OP0128 The Regulation of MRP8/14 in Pstpip1-Associated Myeloid-Related-Proteinaemia Inflammatory Syndrome (PAMI)

Background MRP8 and MRP14 are phagocyte-derived Damage Associated Molecular Pattern (DAMP) proteins and can be used as biomarkers in inflammatory diseases e.g. juvenile idiopathic arthritis. We found that the MRP8/14 complex (calprotectin) is highly elevated in the serum of patients with pyogenic arthritis, pyoderma gangrenosum, and acne (PAPA) syndrome and is even significantly higher in hypercalprotectinaemia and hyperzincaemia (Hz/Hc) [1]. For PAPA, mutations in the proline serine threonine phosphatase-interacting protein 1 (PSTPIP1) gene are described [2]. We have recently identified novel autosomal dominant mutations in PSTPIP1 Hz/Hc patients. All are heterozygous carrier of an E250K or E257K substitution encoded by exon 11 of the PSTPIP1 gene. These patients show an excessively high serum concentration (0.9-12.0 g/l, normal range