Heat shock protein-containing exosomes in mid-trimester amniotic fluids.

Exosomes are multivesicular bodies formed by inverse membrane budding into the lumen of an endocytic compartment. Fusion with the plasma membrane leads to their release into the external milieu. The incorporation of heat shock proteins into exosomes has been associated with immune regulatory activity. We have examined whether heat shock protein-containing exosomes are present in mid-trimester amniotic fluid. Exosomes were isolated from mid-trimester amniotic fluids by sequential low-speed and high-speed centrifugation followed by sucrose density gradient centrifugation. Biochemical characterization included floatation pattern in sucrose gradients, acetylcholinesterase (AChE) activity and Western blot analysis for exosome-containing proteins. Exosomes were present in each of 23 amniotic fluids tested. They banded at a density of 1.17g/ml in sucrose gradients, were positive for AChE activity and contained tubulin, the inducible 72kDa heat shock protein, Hsp72 and the constitutively expressed heat shock protein, Hsc73; they were negative for calnexin. Exosome concentrations correlated positively with the number of pregnancies. Heat shock protein-containing exosomes are constituents of mid-trimester amniotic fluids and may contribute to immune regulation within the amniotic cavity.

Outcomes of preterm premature rupture of membranes in twin pregnancies.

OBJECTIVE: To describe outcomes in twin pregnancies with preterm premature rupture of membranes (PPROM). METHODS: Dichorionic twin pregnancies complicated by PPROM at <34 weeks of gestation for the period 2003 to 2006 were identified. Outcomes were obtained through chart review. The relationship between gestational age at premature rupture of membranes (PROM), latency from PROM to delivery, and infection were examined. RESULTS: In 49 twin pregnancies, the median gestational age at PROM was 31 weeks with a median latency between PROM and delivery of 0 days (interquartile range 0-6). Latency intervals of >or=2 and >or=7 days were achieved by 40.8% and 22.4%, respectively. PPROM at <30 weeks was associated with significantly higher rates of latency of >or= 2 days (70.6% vs. 25.0%) and >or=7 days (47.1% vs. 9.4%). There was a significant relationship between latency and clinical and histologic signs of infection. CONCLUSIONS: After 30 weeks, most twin pregnancies with PPROM delivered within 2 days. Infection appears to be a consequence rather than a cause of PPROM in most cases.

Ex vivo cytokine production by whole mid-trimester amniotic fluid.

We hypothesized that ex vivo measurement of intraamniotic production of immune mediators differed from analysis of these mediators within unincubated amniotic fluid. Mid-trimester amniotic fluid from 72 women were incubated ex vivo with or without 50 ng/ml lipopolysaccharide (LPS). Supernatants and the corresponding unincubated amniotic fluids were tested for interleukin (IL)-6, IL-1 receptor antagonist (IL-1ra), IL-10 and nitric oxide. Ex vivo culture resulted in increased release of IL-6, IL-10 and nitric oxide; IL-1ra levels were decreased following the incubation. A spontaneous preterm birth (SPTB) occurred in 12 (16.7%) of the subjects. Women with a subsequent SPTB had decreased IL-6 and increased IL-10 production following ex vivo culture compared to women with a term delivery. This association was not evident with unincubated amniotic fluids. Conversely, IL-1ra concentrations were elevated in women with subsequent SPTB only in unincubated amniotic fluids. Immune mediator production by ex vivo amniotic fluid culture differs from that present in amniotic fluid supernatants and may provide a more accurate indication of the immune potential of the intraamniotic environment.

Antibodies to the 70 kDa heat shock protein in midtrimester amniotic fluid and intraamniotic immunity.

OBJECTIVE: Antibodies to the 70 kDa heat shock protein (hsp70) immunoglobulin (Ig) G are markers for exposure to adverse or nonphysiological stimuli. In addition, these antibodies cross-link hsp-70 microbial antigen complexes and enhance development of antimicrobial immunity. The association between intraamniotic hsp70 IgG concentrations and intraamniotic immune responses were evaluated. STUDY DESIGN: Midtrimester amniotic fluids from 90 women undergoing an amniocentesis were tested for hsp70 IgG, hsp70 antigen, tumor necrosis factor (TNF)-alpha, secretory leukocyte protease inhibitor (SLPI), and interferon (IFN)-alpha by enzyme-linked immunosorbent assay. Clinical outcomes were obtained after completion of all testing. Associations were analyzed by nonparametric statistics. RESULTS: Intraamniotic hsp70 IgG concentrations, but not hsp70 antigen levels, were positively associated with levels of TNF-alpha (P < .0001), IFN-alpha (P = .0001), and SLPI (P = .0038). There were no associations between hsp70 IgG and maternal age or parity, race/ethnicity or pregnancy outcome. CONCLUSION: The hsp70 IgG levels correlate with intraamniotic concentrations of antimicrobial immune mediators. This antibody may potentiate antimicrobial immunity during fetal development.

Inpatient management for a shortened cervix: who is really at risk?

OBJECTIVE: The objective of the study was to identify risk factors associated with spontaneous preterm delivery (SPD) within 2 weeks of admission in patients with a shortened cervix. STUDY DESIGN: We reviewed records of patients hospitalized in 2003-2004 with a cervix of 25 mm or less at less than 32 weeks' gestation. The primary outcome was SPD 2 weeks or less of admission. RESULTS: Sixty-six patients met inclusion criteria. Twelve delivered at 2 weeks or less of admission. There were no differences in maternal and gestational age at admission, history of SPD, and rate of multifetal pregnancy. Those with cervical length (CL) of 5 mm or less were more likely to deliver within 2 weeks than those with CLs 6-25 mm (50% vs 12.5%; P = .01). Logistic regression identified CL less than 5 mm as the only independent predictor of delivery within 2 weeks of admission (P = .01). CONCLUSION: CL of less than 5 mm in patients at less than 32 weeks' gestation is associated with a high rate of SPD within 2 weeks of diagnosis.

Does hospitalization prevent preterm delivery in the patient with a short cervix?

This study considers whether admission to the hospital of a patient diagnosed with a short cervix delayed delivery, prevented preterm delivery, and/or decreased the rate of change in the cervical length (CL) on follow-up measurements. The design was a retrospective cohort study of women carrying singleton pregnancies with cervical lengths

Extracellular 70-kd heat shock protein in mid-trimester amniotic fluid and its effect on cytokine production by ex vivo-cultured amniotic fluid cells.

OBJECTIVE: The 70-kd heat shock protein is released from cells in response to stress and functions as a regulator of innate immunity. We hypothesized that 70-kd heat shock protein in mid-trimester amniotic fluid might regulate local immune system activation. STUDY DESIGN: Amniotic fluid that was obtained from 200 women who underwent amniocentesis at 15 to 19 weeks of gestation was tested by enzyme-linked immunosorbent assay for 70-kd heat shock protein, tumor necrosis factor-alpha, and interleukin-1beta and -6. The amniotic fluid cellular fraction also was evaluated for Mycoplasma hominis by gene amplification. Whole amniotic fluids were incubated ex vivo in medium alone or medium that contained peptidoglycan, a TLR2 ligand, or lipopolysaccharide, a TLR4 ligand. After 24 hours, the supernatants were collected and assayed for 70-kd heat shock protein. The influence of exogenous 70-kd heat shock protein on tumor necrosis factor-alpha and interleukin-1beta and -6 production by whole amniotic fluid was assessed similarly. RESULTS: The 70-kd heat shock protein was detected in all amniotic fluids with a median (range) of 11.5 ng/mL (1.2-76.7). The intra-amniotic 70-kd heat shock protein concentration was correlated positively only with amniotic fluid tumor necrosis factor-alpha levels (P = .0002). Detection of M hominis was associated with an increased 70-kd heat shock protein concentration (median, 17.2 ng/mL; P = .01). The addition of peptidoglycan resulted in a stimulation of 70-kd heat shock protein production, and exogenous 70-kd heat shock protein stimulated the release of tumor necrosis factor-alpha by amniotic fluid cells. CONCLUSION: The 70-kd heat shock protein is released from cells in mid-trimester amniotic fluid as a consequence of TLR2 stimulation and potentiates tumor necrosis factor-alpha production.

A sonographic assessment of different patterns of placenta previa "migration" in the third trimester of pregnancy.

OBJECTIVE: The purpose of this study was to compare the rates and patterns of placental "migration" with the mode of fetal and placental delivery and the incidence of peripartum complications. METHODS: This was a retrospective study of 163 cases of placenta previa diagnosed by transvaginal sonography at 28 weeks' gestation that were followed serially by sonography. The patients were stratified into 3 groups depending on the placenta-to-internal cervical os distance: (1) an overlap of 0.0 cm or greater over the cervical os, (2) 0.1 to 2.9 cm, and (3) 3.0 cm or greater. The mean rate of placental migration (millimeters per week) was obtained at 28 to 32 and 32 to 36 weeks' gestation. A pattern of placental migration was classified as one with acceleration or deceleration of the placental migration in the late third trimester based on a comparison between the migration rates at 28 to 32 and 32 to 36 weeks' gestation. RESULTS: At the time of delivery, 22, 29, and 112 patients were included in groups 1, 2, and 3, respectively. The rates of placental migration correlated with the final placental distance from the internal cervical os (0.1 to 4.1 mm/wk for groups 1 and 3, respectively). Significantly higher rates of interventional cesarean delivery (CD) (P=.0002), elective CD (P=.0254), manual placenta removal (P=.0419), and placenta accreta (P=.0039), but not CD for indications other than placenta previa (P=.0752), were associated with a placental distance of less than 2.0 cm away from the cervix and a deceleration pattern of placental migration. In contrast, vaginal delivery was significantly associated with a placental distance of 2.0 cm or greater away from the cervix and an acceleration pattern of placental migration (P=.0034). CONCLUSIONS: A final placental distance of less than 2.0 cm from the internal cervical os and a deceleration pattern of placental migration were significantly associated with an interventional CD and a higher rate of peripartum complications.

Failure of conservative management of placenta previa-percreta.

We present a patient with a placenta previa in which we failed to manage conservatively with methotrexate and uterine embolization. The patient was diagnosed in the second trimester as having a possible placenta previa-increta,and underwent a repeat classical cesarean delivery at 32 weeks of gestation due to significant antepartum vaginal bleeding. Following abdominal closure,the uterine vessels were embolized with the Gel-Foam by interventional radiology. The placenta previa was left in-situ and patient was discharged home in stable condition in five days. The patient reported on the 44th postoperative day with heavy vaginal bleeding. A total abdominal hysterectomy was performed due to an unstable patient's hemodynamic condition in association with fluid resuscitation and multiple blood transfusions. The pathologic findings revealed a 675 g uterus with placenta previa-percreta with extension of chorionic villi to the serosal layer. Our case demonstrates a need for careful selection of patients with placenta previa and suspected accreta/increta/percreta that would be suitable candidates for conservative medical management. Patients who opt for conservative medical management should be informed about the possibility of catastrophic bleeding associated with a retained placenta, that would ultimately require blood transfusions and hysterectomy.