What is the Difference Between Endotoxin and Pyrogen?

The main difference between endotoxin and pyrogen lies in their definition and origin:

• Endotoxin: Endotoxins are a type of pyrogen, specifically lipopolysaccharides present in the cell walls of gram-negative bacteria. They are deadly to humans because they trigger the innate immune system and produce fever when they enter the body. Endotoxins are the most ubiquitous pyrogenic contaminants for medical devices or products.
• Pyrogen: Pyrogens are any molecules or substances that cause a feverous reaction when they enter the human body. They can be classified as endogenous pyrogens (found naturally within the human body) or exogenous pyrogens (introduced into the body from the environment). Pyrogens include bacterial pyrogens, high-molecular-weight endogenous pyrogens, low-molecular-weight endogenous pyrogens, and chemical pyrogens.

In summary, bacterial endotoxins belong to pyrogens, but pyrogens are not necessarily bacterial endotoxins. The risk of pyrogenic reaction in medical devices and products needs to be reduced through production processes and process control.

Comparative Table: Endotoxin vs Pyrogen

The main difference between endotoxin and pyrogen lies in their origins and components. Here is a comparison table highlighting the differences between the two:

In summary, endotoxins are a specific type of pyrogens produced by gram-negative bacteria, while pyrogens are substances that induce fever when entering the blood circulation, including endotoxins and other microbial substances.