Serum cytokine levels show considerable promise as immunological biomarkers in studies of asthma and environmental exposures.  Ethnic and racial differences have been reported for a variety of immunological parameters, including IgE and other immunoglobulins, but comparable data for cytokines is limited.  We analyzed serum levels of IgE and a panel of cytokines in an ethnically diverse population of pregnant women (at 10 – 12 weeks of pregnancy and at delivery) and in cord blood samples at delivery.  Serum concentrations of IL-2, IL-4, IL-6, IL-10, IFN-gamma and GM-CSF were measured using chemiluminescence ELISA and IgE was measured using ELISA.  At enrollment and at delivery, Hispanic women had significantly higher levels of IL-4, IFN-gamma and IgE than white women (see Table).  Cord blood IgE levels but not cytokine levels  were also higher among  Hispanics.  In preliminary analysis, these differences do not appear to be attributable to differences in asthma or allergy status or cigarette smoking.  Analyses are proceeding to identify the relationships between cytokine levels and asthma status in these women and their offspring.  These data emphasize the importance of controlling for ethnic background when assessing cytokine levels in studies of diverse populations.

                                                                                

	IgE		IL-4		IFN-gamma
	Enrollment	L & D	Enrollment	L & D	Enrollment	L & D
Hispanic	3.79 (N=297)	3.28 (N=180)	3.63 (N=126)	3.35 (N=144)	1.76 (N=126)	1.57 (N=133)
White	3.16 (N=344)	2.91 (N=315)	3.12 (N=226)	2.96 (N=251)	1.19 (N=227)	1.23 (N=239)
p value	<0.0001	<0.001	0.0001	<0.005	<0.0001	<0.02

^*Values are expressed as natural log of IgE or cytokine level