Maternal and fetal alternative complement pathway activation in early severe preeclampsia

PROBLEM

We sought to determine whether alternative complement activation fragment Bb (Bb) levels are elevated in the maternal, fetal, and placental blood in cases of severe preeclampsia (PE) compared with normotensive controls.

METHOD OF STUDY

This was a cross-sectional study of women admitted at ≥24 weeks gestation with or without severe PE. Maternal plasma was collected at the time of enrollment. Umbilical venous cord and intervillous space blood were collected at delivery. Plasma Bb levels were assessed using ELISA. Bb levels were compared between cases and controls.

RESULTS

Median Bb levels were higher in the maternal plasma of severe PE subjects (n = 24) than in controls (n = 20), 1.45 ± 1.03 versus 0.65 ± 0.23 μg/mL, P < 0.001. In umbilical venous plasma, Bb levels were higher in severe PE subjects (n = 15) compared with controls (n = 15), 2.48 ± 1.40 versus 1.01 ± 0.57 μg/mL, P = 0.01.

CONCLUSION

Activation fragment Bb is increased in the maternal and umbilical venous blood of cases of severe PE when compared with normotensive controls. These data provide support for alternative complement pathway involvement in the pathogenesis of severe PE and demonstrate that alternative complement activation occurs not only in the maternal but also in the fetal compartment.

Siglec-6 expression is increased in placentas from pregnancies complicated by preterm preeclampsia

Sialic acid immunoglobulin-like lectin (Siglec)-6 is a transmembrane receptor that binds sialyl-TN glycans and leptin. Among eutherian mammals, only human placentas express Siglec-6. Previous work has implicated Siglec-6 in preeclampsia (PE). Preeclampsia, a leading cause of maternal and perinatal morbidity and mortality, is characterized by placental abnormalities. This study provides a comprehensive analysis of Siglec-6 protein expression during human pregnancy by disease state (PE), biologic compartment (basal plate, chorionic villi, or maternal plasma), gestational age (24-41 weeks), and labor status. Siglec-6 protein was increased in both the basal plate and chorionic villi of preterm PE placentas (P < .05). However, expression did not differ at term by disease state, compartment, or labor status. Siglec-6 was not detectable in maternal serum. Overexpression of Siglec-6 protein in preterm PE placentas may contribute to or represent a response to PE pathogenesis and suggests that preterm PE pathogenesis is distinct from term PE.

Gestational age at initiation of 17-hydroxyprogesterone caproate (17P) and recurrent preterm delivery

OBJECTIVE

To compare rates of recurrent preterm birth between women starting treatment with 17alpha-hydroxyprogesterone caproate (17P) at 16-20.9 weeks of gestation versus 21-26.9 weeks.

METHODS

Women enrolled in an outpatient program of education, nursing assessment and weekly 17P injections beginning at 16-26.9 weeks were eligible. Included were patients with singleton pregnancies and a history of preterm delivery (PTD). Pregnancy outcome was compared between women starting 17P at 16-20.9 weeks (n=156) and those starting 17P at 21-26.9 weeks (n=119) using Fisher's exact and Mann-Whitney U test statistics (p<0.05 considered significant).

RESULTS

Mean gestational age at delivery (36.8 +/- 3.0 vs. 36.7 +/- 2.5) and rates of PTD at <37 weeks (40.4% vs. 48.7%), <35 weeks (16.7% vs. 16.8%) and <32 weeks (5.1% vs. 5.0%) were similar between the groups; all p > 0.05.

CONCLUSIONS

Rates of preterm delivery were similar in patients initiating 17P at 16-20.9 or 21-26.9 weeks. A larger sample size is warranted in order to confirm our findings.

Pregnancy at or beyond age 40 years is associated with an increased risk of fetal death and other adverse outcomes

OBJECTIVE

The objective of the study was to determine the frequency of fetal death in women 40 years of age or older (AMA).

STUDY DESIGN

Retrospective study of all singleton pregnancies delivered at our institution between the years 1989 and 2004 was performed. The primary outcome measure was the risk of fetal death at various gestational ages. We also investigated the frequency of maternal comorbidities, preterm delivery (PTD), and low and very low birth weights (LBW, VLBW).

RESULTS

Data were available for 126,402 singleton deliveries. AMA was an independent risk factor for fetal death at 28-31 weeks (adjusted odds ratio [AOR] 2.93, 95% confidence interval [CI] 1.76-4.92), 32-36 (AOR 1.73, 95% CI 1.05-2.83), 37-39 weeks (AOR 1.63, 95% CI 0.97-2.75), and 40-41 weeks (AOR 2.28, 95% CI 1.18-4.4). AMA was associated with increased rates of PTD, LBW, and VLBW.

CONCLUSION

AMA is associated with an increased rate of fetal death and other adverse obstetrical outcomes. Antepartum fetal surveillance may be warranted in these women.

Significance of accidental extensions in the lower uterine segment during cesarean delivery

OBJECTIVES

This study was undertaken to determine risk factors and perioperative complications associated with accidental extensions in the lower uterine segment during cesarean deliveries (CDs).

STUDY DESIGN

This is a retrospective chart review of all CDs performed at Jackson Memorial Hospital/University of Miami between the years 1999 and 2002. Operative reports were reviewed to abstract data on the occurrence of extensions. Indication for CD, cervical status at the time of CD, birth weight, and fetal presentation and position were included in the analyses. Postoperative hematocrits, length of surgery, estimated blood loss, decline in hematocrit by 10%, need for transfusion, or hysterectomy were compared among CD with and without extensions.

RESULTS

A total of 2,811 CDs were available for this study. Accidental extensions in the lower uterine segment occurred in 6.6% of the cases. Extensions were more commonly found in primary CD (8% vs 5%, P < .01. Extensions were more frequent if cervical dilatation was 8 cm or greater (18.3% vs 7%, P < .01), complete effacement (15% vs 8%, P < .01) station greater than +1 (16% vs 6.9%, P < .01), and if the fetal position was noted to be in the occiput posterior position (10% vs 5%, P < .01). When extensions were present, length of surgery was longer (56 vs 49 minutes, P < .01) and estimated blood loss was greater (994 +/- 675 mL vs 936 +/- 370 mL, P < .01). Arrest of descent as indication for CD was found to be an independent risk factor for the occurrence of extensions during CD (odds ratio 2.6, 95% CI 1.5-4.5, P = .001).

CONCLUSION

Extensions in the lower uterine segment during CD do not increase maternal morbidity.

Teen pregnancy in South Carolina: a local needs assessment of Charleston County

Although there has been recent improvement, teen pregnancy continues to be a significant problem, especially in South Carolina where the birth rate to adolescents is higher than the national average. As this is a complex issue, many different interventions including both primary and secondary prevention as well as modification of programs to fit each individual community will be necessary. One initial approach to pregnancy prevention program implementation is a needs assessment of current interventions compared with teen birth rates in a community. This report of a needs assessment for Charleston County revealed a discrepancy between the location of most pregnancy prevention programs (urban areas of the county) and the higher teen birth rates (rural areas of the county,) establishing areas that will be targeted for additional services. Other counties throughout South Carolina may find this approach useful in coordination of community efforts to reduce teen pregnancy.

Insulin-like growth factor II in gynecological cancers: a preliminary study

PROBLEM

We have previously reported elevated serum levels of cervical human papilloma viral proteins E6 and E7 and serum insulin-like growth factor II (IGF-II) in women with cervical cancer and advanced cervical intraepithelial neoplasia. As most women with cervical cancer have elevated levels of serum IGF-II, we sought to determine whether the cervical cancer and lymph node biopsies from these women demonstrated increased production of IGF-II and whether this elevation was also present in ovarian and endometrial cancers.

METHOD OF STUDY

We used the semi-quantitative immunofluorescent antibody assay established in our laboratory to identify the levels of IGF-II in 21 cervical cancers (seven with matching lymph nodes), 18 benign cervical biopsies, 13 endometrial cancers, 15 benign endometrial biopsies, 5 ovarian cancers, and 15 benign ovarian biopsies.

RESULTS

The immunofluorescent IGF-II levels (relative intensity per pixel) were the highest in cervical cancers; they were significantly higher than in matched controls. IGF-II levels were not higher in ovarian cancers and only slightly elevated in endometrial cancers. The presence of IGF-II in pelvic lymph nodes of women with cervical cancer paralleled with those in the cervical cancers. Interestingly, we could identify small nests of metastases of malignant cells in the nodes (pauci-cellular metastasis) by using IGF-II as the marker.

CONCLUSION

We propose that measurement and identification of IGF-II in the cervical biopsy may be a sensitive method of detecting cervical cancer and metastatic spread in the lymph nodes.

Antagonism of vaccine-induced HIV-1-specific CD4+ T cells by primary HIV-1 infection: potential mechanism of vaccine failure

Prior immunity to HIV-1 elicited by vaccination may modify subsequent responses upon exposure to infectious HIV-1. An HIV-1-uninfected person entered in a vaccine trial that included immunizations to HIV-1(LAI) envelope with a recombinant vaccinia vector and recombinant protein developed envelope-specific CD4+ T cell responses, including proliferative and cytolytic responses, but was not protected from a high risk HIV-1 exposure. CD4+ T cell clones derived from blood at the peak of vaccine-induced immunity recognized and lysed autologous target cells expressing four distinct regions within the HIV-1(LAI) envelope region; three of these CTL clones also recognized targets expressing envelope from a similar viral subtype, HIV-1(MN). The epitope specificity of CD4+ clone 9G8, recognizing both HIV-1(LAI) and HIV-1(MN) envelope, was within the 571-590 amino acid envelope region. Sequence analysis of the first infectious autologous strain revealed two amino acid mutations within this region. The 9G8 CTL clone induced by immunization failed to recognize targets expressing the corresponding CTL epitope from the infecting virus. Moreover, a peptide based on the epitope sequence of the infecting isolate antagonized the vaccine-induced CTL clone such that the CTL clone was no longer able to recognize the vaccine strain or HIV-1(MN) epitope. These findings suggest a potentially novel mechanism associated with vaccine failure whereby the infecting virus may not only escape from CTL activity, but also alter the ability of CTL to recognize other variants in an individual.

Antagonism of vaccine-induced HIV-1-specific CD4+ T cells by primary HIV-1 infection: potential mechanism of vaccine failure

Prior immunity to HIV-1 elicited by vaccination may modify subsequent responses upon exposure to infectious HIV-1. An HIV-1-uninfected person entered in a vaccine trial that included immunizations to HIV-1(LAI) envelope with a recombinant vaccinia vector and recombinant protein developed envelope-specific CD4+ T cell responses, including proliferative and cytolytic responses, but was not protected from a high risk HIV-1 exposure. CD4+ T cell clones derived from blood at the peak of vaccine-induced immunity recognized and lysed autologous target cells expressing four distinct regions within the HIV-1(LAI) envelope region; three of these CTL clones also recognized targets expressing envelope from a similar viral subtype, HIV-1(MN). The epitope specificity of CD4+ clone 9G8, recognizing both HIV-1(LAI) and HIV-1(MN) envelope, was within the 571-590 amino acid envelope region. Sequence analysis of the first infectious autologous strain revealed two amino acid mutations within this region. The 9G8 CTL clone induced by immunization failed to recognize targets expressing the corresponding CTL epitope from the infecting virus. Moreover, a peptide based on the epitope sequence of the infecting isolate antagonized the vaccine-induced CTL clone such that the CTL clone was no longer able to recognize the vaccine strain or HIV-1(MN) epitope. These findings suggest a potentially novel mechanism associated with vaccine failure whereby the infecting virus may not only escape from CTL activity, but also alter the ability of CTL to recognize other variants in an individual.

Immune responses elicited by recombinant vaccinia-human immunodeficiency virus (HIV) envelope and HIV envelope protein: analysis of the durability of responses and effect of repeated boosting

Previous studies indicate that immunization with recombinant (r) vaccinia-human immunodeficiency virus type 1 (HIV-1) gp160 and boosting with baculovirus-derived HIV-1 rgp160 results in stronger cellular and antibody responses than those following either vaccine alone. The durability of immunity over 1 year was evaluated in 12 recipients. Both cellular and binding antibody responses remained detectable but diminished, and neutralizing antibodies were absent. To boost immunity, rgp160 was given again 1 year after the initial boost. Reboosting elicited strong HIV-specific lymphoproliferative responses. Binding antibody levels also rose dramatically, and the magnitude of the peak responses was significantly greater following the 2-year than following the 1-year boost. However, neutralizing antibody titers were low (1:10-1:20) and detected in only 4 of 12 persons. Moreover, persistent CD8+ cytolytic responses were not induced. Thus, although repeated rgp160 boosting after vaccinia-envelope priming can augment selected immune components, an altered regimen may be necessary to achieve protective long-term immunity to HIV-1.

Safety of and immunological response to a recombinant vaccinia virus vaccine expressing HIV envelope glycoprotein

In a randomised phase I trial of a recombinant vaccina virus vaccine expressing the gp160 envelope gene of the human immunodeficiency virus (HIVAC-1e) 35 healthy, HIV-seronegative males, 31 of whom had a history of smallpox immunisation and 4 of whom were vaccinia naive, were vaccinated and then boosted 8 weeks later with HIVAC-1e or standard NY strain vaccinia virus. The frequency, duration, and titre of virus isolation from the vaccination site and occurrence of local side-effects were similar between the two groups of vaccinees. Vaccinia-naive (vac-n) subjects shed virus from the vaccination site for longer and at a higher titre than did vaccinia-primed (vac-p) individuals (19 vs 7 days and 10(7) vs 10(5) pfu/ml, respectively). In-vitro T-cell proliferative responses to one or more HIV antigen preparations developed in 13 of 16 vaccinia-primed subjects inoculated with HIVAC-1e. T-cell responses were, however, transient and in no subject did antibodies to HIV become detectable. The 2 vaccinia-naive subjects vaccinated with HIVAC-1e showed strong T-cell responses to homologous and heterologous strains of whole virus and to recombinant gp160 protein that remained detectable for over a year; antibodies to HIV envelope also developed in both. Recombinant vaccinia virus vaccines induce T-cell priming to the foreign gene products in most individuals. If used as the sole immunising agent they will be most efficacious in vaccinia-naive individuals.