Increased interferon-gamma- and interleukin-4-synthesizing subsets of circulating T lymphocytes in pregnant asthmatics

Asthma in pregnancy

Background: Asthma is a frequent and potentially life-threatening disease that complicates many pregnancies. There are extensive data with regard to the diagnosis and treatment of asthma during pregnancy. Medical providers require an up-to-date summary of the critical aspects of asthma management during pregnancy. Objective: This review aimed to summarize the available data from clinical trials, cohort studies, expert opinions, and guideline recommendations with regard to asthma in pregnancy. Methods: A search through PubMed was conducted by using keywords previously mentioned and MeSH (Medical Subject Headings) terminology. Clinical trials, observational studies, expert opinions, guidelines, and other reviews were included. The quality of the studies was assessed, and data were extracted and summarized. Results: Asthma worsens in ∼40% of pregnant women, which can be associated with maternal and fetal complications. Physiologic changes in the respiratory, cardiovascular, and immune systems during pregnancy play a critical role in the manifestations of asthma. The diagnosis and the treatment of asthma are similar to that of patients who are not pregnant. Nonetheless, concern for fetal malformations, preterm birth, and low birth weight must be considered when managing pregnant patients with asthma. Importantly, cornerstones of the pharmacotherapy of asthma seem to be safe during pregnancy. Conclusion: Asthma in pregnancy is associated with adverse outcomes. Roadblocks to management include associated comorbidities, medication nonadherence, atopy, lack of education, and smoking habits. These need to be acknowledged and addressed for successful asthma management during pregnancy.

Maternal asthma and the risk of hypertensive disorders of pregnancy: a systematic review and meta-analysis of cohort studies

Objective: The aim of this study was to demonstrate the association between maternal asthma and the risk of hypertensive disorders of pregnancy.Methods: A systematic search of seven databases was conducted. A meta-analysis was performed to calculate risk ratios and 95% CI using random-effects models.Results: Asthma was associated with an increased risk of pregnancy-induced hypertension (RR 1.45, 95%CI 1.29-1.63), transient hypertension of pregnancy (RR 2.00, 95%CI 1.52-2.63), preeclampsia or eclampsia (RR 1.28, 95%CI 1.25-1.32), preeclampsia (RR 1.43, 95%CI 1.31-1.57) and eclampsia (RR 1.56, 95%CI 1.13-2.15).Conclusion: The meta-analysis illustrated that asthma was significantly increased risk of hypertension during pregnancy.

Uncontrolled maternal chronic respiratory diseases in pregnancy: A new potential risk factor suggested to be associated with anorectal malformations in offspring

BACKGROUND

Chronic respiratory diseases and use of antiasthmatic medication during pregnancy may both play a role in the etiology of congenital anorectal malformations (ARM). However, it is unclear, whether the medication use or the underlying condition would be responsible. Therefore, our aim was to unravel the role of maternal chronic respiratory diseases from that of antiasthmatic medication in the etiology of ARM.

METHODS

We obtained 412 ARM patients and 2,137 population-based controls from the Dutch AGORA data- and biobank. We used maternal questionnaires and follow-up telephone interviews to obtain information on chronic respiratory diseases, antiasthmatic medication use, and potential confounders. Multivariable logistic regression analyses were performed to estimate odds ratios (ORs) with 95% confidence intervals (95% CI).

RESULTS

We observed higher risk estimates among women with chronic respiratory diseases with and without medication use (1.4 [0.8-2.7] and 2.0 [0.8-5.0]), both in comparison to women without a chronic respiratory disease and without medication use. Furthermore, increased ORs of ARM were found for women using rescue medication (2.4 [0.8-7.3]) or a combination of maintenance and rescue medication (2.5 [0.9-6.7]). In addition, increased risk estimates were observed for women having nonallergic triggers (2.5 [1.0-6.3]) or experiencing exacerbations during the periconceptional period (3.5 [1.4-8.6]).

CONCLUSIONS

Although the 95% CIs of most associations include the null value, the risk estimates all point towards an association between uncontrolled chronic respiratory disease, instead of antiasthmatic medication use, with ARM in offspring. Further in-depth studies towards mechanisms of this newly identified risk factor are warranted.

Microglia from offspring of dams with allergic asthma exhibit epigenomic alterations in genes dysregulated in autism

Dysregulation in immune responses during pregnancy increases the risk of a having a child with an autism spectrum disorder (ASD). Asthma is one of the most common chronic diseases among pregnant women, and symptoms often worsen during pregnancy. We recently developed a mouse model of maternal allergic asthma (MAA) that induces changes in sociability, repetitive, and perseverative behaviors in the offspring. Since epigenetic changes help a static genome adapt to the maternal environment, activation of the immune system may epigenetically alter fetal microglia, the brain's resident immune cells. We therefore tested the hypothesis that epigenomic alterations to microglia may be involved in behavioral abnormalities observed in MAA offspring. We used the genome-wide approaches of whole genome bisulfite sequencing to examine DNA methylation and RNA sequencing to examine gene expression in microglia from juvenile MAA offspring. Differentially methylated regions were enriched for immune signaling pathways and important microglial developmental transcription factor binding motifs. Differential expression analysis identified genes involved in controlling microglial sensitivity to the environment and shaping neuronal connections in the developing brain. Differentially expressed genes significantly overlapped genes with altered expression in human ASD cortex, supporting a role for microglia in the pathogenesis of ASD.

The Association of Maternal Asthma and Early Pregnancy Vitamin D with Risk of Preeclampsia: An Observation From Vitamin D Antenatal Asthma Reduction Trial (VDAART)

BACKGROUND

Maternal asthma, uncontrolled asthma, and low vitamin D levels during pregnancy have been individually linked to increased risk of preeclampsia.

OBJECTIVE

To investigate the association of history of physician-diagnosed asthma and uncontrolled asthma status during pregnancy with the risk of preeclampsia and the effects of early pregnancy vitamin D concentrations on this relationship.

METHODS

A total of 816 subjects with available pregnancy outcome data and risk factors of interest were analyzed. A group of experienced obstetricians and gynecologists from 3 study centers validated the preeclampsia diagnoses. Vitamin D was measured using the DiaSorin method at 10 to 18 weeks of gestation. The Pregnancy-Asthma Control Test was used to assess asthma control during pregnancy. Criterion-based stepwise variable selection algorithm was applied to investigate the relationships of risk factors of interest (history of asthma diagnosis, uncontrolled asthma during pregnancy, and vitamin D) to preeclampsia.

RESULTS

The incidence of preeclampsia was not related to the presence of asthma diagnosis (8.9% with vs 7.4% without). The adjusted odds of preeclampsia controlled for maternal serum 25-hydroxyvitamin D (25OHD) concentrations was higher for women with a higher proportion of uncontrolled asthma months per visit during pregnancy (adjusted odds ratio, 3.55; 95% CI, 1.15-13.0). Adjusting for asthma control status during pregnancy, an additional decrease in the associated preeclampsia risk by 7% was observed for a 10-unit (ng/mL) increase in early pregnancy 25OHD levels (adjusted odds ratio10-unit, 0.60; 95% CI, 0.43-0.82) as compared with the previous risk estimate of preeclampsia associated with low maternal 25OHD unadjusted for asthma control status.

CONCLUSIONS

Uncontrolled asthma during pregnancy is associated with an increased risk of preeclampsia. Early pregnancy 25OHD contributes to the association of uncontrolled asthma status with preeclampsia.

Algorithm for the management of asthma in pregnant women: a protocol to optimize processes in healthcare

INTRODUCTION

Asthma is the most common chronic disease in pregnant women. Its evolution during pregnancy could improve, stay the same or worsen, especially in cases where there is a loss of clinical control. This can lead to maternal and fetal hypoxia with serious adverse perinatal outcomes. Areas covered: This article reviews physiological modifications in pregnancy, effects of pregnancy on asthma, and possible consequences on fetus development. Furthermore, it reviews evidence on assessment and both pharmacological and non-pharmacological management of asthma in pregnant and breastfeeding women as well as in acute exacerbations. Electronic databases, such as PUBMED, were searched for terms pregnan* or perinat* or obstet* and breastfeeding or asthma or wheeze, as well as a book published by the present authors. Expert commentary: A patient-centered multidisciplinary approach, where the respiratory specialists have a key role in assessing and achieving control, as well as the education interventions for self-monitoring and adherence are at least as important as adequate pharmacological treatment.

Pharmacological difficulties in the treatment of asthma in pregnant women

INTRODUCTION

This is a review of the diagnosis and management of asthma in the pregnant patient. Asthma may adversely affect both maternal quality of life and, perinatal outcomes. Optimal management of asthma is thus important for both mother and baby. Areas covered: Special attention is paid to the challenges in diagnosis and management of asthma during pregnancy. Expert commentary: This article reviews the safety of asthma medications commonly used during pregnancy.

Allergic fetal priming leads to developmental, behavioral and neurobiological changes in mice

The state of the mother's immune system during pregnancy has an important role in fetal development and disruptions in the balance of this system are associated with a range of neurologic, neuropsychiatric and neurodevelopmental disorders. Epidemiological and clinical reports reveal various clues that suggest a possible association between developmental neuropsychiatric disorders and family history of immune system dysfunction. Over the past three decades, analogous increases have been reported in both the incidence of neurodevelopmental disorders and immune-related disorders, particularly allergy and asthma, raising the question of whether allergic asthma and characteristics of various neurodevelopmental disorders share common causal links. We used a mouse model of maternal allergic asthma to test this novel hypothesis that early fetal priming with an allergenic exposure during gestation produces behavioral deficits in offspring. Mothers were primed with an exposure to ovalbumin (OVA) before pregnancy, then exposed to either aerosolized OVA or vehicle during gestation. Both male and female mice born to mothers exposed to aerosolized OVA during gestation exhibited altered developmental trajectories in weight and length, decreased sociability and increased marble-burying behavior. Moreover, offspring of OVA-exposed mothers were observed to have increased serotonin transporter protein levels in the cortex. These data demonstrate that behavioral and neurobiological effects can be elicited following early fetal priming with maternal allergic asthma and provide support that maternal allergic asthma may, in some cases, be a contributing factor to neurodevelopmental disorders.

Asthma in pregnancy

Asthma affects approximately 8% of women during pregnancy. Pregnancy results in a variable course for asthma control, likely contributed to by physiological changes affecting the respiratory, immune, and hormonal systems. While asthma during pregnancy has been associated with an increased risk of maternal and fetal complications including malformations, available data also suggest that active asthma management and monitoring can decrease the risk of adverse outcomes. The diagnosis, disease classification, and goals for asthma management in the pregnant woman are the same as for nonpregnant patients. However, evidence shows that pregnant asthmatics are more likely to be undertreated, resulting in asthma exacerbations occurring in approximately one third and hospitalization in one tenth of patients. Pharmacotherapeutic management of asthma exacerbations in pregnant patients follows standard treatment guidelines. In contrast, the principles of asthma maintenance therapy are slightly modified in the pregnant patient. Patients and practitioners may avoid use of asthma medications due to concern for a risk of fetal complications and malformations. A variable amount of information is available regarding the risk of a given asthma medication to cause adverse fetal outcomes, and it is preferable to use an inhaled product. Nevertheless, based on available data, the majority of asthma medications are regarded as safe for use during pregnancy. And, any increased risk to either the mother or fetus from medication use appears to be small compared to that associated with poor asthma control.

Circulating survivin levels in healthy and asthmatic pregnancy

BACKGROUND

Asthma is one of the most common conditions which complicate pregnancy. Pro- and anti-apoptotic mechanisms can be modulated by asthma accompanying pregnancy. Survivin, an anti-apoptotic protein has been implicated in the pathomechanism of asthma and also in the development of pathological pregnancies; however survivin has not been studied in pregnant asthmatics.

METHODS

Twenty-eight asthmatic pregnant (AP), 25 asthmatic non-pregnant (ANP), 21 healthy pregnant (HP) and 29 healthy non-pregnant (HNP) women were enrolled in this cross-sectional study. Plasma survivin concentration was determined by ELISA.

RESULTS

Plasma survivin was significantly lower in HP (1.64 /0-74.9/ pg/ml) than in HNP (24.6 /0-333.3/ pg/ml, p = 0.01). However, this difference was not observed between the asthmatic groups (p = 0.64). Similarly, there was no difference either between HNP and ANP (10.5 /0-215.4/ pg/ml, p = 0.23) or between HP and AP (13.9 /0-364.1/ pg/ml, p = 0.30) groups.

CONCLUSIONS

Decreased plasma survivin levels in physiological but not in asthmatic pregnancy may suggest that the normal apoptotic mechanisms are compromised in asthmatic gestation.

J, Losonczy G, Vásárhelyi B, Tamási L. Relationship of circulating hyaluronic acid levels to disease control in asthma and asthmatic pregnancy

Uncontrolled asthma is a risk factor for pregnancy-related complications. Hyaluronic acid (HA), a potential peripheral blood marker of tissue fibrosis in various diseases, promotes eosinophil survival and plays a role in asthmatic airway inflammation as well as in physiological processes necessary to maintain normal pregnancy; however the level of circulating HA in asthma and asthmatic pregnancy is unknown. We investigated HA levels in asthmatic patients (N = 52; asthmatic pregnant (AP) N = 16; asthmatic non-pregnant (ANP) N = 36) and tested their relationship to asthma control. Serum HA level was lower in AP than in ANP patients (27 [24.7-31.55] vs. 37.4 [30.1-66.55] ng/mL, p = 0.006); the difference attenuated to a trend after its adjustment for patients' age (p = 0.056). HA levels and airway resistance were positively (r = 0.467, p = 0.004), HA levels and Asthma Control Test (ACT) total score inversely (r = -0.437, p = 0.01) associated in ANP patients; these relationships remained significant even after their adjustments for age. The potential value of HA in the determination of asthma control was analyzed using ROC analysis which revealed that HA values discriminate patients with ACT total score ≥20 (controlled patients) and <20 (uncontrolled patients) with a 0.826 efficacy (AUC, 95% CI: 0.69-0.97, p = 0.001) when 37.4 ng/mL is used as cut-off value in ANP group, and with 0.78 efficacy (AUC, 95% CI: 0.65-0.92, p = 0.0009) in the whole asthmatic cohort. In conclusion circulating HA might be a marker of asthma control, as it correlates with airway resistance and has good sensitivity in the detection of impaired asthma control. Decrease of HA level in pregnancy may be the consequence of pregnancy induced immune tolerance.

The risk of maternal and placental complications in pregnant women with asthma: a systematic review and meta-analysis

OBJECTIVE

To investigate if maternal asthma is associated with an increased risk of maternal and placental complications in pregnancy.

METHODS

Electronic databases were searched for the following terms: (asthma or wheeze) and (pregnan* or perinat* or obstet*). Cohort studies published between January 1975 and March 2012 were considered for inclusion. Forty publications met the inclusion criteria, reporting at least one maternal or placental complication in pregnant women with and without asthma. Relative risk (RR) with 95% confidence intervals (CIs) was calculated.

RESULTS

Maternal asthma was associated with a significantly increased risk of cesarean section (RR = 1.31, 95%CI = [1.22-1.39]), gestational diabetes (RR = 1.39, 95%CI = [1.17-1.66]), hemorrhage (antepartum: RR = 1.25, 95%CI = [1.10-1.42]; postpartum: RR = 1.29, 95%CI = [1.18-1.41]), placenta previa (RR = 1.23, 95%CI = [1.07-1.40]), placental abruption (RR = 1.29, 95%CI = [1.14-1.47]) and premature rupture of membranes (RR = 1.21, 95%CI = 1.07-1.37). Moderate to severe asthma significantly increased the risk of cesarean section (RR = 1.19, 95%CI = [1.09-1.31]) and gestational diabetes (RR = 1.19, 95%CI = [1.06-1.33]) compared to mild asthma. Bronchodilator use was associated with a significantly lowered risk of gestational diabetes (RR = 0.64, 95%CI = [0.57-0.72]).

CONCLUSIONS

Pregnant women with asthma are at increased risk of maternal and placental complications, and women with moderate/severe asthma may be at particular risk. Further studies are required to elucidate whether adequate control of asthma during pregnancy reduces these risks.

Relationship of circulating soluble urokinase plasminogen activator receptor (suPAR) levels to disease control in asthma and asthmatic pregnancy

Asthma has a high burden of morbidity if not controlled and may frequently complicate pregnancy, posing a risk for pregnancy outcomes. Elevated plasma level of the inflammatory biomarker soluble urokinase plasminogen activator receptor (suPAR) is related to a worse prognosis in many conditions such as infectious, autoimmune, or pregnancy-related diseases; however the value of suPAR in asthma and asthmatic pregnancy is unknown. The present study aimed to investigate the suPAR, CRP and IL-6 levels in asthma (asthmatic non-pregnant, ANP; N = 38; female N = 27) and asthmatic pregnancy (AP; N = 15), compared to healthy non-pregnant controls (HNP; N = 29; female N = 19) and to healthy pregnant women (HP; N = 58). The relationship between suPAR levels and asthma control was also evaluated. The diagnostic efficacy of suPAR in asthma control was analyzed using ROC analysis. IL-6 and CRP levels were comparable in all study groups. Circulating suPAR levels were lower in HP and AP than in HNP and ANP subjects, respectively (2.01 [1.81–2.38] and 2.39 [2.07–2.69] vs. 2.60 [1.82–3.49] and 2.84 [2.33–3.72] ng/mL, respectively, p = 0.0001). suPAR and airway resistance correlated in ANP (r = 0.47, p = 0.004). ROC analysis of suPAR values in ANP patients with PEF above and below 80% yielded an AUC of 0.75 (95% CI: 0.57–0.92, p = 0.023) and with ACT total score above and below 20 an AUC of 0.80 (95% CI: 0.64–0.95, p = 0.006). The cut-off value of suPAR to discriminate between controlled and not controlled AP and ANP was 4.04 ng/mL. In conclusion, suPAR may help the objective assessment of asthma control, since it correlates with airway resistance and has good sensitivity in the detection of impaired asthma control. Decrease in circulating suPAR levels detected both in healthy and asthmatic pregnant women presumably represents pregnancy induced immune tolerance.

Changes in exhaled breath condensate pH in healthy and asthmatic pregnant women

OBJECTIVE

Asthma is a common chronic disease complicating pregnancy with a risk for perinatal complications. Control of airway inflammation in the asthmatic pregnancy improves pregnancy outcomes. Our aim was to evaluate pH of exhaled breath condensate (EBC), a non-invasive method for the assessment of asthmatic airway inflammation, in healthy and asthmatic pregnancies.

DESIGN

Cross-sectional study.

SETTING

Hungarian university clinics.

POPULATION

Seventeen healthy pregnant women, 21 asthmatic pregnant women, 23 healthy non-pregnant women and 22 asthmatic non-pregnant women.

METHODS

EBC samples were collected using a portable condenser, EBC pH was measured after argon deaeration.

MAIN OUTCOME MEASURE

EBC pH.

RESULTS

EBC pH (mean ± SD) of healthy non-pregnant and asthmatic non-pregnant women was similar (7.75 ± 0.27 vs. 7.54 ± 0.57; p = 0.118), probably indicating an optimal control of airway inflammation in asthmatic women. On the other hand, EBC pH was higher in healthy pregnant women compared with healthy non-pregnant women (8.02 ± 0.43 vs. 7.75 ± 0.27; p = 0.017). Higher EBC pH accompanying healthy pregnancy was absent in asthmatic pregnant patients whose EBC pH was lower (7.65 ± 0.38) than that of healthy pregnant women (p = 0.006), and it was similar to that in asthmatic and healthy non-pregnant women (p = 0.470 and p = 0.300, respectively). The EBC pH in asthmatic pregnant women correlated positively with birthweight (r = 0.49, p = 0.047) and negatively with forced vital capacity (r = 0.45, p = 0.039). EBC pH was not related to blood pH.

CONCLUSIONS

EBC pH is higher in healthy pregnant women but not in asthmatic pregnant women compared with data from healthy non-pregnant women, indicating that oxidative inflammatory processes induced by asthma may compromise the regulatory mechanisms causing alkaline pH in the airways during pregnancy.

Management of asthma during pregnancy

Asthma is an inflammatory lung condition that is the most common chronic disease affecting pregnancy. The changes in pulmonary physiology during pregnancy include increased minute ventilation, decreased functional residual capacity, increased mucus production, and airway mucosa hyperemia and edema. Pregnancy is also associated with a physiological suppression of the immune system. Many studies have described the heterogeneous immune system response in women with asthma during pregnancy, which partly explains why asthma has been shown to worsen, improve, or remain stable in equal proportions of women during pregnancy. Asthma may be associated with poor maternal and fetal outcomes. However, better maternal and fetal outcomes are observed with better asthma control. Asthma controller medications are generally thought to be safe during pregnancy, but limited data are available for some of the medicines. Newer medications like omalizumab open avenues for the treatment of asthma, but also pose a challenge, as there is limited experience with their use. Therefore, a multidisciplinary approach, including obstetricians, asthma specialists, and pediatricians should collaborate with the patient to carefully weigh the risks and benefits to determine an optimal management plan for each individual patient. The aim of this review article is to summarize the most recent literature about the immunological changes that occur during pregnancy, physiological and clinical implications of asthma on pregnancy, and asthma management and medication use in pregnant women.

Relation of circulating T cell profiles to airway inflammation and asthma control in asthmatic pregnancy

Asthmatic inflammation during pregnancy poses a risk for maternal and fetal morbidities. Circulating T cell immune phenotype is known to correlate with airway inflammation (detectable by fractional concentration of nitric oxide present in exhaled breath (FENO)) in non-pregnant allergic asthmatics. The aim of this study was to assess the relationship of peripheral T cell phenotype to FENO and clinical variables of asthma during pregnancy.We examined 22 pregnant women with allergic asthma in the 2nd/3rd trimester. The prevalence of Th1, Th2, regulatory T (Treg) and natural killer (NK) cell subsets was identified with flow cytometry using cell-specific markers. FENO, Asthma Control Test (ACT) total score and lung function were evaluated.Peripheral blood Th1, Th2, Treg, and NK cell prevalence were not significantly correlated to airway inflammation assessed by FENO in asthmatic pregnant women (all cells p > 0.05; study power > 75%). However, an inverse correlation was detected between Th2 cell prevalence and ACT total scores (p = 0.03) in asthmatic pregnancy.Blunted relationship between T cell profile and airway inflammation may be the result of pregnancy induced immune tolerance in asthmatic pregnancy. On the other hand, increased Th2 response impairs disease control that supports direct relationship between symptoms and cellular mechanisms of asthma during pregnancy.

Circulating and exhaled vascular endothelial growth factor in asthmatic pregnancy

CONTEXT

Vascular endothelial growth factor (VEGF) plays a role in asthma and pathological pregnancies.

OBJECTIVE

This is the first study assessing plasma and exhaled breath condensate VEGF levels in asthmatic pregnancy.

MATERIAL AND METHODS

Thirty-one asthmatic pregnant, 29 asthmatic nonpregnant, 28 healthy pregnant and 22 healthy nonpregnant women were enrolled. Plasma was collected in all subjects, EBC in 57 volunteers for VEGF measurements.

RESULTS

Plasma VEGF decreased in both pregnant groups (p < 0.01), without any differences between the asthmatic and the respective nonasthmatic groups (p > 0.05). VEGF was undetectable in EBC.

CONCLUSION

Concomitant asthma does not affect plasma VEGF during pregnancy.

Peripheral T(h)1/T(h)2/T(h)17/regulatory T-cell balance in asthmatic pregnancy

Asthma is a common chronic disease that may complicate pregnancy and a risk factor for complications; however, immunological mechanisms of the bilateral interactions between asthma and pregnancy are not fully understood. Healthy gestation is characterized by a sensitive balance of T(h)1/T(h)2/T(h)17/regulatory T (Treg) cells that may be altered in asthmatic pregnancy. The aim of this study was to describe the prevalence of these cell subsets in asthmatic compared with healthy pregnancy. The prevalence of T(h)1, T(h)2, T(h)17 and Treg lymphocytes was identified by cell surface and intracellular marker staining in blood samples of 24 healthy non-pregnant (HNP), 23 healthy pregnant (HP), 15 asthmatic non-pregnant (ANP) and 15 asthmatic pregnant (AP) women using flow cytometry. The T(h)1/T(h)2 cell ratio was decreased in both HP and ANP compared with HNP women; however, no further decrease was observed in the AP group. The T(h)17/Treg ratio was decreased in HP, but not in AP women, compared with HNP data. Healthy pregnancy increased Treg cell prevalence compared with HNP data (4.64% versus 2.98%; P < 0.05), and this pregnancy-induced elevation was absent in AP women (2.52% versus 4.64%; P < 0.05). T(h)17 cell prevalence was similar in the HP and HNP groups (2.78% versus 3.17%; P > 0.05). Asthma increased T(h)17 prevalence in non-pregnant patients (3.81% versus 3.17%; P < 0.05), and this asthma-specific increase of T(h)17 cell prevalence was also observed in AP patients (AP versus HP: 3.44% versus 2.78%; P < 0.05). The abnormal asthma-dependent T(h)17 elevation together with blunted Treg increase may play a role in the compromised immune tolerance characterizing asthmatic pregnancy.

Peripheral T(h)1/T(h)2/T(h)17/regulatory T-cell balance in asthmatic pregnancy

Asthma is a common chronic disease that may complicate pregnancy and a risk factor for complications; however, immunological mechanisms of the bilateral interactions between asthma and pregnancy are not fully understood. Healthy gestation is characterized by a sensitive balance of T(h)1/T(h)2/T(h)17/regulatory T (Treg) cells that may be altered in asthmatic pregnancy. The aim of this study was to describe the prevalence of these cell subsets in asthmatic compared with healthy pregnancy. The prevalence of T(h)1, T(h)2, T(h)17 and Treg lymphocytes was identified by cell surface and intracellular marker staining in blood samples of 24 healthy non-pregnant (HNP), 23 healthy pregnant (HP), 15 asthmatic non-pregnant (ANP) and 15 asthmatic pregnant (AP) women using flow cytometry. The T(h)1/T(h)2 cell ratio was decreased in both HP and ANP compared with HNP women; however, no further decrease was observed in the AP group. The T(h)17/Treg ratio was decreased in HP, but not in AP women, compared with HNP data. Healthy pregnancy increased Treg cell prevalence compared with HNP data (4.64% versus 2.98%; P < 0.05), and this pregnancy-induced elevation was absent in AP women (2.52% versus 4.64%; P < 0.05). T(h)17 cell prevalence was similar in the HP and HNP groups (2.78% versus 3.17%; P > 0.05). Asthma increased T(h)17 prevalence in non-pregnant patients (3.81% versus 3.17%; P < 0.05), and this asthma-specific increase of T(h)17 cell prevalence was also observed in AP patients (AP versus HP: 3.44% versus 2.78%; P < 0.05). The abnormal asthma-dependent T(h)17 elevation together with blunted Treg increase may play a role in the compromised immune tolerance characterizing asthmatic pregnancy.

Increased midgestational IFN-γ, IL-4 and IL-5 in women bearing a child with autism: A case-control study

Background

Immune anomalies have been documented in individuals with autism spectrum disorders (ASDs) and their family members. It is unknown whether the maternal immune profile during pregnancy is associated with the risk of bearing a child with ASD or other neurodevelopmental disorders.

Methods

Using Luminex technology, levels of 17 cytokines and chemokines were measured in banked serum collected from women at 15 to 19 weeks of gestation who gave birth to a child ultimately diagnosed with (1) ASD (n = 84), (2) a developmental delay (DD) but not autism (n = 49) or (3) no known developmental disability (general population (GP); n = 159). ASD and DD risk associated with maternal cytokine and chemokine levels was estimated by using multivariable logistic regression analysis.

Results

Elevated concentrations of IFN-γ, IL-4 and IL-5 in midgestation maternal serum were significantly associated with a 50% increased risk of ASD, regardless of ASD onset type and the presence of intellectual disability. By contrast, elevated concentrations of IL-2, IL-4 and IL-6 were significantly associated with an increased risk of DD without autism.

Conclusion

The profile of elevated serum IFN-γ, IL-4 and IL-5 was more common in women who gave birth to a child subsequently diagnosed with ASD. An alternative profile of increased IL-2, IL-4 and IL-6 was more common for women who gave birth to a child subsequently diagnosed with DD without autism. Further investigation is needed to characterize the relationship between these divergent maternal immunological phenotypes and to evaluate their effect on neurodevelopment.

A meta-analysis of adverse perinatal outcomes in women with asthma

BACKGROUND

Asthma is a common condition during pregnancy and may be associated with adverse perinatal outcomes.

OBJECTIVE

This meta-analysis sought to establish if maternal asthma is associated with an increased risk of adverse perinatal outcomes, and to determine the size of these effects.

SEARCH STRATEGY

Electronic databases were searched for the following terms: (asthma or wheeze) and (pregnan* or perinat* or obstet*).

SELECTION CRITERIA

Cohort studies published between 1975 and March 2009 were considered for inclusion. Studies were included if they reported at least one perinatal outcome in pregnant women with and without asthma.

DATA COLLECTION AND ANALYSIS

A total of 103 articles were identified, and of these 40 publications involving 1,637,180 subjects were included. Meta-analysis was conducted with subgroup analyses by study design and active asthma management.

MAIN RESULTS

Maternal asthma was associated with an increased risk of low birthweight (RR 1.46, 95% CI 1.22-1.75), small for gestational age (RR 1.22, 95% CI 1.14-1.31), preterm delivery (RR 1.41, 95% CI 1.22-1.61) and pre-eclampsia (RR 1.54, 95% CI 1.32-1.81). The relative risk of preterm delivery and preterm labour were reduced to non-significant levels by active asthma management (RR 1.07, 95% CI 0.91-1.26 for preterm delivery; RR 0.96, 95% CI 0.73-1.26 for preterm labour).

AUTHOR'S CONCLUSIONS

Pregnant women with asthma are at increased risk of perinatal complications, including pre-eclampsia and outcomes that affect the baby's size and timing of birth. Active asthma management with a view to reducing the exacerbation rate may be clinically useful in reducing the risk of perinatal complications, particularly preterm delivery.

Asthma in pregnancy

Worldwide the prevalence of asthma among pregnant women is on the rise, and pregnancy leads to a worsening of asthma for many women. This article examines the changes in asthma that may occur during pregnancy, with particular reference to asthma exacerbations. Asthma affects not only the mother but the baby as well, with potential complications including low birth weight, preterm delivery, perinatal mortality, and preeclampsia. Barriers to effective asthma management and opportunities for optimized care and treatment are discussed, and a summary of the clinical guidelines for the management of asthma during pregnancy is presented.

Asthma in pregnancy--immunological changes and clinical management

Asthma is one of the most common diseases complicating pregnancy and a risk factor for several maternal and fetal complications, posing a special challenge for physicians treating asthmatic pregnant women. Asthma influences the outcome of pregnancy and - vice versa - pregnancy affects asthma severity with bidirectional immunological interactions that are currently being examined. Supporting pregnancy-induced immunotolerance is the observation that attenuation of allergic responses can be detected in controlled asthmatic pregnant patients. However, uncontrolled asthmatic pregnant women show significant asthma-associated immune reactions, such as diminished pregnancy specific regulatory T cell proliferation, that may - besides other factors - influence fetal growth. Uncontrolled, symptomatic asthma may increase the risk of adverse perinatal outcomes; thus adequate regular anti-asthmatic treatment resulting in optimal asthma control represents a vital need during pregnancy. This review summarizes immunological changes characterizing pregnancy in asthmatic women together with the clinical implications of asthma management during pregnancy.

Asthma in pregnancy - from immunology to clinical management

Asthma is one of the most common chronic medical conditions that may complicate pregnancy. Asthma influences the outcome of pregnancy and, vice versa, pregnancy affects asthma severity, but the underlying immunological mechanisms of this interaction are not fully understood. As a sign of pregnancy-induced immunotolerance, attenuation of allergic responses can be detected in controlled asthmatic pregnant patients; however non controlled asthmatic pregnant women show significant asthma-associated immune reactions that may, beside other factors, influence fetal growth. Generally, although uncontrolled asthma may increase the risk of adverse perinatal outcomes, women with well-controlled and adequately treated disease during pregnancy do not develop maternal or fetal complications.

Increased circulating heat shock protein 70 levels in pregnant asthmatics

Asthma is one of the most common diseases complicating pregnancy and represents a risk factor for several maternal and perinatal complications. The natural history of asthma is known to change in pregnancy, but very few data are available in the terms of pathomechanism of this change during gestation. Circulating heat shock protein 70 (Hsp70) levels are decreased in healthy pregnancy, which might reflect physiological immunotolerance. The aim of our study was to determine the serum levels of Hsp70 in asthmatic women during gestation. Forty pregnant women with bronchial asthma and 40 healthy pregnant women matched for maternal and gestational age were involved in this case-control study. Serum Hsp70 levels were measured using the ELISA Kit of R&D Systems. Spirometry and oxygen saturation measurements were performed in asthmatic patients. In asthmatic pregnant women, an increase of serum Hsp70 levels was observed compared to healthy pregnant women (median (25-75 percentile): 0.44 ng/ml (0.36-0.53) versus 0.21 ng/ml (0-0.27), p < 0.001). Fetal birth weight of asthmatic mothers was significantly smaller than of healthy controls, but in the normal range (3,230 g (2,690-3,550) versus 3,550 g (3,450-3,775), p < 0.05). A statistically significant negative correlation between maternal age and serum Hsp70 concentrations (Spearman R = -0.48, p = 0.0018) and a significant positive correlation between gestational age and serum Hsp70 levels (Spearman R = 0.83, p < 0.001) were detected in healthy pregnant women. In conclusion, this study proves an elevation of circulating Hsp70 levels during asthmatic pregnancy compared to healthy pregnant women. However, further studies are warranted to determine the role of circulating Hsp70 in the pathogenesis of maternal and perinatal complications of asthma in pregnancy.

Surface markers of lymphocyte activation in pregnant asthmatics

PROBLEM

Pregnancy-associated immunologic alterations may improve the course of asthma. Severe maternal asthma with an exacerbation impairs fetal growth.

METHOD OF STUDY

Lymphocyte activation was estimated by flow cytometry analysis of surface markers in non-pregnant healthy and mild or moderate persistent asthmatic women and healthy as well as mild or moderate persistent asthmatic, third trimester pregnant women.

RESULTS

Compared with non-pregnant healthy subjects (n = 12) activated pools within CD4 and CD8 T cells were larger and the number of NK T cells were increased both in non-pregnant asthmatic (n = 12) and in healthy pregnant (n = 13) subjects (all p\0.05). No further lymphocyte activation was observed in pregnant asthmatics (n = 21) compared either with non-pregnant asthmatic, or pregnant healthy women. Average birth weight of newborns was lower (p\0.05) in the asthmatic than in the healthy pregnant group.

CONCLUSION

Pregnancy is a state of wide-spread lymphocyte activation but it may blunt lymphocyte activation which characterizes bronchial asthma.

Exhaled nitric oxide in pregnant healthy and asthmatic women

BACKGROUND

Measurement of fractioned exhaled nitric oxide (FE(NO)) is useful for monitoring airway inflammation in asthma. Asthma is one of the most common diseases complicating pregnancy, and FE(NO) may be helpful for monitoring asthma in pregnancy. However, some physiological alterations of FE(NO) may be expected during healthy pregnancy due to vascular nitric oxide production. Until now no study assessed the level of FE(NO) in asthmatic pregnant patients.

OBJECTIVE

We aimed to assess the possible use and reproducibility of FE(NO) measurements in pregnant asthmatic women. We compared FE(NO) concentrations between four groups of subjects: healthy nonpregnant and pregnant females and asthmatic nonpregnant and pregnant patients. We also investigated the relationship between FE(NO) values and the level of asthma control in pregnant asthmatic patients.

METHODS

A total of 102 female subjects (35 healthy nonpregnant and 27 healthy pregnant females; 20 nonpregnant and 20 pregnant asthmatic women) were included in this cross-sectional study. Two FE(NO) measurements were performed in each subject using an electrochemical sensor based device (NIOX MINO, Aerocrine, Solna, Sweden). Data are given as median with range.

RESULTS

The repeatability of FE(NO) measurement was similar in pregnant and nonpregnant subjects. FE(NO) levels did not differ significantly between healthy pregnant versus nonpregnant subjects (16.0 [8, 31] vs. 16.0 [9, 35] ppb). FE(NO) levels were significantly increased in asthmatic women compared to healthy females (nonpregnant asthmatics: 38 [9, 54] ppb, p < 0.001 vs. healthy nonpregnant; pregnant asthmatic patients: 28 [10, 56] ppb; p < 0.05 vs. healthy pregnant).

CONCLUSIONS

FE(NO) level is not influenced by healthy pregnancy. In pregnant asthmatic patients FE(NO) level is elevated compared to healthy pregnant subjects and correlates with the level of asthma control. Further studies are required to assess the use of FE(NO) measurement to monitor asthma in this patient group.

Maternal cytokine production during pregnancy and the development of childhood wheezing and allergic disease in offspring three years of age

Allergic diseases are multifactorial; they develop from complex interactions between genes and the environment. The immunological bias toward atopy and asthma might be established during in utero development of the fetal immune system. We prospectively investigated the association between maternal cytokine changes during pregnancy and the development of childhood wheezing and atopy at three years of age. Blood samples from 90 pregnant women were assayed for TNF-alpha, TGF-beta, IFN-gamma, IL-4, IL-6, and IL-2 at 18 weeks of gestation and at 6 weeks after delivery. Telephone interviews were performed and a questionnaire administered to assess wheezing and allergic disease in the children. The serum total IgE and specific IgE to eggs, milk and dust mites were measured. Maternal IFN-gamma, TNF-alpha and TGF-beta levels significantly decreased during pregnancy compared to the levels after delivery. However, the IL-4 levels did not change. Maternal TNF-alpha and IFN-gamma levels were decreased both before and after delivery in children with reported wheezing. Individual maternal IL-4 levels, before delivery, were higher than after delivery in the children that developed wheezing. There were no significant differences in maternal cytokine levels between children with and without asthma. In children with atopy, the maternal IFN-gamma /IL-4 ratio, during the first trimester, had a tendency to decrease compared to the children without atopy, whereas the maternal IL-2 levels at 6 weeks after delivery were increased. A first pregnancy showed higher concentrations of IL-4 before and after delivery than did women with multiple pregnancies. Maternal cytokine levels begin to change toward a Th2 immunity starting in the first trimester. A stronger Th2 immune response during the first trimester of pregnancy is associated with childhood wheezing and atopy at three years of age, and a first pregnancy.

Maternal transmission of asthma risk

Maternal asthma significantly increases the risk of asthma in offspring, but the mechanisms remain poorly defined. We review animal models used to study the maternal effect, focusing on a murine model developed in our laboratory. Mother mice rendered allergic to ovalbumin produce offspring that are more susceptible to allergic sensitization, seen as airway hyperresponsiveness and allergic airway inflammation after a sensitization protocol, which has minimal effects on newborns from normal mothers. Mechanistic analyses identify a role for interleukin-4 (based on pre-mating injection of neutralizing antibodies), dendritic cells and allergen-specific T cells (based on adoptive transfer experiments). Other maternal exposures (e.g. pollutant exposure and non-pulmonary allergy) can increase asthma susceptibility in offspring. This observation implies that the maternal transmission of asthma represents a final common pathway to various types of inflammatory stimuli. Identification of the shared molecular mechanisms in these models may allow better prevention and therapy. Current knowledge, gaps in knowledge and future directions are discussed.

Gender difference, sex hormones, and immediate type hypersensitivity reactions

Gender differences in the development and prevalence of human diseases have long been recognized. Immense interest grows in the understanding of the role of sex hormones in the homeostasis of immunity. Asthma predominates in boys before puberty and this gender preference reverses after puberty and in adulthood, when adult women tend to have a more severe disease, often recalcitrant to treatment. Atopic eczema in preschool children shows insignificant gender difference or male preponderance in different studies, with more adult females suffering from atopic eczema. The limited data on the prevalence of immediate hypersensitivity to hymenoptera venom show controversial results. Discrepancy exists regarding the gender difference in food allergy, with females reporting significantly more allergic reactions in questionnaire studies. In general, adverse reactions to nonionic iodinated radiocontrast media are more commonly observed in females. The course of allergic diseases varies unpredictably during pregnancy, whereas hormone replacement therapy in postmenopausal women usually has a favorable influence on the course of asthma. Experiments in rodents confirm an effect of estrogens on mast cell activation and allergic sensitization, while progesterone is shown to suppress histamine release but potentiate IgE induction. Dehydroepiandrosterone may antagonize the production of Th2 cytokines but the effect of testosterone and the other androgens remains less defined. Actual data from human studies are lacking.

Pregnancy IFN-gamma responses to foetal alloantigens are altered by maternal allergy and gravidity status

BACKGROUND

During pregnancy, variations in maternal-foetal cellular interactions may influence immune programming. This study was carried out to determine if maternal responses to foetal alloantigens are altered by maternal allergic disease and/or previous pregnancies.

METHODS

For this cohort study, peripheral blood was collected from allergic (n = 69) and nonallergic (n = 63) pregnant women at 20, 30, 36-week gestation and 6-week postpartum (pp). Cord blood was collected at delivery. Mixed lymphocyte reactions were used to measure maternal cytokine responses [interleukin-6 (IL-6), IL-10, IL-13 and (interferon-gamma) IFN-gamma] at each time point towards foetal mononuclear cells.

RESULTS

Maternal cytokine responses during pregnancy (20, 30 and 36 weeks) were suppressed compared to the responses at 6-week pp. The ratio of maternal IFN-gamma/IL-13 and IFN-gamma/IL-10 responses were lower during pregnancy. Allergic mothers had lower IFN-gamma responses at each time-point during pregnancy with the greatest difference in responses observed at 36-week gestation. When allergic and nonallergic women were further stratified by gravidity group, IFN-gamma responses of allergic multigravid mothers were significantly lower than nonallergic multigravid mothers during pregnancy.

CONCLUSIONS

During normal pregnancy, peripheral T-cell cytokine responses to foetal alloantigens may be altered by both allergic status of the mother and previous pregnancies. These factors could influence the cytokine milieu experienced by the foetus and will be further explored in the development of allergic disease during early life.

Maternal and cord plasma cytokine and chemokine profile in pregnancies complicated by asthma

The mechanisms contributing to worsening of asthma during pregnancy have not been well characterized. Both asthma and pregnancy are conditions associated with a skewing of the immune response from T helper (Th) 1 toward a Th2 response. We hypothesise that worsening of asthma during pregnancy may be due to an enhanced production of circulating proinflammatory cytokines and chemokines and this may be modified by the use of inhaled glucocorticoid treatment. Peripheral blood was collected from asthmatic (n=35) and control non-asthmatic patients (n=13) in the third trimester (30-37 weeks) of pregnancy. Fetal blood was collected from the umbilical vein of the placenta after delivery from normal (n=24) and pregnancies complicated by asthma (n=24). Plasma samples were assayed for IL-6, -8, eotaxin and RANTES using conventional ELISA. In addition, a range of Th1 and Th2 cytokines measured using Luminex system. There were no significant differences in the levels of maternal IL-6, IL-8, eotaxin and RANTES between asthmatics and nonasthmatics. The results of this study suggest that the presence of asthma does not result in an enhanced circulation of Th2 related cytokines and chemokines during the third trimester of pregnancy. Furthermore peripheral blood cytokine concentrations appear unaffected by inhaled glucocorticoid treatment. Cord plasma eotaxin concentrations were increased in pregnancies complicated by asthma, compared with control. This is the first study to show increased eotaxin production in the feto-placental unit of asthmatic pregnancies and may be one mechanism by which allergy susceptibility is increased in the offspring of asthmatic women.

T-helper type 2 polarization among asthmatics during and following pregnancy

BACKGROUND

Asthma is the most common medical condition during pregnancy. While increased production of T helper cytokines has been reported to occur in both asthma and pregnancy, the effect of T-helper type 2 (Th2) polarization on asthma symptoms during pregnancy has not been well-characterized.

OBJECTIVE

We hypothesized that systemic Th2 cytokine and chemokine polarization occurs among asthmatics to a greater extent during their pregnancy, and is associated with more severe asthma and increased Th2 polarization in the newborn.

METHODS

Fifty-six pregnant asthmatics were recruited from prenatal clinics affiliated with New York Presbyterian Hospital. Systemic production of interleukin-4, interferon-gamma, eotaxin and IP10 were measured by intracytoplasmic staining or ELISA at recruitment, peripartum and post-partum, and in the cord blood. The frequency of asthma symptoms was measured by questionnaires and compared with Th biomarkers.

RESULTS

The chemokine ratio (IP10/eotaxin) declined over the course of pregnancy (from 3.3 +/- 1.3 to 1.4 +/- 0.2, P = 0.016), but IP10 and eotaxin increased post-partum. The decrease in the chemokine ratio was associated with more frequent asthma symptoms. A non-significant trend towards decreased interferon-gamma and increased interleukin-4 production was detected. Cord blood eotaxin levels correlated with maternal levels (r = 0.35, P = 0.03). Other peripartum biomarkers were not associated with Th2 polarization nor with subsequent respiratory symptoms in the newborn.

CONCLUSION

IP10/eotaxin declined over the course of pregnancy and was associated with worse asthma symptoms. Alterations of Th1/Th2 chemokine balance during pregnancy may identify women prone to more severe asthma during pregnancy.