Lupus Nephritis with Autoantibodies to Complement Alternative Pathway Proteins and C3 Gene Mutation

Dr. Boddepalli Madhuri

Abstract: Background: Lupus is a systemic inflammatory disorder that affects several organs and causes tissue damage mostly via complement activation; one of the most serious consequences of lupus is glomerulonephritis. Because of this activation, hypocomplementemia is seen in active lupus patients during illness flares; however, levels of C3 and C4 are restored in between episodes. Case presentation: Here we depict a patient who had two episodes of lupus nephritis in five years, went into full reduction each time thanks to therapy, but whose C3 levels remained consistently low. The patient was found to have a mutation in the C3 gene, as indicated by the genetic analysis. Autoantibodies that complement proteins in the alternative route (Factor I, Factor B, C3, and Properdin) were discovered in serial sera samples. The results of the functional tests demonstrated that these autoantibodies activate the alternate route. Conclusion: Lupus nephritis and autoantibodies against supplement elective course proteins (Variable I, Component B, C3, and Properdin) had never been seen before until this first instance of a heterozygous C3 mutation was published. It is possible that the tissue damage is limited to the kidneys because these autoantibodies activate this route. Electronic supplementary material: Users with the proper authorization may access the additional materials included in the online version of this article (doi: 10.1186/s12882 - 015 - 0032 - 6).

Keywords: Autoantibodies, Lupus nephritis, Complement C3, and the alternative complement pathway