Gpr84 is a marker of metastatic penetrating disease in human IBD.

Efforts at reducing or eliminating morbidity in the community require identification of markers of disease for prevention and enhanced, early diagnosis and treatment. We recently described identification of Gpr84 as a marker of disease in humans with Crohn's Disease. We report here discovery of Gpr84 as a marker of metastatic penetrating disease in humans with the inflammatory bowel disease Crohn's Disease. Gpr84, separate from marking patients with disease and identifying patients whose disease was active, was able to retrospectively identify patients with Montreal B3 penetrating/fistulizing-type disease. Consistent with a role for Gpr84 in a disease with penetrating, metastatic features emerging from the hematopoietic compartment, Gpr84 marked cells in the second major hematopoietic disease type in which patients are known to develop fistula, chronic granulomatous disease. The marker has prognostic and diagnostic utility with value in reducing disease burden in the county and has separate importance in providing insight into a metastatic disease process in an autoimmune disorder.