2081 Idiopathic Thrombocytopenic Purpura: An Uncommon Extra-intestinal Manifestation of Crohn's Disease

Abstract

INTRODUCTION: Idiopathic thrombocytopenic purpura (ITP) is characterized by the presence of autoantibodies against platelet surface antigens with immune-mediated platelet destruction. While the association of ITP and inflammatory bowel disease (IBD) has been described in few case reports, management of ITP as an extra-intestinal manifestation of Crohn’s disease (CD) is less studied. CASE DESCRIPTION/METHODS: A 27-year-old man with history of CD and ITP presented with 3 days of bloody diarrhea and non-bloody, nonbilious vomiting. Physical exam notable for mild periumbilical tenderness, no hepatosplenomegaly present. Admission labs showed platelets of 18, ESR of 49, CRP of 8.04. He was started on IV methylprednisone and given platelet transfusions with only a brief response in platelet count. He was then treated with 2 doses of intravenous immunoglobulin (IVIg). His platelet count had only a transient response to combined steroids and IVIg, so rituximab was given on hospital day 10. He continued to have hematochezia and underwent endoscopy, revealing body and fundus gastropathy as well as moderate-severe proctosigmoiditis. Given a history of thrombocytopenia with adalimumab and infliximab, he received ustekinumab for his CD flare on day 14. He was taken to the operating room for colectomy and splenectomy on day 25 for ongoing CD flare and thrombocytopenia requiring daily transfusions. After surgery, platelets increased without transfusions. Discharge platelet count was 571. Colon pathology showed changes consistent with chronic IBD, severe disease activity. His CD has been controlled on maintenance ustekinumab and 6-mercaptopurine in the 5 months following discharge. Platelets remain stable at 170 without additional medical management. DISCUSSION: There are roughly a dozen cases published on the management of dually diagnosed CD/ITP patients. Previous reports postulate that the mechanism of ITP in CD is through the presence of circulating immune complexes in the serum and antigenic mimicry due to increased mucosal permeability in active colitis, which may explain why CD surgery can also result in remission of ITP. Indeed, our literature review identified 1 case where ITP was refractory to steroids and splenectomy, but responded after bowel resection and another case where medically refractory ITP responded to bowel resection alone. These cases, as well as the one we have presented, suggest that colectomy should be considered in the treatment of medically refractory ITP among patients with concomitant CD.