Regulatory Cytokine Expression and Preterm Birth: Case-Control Study Nested in a Cohort

• Published in: PloS one 2016-08, Vol.11 (8), p.e0158380-e0158380
• Main Authors: Pereira, Thaís Basso de Brito, Thomaz, Erika Barbara Abreu Fonseca, Nascimento, Flávia Raquel Fernandes do, Santos, Ana Paula Silva de Azevedo Dos, Batista, Rosângela Lucena Fernandes, Bettiol, Heloisa, Cavalli, Ricardo de Carvalho, Barbieri, Marco Antônio, Silva, Antônio Augusto Moura da
• Format: Article
• Language: English
• Subjects: Abortion; Adult; Analysis; Bacteria; Biology and Life Sciences; Birth; Bone morphogenetic proteins; Brazil - epidemiology; Case-Control Studies; Confidence intervals; Cytokines; Dating techniques; Female; Fetuses; Gestational age; Health sciences; Humans; Immunology; Independent variables; Infectious diseases; Interleukin 10; Interleukin-10 - metabolism; Interleukins; Medicine and Health Sciences; Odds Ratio; Pediatrics; Preeclampsia; Pregnancy; Pregnancy Complications, Infectious - epidemiology; Pregnancy Trimester, Second; Pregnant women; Premature birth; Premature Birth - epidemiology; Premature Birth - immunology; Premature infants; Prospective Studies; Public health; Random sampling; Regression analysis; Research and Analysis Methods; Risk analysis; Risk Factors; Statistical analysis; Studies; Transforming growth factor; Transforming Growth Factor beta - metabolism; Transforming growth factor-b; Transforming growth factors; Ultrasonic imaging; Ultrasound; Umbilical cord; Vaginosis; Vaginosis, Bacterial - epidemiology; Womens health; Young Adult
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0158380

Currently known risk factors explain only a small fraction of preterm birth (PTB). Previous PTB is one of the most important predictors. However, this information is not available in primiparous women. Few studies have looked at associations between regulatory cytokine expression (RCE) and PTB and the results are conflicting. To investigate the association of RCE-Interleukin 10 (IL-10) and Transforming Growth Factor β (TGF-β)-with PTB, and to assess whether bacterial vaginosis (BV) is involved in this relationship. This was a case-control study nested in a prospective cohort-called BRISA. Women with singleton pregnancies were interviewed from 22 to 25 weeks of gestational age (GA). Women were recruited from health services in São Luís, Brazil. A blood sample was collected and gynecological examination was performed. Serum IL-10 and TGF-β were determined using cytometric bead array. Nugent score >7 and/or the presence of clue cells were used for BV diagnosis. All PTB estimated by ultrasound dating performed before 20 weeks of gestational age were considered cases. Controls were selected by simple random sampling from the rest of the cohort, at a 2:1 ratio. Different models were tested, according to the main independent variable. Odds ratios (OR) and 95% confidence intervals (95%CI) were estimated by regression analyses. The study included 327 pregnant women, 109 cases and 218 controls. No associations were found between BV and PTB (P = 1.44; 95%CI: 0.51-3.77). Low levels of IL-10 (OR = 2.92 95%CI: 1.38-6.16) or TGF-β (OR = 16.90 95%CI: 6.42-44.51) or both simultaneously (OR = 77.16 95%CI: 7.99-744.88) were associated with increasing odds of PTB, even after adjustment for confounding. Decreased RCE is a risk factor for PTB. This relationship, however, is not triggered by the presence of BV. Low IL-10/TGF-β levels from 22 to 25 weeks of GA could be used as early predictors of PTB. We suggest monitoring of these RCE, especially among primiparous women, for whom history of previous PTB is not available.