The invention provides lipid particles, etc., containing a double-stranded nucleic acid as a drug, and a cationic lipid represented by formula (A), etc., the double-stranded nucleic acid comprising a sense strand and an antisense strand including a double-stranded region of at least 11 base pairs and is complementary to a target [beta]2GPI mRNA sequence selected from the group listed in Table 2-1 to Table 2-16 in an oligonucleotide strand of a strand length of 17-30 nucleotides in the antisense strand.本發明提供一種包含作為藥物之雙鏈核酸、與式(A)等所表示之陽離子性脂質的脂質粒子等，該雙鏈核酸係包含正義鏈及反義鏈，且包含至少11個鹼基對之雙鏈區域者，並且該反義鏈中之17個~30個核苷酸之鏈長之寡核苷酸鏈係與選自表2-1~表2-16所記載之群中之靶β2GPI mRNA序列互補。
