 9.95) as compared to both RA without infection (7.46 + 4.51), as well as controls (9.93 + 4.31) p < 0.01 and p < 0.001 respectively.

The sensitivity of CD64 on neutrophils for diagnosis of infection (using the cut off value of CD64 level of 10.92) was found to have sensitivity of 100% and specificity of 75%.

There was no significant difference between the mean + SD of CD64 levels among RA patients receiving steroids (24.11 + 18.86) and that of those receiving DMARDs (21.34 + 18.52) p > 0.05.

Conclusions : Our results suggest that quantitative measurement of CD64 expression on neutrophils can be used as a sensitive and specific marker to detect infection complicating RA.