Bacterial endotoxin pyrogen

US FDA, ITG subject bacterial endotoxins/pyrogens. In Office of Regulatory Affairs (Ed.), Inspector s Technical Guide, Washington, DC, 1987. 

The General Tests and Assays. This section of the USP gives methods for tests that are general in nature and apply to a number of the substances. Procedures are iacluded for such tests as heavy metals, melting point, chloride, sulfate, sterility, bacterial endotoxins, and pyrogens. Also iacluded are descriptions of various analytical techniques, such as spectrophotometry, chromatography, and nmr, and descriptions of tests to be used on glass or plastic containers, mbber closures, etc. 

D12. DeRijk, R. H., Van Rooijen, N. Tilders, F. J. H., Besedovsky, H. O., Del Rey, A., and Berken-bosch, F., Selective depletion of macrophages prevents pituitary-adrenal activation in response to subpyrogenic, but not to pyrogenic, doses of bacterial endotoxin. Endocrinology 129, 330-338(1991). 

The opposite of harmony is disharmony. An example of disharmony is the need to repeat tests using rabbits for pyrogen where testing for bacterial endotoxin is otherwise prescribed. This represents the most extreme disharmony of methods. But there is even a greater disharmony, and that would be to reach different eonelusions as to pass/fail the speeimen. In this ease, the quality control professionals must make a judgment as to whether or not this material can be sold in one or more regions. Functionally equivalent to harmonization is the absence of disharmony. Because of a difference in policy, pharmacopoeias may not differ on adoption of a test at all. If certain tests are eonsidered neeessary by one pharmacopeia in order to protect the consumer, it is appropriate for that pharmacopeia to adopt the test without reference to any other region. 

Watson, D.W., and Kim, Y.B7T1963). Modifications of host response to bacterial endotoxins. I. Specificity of pyrogenic tolerance and role of hypersensitivity in pyrogenicity, lethality, and skin reactivity. J. exp. Med., 1 18, 425-446... 

The USP now recognizes two tests—the pyrogen test conducted with rabbits and the bacterial endotoxins test, also termed the limulus amebocyte lysate... 

When genetic engineering is used to produce the therapeutic Hb, three challenges present potential limitations to utility. First, the production scale itself presents a significant challenge. A second challenge is related to the expression system and its current limitations and third, bacterial endotoxins or other pyrogens must be removed. 

Endotoxin pyrogen induces fever by an indirect process. On entry into the circulatory system, endotoxin is bound to LPS-binding protein (LPB) that transports it to receptor cells in the reticuloendothelial system. The main target cells are circulating mononuclear cells, which produce proinflammatory cytokines such as interleukin-1 (IL-1), interleukin-6 (IL-6), and tumor necrosis factor-a (TNFot). These cytokines are involved in acute and chronic inflammation, induce fever, and modulate the host s response to bacterial infection. ° ... 

As mentioned earlier, bacterial endotoxin is a concern to the pharmaceutical industry because of its ability to induce pyrogenic reactions at intravenous dosages as low as Ing/kg. In higher dosages, endotoxin can be lethal. In one report, a self-administered intravenous... 

Greisman, S.E. Hornick, R.B. Comparative pyrogenic 50. reactivity of rabbit and man to bacterial endotoxin. Proc. 

Bacterial endotoxins, or pyrogens, are substances that will cause a variety of symptoms such as a rise in body temperature when injected in large amounts into human or animal bodies. In pharmaceutical products and medical devices intended for parenteral injection, the absence of endotoxins has equal or greater importance than sterility. None of the other large-scale... 

Two pharmacopoeial limit tests exist. That for pyrogens uses rabbits to assess pharmacological activity and therefore the presence of pyrogens of all kinds. The test for bacterial endotoxins uses lysed amoebocytes (blood cells) of the horseshoe crab and is therefore termed the Limulus amoebocyte lysate (LAL) test. This may be extended to many drug and device products and clearly will be developed in the future to assess the presence of endotoxins in biotechnology products. 

Pyrogenicity, i.e., fever-inducing effects but more generally induction of inflammation, might be considered a special form of immunotoxicity however, it is typically not produced by the test material but by contaminations, mostly bacterial endotoxins. However, a series of cellular methods based on the activation for cytokine release of blood monocytes or derived cells has been validated [63, 67] and accepted for regulatory use. The author has been particularly involved in the development of a whole-blood pyrogen test [61, 62, 97]. The enormous potency of endotoxins... 

Pyrogenicity. Pyrogens are bacterial endotoxins consisting of polysaccharides or proteins produced by the metabolism of microorganisms and upon... 

Tests for pyrogens include a rabbit test, in which rabbits are administered with the radiopharmaceutical and their rectal temperatures are monitored. From the rise in temperature in the rabbits, pyrogenicity of a sample is determined. However, a simpler and quicker method is the so-called limsulus amebocyte lysate (LAL) test, also called the bacterial endotoxin test (BET). In this test, the lysate of amebocytes from the blood of the horseshoe crab (Limulus polyphemus) is mixed with the sample and incubated at 37° C. An opaque gel is formed within 15-60 min depending on the concentration of pyrogens. 

BSP retention accompanied by other biochemical abnormalities but without jaundice is common in septicemia (N4). Findings in patients with intrahepatic infection are the same as in those with extrahepatic infection (B54). Reduced BSP handling is common also in malaria (F6, K13, M3). Injections of pyrogens such as typhoid-paratyphoid A and B vaccine (TAB) in man (M3) or bacterial endotoxin in rabbits (H15) cause increased BSP retention (see Section 6.5). 

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