Crohn's disease. Ultrastructural studies showing basophil leukocyte granule changes and lymphocyte parallel tubular arrays in peripheral blood.

Buffy coat preparations from the peripheral blood of a 40-year-old woman with a six-year history of Crohn's disease were studied by electron microscopy. This patient did not receive treatment with prednisone, sulfasalazine, or azathioprine, and the blood samples for this study were taken prior to ileocolectomy. Four patients without Crohn's disease were studied as controls. In the circulating blood from the patient with Crohn's disease, there were several significant findings: lymphocytes that contained parallel tubular arrays were prominent, and degranulation was observed in the circulating basophilic leukocytes. These observations may be related to defective immunologic inflammatory processes in this disease, which is of unknown origin, and may lead to an understanding of some of the extraintestinal symptoms experienced by patients with Crohn's disease.