Considering the results of increased plasma levels of C3a and C5a in children with acute HSP and the constitutive expression of C3R and CD88 on HMVEC-d, we further wanted to test whether C3a and C5a could induce the secretion of chemokines by HMVEC-d that assists in PMN accumulation and activation. Here, C5AR1 is linked to hereditary spastic paraplegia.