Maternal Alcohol Abuse and Neonatal Infection

In utero ethanol exposure impairs defenses against experimental group B streptococcus in the term Guinea pig lung

BACKGROUND

The effects of fetal alcohol exposure on the risks of neonatal lung injury and infection remain under investigation. The resident alveolar macrophage (AM) is the first line of immune defense against pulmonary infections. In utero ethanol (ETOH) exposure deranges the function of both premature and term guinea pig AM. We hypothesized that fetal ETOH exposure would increase the risk of pulmonary infection in vivo.

METHODS

We developed a novel in vivo model of group B Streptococcus (GBS) pneumonia using our established guinea pig model of fetal ETOH exposure. Timed-pregnant guinea pigs were pair fed +/-ETOH and some were supplemented with the glutathione (GSH) precursor S-adenosyl-methionine (SAM-e). Term pups were given GBS intratracheally while some were pretreated with inhaled GSH prior to the experimental GBS. Neonatal lung and whole blood were evaluated for GBS while isolated AM were evaluated using fluorescent microscopy for GBS phagocytosis.

RESULTS

Ethanol-exposed pups demonstrated increased lung infection and sepsis while AM phagocytosis of GBS was deficient compared with control. When SAM-e was added to the maternal diet containing ETOH, neonatal lung and systemic infection from GBS was attenuated and AM phagocytosis was improved. Inhaled GSH therapy prior to GBS similarly protected the ETOH-exposed pup from lung and systemic infection.

CONCLUSIONS

In utero ETOH exposure impaired the neonatal lung's defense against experimental GBS, while maintaining GSH availability protected the ETOH-exposed lung. This study suggested that fetal alcohol exposure deranges the neonatal lung's defense against bacterial infection, and support further investigations into the potential therapeutic role for exogenous GSH to augment neonatal AM function.

Maternal smoking during pregnancy increases the risk of postnatal infections in preterm neonates

BACKGROUND

Maternal smoking during pregnancy is known to be associated with perinatal complications such as preterm delivery, low birth weight, and sudden infant death syndrome.

OBJECTIVE

The purpose of this study was to evaluate the influence of smoking during pregnancy on the risk of postnatal infections in preterm neonates.

METHOD

We examined 80 preterm infants (gestational age 24-36 weeks), of whom 40% had been exposed to tobacco smoking during pregnancy.

RESULTS

Infections occurred in 31 infants. Gestational age and maternal smoking had a significant effect on the occurrence of infections (p < 0.001 and p = 0.015, respectively). An increase in maternal tobacco consumption by 10 cigarettes/day showed an odds ratio of 2.7 (95% confidence interval 1.1-6.4) for occurrence of infections.

CONCLUSIONS

A significant association between maternal use of tobacco and the occurrence of infections in preterm neonates was found. Thus, campaigns about the damaging effects of tobacco are still warranted.

Herbal mixtures consisting of puerarin and either polyenylphosphatidylcholine or curcumin provide comprehensive protection against alcohol-related disorders in P rats receiving free choice water and 15% ethanol in pure water

Chronic alcohol drinking has been associated with the development of a number of abnormalities, including neuron-behavioral disorders, liver, pancreas, and heart-related diseases and inflammation and immune disorders. Because diverse mechanisms are involved in the development of these disorders, the commonly used receptor- or enzyme-specific drugs do not provide comprehensive protection against the adverse effects of alcoholism. This study describes possible therapeutic potency of puerarin (PU) from kudzu root, polyenylphosphatidylcholine from soy (SPCh), and curcumin (CU) from turmeric against alcohol's addiction-related and inflammatory-related abnormalities in alcohol-preferring P rats receiving free choice water and 15% ethanol in water. P-rats were fed once daily either the vehicle (for control) or different doses of PU, SPCh, CU, PU + SPCh, or PU + CU. The rats were divided in two groups: one received water alone, and the other free choice water and ethanol. Four rats from each group were fitted with electroencephalogram (EEG) electrodes for EEG recording. After 70 days of alcohol drinking, alcohol was withdrawn for 2 weeks, and the withdrawal symptoms were assessed. This study showed that alcohol drinking for 70 days (1) caused liver inflammation characterized by elevated tumor necrosis factor-alpha, interleukin-1beta, and matrix metalloproteinase-9 expression and (2) dysregulated lipopolysaccharide (LPS)-induced pleurisy. Alcohol withdrawal after 70 days of drinking generated severe withdrawal symptoms including seizure-type EEG activity. PU suppressed the addiction-mediated abnormalities but did not affect the inflammation-related abnormalities, while SPCh or CU suppressed only the inflammation-related abnormalities in alcohol-drinking rats subjected to LPS-induced pleurisy. A combination of PU with SPCh or CU suppressed both the addiction-related and inflammation-related abnormalities of alcohol drinking. Therefore, a mixture consisting of PU and either SPCh or CU may provide alternative therapy for alcohol-related disorders.

Maternal alcohol ingestion reduces surfactant protein A expression by preterm fetal lung epithelia

In addition to neurodevelopmental effects, alcohol consumption at high levels during pregnancy is associated with immunomodulation and premature birth. Premature birth, in turn, is associated with increased susceptibility to various infectious agents such as respiratory syncytial virus (RSV). The initial line of pulmonary innate defense includes the mucociliary apparatus, which expels microorganisms trapped within the airway secretions. Surfactant proteins A and D (SP-A and SP-D, respectively) are additional components of pulmonary innate immunity and have an important role in pulmonary defense against inhaled pathogens. The purpose of this study was to determine if chronic alcohol consumption during the third trimester of pregnancy alters the function of the mucociliary apparatus and expression of SP-A and SP-D of fetal lung epithelia. Sixteen, date-mated ewes were assigned to two different groups; an ethanol-exposed group in which ewes received ethanol through surgically implanted intra-abomasal cannula during the third trimester of pregnancy, and a control group in which ewes received the equivalent amount of water instead of ethanol. Within these two groups, ewes were further randomly assigned to a full-term group in which the lambs were naturally delivered, and a preterm group in which the lambs were delivered prematurely via an abdominal incision and uterotomy. Ethanol was administered five times a week as a 40% solution at 1g/kg of body weight. The mean maternal serum alcohol concentration measured 6h postadministration was 16.3+/-4.36 mg/dl. Tracheas from six full-term lambs were collected to assess ciliary beat frequency (CBF). The lung tissue from all (24) lambs was collected for immunohistochemistry analysis of SP-A and SP-D protein production and fluorogenic real-time quantitative polymerase chain reaction analysis of SP-A and SP-D mRNA levels. Exposure to ethanol during pregnancy significantly blocked stimulated increase in CBF through ethanol-mediated desensitization of cAMP-dependent protein kinase. In addition, preterm born/ethanol-exposed lambs showed significantly decreased SP-A mRNA expression when compared with the preterm born/control group (P=.004); no significant changes were seen with SP-D. The full-term/ethanol-exposed lambs had no significant alterations in mRNA levels, but had significantly less detectable SP-A protein when compared with the full-term/control lambs (P=.02). These findings suggest that chronic maternal ethanol consumption during the third trimester of pregnancy alters innate immune gene expression in fetal lung. These alterations may underlie increased susceptibility of preterm infants, exposed to ethanol in utero, to RSV and other microbial agents.

Combining Internal and External Validation Data to Correct for Exposure Misclassification

Internal validation data offer a well-recognized means to help correct for exposure misclassification or measurement error. When available, external validation data offer the advantage of cost-effectiveness. However, external data are a generally inefficient source of information about misclassification parameters. Furthermore, external data are not necessarily "transportable", for example, if there are differences in the design or target populations of the main and validation studies. Recent work has suggested weighted estimators to simultaneously take advantage of internal and external validation data. We explore efficiency and transportability in the fundamental case of estimating the odds ratio for binary exposure in a case-control setting. Our results support the use of closed-form weighted log odds ratio estimators in place of computationally demanding maximum likelihood estimators under both types of validation study designs (using internal data only, and combining internal and external data). We also provide and assess a formal test of the transportability assumption, and introduce a new log odds ratio estimator that is inherently robust to violation of that assumption. A case-control study of the association between maternal antibiotic use and sudden infant death syndrome provides a real-data example.

Infectious disease morbidity among young HIV-1-exposed but uninfected infants in Latin American and Caribbean countries: the National Institute of Child Health and Human Development International Site Development Initiative Perinatal Study

OBJECTIVE

The goal was to describe the frequency, characteristics, and correlates of infectious disease morbidity during the first 6 months of life among HIV-1-exposed but uninfected infants.

METHODS

The study population consisted of infants enrolled in the National Institute of Child Health and Human Development International Site Development Initiative Perinatal Study who were HIV-1 uninfected and had follow-up data through the 6-month study visit. Definitive and presumed infections were recorded at study visits (birth, 6-12 weeks, and 6 months).

RESULTS

Of 462 HIV-1-uninfected infants with 11,644 child-weeks of observation, 283 experienced > or = 1 infection. These 283 infants experienced 522 infections (1.8 infections per infant). The overall incidence rate of infections was 4.5 cases per 100 child-weeks of observation. Overall, the most common infections were skin or mucous membrane infections (1.9 cases per 100 child-weeks) and respiratory tract infections (1.7 cases per 100 child-weeks). Thirty-six percent of infants had > 1 respiratory tract infection (1.8 cases per 100 child-weeks). Incidence rates of upper and lower respiratory tract infections were similar (0.89 cases per 100 child-weeks and 0.9 cases per 100 child-weeks, respectively). Cutaneous and/or oral candidiasis occurred in 48 neonates (10.3%) and 92 older infants (19.3%). Early neonatal sepsis was diagnosed in 12 infants (26.0 cases per 1000 infants). Overall, 81 of 462 (17.5%) infants were hospitalized with an infection. Infants with lower respiratory tract infections were hospitalized frequently (40.7%). The occurrence of > or = 1 neonatal infection was associated with more-advanced maternal HIV-1 disease, tobacco use during pregnancy, infant anemia, and crowding. Lower maternal CD4+ cell counts, receipt of intrapartum antibiotic treatment, and country of residence were associated with postneonatal infections.

CONCLUSIONS

Close monitoring of HIV-1-exposed infants, especially those who are anemic at birth or whose mothers have more-advanced HIV-1 disease or who smoked during pregnancy, remains important.

In Vivo Dysfunction of the Term Alveolar Macrophage After in Utero Ethanol Exposure

BACKGROUND

The effects of in utero alcohol exposure on the immune function of the newborn remain under investigation. Fetal ethanol (ETOH) exposure increases oxidative stress in the developing lung, in part due to decreased availability of the antioxidant glutathione (GSH). We have previously shown that in utero ETOH impairs alveolar macrophage phagocytosis and viability in the premature pup, while maintaining GSH availability with maternal supplementation of S-adenosyl-methionine (SAM) during ETOH ingestion improves macrophage function and viability. We hypothesized that dysfunction of the neonatal alveolar macrophage exposed to ETOH in utero would persist at term gestation.

METHODS

Using a guinea-pig model of fetal ETOH exposure, timed-pregnant guinea-pigs were pair-fed ETOH+/-the GSH precursor SAM and the diet continued until spontaneous delivery. Term alveolar macrophages were evaluated using fluorescent microscopy for phagocytosis and apoptosis after in vitro incubation with Staphalococcus aureus. Using an in vivo model of intranasal Staph. aureus inoculation, the in vivo function of the term alveolar macrophage was also investigated using confocal fluorescent analysis.

RESULTS

In utero ETOH exposure increased oxidant stress in the alveolar macrophage and decreased phagocytosis and viability in vitro and in vivo. Confocal analysis of phagocytosis in vivo demonstrated a marked impairment of internalization of the bacteria by the ETOH-exposed alveolar macrophage. The addition of SAM during maternal ETOH ingestion prevented loss of alveolar macrophage function and viability in vitro and in vivo.

CONCLUSIONS

In utero ETOH exposure impairs alveolar macrophage function and viability in vitro and in vivo even at term gestation. The ETOH-induced changes in macrophage function and viability can be ablated with maternal SAM supplementation. Further investigations are required to identify the mechanisms of ETOH-induced derangement of phagocytosis in the neonatal alveolar macrophage and the clinical ramifications of altered immune function after in utero alcohol exposure for the newborn.

Fetal Ethanol Exposure Disrupts the Daily Rhythms of Splenic Granzyme B, IFN-gamma, and NK Cell Cytotoxicity in Adulthood

BACKGROUND

Circadian (and daily) rhythms are physiological events that oscillate with a 24-hour period. Circadian disruptions may hamper the immune response against infection and cancer. Several immune mechanisms, such as natural killer (NK) cell function, follow a daily rhythm. Although ethanol is known to be a potent toxin for many systems in the developing fetus, including the immune system, the long-term effects of fetal ethanol exposure on circadian immune function have not been explored.

METHODS

Daily rhythms of cytotoxic factors (granzyme B and perforin), interferon-gamma (IFN-gamma), and NK cell cytotoxic activity were determined in the spleens of adult male rats obtained from mothers who were fed during pregnancy with chow food or an ethanol-containing liquid diet or pair-fed an isocaloric liquid diet.

RESULTS

We found that adult rats exposed to ethanol during their fetal life showed a significant alteration in the physiological rhythms of granzyme B and IFN-gamma that was associated with decreased NK cell cytotoxic activity.

CONCLUSION

These data suggest that fetal ethanol exposure causes a permanent alteration of specific immune rhythms that may in part underlie the immune impairment observed in children prenatally exposed to alcohol.

The use of record linkage to examine illicit drug use in pregnancy

AIMS

To examine the obstetric and perinatal outcomes for women with a drug-related hospital admission during pregnancy.

DESIGN

Antenatal and birth admissions to New South Wales (NSW) hospitals from the NSW Inpatient Statistics Collection were linked to birth information from the NSW Midwives Data Collection over a 5-year period (1998-2002).

MEASUREMENTS

Birth admissions were flagged as positive for drug use where a birth admission or any pregnancy admission for that birth involved an opioid, cannabis or stimulant-related International Classification of Diseases version 10 Australian modification (ICD-10AM) code.

FINDINGS

A total of 416 834 live births were analysed over a 5-year period (1998-2002). Of these, 1974 pregnancies had an opioid ICD-10AM diagnosis recorded, 552 a stimulant-related ICD-10AM and 2172 a cannabis ICD-10AM diagnosis. Births in each of the drug groups were to women who were younger, had a higher number of previous pregnancies, were indigenous, smoked heavily and were not privately insured. These women also presented later in their pregnancy to antenatal services and were more likely to arrive at hospital unbooked. Neonates born to women in each of the drug groups were more likely to be premature and were admitted to neonatal intensive care and special care nursery more often, with neonates born to women in the opioid group admitted most often.

CONCLUSIONS

Linked population level administrative data is a powerful method for examining the maternal and neonatal outcomes associated with the use of specific illicit drugs during pregnancy.

Use of Record Linkage to Examine Alcohol Use in Pregnancy

BACKGROUND

To date, no population-level data have been published examining the obstetric and neonatal outcomes for women with an alcohol-related hospital admission during pregnancy compared with the general obstetric population. This information is critical to planning and implementing appropriate services.

METHODS

Antenatal and delivery admissions to New South Wales (NSW) hospitals from the NSW Inpatient Statistics Collection were linked to birth information from the NSW Midwives Data Collection over a 5-year period (1998-2002). Birth admissions were flagged as positive for maternal alcohol use where a birth admission or any pregnancy admission for that birth involved an alcohol-related International Statistical Classification of Diseases and Related Health Problems, 10th Revision, Australian Modification (ICD-10-AM) code. Key demographic, obstetric, and neonatal variables were compared for births to mothers in the alcohol group with births where no alcohol-related ICD10-AM was recorded.

RESULTS

A total of 416,834 birth records were analyzed over a 5-year period (1998-2002). In this time, 342 of these were coded as positive for at least 1 alcohol-related ICD-10-AM diagnosis. Mothers in the alcohol group had a higher number of previous pregnancies, smoked more heavily, were not privately insured, and were more often indigenous. They also presented later on in their pregnancy to antenatal services and were more likely to arrive at hospital unbooked for delivery. Deliveries involved less epidural and local and more general anesthesia. Cesarean sections were more common to women in the alcohol group and were performed more often for intrauterine growth retardation. Neonates born to women in the alcohol group were smaller for gestational age, had lower Apgar scores at 5 minutes, and were admitted to special care nursery more often.

CONCLUSIONS

This study shows that linked population-level administrative data provide a powerful new source of information for examining the maternal and neonatal outcomes associated with alcohol use in pregnancy.

In utero exposure to alcohol alters cell fate decisions by hematopoietic progenitors in the bone marrow of offspring mice during neonatal development

Fetal alcohol syndrome and alcohol related birth defects represent a spectrum of disorders that can result from the consumption of alcohol during pregnancy. Previous studies from this laboratory have shown that alcohol exposure in utero adversely affects hematopoietic progenitors in the bone marrow. Neonatal mice that were exposed in utero to alcohol showed a marked delay in B lymphocyte development. Recent studies have focused on an oligopotential progenitor cell, with the phenotype of HSA(lo)CD43(lo)Lin(-), which yields both B cells and myeloid lineage cells at a high frequency when cultured in vitro with stromal cells and the appropriate cytokines. However, these progenitor cells isolated from neonatal offspring of alcohol fed dams showed a significant decrease in the frequency of B cell formation following in vitro culture. In order to understand the mechanism underlying this defect we examined the expression of key transcription factors (early B cell factor, EBF, and Pax5) in this progenitor pool. Here, we report that >95% of HSA(lo)CD43(lo)Lin(-) cells express EBF and 5% express Pax5. Following liquid culture in the presence of IL-7, these progenitor cells respond by up-regulating Pax5 and the surface expression of CD19 indicating that the cells have committed to the B lineage. By contrast 75% of HSA(lo)CD43(lo)Lin(-) cells isolated from the bone marrow of neonatal animals exposed in utero to alcohol expressed EBF but at a level that was less than 25% the level of cells isolated from control animals. Furthermore, these alcohol-exposed progenitor cells failed to up-regulate Pax5 in response to IL-7 indicating a greatly reduced capacity to expand and differentiate to B lineage cells in liquid cultures. However, the HSA(lo)CD43(lo)Lin(-) cells isolated from the alcohol exposed animals retained the capacity to differentiate to myeloid lineage cells. These results suggest that the interference with the sequential expression of transcription factors in early progenitor cells by in utero alcohol exposure is a potential mechanism for the observed decrease in B lymphocytes in neonatal mice.