Prolidase deficiency breaks tolerance to lupus-associated antigens.

Aim: Prolidase deficiency is a rare autosomal recessive disease in which one of the last steps of collagen metabolism, cleavage of proline-containing dipeptides, is impaired. Only about 93 patients have been reported with about 10% also having systemic lupus erythematosus (SLE).

Methods: We studied a large extended Amish pedigree with four prolidase deficiency patients and three heterozygous individuals for lupus-associated autoimmunity.