Problem: Pregnancy-associated immunologic alterations may improve the course of asthma. Severe maternal asthma with an exacerbation impairs fetal growth.
Method of study: Lymphocyte activation was estimated by flow cytometry analysis of surface markers in non-pregnant healthy and mild or moderate persistent asthmatic women and healthy as well as mild or moderate persistent asthmatic, third trimester pregnant women.
Results: Compared with non-pregnant healthy subjects (n = 12) activated pools within CD4 and CD8 T cells were larger and the number of NK T cells were increased both in non-pregnant asthmatic (n = 12) and in healthy pregnant (n = 13) subjects (all p\0.05). No further lymphocyte activation was observed in pregnant asthmatics (n = 21) compared either with non-pregnant asthmatic, or pregnant healthy women. Average birth weight of newborns was lower (p\0.05) in the asthmatic than in the healthy pregnant group.
Conclusion: Pregnancy is a state of wide-spread lymphocyte activation but it may blunt lymphocyte activation which characterizes bronchial asthma.