Eosinophil cell: pray tell us what you do!

PURPOSE OF REVIEW: We will review the role of the eosinophil as an innate immune cell. There have been recent advances in the regulatory mechanisms of the eosinophil, in terms of priming and migration. Additionally, we will discuss certain pulmonary diseases that are associated with eosinophilia.

RECENT FINDINGS: Rapid binding of immunoglobulin A-coated beads can prime the eosinophil cell in the trafficking process. Tissue factor has been shown to be expressed within eosinophil granules. It is believed to serve as a critical eosinophil mediator within the peripheral bloodstream. Interleukin-8 serves as a chemoattractant through IL8RA and IL8RB receptors, but patients with an IL8RA-B ht2 have peripheral eosinophilia. Interleukin-10 and eotaxin correlate with eosinophilia and an active infection prior to therapy. After therapy, interleukin-5 and 6 correlated appropriately with eosinophilia. A wide differential diagnosis exists for peripheral eosinophilia. One study has shown that 86 out of 103 patients with unknown causes for peripheral eosinophilia had positive toxocara enzyme-linked immunosorbent assay results.

SUMMARY: The effect of the cytotoxic eosinophil cell is not only harmful to foreign invaders within the body, but through an intricate immunological pathway, eosinophils can become detrimental to the host organs.