Th2 cells are higher in women, but not men, with severe asthma
Examining asthmatics stratified by sex and severity showed, as expected,
both women and men with severe asthma were taking higher daily doses of
ICS than those with mild/moderate disease (Table 2). Women with severe
asthma, however, were more likely to be hospitalized for their asthma,
to have more neutrophils, higher serum IL-13 and more circulating
peripheral blood Th2 cells than women with mild/moderate asthma (Table
2, Fig. 1A). In contrast, comparison of men with mild/moderate and
severe asthma showed no differences in type 2 inflammation (Table 2,
Fig. 1A). Women with severe asthma had more hospitalizations and higher
proportions of circulating Th2 cells than men with severe asthma (Table
2; Fig. 1A). Women also had more Th2 cells when those on oral CS
(>50% of the year) or anti-type 2 biologic therapy
(anti-IgE or anti-IL-5) were removed from the analysis (Fig. 1B). Though
men and women with asthma were taking similar amounts of ICS (Table 1),
only women exhibited positive correlations between total daily dose of
ICS and circulating Th2 cells, while CRTh2 mRNA and eosinophils (Fig.
1C, 1E and Table S1) were inversely correlated with FEV1(Fig. 1G). No relationships between these parameters were observed in
men (Figs. 1D, F, H). Collectively, these observations suggest that
asthma severity in women associates with type 2 inflammation.