Sifalimumab treatment in a responding systemic lupus erythematosus patient. Effect of sifalimumab treatment in a single systemic lupus erythematosus patient who responded to 10 mg/kg drug treatment. (a) Immunohistochemical analyses of paired biopsies (days 0 predosing and day 14 postdosing) from lesional skin obtained from this patient. BDCA2 is a specific marker for plasmacytoid dendritic cells, and CD83 is a marker for myeloid dendritic cells. IP10 is a type I interferon-inducible protein whose overexpression that was observed in lesional skin at day 0 was decreased at day 14. There is a concordant reduction of IP10 protein expression and mRNA expression in the lesional skin of this patient with sifalimumab treatment. (b) Skin lesion clearance in this patient following sifalimumab treatment (day 0 predosing; days 7, 14, and 28 postdosing).