not necessarily, the MPO-activity does correlate with neutrophils activation but I would assess neutrophil numbers by additional means- depending on the assay you perform.

Best, Christina

While neutrophils do produce MPO, MPO activity is definitely not a good marker of neutrophil number. I work with neutrophils often and might be able to offer suggestions, if you can provide more details regarding the assay and end goal of the experiment?

Thank you, guys!

I am working on an animal model where I found that drug A induces more inflammation and tissue damage in a gene B-/- mice, but the knockout is a conditional knockout and it happens only in myeloid lineage cells like macrophages or neutrophils. And also, I found that MPO activity increases a lot in gene B-/- mice tissue. This really confused me cuz if the MPO activity is higher that means neutrophils are eating pathogen more efficiently and how come the inflammation and tissue damage is more severe?

Our lab is not working on immunology so I got a lot of trouble interpreting these data.

I appreciate any explaination, guys,

thank you in advance!

Neutrophil functions such as ROS-production and the formation of neutrophil extracellular traps (though primarily serving to kill and trap pathogens) also lead to inflammation, tissue damage and immunpathology- especially when not appropriately regulated. Since MPO-activity is increased in your gene B-/- mice, maybe the gene function regulates neutrophil mediated inflammation? do you have information on the role of gene B in neutrophils?

Best, Christina