Assay of pyrogenic contamination in pharmaceuticals by cytokine release from monocytes

Area of Science:

• Biotechnology
• Immunology
• Pharmacology

Background:

• Human recombinant growth hormone, despite passing standard pyrogen tests, was found to be pyrogenic in humans.
• This pyrogenicity was linked to the release of leukocyte pyrogen, a mixture of interleukin-1 (IL-1) and Tumour Necrosis Factor (TNF), from monocytes.
• IL-1 and TNF are potent pyrogenic and inflammatory lymphokines produced by activated monocytes.

Purpose of the Study:

• To develop and evaluate a new pyrogen test utilizing the in vitro release of IL-1 and TNF by human monocytes.
• To assess the suitability of this "monocyte test" as a replacement or complement to the traditional rabbit pyrogen test for biological medicines.
• To investigate the use of monocytic cell lines as an alternative to primary human monocytes for pyrogen testing.

Main Methods:

• Development of sensitive bioassays and immunoassays for IL-1 and TNF at NIBSC.
• Establishing a pyrogen test based on the in vitro release of IL-1 and TNF by human peripheral blood monocytes.
• Evaluating the efficacy of this monocyte-based assay in detecting pyrogenic contamination.

Main Results:

• The monocyte-based pyrogen test has demonstrated utility in identifying pyrogenic contamination.
• This new method successfully detected pyrogenic contamination in a parenteral product that passed the rabbit pyrogen test.
• The product caused adverse reactions in patients, highlighting the limitations of the rabbit test.

Conclusions:

• The in vitro monocyte test offers a sensitive alternative for pyrogen detection in biological medicines.
• This assay has the potential to improve patient safety by identifying pyrogenic contaminants missed by conventional methods.
• Further studies are ongoing to optimize the test, including the evaluation of monocytic cell lines.