C4A and Hypertension: Between the two groups,there were statistically significant differences in age, hypertension, previous strokes, WBC, neutrophil, monocyte, eosinophil, albumin, BUN, Cr, free IL-2, IgA, IgG, CRP, C4 (p < 0.05), and the other factors were not significantly different (p > 0.05, Table 5).