Complement in structure and immune homeostasis in placenta

Abstract

Aberrant complement activation can induce “thrombo-inflammation” attacks to host tissue. Beside kidney and blood vessel, the placenta is also susceptible to these attacks. Complement dysregulation is recently classified as one of the new mechanisms leading to pregnancy disorders. Studies have indicated that dampening complement activation can ameliorate pregnancy outcomes. During pregnancy, the mother’s immune system is finely domesticated to accept the semi-allogeneic fetal antigens. As an important part of the innate immune system, some interesting changes have also taken place in complement system during pregnancy. The complement proteins are highly expressed in placenta, and their split products are increased. They are tuned in maintain placental immunity and structural homeostasis. An abundance of evidence shew that complement protein deficiency lead to autoimmunity disease and pathological pregnancy marked by excessive inflammation. Although complement suppressing strategies have been proven effective in treating some pathological pregnancy in individual case studies. we should take the dual role of the complement into consideration that fully and completely inhibit of complement may not be a wise choice.

Is the Complement System Dysregulated in Preeclampsia Comorbid with HIV Infection?

“…The deposition of complement components is also enhanced in the walls of uterine spiral arteries, foetal stem vessels, and kidney glomerular capillary walls [ 85 ]. Moreover, this deposition is lower in normal-term and normal-preterm placentas compared to PE [ 86 ]. According to Kitzmiller et al [ 87 ], these findings might point to a comparable function for the MBL pathway in PE to the microvascular problems associated with diabetes, hypoxia/reperfusion injury, or kidney transplant rejection [ 87 ].…”

An Update Review of the Pathogenesis Hypothesis in Preeclampsia

“…Pregnancy can be considered as an immunehomeostasis between the pregnant woman's tolerance and the protection of the fetus [54]. Normal pregnancy is a state that immune system is activated and pregnancies affected by preeclampsia are regarded to involve more complex immunological processes.…”