C4A and Arthritis: In addition, heterozygote TA rs5749201 was associated with arthritis (p < 0.001), leucopenia (p < 0.001), thrombocytopenia (p = 0.004), higher C4 (p = 0.034), more dsDNA percentage (p < 0.001), and higher SLEDAI score (p = 0.003).