FcRn antibodies and methods of use thereof

A method of treating lupus in a pregnant subject, wherein the method comprises administering an antibody to the pregnant subject, wherein the antibody comprises:

• (1) a light chain variable region comprising a CDR L1, a CDR L2, and a CDR L3 and (2) a heavy chain variable region comprising a CDR H1, a CDR H2, and a CDR H3, wherein
• the CDR L1 comprises a sequence X1GTGSDVGSYNX2VS (SEQ ID NO:
• 12),
• the CDR L2 comprises a sequence GDX3X4RPS (SEQ ID NO:
• 13),
• the CDR L3 comprises a sequence X5SYX6GSGIYV (SEQ ID NO:
• 14),
• the CDR H1 comprises a sequence Z1YAMG (SEQ ID NO:
• 15),
• the CDR H2 comprises a sequence Z7IGZ2SGZ3QTZ4YADS (SEQ ID NO:
• 16), and
• the CDR H3 comprises a sequence LAZ5Z6DSY (SEQ ID NO:
• 17), wherein
• X1 is a polar or hydrophobic amino acid,
• X2 is a hydrophobic amino acid,
• X3 is a polar amino acid,
• X4 is a polar or acidic amino acid,
• X5 is a polar or hydrophobic amino acid,
• X6 is a hydrophobic amino acid,
• Z is a polar or acidic amino acid,
• Z2 is a polar or hydrophobic amino acid,
• Z3 is G, S, or A,
• Z4 is a basic amino acid,
• Z5 is a hydrophobic or basic amino acid,
• Z6 is G, S, D, Q, or H, and
• Z7 is S or T, and wherein administering the antibody treats lupus in the pregnant subject.