Preterm prelabour amniorrhexis: intrauterine infection and interval between membrane rupture and delivery

This study aimed to determine if fetal bacteraemia and amniotic fluid infection at the time of membrane rupture reduces the interval between membrane rupture and the onset of labour in pregnancies complicated by preterm prelabour amniorrhexis. Sixty nine pregnancies with preterm prelabour amniorrhexis at 12-36 weeks' gestation that were managed expectantly had spontaneous onset of labour. In all cases cordocentesis and amniocentesis were performed and fetal blood and amniotic fluid were cultured for aerobic and anaerobic bacteria. In the group with negative fetal blood and amniotic fluid cultures (group 1) the median interval from amniorrhexis to delivery was 41 days (range 1-161) and there was an inverse correlation between gestational age at amniorrhexis and delivery interval. In the group with negative fetal blood but positive amniotic fluid cultures (group 2) the median amniorrhexis to delivery interval was nine days (range 1-37), and in the group with positive fetal blood cultures (group 3) the interval was two days (range 1-5). These findings suggest that pregnancies complicated by preterm prelabour amniorrhexis and fetal bacteraemia undergo spontaneous labour within five days of membrane rupture, and if labour does not occur then infection is unlikely.

Induction of interleukin-1 receptor antagonist in rhesus monkeys after intraamniotic infection with group B streptococci or interleukin-1 infusion

OBJECTIVE

Interleukin-1 receptor antagonist is a natural inhibitor of interleukin-1, a cytokine implicated in the initiation of preterm labor after intraamniotic infection. The effects of intraamniotic infection and interleukin-1 infusion on the appearance of interleukin-1 receptor antagonist in amniotic fluid and fetal and maternal plasma were assessed with a monkey model.

STUDY DESIGN

On day 130 of pregnancy four chronically catheterized rhesus macaques received intraamniotic inoculations of group B streptococci, three monkeys received intraamniotic infusions of recombinant human interleukin-1 beta, and three monkeys received buffered saline solution infusions. At timed intervals samples of amniotic fluid, fetal plasma, and maternal plasma were assayed for interleukin-1 beta and interleukin-1 receptor antagonist by immunoassays. Uterine activity was continuously monitored by intraamniotic pressure catheters and by electromyographic activity.

RESULTS

Interleukin-1 receptor antagonist, but not interleukin-1 beta, was present in the amniotic fluids of all monkeys before intervention. Infection induced the appearance of interleukin-1 beta and an increase in interleukin-1 receptor antagonist in the amniotic fluid. Interleukin-1 beta infusion resulted in a similar increase in the intraamniotic concentration of interleukin-1 receptor antagonist. Both infection and interleukin-1 beta infusion were followed by the transient appearance of interleukin-1 receptor antagonist in the plasma of all fetuses. The subsequent decrease in plasma levels was paralleled by increased amniotic fluid levels of interleukin-1 receptor antagonist. Interleukin-1 beta and interleukin-1 receptor antagonist were not detected in maternal plasma. Both infection and interleukin-1 infusion induced preterm labor in all treated animals.

CONCLUSIONS

Interleukin-1 receptor antagonist is a normal component of monkey amniotic fluid. Intraamniotic infection or the appearance of interleukin-1 beta in the amniotic fluid results in increased production of interleukin-1 receptor antagonist. Under physiologic conditions interleukin-1 receptor antagonist in amniotic fluid may inhibit interleukin-1-induced preterm labor.

Polymerase chain reaction for detection of Borrelia coriaceae, putative agent of epizootic bovine abortion

The nucleotide sequence of a chromosomally encoded antigen-expressing gene of Borrelia coriaceae was determined and used as a target for the polymerase chain reaction (PCR). Two primer sets were designed specifying the amplification of 269- and 701-bp DNA fragments. Primer set I, producing the short amplicon, was tenfold more sensitive than primer set II. As little as 10 fg of purified B coriaceae DNA could consistently be detected. The PCR assays, containing controlled numbers of whole spirochetes, allowed detectable amplification of 2 to 10 organisms. An internal, nonradioactively labeled gene-specific probe verified specificity of the PCR amplicons. Neither primer set cross-reacted with other related spirochetes. This PCR assay was adapted and found suitable for identification of B coriaceae in biological samples, such as blood and thymus. Evidence for presence of B coriaceae in biological samples was not found in tissue samples obtained from experimentally infected cows and their fetuses. These data failed to establish a definite association between B coriaceae and epizootic bovine abortion.

An assessment of the timing of mother-to-child transmission of human immunodeficiency virus type 1 by means of polymerase chain reaction

To approximate the contributions of in utero, intrapartum, and postnatal transmission of human immunodeficiency virus type-1 (HIV-1) and to evaluate polymerase chain reaction (PCR) as a diagnostic tool for pediatric HIV infection, blood was collected at birth (cord blood), and at 3, 6-12, and 13-24 months in 218 children born to HIV-1-seropositive mothers in Kigali, Rwanda. Proviral DNA was detected by a double PCR using two sets of three primers (gag, pol, and env). Pediatric HIV-1 infection was defined according to serological and clinical criteria. The probability of having a positive PCR at a given time was calculated by a nonparametric method. Among children with unequivocal evidence of infection (n = 47), it was 30.5% on cord blood and 80.6% at 3 months. Thus, in children born to HIV-1-infected mothers, the estimated rate of transmission in the late postnatal period is 4.9%, and the rate of transmission in the intrapartum plus postnatal periods is 17.6%. Among 117 HIV-1-uninfected children born to HIV-1-infected mothers, six (5%) had a false-positive PCR on cord blood. These results should be taken into account in designing intervention trials aimed at reducing mother-to-child transmission of HIV-1.

The incidence of prenatal syphilis at the Boston City Hospital: a comparison across four decades

OBJECTIVE

To examine the incidence and epidemiologic correlates of congenital syphilis at an inner-city Boston hospital, and draw comparisons with the situation at the same hospital 40 years ago.

DESIGN

Chart review and comparison with data collected in 1951.

SETTING

Maternity and pediatric services at Boston City Hospital.

METHODS

A study conducted in 1951 on the maternity service of Boston City Hospital in which demographic data were collected on all women admitted in labor over a 5-month period was replicated. Serologic testing for syphilis was carried out on these women, and the demographic and medical correlates of positive maternal syphilis serology were examined. This study was repeated exactly 40 years later, using the cord blood screening for syphilis done routinely at delivery and a review of prenatal records.

RESULTS

From a group made up largely of married white women in 1951, the study population shifted in 1991 to a group made up mostly of minority women, with 75% unmarried. In 1951, 24 patients were diagnosed with syphilis either before or during the pregnancy, giving a prevalence rate of 2.4%. In 1991, 25 of 647 women were diagnosed with syphilis, for a prevalence rate of 3.9%. The women with positive cord blood serologies had a higher rate of other sexually transmitted diseases and substance abuse. No symptomatic cases of congenital syphilis were seen in 1951 or in 1991, although at least 11 of the 26 infants born to mothers with positive serologies in 1991 received intravenous penicillin therapy.

CONCLUSIONS

The continued prevalence of diagnosed syphilis in women at delivery reflects an inner-city epidemic of congenital syphilis that is tied to substance abuse, human immunodeficiency virus, and changing social patterns, as well to older problems of serologic screening, prenatal care, treatment failures, and maternal reinfection. It is essential that screening programs be maintained and improved in this high-risk population, and that infants born to mothers with positive serologies receive full and adequate treatment if there is any doubt at all about their infection status.

HTLV-I proviral DNA in umbilical cord blood of babies born to carrier mothers

Human T-lymphotropic virus type I (HTLV-I) in cord blood raises the possibility of intrauterine transmission as an alternative pathway to transmission via breast milk. However, none of 7 children with HTLV-I proviral DNA positive cord blood had seroconverted by 24-48 months. Contamination of cord blood by maternal blood was precluded on the basis of viral load and IgA concentration. Thus cord blood proviral DNA is not a hallmark of intrauterine infection. Moreover, none of the cord blood samples of 9 formula-fed children later confirmed to be infected was positive for HTLV-I, indicating that intrauterine infection is not a likely candidate as an alternative pathway.

Intervention of maternal transmission of HTLV-1 in Nagasaki, Japan

Seroepidemiological and laboratory virological evidences strongly suggested that endemicity of HTLV-1 in Nagasaki Japan depends on maternal infant infections via breast milk. The most obvious way to prove this concept was an intervention study with refraining from breast-feeding by carrier mothers. Most infected babies seroconverted by the age of 12 months, which made it possible to diagnose the infection at the age of 12 months for the statistical purpose. Serology and PCR on both adults and children were consistent each other, suggesting the absence of seronegative carriers. The intervention study revealed that approximately 80% of maternal infection was prevented by refraining from breast feeding by carrier mothers. The remaining fraction of infections in formula-fed babies suggested an alternative infection pathway. Although intrauterine infections has been suggested by others to explain the PCR-positive cord blood samples. However, groups of cord blood-positive children and seroconverted children were distinct each other. Therefore, the presence of HTLV-1 provirus in the cord blood can not be a marker of intrauterine infection. Mothers who infected a child has approximately 10 times higher risk of another infection for the next baby than those who did not.

[Cytomegalovirus infection in pregnant women and perinatal infants]

Perinatal cytomegalovirus (CMV) infection was studied, using method of CMV-IgM ELISA, in 256 pregnant women at different periods and in the cord blood of 84 babies born by CMV positive mothers. Results showed that in 42 cases at early and midtrimester pregnancy, 17 were CMV-IgM positive with an infection rate of 40.48%. Among the 214 women at late pregnancy, 84 were positive (39.25%). There was a higher prevalence of perinatal morbidity, neonatal asphyxia, malformation, intrauterine death, and poor obstetrical outcome in the CMV positive mothers as compared with the CMV negative group (P < 0.01). This study showed that the presence of CMV-IgM indicated a recent or recurrent CMV infection during pregnancy and the babies should be carefully monitored.

Increased susceptibility of neonatal monocyte/macrophages to HIV-1 infection

The relative susceptibility of neonatal/cord blood monocyte/macrophages to productive infection with human immunodeficiency virus type 1 (HIV-1) was investigated. In addition, the effect of HIV-1 infection of cord blood monocyte/macrophages in various stages of maturation/differentiation as represented by differing ages of monocytes in culture was examined. Monocyte/macrophages were infected with two viral strains isolated and cloned from primary clinical isolates, each with different cell tropisms. Cord blood and adult monocyte/macrophages were infected with either the macrophage-tropic strain HIV-1(JR-FL) or the predominantly lymphocyte-tropic strain HIV-1(JR-CSF). p24gag antigen levels were measured in supernatants by ELISA. Cord monocyte/macrophages at three different ages in culture (4, 7, and 11 days) were more productively infected by both viral strains than were adult monocyte/macrophages infected in parallel. In addition, the less differentiated cells (cord and adult monocyte/macrophages infected after growing 4 days in culture) were more productively infected than were the more differentiated monocyte/macrophages (cells infected after growing 7 or 11 days in culture). The mechanism for this increased susceptibility of cord monocyte/macrophages to HIV-1 infection as compared to adult cells was also investigated. A measurable increase in DNA synthesis was found in the infected cord cells when compared to infected adult cells and to uninfected adult or cord cells as represented by increased [3H]thymidine incorporation, suggesting that increased cell proliferation of cord monocyte/macrophages may enhance the permissivity of infection. This article suggests that cord monocyte/macrophages may play an important role in the pathogenesis of perinatal HIV-1 infection.(ABSTRACT TRUNCATED AT 250 WORDS)

The incidence of vertical transmission of hepatitis C virus

This study was undertaken to clarify the incidence of the vertical transmission of hepatitis C virus (HCV). During the third trimester, 2015 pregnant women were examined as to anti-HCV antibodies. Anti-HCV antibody seropositive women were examined for HCV-RNA in peripheral blood at labor and in breast milk. Their offspring were also examined for HCV-RNA in umbilical cord blood and peripheral blood one week after birth and during subsequent outpatient visits. The following results were obtained: (1) Twelve of the 2015 pregnant women (0.6%) were seropositive for anti-HCV antibodies; (2) Seven of the twelve women (58%) seropositive for anti-HCV antibodies were also seropositive for HCV-RNA; (3) Three newborns of the seven HCV-RNA seropositive women (43%) were found to have HCV-RNA in the cord blood; (4) In the three newborns HCV-RNA had disappeared from the peripheral blood within one month after birth; (5) Two of the seven HCV-RNA seropositive women (29%) had HCV-RNA positive breast milk; (6) The possibility of infection via breast milk was shown in one infant at ten months after birth. Based on these results, it is indicated that HCV vertical transmission is possible in more than half of the HCV-RNA seropositive mothers. However, because of the disappearance of HCV from the infants' peripheral blood, further following study is needed.

Studies on transmission of hepatitis C virus from mother-to-child in the perinatal period

To elucidate whether breast milk, vaginal discharge and contamination with maternal blood at birth are possible routes of mother-to-child transmission of hepatitis C virus (HCV), we examined HCV RNA in the cord and peripheral blood of infants, and in the blood, vaginal discharge, and breast milk of anti-HCV seropositive mothers. From July 1991 to July 1992, we studied 20 healthy pregnant women, who were seropositive with the Ortho anti-HCV EIA, and their infants. Using a sensitive nested polymerase chain reaction (nested PCR), we investigated the presence or absence of hepatitis C virus in the above-mentioned specimens. Moderate elevation of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) was observed in only one woman in the first and third trimesters. The nested PCR and subsequent Southern hybridization detected 0.5-5.5 copies of HCV c-DNA. HCV RNA was detected in 17/20 blood samples (85%), 7/14 vaginal discharge samples (50%) and 4/10 cord blood samples (40%). However, no HCV RNA was identified in the peripheral blood of infants or breast milk. The mother-to-child transmission of HCV at delivery or via breast milk does not appear to contribute much to maintaining the global HCV reservoir.

A rapid test for the detection of human immunodeficiency virus antibodies in cord blood

A commercially available rapid test (HIVCHEK) was compared with an enzyme-linked immunosorbent assay (ELISA) for identifying human immunodeficiency virus type 1 in the serum of newborn infants. Of 1309 cord blood samples tested, the HIVCHEK test detected all the true-positive samples detected by ELISA. Of the 35 samples with positive ELISA results, six had negative results on Western blot; only 1 of the 30 samples with positive HIVCHEK results had negative results on Western blot. Thus the HIVCHEK test can be used to facilitate the rapid identification of HIV-1 in the serum of newborn infants.

Diminished cord blood lymphocyte L-selectin expression in neonatal bacterial infection

L-Selectin, a leukocyte surface glycoprotein involved in white blood cell extravasation, is rapidly down-regulated after leukocyte activation. We prospectively determined lymphocyte L-selectin expression in freshly obtained cord blood samples of 98 neonates (gestational age 25-42 weeks). In eight infants with bacterial infection, the mean percentage of L-selectin(high) lymphocytes was 32.5% (SD 20.1%), compared to 60.1% (SD 18.7%) in the control group (P < 0.01). A percentage of L-selectin(high) lymphocytes of less than 42% had a sensitivity of 75% and a specificity of 82% in identifying infected newborns. Cord blood lymphocyte L-selectin expression was independent of gestational age, birth weight, umbilical artery pH, hematocrit, white blood cell count, absolute neutrophil count, C-reactive protein level, or maternal fever before delivery while there was a weak correlation with the newborn's immature/total ratio and platelet count. To our knowledge, this is the first report demonstrating downregulation of human lymphocyte L-selectin expression following activation of the immune system in vivo.

Cytomegalovirus seroprevalence in women bearing children in Jefferson County, Kentucky

Symptomatic congenital cytomegalovirus (CMV) disease occurs almost exclusively in infants born to seronegative mothers who acquire the virus during pregnancy. This study sought to determine patterns of CMV immunity in women of childbearing age at one center participating in a national study. Cord blood specimens from 100 consecutive deliveries at each of three hospitals were tested for CMV-specific IgG. Mean age of women in this sample was 25.7 years; 76% were white, 60% were from middle and upper socioeconomic status, 64% were married, and 57% had other living children. Overall seroprevalence rate was 62%. Univariate analysis showed strong associations between seropositivity and lower socioeconomic status, non-white race, and age younger than 25 years (odds ratios, 4.4, 3.9, and 2.5, respectively). Stratification by socioeconomic status and race eliminated the effect of age. Stratification by socioeconomic status markedly reduced the effect of race, whereas stratification by race only moderately reduced the effect of lower socioeconomic status, which was the strongest predictor of seropositivity (odds ratio, 3.4). Seroprevalence was lowest among older white women of middle and upper socioeconomic status (47% seropositive). Development of longitudinal regional seroprevalence data will facilitate interpretation of data generated by the National CMV Registry.

In vitro infection of human macrophages with human T-cell leukemia virus type 1

The tropism of the human T-cell leukemia virus type 1 (HTLV-1) for the cells of monocyte-macrophage lineage was evaluated by the coculture of blood monocyte-derived macrophages, with irradiated cells of HTLV-1 producing cell lines MT2 or C91/PL. The susceptibility to HTLV-1 was assessed by the detection of viral DNA using the polymerase chain reaction method. HTLV-1 gene expression in the cells was detected using in situ hybridization and by immunofluorescent staining of viral antigen. The presence of type C virus-like particles detected by electron microscopy and the ability to infect normal cord blood lymphocytes demonstrated that the infected macrophages produced infectious virus. These results indicate that human macrophages are susceptible in vitro to productive HTLV-1 infection, and thus might be involved in the pathogenesis of HTLV-1-related diseases.

Combined treatments with interferon (alpha,beta) plus PGA1 to control early infection with HTLV-I in primary cord blood-derived mononuclear cells

Interferon (IFN) alpha and beta can activate an antiviral and immunomodulating response in primary cord blood-derived mononuclear cells (CBMC) exposed to infection with Human T-cell Leukemia Virus type I (HTLV-I), resulting in partial inhibition of early infection in vitro. On the other hand, PGA1, a PGE1-derived cyclopentenone prostaglandin, can inhibit in vitro the proliferation of virus-infected CBMC, preventing the emergence of the potentially transformed clone. In order to achieve a complete control of HTLV-I infection in this experimental model, we evaluated whether the antiviral activity of IFNs and the antiproliferative activity of PGA1 could be preserved in a combination therapy scheme. Recipient CBMC were treated with IFN alpha or beta (1000 IU/ml) at the onset of the co-culture with lethally irradiated virus-donor MT-2 cells, followed by multiple treatments with PGA1 (4 micrograms/ml every 4 days, starting on day 0) for 6 weeks post infection (p.i.). In PGA1-treated co-cultures the percentage of virus-positive CBMC was constantly doubled during culture time as well as the amount of viral transcripts and p19 virus core protein production were increased. The antiviral effects of IFNs, resulting in about a 50% reduction of the percentage of virus-positive CBMC and consequently in a partial inhibition of virus expression (HTLV-I transcription and p19 production) until 4 weeks p.i., were suppressed by multiple PGA1 treatments. However, the antiproliferative effect of PGA1 was enforced in IFN-treated co-cultures, leading to earlier control of proliferation of virus-infected cells. Interestingly, infection of CBMC with HTLV-I was associated with persistent expression of 70 kDa heat shock protein (HSP70), for at least 4 weeks p.i. IFNs and PGA1 showed antagonistic effects on HSP70 production in infected CBMC. In fact, production of HSP70 was suppressed (or prevented) in IFN-treated co-cultures, tested 2 and 4 weeks p.i. The fact that the expression of HSP70 is apparently suppressed (or prevented) by IFN treatment is surprising, since expression of this protein family has been associated with antiviral immunity. PGA1 could totally reverse the IFN-mediated suppression of HSP70 expression in these co-cultures. It is presently unclear whether HSP70 expression is directly involved in the control of proliferation exerted by PGA1 against virus-infected CBMC or is an epiphenomenon associated with inhibition of cell growth.

Thiol suppression of human immunodeficiency virus type 1 replication in primary cord blood monocyte-derived macrophages in vitro

We investigated the effects of glutathione (GSH), the major naturally occurring thiol, and a pharmacologic thiol precursor of GSH, N-acetyl cysteine (NAC), on the expression of human immunodeficiency type 1 (HIV-1) in primary cord blood and adult donor monocyte-derived macrophages (MDM). HIV-1 infection of cord blood and adult MDM was accomplished after incubating 10-15-d-old cultures for 4 h with a monocyte-tropic strain of HIV-1 (Bal). After 1 wk in culture cell supernatants were tested for reverse transcriptase (RT) activity. MDM were exposed to 5, 10 and 20 mM concentrations of both GSH and NAC before infection, during infection, and after infection was established. GSH and NAC suppressed the replication of HIV-1 in both primary cord blood and adult donor MDM in a concentration dependent fashion. These suppressive effects were more pronounced in cord-derived cells than in adult-derived cells. In cells treated with GSH or NAC before infection, there was no significant rise in RT activity as compared with controls. Similarly, when cells were treated with GSH and NAC and simultaneously infected, there was also no significant rise in RT activity after 1 wk in culture. In cells treated after infection was established, RT values were suppressed 80-90% that of untreated controls. This effect persisted for 1-2 wk after exposure to GSH and NAC. Untreated controls demonstrated syncytium formation and lost characteristics of spreading and elongation 2 wk after HIV-1 infection, whereas most of the treated cells remained free of syncytium and retained cytoplasmic spreading, adherence, and elongation. These data are consistent with other studies of thiol suppression of HIV-1 replication and demonstrate a similar observation for primary cultured cord MDM. These results may offer new approaches toward cellular protection after infection with HIV-1.

Fetal syphilis: correlation of sonographic findings and rabbit infectivity testing of amniotic fluid

Fetal syphilis is the presumed diagnosis when the sonographic findings of fetal hydrops are found in the presence of maternal syphilis. In the absence of fetal hydrops, the diagnosis of fetal infection is difficult. We hypothesized that intra-amniotic infection would be accompanied by anatomic placental and fetal abnormalities that could be detected by ultrasonography. Rabbit infectivity testing (RIT), intratesticular inoculation of rabbits with amniotic fluid, can be used to confirm intra-amniotic infection with Treponema pallidum. Twenty-one gravidas with untreated early (primary, secondary, and early latent) syphilis underwent sonography and amniocentesis for RIT at 24 weeks of gestation or later. Antenatal sonographic findings were compared to their amniotic fluid RIT results. Hepatomegaly was significantly (P < 0.01) associated with amniotic fluid infection detected by RIT. Antenatal detection of hepatomegaly, which is probably the initial sonographic manifestation of hydrops fetalis, may ultimately identify the fetus affected with congenital syphilis.

Comparison of maternal sera, cord blood, and neonatal sera for detecting presumptive congenital syphilis: relationship with maternal treatment

The incidence of congenital syphilis has increased rapidly over the past few years. Most infected mothers and their newborns are asymptomatic at birth and diagnosis depends on serologic testing during pregnancy and at delivery. This study was initiated to compare maternal sera, cord blood, and neonatal sera for detecting presumptive congenital syphilis and to assess the role of maternal treatment (administration of penicillin to the mother at least 1 month before delivery) on the serologic results at the time of delivery. The serologic results from all live deliveries complicated by a positive maternal and/or neonatal test for syphilis during a 12-month period were compared using chi 2 analysis and multiple comparisons for proportions. Of 3306 livebirths, 73 (2.2%) were complicated by a positive maternal or neonatal serology. At delivery, the serologic test was positive in 68 (94%) of 72 maternal sera, 30 (50%) of 60 cord sera, and 43 (63%) of 68 neonatal sera. In the absence of maternal treatment, 95% of the maternal sera, 66% of the cord blood samples, and 86% of the neonatal sera were positive. If the mother had been treated, 94% of maternal sera, 36% of cord sera, and 39% of neonatal sera were positive. Cord blood and neonatal sera appear to be inferior to maternal sera for detecting prenatal exposure to syphilis. Cord serology is also inferior to neonatal serology at 2 to 3 days of age. The most effective way to identify newborns at risk for congenital syphilis is to obtain a maternal serologic diagnosis during pregnancy and to test maternal and neonatal sera at delivery.