Effect of filgrastim (recombinant human granulocyte colony stimulating factor) on IgE responses in human asthma (48.1)

Abstract

Abstract Rationale: The role of peripheral blood progenitor cell mobilization on IgE responses has not been studied. Methods: Distributions of blood lymphocytes (CD4+, CD8+, CD8+CD60+, CD19+, CD23+, CD16/56+, CD25, CD45RA+, CD45RO+, CD34+), and levels of serum immunoglobulins (IgM, IgG, IgA, IgE) were studied in an allergic asthmatic serum IgE+ (181 IU/mL) adult (m/45 y/o) donor undergoing routine stem cell mobilization protocol (American Society of Hematology) before (day -30), during (day 4), and after (1 wk post last dose) filgrastim (subcutaneous, 480 mcg, 2qd) treatment (flow cytometry, nephelometry, UniCAP Total IgE Fluoroenzymeimmunoassay). Results: On day 4 of filgrastim treatment, numbers of CD8+CD60+ T cells and CD23+ blood cells dramatically increased (>2 fold); CD34+ cell numbers also increased. One week after treatment, numbers of these cells decreased to pre-treatment levels. On day 4 of treatment, serum IgE levels decreased (>50%). However, one week after treatment, IgE levels approached pre-treatment levels. Conclusions. Filgrastim treatment transiently increases numbers of CD8+CD60+ T cells known to regulate human IgE responses (Smith-Norowitz, et al., JI, 2008), while also transiently suppressing ongoing IgE responses. These results suggest that filgrastim might be useful in modulating allergic responses.