Moreover, HMVEC-d stimulated by plasma of patients with acute HSP produced more C3 (Fig. 6A) and C5 (Fig. 6B) than controls’ plasma-stimulated cells (C3: 37.1 ± 1.4 vs 18.0 ± 1.6 ng/ml, p = 0.006; C5: 2.7 ± 0.1 vs 1.0 ± 0.2 ng/ml, p = 0.007). This evidence concerns the gene C5 and hereditary spastic paraplegia.