Background: Given that pharmacopoeia pyrogen tests, rabbit pyrogen test, and limulus
amoebocyte lysate (LAL) test have some shortcomings, supplements for pyrogen tests are necessary.
Objective: This study aimed to develop a novel monocyte-based pyrogen test.
Method: The human promyelocytic leukemia cell line (HL-60), which was selected for its high sensitivity
to pyrogens, such as lipopolysaccharide (LPS), zymosan, and lipoteichoic acid (LTA), was evaluated for interleukin-
6 (IL-6) production with IL-6 ELISA kit. The important parameters of the assay were researched, and a novel
pyrogen test was developed. The linearity, reproducibility, and accuracy of the assay were verified, and the assay
was compared with the LAL test by assessing the response to samples containing pyrogen.
Results: HL-60/IL-6 assay was developed as a novel monocyte-based pyrogen test. The linearity between the pyrogen
concentration and IL-6 amount was good (R2 > 0.96), and the RSD of the assay was not more than 20%. The recovery of
pyrogens in biological products, such as monoclonal antibody, vaccine, and blood products, ranged from 50% to 200%.
The pyrogen level detected by the assay was similar to that detected by LAL.
Conclusion: The developed HL-60/IL-6 assay was a good supplement to traditional pyrogen tests for the detection of pyrogens,
such as LPS, zymosan, and LTA.