Anomalous leukopoiesis in two patients with Crohn's disease.

Crohn's disease is a major form of chronic inflammatory bowel disease in the western world. The molecular genetic basis of Crohn's disease is unknown. In this study, we present evidence for anomalous leukopoiesis-namely, the generation of a leukocyte subset characterized by aberrant expression of gammadelta T cell receptor (gammadeltaTCR) with or without CD19 on a myeloid background-in two patients with Crohn's disease.