Participation of the 27kDa heat shock protein (hsp27) in mid-trimester amniotic fluid: Ethnic variability and association with anti-inflammatory immunity

AMNIOTIC FLUID: ETHNIC VARIABILITY AND ASSOCIATION WITH ANTIINFLAMMATORY IMMUNITY SRIRAM C. PERNI, EMRE KARASAHIN, ROBIN B. KALISH, STEPHEN T. CHASEN, STEVEN S. WITKIN, Weill Medical College of Cornell University, Obstetrics and Gynecology, New York, New York OBJECTIVE: Modulation of pro-inflammatory immune responses during gestation is essential for pregnancy prolongation. The extracellular release of the 27 kDa heat shock protein (hsp27) induces anti-inflammatory immunity. However, the possible presence of hsp27 in amniotic fluid (AF) and its interaction with other AF components has not been determined. We investigated whether hsp27 was present in mid-trimester amniotic fluid and determined its relationship with other AF immuno-modulating components and with maternal ethnicity. STUDY DESIGN: 278 pregnant women with singleton gestations who presented for genetic amniocentesis were enrolled. Clara cell protein 16 (CCP16) and cortisol, two anti-inflammatory components of AF, as well as the cytokines interleukin (IL)-1b, IL-1 receptor antagonist (IL-1ra), IL-6, IL-13, and hsp27 were measured by ELISA. Mann-Whitney U tests and linear regression analysis were used for statistical analysis. RESULTS: Hsp27 was detected in all samples with a median (range) of 5.8 ng/ mL (0.2-43.3). Median AF hsp27 concentrations were higher in blacks (6.3 ng/ mL) than in whites (4.5 ng/mL) (P = .04). IL-1b was identified in 67.8% of the AFs with a median concentration of 13.8 pg/mL (1.0-92.8). AF concentrations of hsp27 were strongly negatively correlated with AF IL-1b concentrations (r = .4360, P ! .0001) and positively correlated with CCP16 (r = .2199, P = .0012) and cortisol (r = 0.1396, P = .04) levels. CCP16 concentrations were also negatively associated with IL-1b (r = .1753, P = .006), but not as strongly as hsp27. There was no relationship between cortisol and IL-1 b levels. There was no relationship between hsp27 levels and IL-1ra, IL-6, IL-13 concentrations or neonatal gender. CONCLUSION: Hsp27 is present in AF and contributes to the down-regulation of IL-1b-induced pro-inflammatory immunity during the mid-trimester. Whether differences in baseline hsp27 levels between blacks and whites contribute to observed ethnic variations in rates of preterm birth and neonatal morbidities remains to be determined. Supported by NIH HD41676. 568 UNEXPLAINED INTRAUTERINE FETAL DEATH IS ACCOMPANIED BY ACTIVATION OF COMPLEMENT KARINA RICHANI, ELEAZAR SOTO, JIMMY ESPINOZA, JYH KAE NIEN, TINNAKORN CHAIWORAPONGSA, JERRIE REFUERZO, SEAN BLACKWELL, SAMUEL EDWIN, MOSHE MAZOR, ROBERTO ROMERO, Wayne State University School of Medicine, Detroit, Michigan, Perinatology Research Branch, NICHD, NIH, DHHS, Bethesda, Maryland, Wayne State University School of Medicine, Department of Obstetrics and Gynecology, Detroit, Michigan, Soroka University Medical Center, Beer Sheva, Israel, Israel OBJECTIVE: The complement system has recently been implicated in the mechanisms of fetal loss in the anti-phospholipid antibody syndrome (JCI 2003; 112:1644). We propose that complement activation may also be involved in other causes of intrauterine fetal death (IUFD) in the second and third trimesters of pregnancy. This study was conducted to determine if IUFD is associated with changes in maternal plasma C5a concentration, the most biologically relevant product generated during complement activation. STUDY DESIGN: A cross-sectional study was designed to include normal pregnant women (n = 60) and patients with IUFD (n = 60). The IUFD group was classified according to the cause of fetal death into: (a) unexplained (n = 44); (b) associated with preeclampsia (n = 8); and (c) chromosomal abnormality or major malformation (n = 8). The plasma concentration of C5a was measured by ELISA. Non-parametric statistics were used for analysis. RESULTS: (1) The median plasma concentration of C5a in patients with IUFD was significantly higher than that of normal pregnant women (median 16.05 ng/mL, range 4.59–402.52 ng/mL vs. median 11.64 ng/mL, range 1.22– 87.13 ng/mL, respectively; P! .001); (2) Among patients with IUFD, those with unexplained fetal death and fetal death with preeclampsia had a median plasma C5a concentration higher than that of normal pregnant women (P = .002 and P ! .001, respectively); (3) There was no significant difference in median plasma concentration of C5a between IUFD with congenital anomalies and normal pregnancy. CONCLUSION: Unexplained IUFD is accompanied by complement activation.