Circulating levels of cytokines during pregnancy: thrombopoietin is elevated in miscarriage.

OBJECTIVE To evaluate the hypothesis that cytokine levels are associated with miscarriage risk using serum samples collected before report of miscarriage. DESIGN A nested case-control study. SETTING Biospecimens from the multisite Collaborative Perinatal Project, University of Florida, laboratory assessment of interleukin (IL)-1 receptor antagonist, IL-1beta, IL-4, IL-6, interferon (IFN)-gamma, tumor necrosis factor (TNF)-alpha, thrombopoietin (TPO), and granulocyte colony-stimulating factor (G-CSF). PATIENT(S) Cases of miscarriage (n = 439) were matched to controls (n = 373) by gestational age at sample collection. INTERVENTION(S) None. MAIN OUTCOME MEASURE(S) Miscarriage. RESULT(S) Increased risk of miscarriage was associated with elevated TPO (adjusted odds ratio [OR] 1.16, 95% confidence interval [CI] 1.00-1.36) and decreased G-CSF (adjusted OR 0.78, 95% CI 0.64-0.95). When analysis was restricted to samples collected more than 35 days before miscarriage, the effect of G-CSF was not observed (adjusted OR 0.96, 95% CI 0.72-1.28), whereas increased risk related to higher TPO remained. CONCLUSION(S) Circulating levels of TPO may be associated with increased risk of miscarriage.