A RESPONSE to antiIL-5 therapy in comorbid patients with chronic rhinosinusitis with nasal polyps and severe asthma: Study protocol.

Background: Chronic rhinosinusitis with nasal polyps (CRSwNP) and severe asthma (SA) are 2 frequently coexisting conditions that are, in most cases, associated with eosinophilic inflammation. The concurrence of both diseases has a negative synergistic impact on disease severity and patients' health-related quality of life. Thus, a holistic, collaborative management of these patients is a critical unmet need.

Engraftment defect of cytokine-cultured adult human mobilized CD34(+) cells is related to reduced adhesion to bone marrow niche elements.

In vitro exposure of haematopoietic stem and progenitor cells (HSPC) to cytokines in expansion or gene therapy protocols reduces homing and engraftment in vivo. We have previously reported that this is related in part to altered tissue specificity of short-term homing, leading to loss of cells in non-haematopoietic tissues. Here we demonstrate that defective engraftment persists when cultured HSPC are transplanted by intrabone injection.