Pyoderma gangrenosum (PG) is a skin disorder affecting approximately 2%–5% of patients with inflammatory bowel disease (IBD). PG can also be part of PAPA syndrome (pyogenic arthritis, pyoderma gangrenosum, and acne), 1, 2 which is an autosomal dominant disease caused by mutations A230T and E250Q in the threonine phosphatase-interacting protein 1 (PSTPIP1; CD2BP1) gene on chromosome 15. 3 The PSTPIP1 mutations lead to elevated levels of interleukin-1b and have been successfully treated with the recombinant human interleukin-1 receptor antagonist, anakinra. 1 Recently a microsatellite variation in the promoter region of PSTPIP1 has been also associated with Crohn’s disease (CD) and aseptic abscesses. 4 We investigated the case of a 42-year-old male diagnosed with ulcerative colitis at the age of 31 who underwent ileal pouch anal anastomosis for medical failure (including failing cyclosporine and infliximab) with the postoperative complication of severe peristomal PG that resolved with stoma closure but then recrudesced 3 years later when he was again given a stoma for proximal small bowel to pouch fistulizing disease. His diagnosis was changed to CD but his severe, near circumferential peristomal PG was nonresponsive to steroid and infliximab treatment. We speculated that this patient may harbor a

PSTPIP1 mutation and therefore be responsive to anakinra treatment. Peripheral blood B cells and Epstein–Barr virus (EBV)-transformed B cell lines were prepared from blood samples from pyoderma and IBD patients and non-IBD controls. Intestinal tissues of IBD patients were obtained at the time of surgery, and intestinal tissues of non-IBD individuals acquired from NDRI (National Disease Resource Interchange, Philadelphia, PA). Genomic DNA and total RNA were isolated with Qiagen (Chatsworth, CA) kits. We genotyped the two known PAPA syndrome-associated mutations of the PSTPIP1 gene, A230T and E250Q, using a polymerase chain reaction (PCR)-based restriction fragment length polymorphism (RFLP method). No mutation was found for either single nucleotide polymorphism (SNP) in the study case, nor in seven additional IBD patients with pyoderma. To confirm the genotyping result and search for any other mutations in the gene, we directly sequenced a 1363 bp of PCR fragment including the entire amino acid coding sequences, 44 nt of 5 0 untranslated region (UTR) and 50 nt of 3 0 UTR. No mutation was detected from the sequenced regions. Recently, Andre et al4 detected three microsatellite variants (CCTG) 4,(CCTG) 5, and (CCTG) 7 at nt À405 upstream of the translational start codon ATG. The longest form (CCTG) 7 was associated with aseptic abscesses syndrome (AA). AA is a relapsing inflammatory condition that is associated with IBD in 66% of cases (mainly CD in 57%), and also with neutrophilic dermatosis (ND) in 20%. 4, 5 Similar to a previous study, 4 the study case was affected with PG and also IBD. We directly sequenced 370 bp of a PCR fragment containing the microsatellite repeats, and found that the study case was homozygous for (CCTG) 5 allele, ie, did not have the allele shown to be associated with AA. 4 Summarizing the results described above, we conclude that the study case did not carry any known mutation in the entire cDNA nor the promoter region of