The use of human peripheral blood monocytic cells:A novel method for pyrogen testing

Objective:To explore a novel pyrogen test using human peripheral blood monocytic cells(PBMC) from Chinese individuals,which improves conventional pyrogen tests.Methods:This novel pyrogen test based on the mechanism of human fever reaction uses human peripheral blood monocytic cells(PBMC) as model of body,which are incubated with standard(lipopolysaccharide,LPS),samples respectively,then compares the quantity of endogenous pyrogen interlukin 6(IL-6) in culture of them by ELISA to reflect the pyrogen activity and contaminant of samples.Results:① Using IL-6 as indicator,17-24 h was recommended to the incubation time of PBMC test.② PBMC—IL-6 test had a wide detection spectrum to pyrogens [e.g.LPS from Gram-negative bacteria,lipoteichoic acid(LTA) from Gram-positive bacteria,zymosan from fungi],which was also more sensitive than rabbits to those pyrogens generally.③ The detection limit of PBMC—IL-6 test to LPS was 0.0125 EU·mL-1,LPS dose dependently increased IL-6 secretion in the range of 0.0125-0.4 EU·mL-1.④ The novel pyrogen testing could be widely applicable [e.g.biological products(H1N1 influenza vaccine),traditional Chinese medicine(shuanghuanglian injection),chemic drug(sodium chloride injection,glucose injection,mannitol injection,fluconazole injection,paliperidone palmitate injection)].⑤ The within-laboratory reproducibility of this method was 100%,86.7%,91.7%,91% in four laboratories respectively,the inter-laboratory reproducibility was 95.7%,90.5%,84%,86.7%,78.5%,80% in six pairs-wise laboratory.⑥ The sensitivity of PBMC—IL-6 test,which described the probability of correctly classifying positive samples,was 90.1%(100/111) and specificity,which described the probability of correctly classifying negative samples,was 92.3%(72/78).Conclusion:The PBMC—IL-6 test,with a wide detection spectrum to pyrogens,high sensitivity and wide application,should get further application as a supplement to conventional pyrogen tests.