Sphingolipid classes and the interrelationship with pediatric asthma and asthma risk factors.

BACKGROUND: While dysregulated sphingolipid metabolism has been associated with risk of childhood asthma, the specific sphingolipid classes and/or mechanisms driving this relationship remain unclear. We aimed to understand the multifaceted role between sphingolipids and other established asthma risk factors that complicate this relationship. METHODS: We performed targeted LC-MS/MS-based quantification of 77 sphingolipids in plasma from 997 children aged 6 years from two independent cohorts (VDAART and COPSAC2010 ). We examined associations of circulatory sphingolipids with childhood asthma, lung function, and three asthma risk factors: functional SNPs in ORMDL3, low vitamin D levels, and reduced gut microbial maturity. Given racial differences between these cohorts, association analyses were performed separately and then meta-analyzed together. RESULTS: We observed elevations in circulatory sphingolipids with asthma phenotypes and risk factors; however, there were differential associations of sphingolipid classes with clinical outcomes and/or risk factors. While elevations from metabolites involved in ceramide recycling and catabolic pathways were associated with asthma and worse lung function [meta p-value range: 1.863E-04 to 2.24E-3], increased ceramide levels were associated with asthma risk factors [meta p-value range: 7.75E-5 to .013], but not asthma. Further investigation identified that some ceramides acted as mediators while some interacted with risk factors in the associations with asthma outcomes. CONCLUSION: This study demonstrates the differential role that sphingolipid subclasses may play in asthma and its risk factors. While overall elevations in sphingolipids appeared to be deleterious overall; elevations in ceramides were uniquely associated with increases in asthma risk factors only; while elevations in asthma phenotypes were associated with recycling sphingolipids. Modification of asthma risk factors may play an important role in regulating sphingolipid homeostasis via ceramides to affect asthma. Further function work may validate the observed associations.

The relationship of fetal sex and maternal race and ethnicity with early and late pregnancy C-reactive protein and interleukin-8.

PROBLEM: Promotion of a healthy pregnancy is dependent on a coordinated immune response that minimizes inflammation at the maternal-fetal interface. Few studies investigated the effect of fetal sex on proinflammatory biomarkers during pregnancy and whether maternal race could impact this association. We aimed to examine whether fetal sex could, independently of maternal race/ethnicity and the condition of pregnancy (normal vs. complicated), impact inflammatory markers (C-reactive protein [CRP] and interleukin-8 [IL-8] levels) in early and late pregnancy. METHODS OF STUDY: This study was a cohort analysis using prospectively collected data from pregnant women who participated in the Vitamin Antenatal Asthma Reduction Trial (VDAART, N = 816). Maternal serum CRP and IL-8 levels were measured in early and late pregnancy (10-18 and 32-38 weeks of gestation, respectively). Five hundred and twenty-eight out of 816 pregnant women who participated in the trial had available CRP and IL-8 measurements at both study time points. We examined the association of fetal sex with early and late CRP and IL-8 levels and their paired sample difference. We further investigated whether maternal race/ethnicity, pregnancy complications (i.e., preeclampsia and gestational diabetes), and early pregnancy body mass index (BMI) could affect the association between these two biomarkers and fetal sex adjusting for potential confounders. For this purpose, we used generalized linear and logistic regression models on log-normalized early and late CRP and IL-8 levels as well as their split at median to form high and low groups. RESULTS: Women pregnant with male fetuses (266/528 = 56.5%) had higher CRP levels in early to mid-pregnancy (ß = .18: 95% confidence interval [CI]: CI = 0.03-0.32; p = .02). Twenty-seven percent (143/528) of the study subjects were Hispanic. Hispanic African American [AA] women and women of races other than White and AA had higher levels of CRP at early to mid-pregnancy compared with White women (ß = .57; 95% CI: 0.17-0.97; p < .01 and ß = .27; 95% CI: 0.05-0.48; p = .02, respectively). IL-8 levels were not associated with fetal sex in early and late pregnancy (p's > .05). Other factors such as gestational diabetes and early pregnancy BMI were associated with higher CRP levels and higher CRP and IL-8 levels, respectively. Dichotomizing log-normalized cytokine levels at the median in a sensitivity analysis, women with male fetuses had lower odds of high (above-median) IL-8 levels at early pregnancy. Also, women with races other than AA and White carrying male fetuses had higher odds of having high (above-median) late-pregnancy CRP and early-pregnancy IL-8 levels (adjusted odds ratio [aOR] = 3.80, 95% CI: 0.24-1.23; p = .02 and aOR = 3.57; 95% CI: 0.23-1.03; p = .02, respectively). Of the pregnancy complications, women with gestational diabetes mellitus had a higher paired difference of early and late pregnancy CRP levels (ß = .38; 95% CI: 0.09-0.68; p = .01), but no difference in IL-8 levels (p's > .05). No associations between the inflammatory markers and preeclampsia were found. CONCLUSION: Fetal sex is associated with CRP in early pregnancy and an association with IL-8 in early pregnancy is implied. Our study further indicates that maternal race/ethnicity could be a contributing factor in the relationship between fetal sex and inflammatory responses during pregnancy. However, the specificity and level of the contribution might vary by type of cytokine, pregnancy stage, and other confounding factors such as BMI that may impact these associations.

The Association of Prenatal C-Reactive Protein and Interleukin-8 Levels with Maternal Characteristics and Preterm Birth.

OBJECTIVE: The determinants of preterm birth remain unknown. Excessive maternal inflammation during pregnancy may play an important role in the pathogenesis of preterm birth. Our objective was to describe the association of prenatal levels of proinflammatory C-reactive protein (CRP) and interleukin-8 (IL-8) with preterm birth in participants of the Vitamin D Antenatal Asthma Reduction Trial. STUDY DESIGN: Five hundred and twenty-eight patients with available samples of both first- and third-trimester plasma were included in this analysis. CRP and IL-8 were measured from maternal prenatal samples. We examined the association between prenatal CRP and IL-8 with maternal health characteristics and the outcome of preterm birth. We also described the patterns of change in CRP and IL-8 from first to third trimester and their association with preterm birth. A subgroup analysis comparing only those with a spontaneous preterm birth phenotype to those with term birth was also performed. RESULTS: Maternal characteristics including lower educational attainment, higher prepregnancy body mass index, gestational diabetes, lower vitamin D, and an unhealthy diet were associated with elevated levels of prenatal CRP and IL-8. Higher third trimester CRP and an increase in CRP from first to third trimester were associated with an increased odds of preterm birth when compared to lower levels of CRP (adjusted odds ratio [aOR] = 1.49, 95% confidence interval: 1.02, 2.23, p = 0.04) or a decrease in CRP over pregnancy (aOR = 3.06, 95% CI = 1.31,7.55, p = 0.01), after adjusting for potential confounders. These associations were strengthened when comparing only patients with spontaneous preterm birth (n = 22) to those with term births. CONCLUSION: Higher levels of the proinflammatory markers CRP and IL-8 are associated with indicators of poor maternal health and preterm birth. Prenatal CRP levels may reflect maternal prenatal health status and serve as a predictor of preterm birth, especially among those with spontaneous preterm birth. KEY POINTS: · Elevated prenatal CRP is associated with poor maternal health.. · High prenatal CRP may predict premature birth, especially spontaneous premature birth phenotypes.. · Vitamin D insufficiency may be a modifiable risk factor for prenatal inflammation..

The Association of Prenatal C-Reactive Protein Levels With Childhood Asthma and Atopy.

BACKGROUND: The pathogenesis of childhood asthma is complex, and determinants of risk may begin in utero. OBJECTIVE: To describe the association of systemic prenatal inflammation, measured by plasma C-reactive protein (CRP), with childhood asthma, eczema, and allergic rhinitis. METHODS: A total of 522 maternal-offspring pairs from the Vitamin D Antenatal Asthma Reduction Trial were included. Prenatal plasma CRP level was measured between 10 and 18 weeks of gestation and between 32 and 38 weeks of gestation. Offspring asthma, eczema, and allergic rhinitis were assessed quarterly between birth and age 6 years. We performed mediation analyses of prenatal CRP on the association between several maternal characteristics and offspring asthma. RESULTS: Elevated early and late prenatal CRP and an increase in CRP from early to late pregnancy were associated with asthma by age 6 years (early: adjusted odds ratio [aOR], 1.76, 95% CI, 1.12-2.82, P = .02; late: aOR, 2.45, 95% CI, 1.47-4.18, P < .001; CRP increase: aOR, 2.06, 95% CI, 1.26-3.39, P < .004). Prenatal CRP and childhood asthma associations were strengthened among offspring with atopic asthma (early: aOR, 3.78, 95% CI, 1.49-10.64, P = .008; late: aOR, 4.84, 95% CI, 1.68-15.50, P = .005; CRP increase: aOR, 3.01, 95% CI, 1.06-9.16, P = .04). Early and late prenatal CRP mediated 96% and 86% of the association between maternal prepregnancy body mass index and offspring asthma, respectively. CONCLUSIONS: Higher prenatal CRP and an increase in CRP from early to late pregnancy are associated with childhood asthma. Systemic inflammation during pregnancy associated with modifiable maternal characteristics may be an important determinant of childhood asthma risk.

The Association of Prenatal Vitamin D Sufficiency With Aeroallergen Sensitization and Allergic Rhinitis in Early Childhood.

BACKGROUND: The role of prenatal vitamin D sufficiency and supplementation in the development of childhood aeroallergen sensitization and allergic rhinitis remains uncertain. OBJECTIVE: To describe the association of prenatal vitamin D sufficiency with childhood allergic outcomes in participants of the Vitamin D Antenatal Asthma Reduction Trial, a randomized controlled trial of prenatal vitamin D supplementation. METHODS: We included 414 mother-offspring pairs with offspring aeroallergen sensitization data available at age 6 years in this analysis. We examined the association between prenatal vitamin D sufficiency status, based on vitamin D levels measured in the first and third trimesters, or vitamin D supplementation treatment assignment with the outcomes of aeroallergen sensitization, parent-reported clinical allergic rhinitis, parent-reported clinical allergic rhinitis with aeroallergen sensitization, food sensitization, any sensitization, eczema, and total IgE at ages 3 and 6 years. RESULTS: Compared with early and late insufficiency, early prenatal vitamin D insufficiency with late sufficiency was associated with reduced development of clinical allergic rhinitis with aeroallergen sensitization at 3 years (adjusted odds ratio [aOR] = 0.34; 95% confidence interval [CI], 0.13-0.82; P = .02) and 6 years (aOR = 0.54; 95% CI, 0.29-0.98; P = .05). At 6 years, clinical allergic rhinitis with sensitization was significantly decreased in offspring whose mothers received high-dose vitamin D (aOR = 0.54; 95% CI, 0.32-0.91; P = .02) compared with offspring whose mothers who received low-dose vitamin D. Associations of prenatal vitamin D with aeroallergen sensitization were strengthened among children who also developed asthma or who had a maternal history of atopy. CONCLUSIONS: Among mothers with first-trimester vitamin D insufficiency, we detected a protective effect of third-trimester prenatal vitamin D sufficiency on the development of clinical allergic rhinitis with aeroallergen sensitization at ages 3 and 6 years.

Rifaximin suppresses background intestinal 18F-FDG uptake on PET/CT scans.

BACKGROUND: Identification of cancer or inflammatory bowel disease in the intestinal tract by PET/computed tomography (CT) imaging can be hampered by physiological uptake of F-fluorodeoxyglucose (F-FDG) in the normal colon. Previous work has localized this F-FDG uptake to the intestinal lumen, predominantly occupied by bacteria. We sought to determine whether pretreatment with an antibiotic could reduce F-FDG uptake in the healthy colon. PATIENTS AND METHODS: Thirty patients undergoing restaging PET/CT for nongastrointestinal lymphoma were randomly selected to receive rifaximin 550 mg twice daily for 2 days before their scan (post-rifaximin). Their PET/CT images were compared with those from their prior study (pre-rifaximin). Cecal maximum standard uptake value (SUVmax) and overall colonic F-FDG uptake were compared between scans. All PET/CT images were blindly scored by a radiologist. The same comparison of sequential scans was also undertaken in 30 patients who did not receive antibiotics. RESULTS: Thirty post-rifaximin scans were compared with 30 pre-rifaximin scans in the same patients. SUVmax in the cecum was significantly lower in the patient's post-rifaximin scans than in their pre-rifaximin scans (P=0.002). The percentage of scans with greater than grade 1 colonic F-FDG uptake was significantly lower in the post-rifaximin scans than in the pre-rifaximin scans (P<0.05). In contrast, there was no significant difference in the paired sequential scans from control patients, nor a reduction in the percentage of scans with greater than grade 1 colonic F-FDG uptake. CONCLUSION: This pilot study shows that treatment with rifaximin for 2 days before PET/CT scanning can significantly reduce physiological F-FDG uptake in the normal colonic lumen.

Focal physiologic fluorodeoxyglucose activity in the gastrointestinal tract is located within the colonic lumen.

AIM: Physiologic activity of 18F-fluorodeoxyglucose (FDG) in the intestinal tract occurs frequently in patients undergoing PET/computed tomography (CT) imaging, appearing most often in the colon. The purpose of this study is to determine the localization of the FDG within the colon. We hypothesize that intestinal FDG activity is intraluminal. METHODS: In a prospective Institutional Review Board-approved and Health Insurance Portability and Accountability Act-compliant study, patients with physiologic colonic FDG activity on PET/CT scans were enrolled to undergo repeat imaging 2 h after stimulation of colonic motility with a high-fat meal. RESULTS: We identified 13 patients who had focal FDG activity in their colon during a routine clinical PET/CT scan. After administration of a high-fat meal, 10 patients (77%) demonstrated antegrade movement of FDG along the colon, consistent with luminal clearance. CONCLUSION: Our results suggest that normal physiologic FDG activity within the large intestine, seen on PET/CT scans, is intraluminal.