TY - JOUR
T1 - Complement testing in the clinical laboratory
AU - Willrich, Maria Alice V.
AU - Braun, Karin M.P.
AU - Moyer, Ann M.
AU - Jeffrey, David H.
AU - Frazer-Abel, Ashley
N1 - Publisher Copyright:
© 2021 Informa UK Limited, trading as Taylor & Francis Group.
PY - 2021
Y1 - 2021
N2 - The complement system is the human’s first line of defense against microbial pathogens because of its important housekeeping and infection/inflammation roles. It is composed of a series of soluble and cell-bound proteins that are activated in a cascade effect, similar to the coagulation pathways. There are different pattern recognizing molecules that activate the complement system in response to stimuli or threats, acting through three initiation pathways: classical, lectin, and alternative. All three activation pathways converge at the C3 component and share the terminal pathway. The main outputs of the complement system action are lytic killing of microbes, the release of pro-inflammatory anaphylatoxins, and opsonization of targets. Laboratory testing is relevant in the setting of suspected complement deficiencies, as well as in the emerging number of diseases related to dysregulation (over-activation) of complement. Most common assays measure complement lytic activity and the different complement component concentrations. Specialized testing includes the evaluation of autoantibodies against complement components, activation fragments, and genetic studies. In this review, we cover laboratory testing for complement and the conditions with complement involvement, as well as current challenges in the field.
AB - The complement system is the human’s first line of defense against microbial pathogens because of its important housekeeping and infection/inflammation roles. It is composed of a series of soluble and cell-bound proteins that are activated in a cascade effect, similar to the coagulation pathways. There are different pattern recognizing molecules that activate the complement system in response to stimuli or threats, acting through three initiation pathways: classical, lectin, and alternative. All three activation pathways converge at the C3 component and share the terminal pathway. The main outputs of the complement system action are lytic killing of microbes, the release of pro-inflammatory anaphylatoxins, and opsonization of targets. Laboratory testing is relevant in the setting of suspected complement deficiencies, as well as in the emerging number of diseases related to dysregulation (over-activation) of complement. Most common assays measure complement lytic activity and the different complement component concentrations. Specialized testing includes the evaluation of autoantibodies against complement components, activation fragments, and genetic studies. In this review, we cover laboratory testing for complement and the conditions with complement involvement, as well as current challenges in the field.
KW - Complement system
KW - complement deficiency
KW - complement dysregulation
KW - laboratory testing
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U2 - 10.1080/10408363.2021.1907297
DO - 10.1080/10408363.2021.1907297
M3 - Review article
C2 - 33962553
AN - SCOPUS:85105972425
SN - 1040-8363
VL - 58
SP - 447
EP - 478
JO - Critical reviews in clinical laboratory sciences
JF - Critical reviews in clinical laboratory sciences
IS - 7
ER -