To examine whether differences in host immune response to antigen stimulation may explain risk for prior spontaneous preterm birth (SPTB).
Peripheral blood mononuclear cells (PBMC) were isolated from non-pregnant women enrolled in a follow-up study of maternal-infant dyads 5-8 years after a SPTB (n=39) or indicated preterm birth (IPTB, n=26) at 23-31 6/7 weeks and term birth at 37 weeks (n=11). Cells were stimulated with LPS (1.0 μg/ml), incubated 24 hours, and supernatant assayed for cytokines using Luminex x100 (Luminex Corp, Austin, TX) including: Th1 (IFN-, IL-2, IL-12p70); Th2 (IL-4, IL-5, IL-10); general pro-inflammatory (IL-1, IL-6, IL-8, TNF-). Cytokines were considered elevated if >75%ile for the term (control) group.
The cohort was 65% black and 34% white. The mean maternal age at delivery was 24±5 yrs; at follow-up 30±3 yrs. The mean GA at delivery was 29±2 in the SPTB, 29±2 in the IPTB, and 40±1 wks in the term group. No differences were noted in median levels of individual cytokines among birth groups except IL-4 (0.7 vs 1.8 pg/ml, p=0.02) and IL-5 (1.97 vs 2.5 pg/ml, p=0.03) levels were lower in the SPTB vs IPTB group. When evaluating the panel of Th1 or Th1+general pro-inflammatory cytokines, there were no differences among birth groups in the proportion with elevated levels. For the Th2 panel (generally considered anti-inflammatory), women with a prior SPTB were more likely to have none (0/3) of the cytokine levels elevated when compared to IPTB and term (none of Th2 cytokines >75%ile: SPTB 69.2 vs IPTB 34.6 and term 27.3%, p=0.005).
In this cohort of women followed-up 5-8 years after delivery, a prior SPTB was associated with less anti-inflammatory cytokine response after antigen stimulation when compared to women with a prior IPTB or term birth. These findings suggest an altered ability to regulate inflammation in women with a prior SPTB.
© 2008 Mosby, Inc. Published by Elsevier Inc. All rights reserved.