• Register
X
Forgot Password

If you have forgotten your password you can enter your email here and get a temporary password sent to your email.

X

Leaving Community

Are you sure you want to leave this community? Leaving the community will revoke any permissions you have been granted in this community.

No
Yes

Complement C5a receptors and neutrophils mediate fetal injury in the antiphospholipid syndrome.

Antiphospholipid syndrome (APS) is defined by recurrent pregnancy loss and thrombosis in the presence of antiphospholipid (aPL) Ab's. Currently, therapy for pregnant women with APS is focused on preventing thrombosis, but anticoagulation is only partially successful in averting miscarriage. We hypothesized that complement activation is a central mechanism of pregnancy loss in APS and tested this in a model in which pregnant mice receive human IgG containing aPL Ab's. Here we identify complement component C5 (and particularly its cleavage product C5a) and neutrophils as key mediators of fetal injury, and we show that Ab's or peptides that block C5a-C5a receptor interactions prevent pregnancy complications. The fact that F(ab)'2 fragments of aPL Ab's do not mediate fetal injury and that C4-deficient mice are protected from fetal injury suggests that activation of the complement cascade is initiated via the classical pathway. Studies in factor B-deficient mice, however, indicate that alternative pathway activation is required and amplifies complement activation. In contrast, activating Fc gamma Rs do not play an important role in mediating aPL Ab-induced fetal injury. Our findings identify the key innate immune effectors engaged by pathogenic autoantibodies that mediate poor pregnancy outcomes in APS and provide novel and important targets for prevention of pregnancy loss in APS.

Pubmed ID: 14660741

Authors

  • Girardi G
  • Berman J
  • Redecha P
  • Spruce L
  • Thurman JM
  • Kraus D
  • Hollmann TJ
  • Casali P
  • Caroll MC
  • Wetsel RA
  • Lambris JD
  • Holers VM
  • Salmon JE

Journal

The Journal of clinical investigation

Publication Data

December 8, 2003

Associated Grants

  • Agency: NIAID NIH HHS, Id: AI-25011
  • Agency: NIAID NIH HHS, Id: AI-31105
  • Agency: NIGMS NIH HHS, Id: GM-62134

Mesh Terms

  • Abortion, Spontaneous
  • Animals
  • Antiphospholipid Syndrome
  • Complement C4
  • Complement C5
  • Complement Pathway, Alternative
  • Female
  • Mice
  • Mice, Inbred BALB C
  • Mice, Inbred C57BL
  • Neutrophils
  • Pregnancy
  • Pregnancy Complications
  • Receptor, Anaphylatoxin C5a