CD40LG and systemic lupus erythematosus: Furthermore, the levels of the IgG anti-C1-INH367–385 Ac peptide could not be induced in patients with SLE; however, the levels of IgM anti-C1-INH367–385 Ac and IgA anti-C1-INH367–385 Ac in patients with SLE were significantly lower than those in HCs (Figure 4B).