Detection of Bronchiolitis Obliterans Syndrome Following Pediatric Hematopoietic Stem Cell Transplantation. An Official American Thoracic Society Clinical Practice Guideline.

BACKGROUND: Many children undergo allogeneic Hematopoietic Stem Cell Transplantation (HSCT) for the treatment of malignant and non-malignant conditions. Unfortunately, pulmonary complications occur frequently post-HSCT, with bronchiolitis obliterans syndrome (BOS) being the most common non-infectious pulmonary complication. Current international guidelines contain conflicting recommendations regarding post-HSCT surveillance for BOS, and a recent National Institutes of Health workshop highlighted the need for a standardized approach to post-HSCT monitoring. As such, this guideline provides an evidence-based approach to detection of post-HSCT BOS in children. METHODS: A multinational, multidisciplinary panel of experts identified six questions regarding surveillance for, and evaluation of post-HSCT BOS in children. Systematic review of the literature was undertaken to answer each question. The Grading of Recommendations, Assessment, Development, and Evaluation approach was used to rate the quality of evidence and the strength of recommendations. RESULTS: The panel members considered the strength of each recommendation and evaluated the benefits and risks of applying the intervention. In formulating the recommendations, the panel considered patient and caregiver values, the cost of care, and feasibility. Recommendations addressing the role of screening pulmonary function testing and diagnostic tests in children with suspected post-HSCT BOS were made. Following a Delphi process, new diagnostic criteria for pediatric post-HSCT BOS were also proposed. CONCLUSIONS: This document provides an evidence-based approach to detection of post-HSCT BOS in children, while also highlighting considerations for implementation of each recommendation. Further, the document describes important areas for future research.

Computed tomographic findings in TBX4 mutation: a common cause of severe pulmonary artery hypertension in children.

BACKGROUND: Mutations in the T-Box 4 (TBX4) gene are a lesser-known cause of heritable pulmonary arterial hypertension (PAH). Patients with heritable PAH typically have worse outcomes when compared with patients with idiopathic PAH, yet little is known about the phenotypical presentation of this mutation. OBJECTIVE: This article reviews the pattern of chest CT findings in pediatric patients with PAH and TBX4 mutations and compares their radiographic presentation with those of age-matched patients with PAH but without TBX4 mutations. MATERIALS AND METHODS: A retrospective chart review of the pulmonary arterial hypertension database was performed. Pediatric patients with PAH-confirmed TBX4 mutations and an available high CT were included. Fifteen (9 females) patients met the inclusion criteria. Fourteen (8 females) age-matched controls with diagnosed PAH but without TBX4 mutations were also evaluated. The median age at diagnosis was 7.4 years (range: 0.1-16.4 years). Demographic information and clinical outcomes were collected. CTs of the chest were reviewed for multiple airway, parenchymal, and structural abnormalities (16 imaging findings in total). Chi-square tests were used to compare the prevalence of each imaging finding in the TBX4 cohort compared to the control group. RESULTS: Patients with TBX-4 mutations had increased presence of peripheral or subpleural irregularity (73% vs 0%, P < 0.01), cystic lucencies (67% vs 7%, P < 0.01), and linear or reticular opacity (53% vs 0%, P < 0.01) compared to the control group. Ground glass opacities, bronchiectasis, and centrilobular nodules were not significantly different between the two patient groups (P > 0.05). CONCLUSION: TBX4 mutations have distinct imaging phenotypes in pediatric patients with PAH. Compared to patients without this mutation, patients with TBX-4 genes typically present with peripheral or subpleural irregularity, cystic lucencies, and linear or reticular opacity.

Nintedanib in children and adolescents with fibrosing interstitial lung diseases.

BACKGROUND: Childhood interstitial lung disease (ILD) comprises a spectrum of rare ILDs affecting infants, children and adolescents. Nintedanib is a licensed treatment for pulmonary fibrosis in adults. The primary objectives of the InPedILD trial were to determine the dose-exposure and safety of nintedanib in children and adolescents with fibrosing ILD. METHODS: Patients aged 6-17 years with fibrosing ILD on high-resolution computed tomography and clinically significant disease were randomised 2:1 to receive nintedanib or placebo for 24 weeks and then open-label nintedanib. Dosing was based on weight-dependent allometric scaling. Co-primary end-points were the area under the plasma concentration-time curve at steady state (AUCτ,ss) at weeks 2 and 26 and the proportion of patients with treatment-emergent adverse events at week 24. RESULTS: 26 patients received nintedanib and 13 patients received placebo. The geometric mean (geometric coefficient of variation) AUCτ,ss for nintedanib was 175 µg·h·L-1 (85.1%) in patients aged 6-11 years and 160 µg·h·L-1 (82.7%) in patients aged 12-17 years. In the double-blind period, adverse events were reported in 84.6% of patients in each treatment group. Two patients discontinued nintedanib due to adverse events. Diarrhoea was reported in 38.5% and 15.4% of the nintedanib and placebo groups, respectively. Adjusted mean±se changes in percentage predicted forced vital capacity at week 24 were 0.3±1.3% in the nintedanib group and -0.9±1.8% in the placebo group. CONCLUSIONS: In children and adolescents with fibrosing ILD, a weight-based dosing regimen resulted in exposure to nintedanib similar to adults and an acceptable safety profile. These data provide a scientific basis for the use of nintedanib in this patient population.

Chest computed tomography findings of ground-glass nodules with enhancing central vessel/nodule in pediatric patients with BMPR2 mutations and plexogenic arteriopathy.

BACKGROUND: Germline mutation in bone morphogenetic protein type II (BMPR2) is the most common cause of idiopathic/heritable pulmonary hypertension in pediatric patients. Despite the discovery of this gene there are no known descriptions of the CT or CT angiography findings in these children. OBJECTIVE: To correlate the clinical presentation, pathology and chest CT findings in pediatric patients with pulmonary hypertension caused by mutations in the BMPR2 gene. MATERIALS AND METHODS: We performed a search to identify pediatric patients with a BMPR2 mutation and CT or CT angiography with the clinical history of pulmonary hypertension. Three pediatric radiologists reviewed the children's CT imaging findings and ranked the dominant findings in order of prevalence via consensus. RESULTS: We identified three children with pulmonary hypertension and confirmed germline BMPR2 mutations, two of whom had undergone lung biopsy. We then correlated the imaging findings with histopathology and clinical course. CONCLUSION: All of our patients with BMPR2 mutations demonstrated a distinct CT pattern of ground-glass nodules with a prominent central enhancing vessel/nodule. These findings correlated well with the pathological findings of plexogenic arteriopathy.

Stevens-Johnson Syndrome in Children: Consider Monitoring for Bronchiolitis Obliterans.

We reviewed patients with Stevens-Johnson syndrome (SJS) evaluated at Children's Hospital Colorado and investigated the occurrence of bronchiolitis obliterans (BO). Approximately 9% of patients with SJS developed BO. Pediatricians should consider monitoring patients with SJS for BO, especially those with recurrent SJS and patients treated with mechanical ventilation.

Pulmonary Aptamer Signatures in Children's Interstitial and Diffuse Lung Disease.

Rationale: Biomarker signatures are needed in children with children's interstitial and diffuse lung disease (chILD) to improve diagnostic approaches, increase our understanding of disease pathogenesis, monitor disease progression, and develop new treatment strategies. Proteomic technology using SOMAmer (Slow Off-rate Modified Aptamer) nucleic acid-based protein-binding reagents allows for biomarker discovery.Objectives: We hypothesized that proteins and protein pathways in BAL fluid (BALF) would distinguish children with neuroendocrine cell hyperplasia of infancy (NEHI), surfactant dysfunction mutations, and other chILD diagnoses and control subjects.Methods: BALF was collected for clinical indications and banked in patients with chILD and disease control subjects using standardized protocols over 10 years. BALF supernatant was analyzed using an aptamer assay to measure 1,129 protein levels. Protein levels were compared between groups using an ANOVA and adjusted for multiple comparisons using false discovery rate. Proteins were classified into pathways. Hierarchical clustering was used to define endotypes in the group of children with NEHI.Measurements and Main Results: After correcting for multiple testing, children with NEHI (n = 22) had 202 aptamers that were significantly different (P < 0.05) in BALF compared with control subjects (n = 9). Children with surfactant mutation (n = 8) had 51 aptamers significantly different (P < 0.05) in BALF compared with control subjects (n = 9). Proteins associated with pulmonary fibrosis and inflammation were associated with the surfactant dysfunction group but not the NEHI group. Using hierarchical clustering analysis, two distinct NEHI endotypes were identified.Conclusions: Distinct proteins and protein pathways can be determined from BALF of children with chILD, and these hold promise to further our understanding of chILD.

Approaching Clinical Trials in Childhood Interstitial Lung Disease and Pediatric Pulmonary Fibrosis.

Childhood interstitial lung disease (chILD) comprises a spectrum of rare diffuse lung disorders. chILD is heterogeneous in origin, with different disease manifestations occurring in the context of ongoing lung development. The large number of disorders in chILD, in combination with the rarity of each diagnosis, has hampered scientific and clinical progress within the field. Epidemiologic and natural history data are limited. The prognosis varies depending on the etiology, with some forms progressing to lung transplant or death. There are limited treatment options for patients with chILD. Although U.S. Food and Drug Administration-approved treatments are now available for adult patients with idiopathic pulmonary fibrosis, no clinical trials have been conducted in a pediatric population using agents designed to treat lung fibrosis. This review will focus on progressive chILD disorders and on the urgent need for meaningful objective outcome measures to define, detect, and monitor fibrosis in children.

Home Oxygen Therapy for Children. An Official American Thoracic Society Clinical Practice Guideline.

BACKGROUND: Home oxygen therapy is often required in children with chronic respiratory conditions. This document provides an evidence-based clinical practice guideline on the implementation, monitoring, and discontinuation of home oxygen therapy for the pediatric population. METHODS: A multidisciplinary panel identified pertinent questions regarding home oxygen therapy in children, conducted systematic reviews of the relevant literature, and applied the Grading of Recommendations, Assessment, Development, and Evaluation approach to rate the quality of evidence and strength of clinical recommendations. RESULTS: After considering the panel's confidence in the estimated effects, the balance of desirable (benefits) and undesirable (harms and burdens) consequences of treatment, patient values and preferences, cost, and feasibility, recommendations were developed for or against home oxygen therapy specific to pediatric lung and pulmonary vascular diseases. CONCLUSIONS: Although home oxygen therapy is commonly required in the care of children, there is a striking lack of empirical evidence regarding implementation, monitoring, and discontinuation of supplemental oxygen therapy. The panel formulated and provided the rationale for clinical recommendations for home oxygen therapy based on scant empirical evidence, expert opinion, and clinical experience to aid clinicians in the management of these complex pediatric patients and identified important areas for future research.

Transnasal Endoscopy in Unsedated Children With Eosinophilic Esophagitis Using Virtual Reality Video Goggles.

BACKGROUND & AIMS: Evaluation and treatment of children with eosinophilic esophagitis (EoE) requires serial endoscopic, visual, and histologic assessment by sedated esophagogastroduodenoscopy (EGD). Unsedated transnasal endoscopy (TNE) was reported to be successful in a pilot study of children. We evaluated video goggle and virtual reality-based unsedated TNE in children with EoE, collecting data on rates of completion, adverse events, and adequacy of visual and histologic findings. METHODS: We performed a retrospective study of 190 children and young adults (age, 3-22 y) who underwent video goggle or virtual reality-based unsedated TNE from January 2015 through February 2018. We analyzed data on patient demographics, procedure completion, endoscope type, adverse events, visual and histologic findings, estimated costs, and duration in the facility. Esophageal biopsies from the first 173 subjects who underwent TNE were compared with those from previous EGD evaluations. RESULTS: During 300 attempts, 294 TNEs were performed (98% rate of success). Fifty-four patients (age, 6-18 y) underwent multiple TNEs for dietary or medical management of EoE. There were no significant adverse events. Visual and histologic findings were adequate for assessment of EoE. TNE reduced costs by 53.4% compared with EGD (TNE $4393.00 vs EGD $9444.33). TNE was used increasingly from 2015 through 2017, comprising 31.8% of endoscopies performed for EoE. The total time spent in the clinic (front desk check-in to check-out) in 2018 was 71 minutes. CONCLUSIONS: In a retrospective study of 190 children and young adults (age, 3-22 y) who underwent video goggle or virtual reality-based unsedated TNE, TNE was safe and effective and reduced costs of EoE monitoring. Advantages of TNE include reduced risk and cost associated with anesthesia as well as decreased in-office time, which is of particular relevance for patients with EoE, who require serial EGDs.

Emergent high fatality lung disease in systemic juvenile arthritis.

OBJECTIVE: To investigate the characteristics and risk factors of a novel parenchymal lung disease (LD), increasingly detected in systemic juvenile idiopathic arthritis (sJIA). METHODS: In a multicentre retrospective study, 61 cases were investigated using physician-reported clinical information and centralised analyses of radiological, pathological and genetic data. RESULTS: LD was associated with distinctive features, including acute erythematous clubbing and a high frequency of anaphylactic reactions to the interleukin (IL)-6 inhibitor, tocilizumab. Serum ferritin elevation and/or significant lymphopaenia preceded LD detection. The most prevalent chest CT pattern was septal thickening, involving the periphery of multiple lobes ± ground-glass opacities. The predominant pathology (23 of 36) was pulmonary alveolar proteinosis and/or endogenous lipoid pneumonia (PAP/ELP), with atypical features including regional involvement and concomitant vascular changes. Apparent severe delayed drug hypersensitivity occurred in some cases. The 5-year survival was 42%. Whole exome sequencing (20 of 61) did not identify a novel monogenic defect or likely causal PAP-related or macrophage activation syndrome (MAS)-related mutations. Trisomy 21 and young sJIA onset increased LD risk. Exposure to IL-1 and IL-6 inhibitors (46 of 61) was associated with multiple LD features. By several indicators, severity of sJIA was comparable in drug-exposed subjects and published sJIA cohorts. MAS at sJIA onset was increased in the drug-exposed, but was not associated with LD features. CONCLUSIONS: A rare, life-threatening lung disease in sJIA is defined by a constellation of unusual clinical characteristics. The pathology, a PAP/ELP variant, suggests macrophage dysfunction. Inhibitor exposure may promote LD, independent of sJIA severity, in a small subset of treated patients. Treatment/prevention strategies are needed.

High-resolution computed tomography findings of thyroid transcription factor 1 deficiency (NKX2-1 mutations).

BACKGROUND: The expression of the NKX2-1 gene and its encoded protein, thyroid transcription factor 1 (TTF-1), plays a role in pulmonary surfactant homeostasis and lung development. NKX2-1 mutations have been associated with neonatal respiratory distress, hypotonia, choreoathetosis and congenital hypothyroidism. These clinical findings have been coined brain-lung-thyroid syndrome, although not all three organs are always involved. While many of these children develop interstitial lung disease, no systematic review of chest high-resolution CT (HRCT) findings has been reported. OBJECTIVE: To summarize the clinical presentations, pathology and HRCT imaging findings of children with NKX2-1 mutations. MATERIALS AND METHODS: We identified six children with NKX2-1 mutations, deletions or duplications confirmed via genetic testing at our institution. Three pediatric radiologists reviewed the children's HRCT imaging findings and ranked the dominant findings in order of prevalence via consensus. We then correlated the imaging findings with histopathology and clinical course. RESULTS: All children in the study were heterozygous for NKX2-1 mutations, deletions or duplications. Ground-glass opacities were the most common imaging feature, present in all but one child. Consolidation was also a prevalent finding in 4/6 of the children. Architectural distortion was less common. CONCLUSION: HRCT findings of TTF-1 deficiency are heterogeneous and evolve over time. There is significant overlap between the HRCT findings of TTF-1 deficiency, other surfactant dysfunction mutations, and pulmonary interstitial glycogenosis. TTF-1 deficiency should be considered in term infants presenting with interstitial lung disease, especially if hypotonia or hypothyroidism is present.

Unsedated In-office Transgastrostomy Esophagoscopy to Monitor Therapy in Pediatric Esophageal Disease.

Monitoring therapy in esophageal inflammatory disorders such as eosinophilic esophagitis and reflux esophagitis often requires frequent endoscopic evaluation. We recently reported the effective use of unsedated in-office transnasal esophagoscopy that significantly decreased costs and anesthetic exposure associated with pediatric esophagoscopy in eosinophilic esophagitis. Here we report a series of pediatric patients with esophagitis with gastrostomy tubes who underwent unsedated transgastrostomy esophagoscopy (TGE) in an office setting. Nine patients (ages 16 months-21 years) tolerated TGE without significant adverse events. Biopsy specimens were adequate for evaluation. This series confirms that unsedated in-office TGE can be used to successfully obtain mucosal biopsies to monitor esophageal inflammatory conditions in children without the use of sedation.

A Comparative Analysis of Pulmonary and Critical Care Medicine Guideline Development Methodologies.

RATIONALE: The Institute of Medicine (IOM) standards for guideline development have had unintended negative consequences. A more efficient approach is desirable. OBJECTIVES: To determine whether a modified Delphi process early during guideline development discriminates recommendations that should be informed by a systematic review from those that can be based upon expert consensus. METHODS: The same questions addressed by IOM-compliant pulmonary or critical care guidelines were addressed by expert panels using a modified Delphi process, termed the Convergence of Opinion on Recommendations and Evidence (CORE) process. The resulting recommendations were compared. Concordance of the course of action, strength of recommendation, and quality of evidence, as well as the duration of recommendation development, were measured. MEASUREMENTS AND MAIN RESULTS: When 50% agreement was required to make a recommendation, all questions yielded recommendations, and the recommended courses of action were 89.6% concordant. When 70% agreement was required, 17.9% of questions did not yield recommendations, but for those that did, the recommended courses of action were 98.2% concordant. The time to completion was shorter for the CORE process (median, 19.3 vs. 1,309.0 d; P = 0.0002). CONCLUSIONS: We propose the CORE process as an early step in guideline creation. Questions for which 70% agreement on a recommendation cannot be achieved should go through an IOM-compliant process; however, questions for which 70% agreement on a recommendation can be achieved can be accepted, avoiding a lengthy systematic review.

High-resolution CT findings of pulmonary interstitial glycogenosis.

BACKGROUND: Pulmonary interstitial glycogenosis is a form of childhood interstitial lung disease characterized by the histological finding of abundant glycogen-laden mesenchymal cells within the pulmonary interstitium. Patients present in the neonatal period with disproportionate respiratory distress. Often, pulmonary interstitial glycogenosis is accompanied by alveolar simplification complicating recognition and diagnosis. Despite the recognition of pulmonary interstitial glycogenosis as a distinct entity, only a few case reports describing imaging findings are found in the literature, with no published systematic review available. OBJECTIVE: The purpose of this review is to provide a review of CT findings of pulmonary interstitial glycogenosis with histological correlation to aid in early diagnosis and management. MATERIALS AND METHODS: A 10-year retrospective review was performed to identify pediatric patients <18 years who underwent biopsy and CT within the last 10 years at our institution. The inclusion criteria include patients who had a CT within 3 months of biopsy and pathology-proven pulmonary interstitial glycogenosis CTs that were evaluated by three radiologists using a standardized scoring system. RESULTS: Fifteen patients met inclusion criteria (9 male, 6 female). At the time of initial pre-biopsy CT, ages ranged from 2 weeks to 5 months. Pulmonary symptoms presented at birth in the majority of patients (n=13). Two patients presented in early infancy at 3 months (n=1) and 5 months (n=1). Ground glass opacities were the most common CT finding (n=14), which varied from diffuse to scattered. Cystic lucencies (n=11) were noted in the majority of patients as well. Interlobular septal thickening (n=10) and architectural distortion (n=8) were less common findings. CONCLUSION: The most common CT findings of pulmonary interstitial glycogenosis are ground glass opacities with cystic lucencies. While the imaging findings are distinct from the typical presentation of neuroendocrine hyperplasia of infancy, there is significant overlap of these findings with surfactant dysfunction mutations, entities that also present with respiratory distress in the neonatal period. Therefore, imaging findings in pulmonary interstitial glycogenosis are helpful in guiding the need for genetic testing and/or biopsy.

Lung and airway shape in neuroendocrine cell hyperplasia of infancy.

BACKGROUND: Neuroendocrine cell hyperplasia of infancy (NEHI) is a rare lung disease associated with significant air trapping. Although chest CT is crucial in establishing a diagnosis, CT and biopsy findings do not reveal airway abnormalities to explain the air trapping. OBJECTIVE: We compared lung and airway morphology obtained from chest CT scans in children with NEHI and control children. In the children with NEHI, we explored relationships between lung and airway shape and lung function. MATERIALS AND METHODS: We performed a retrospective review of children with NEHI who underwent clinical chest CT. We identified control children of similar size and age. We created lung masks and airway skeletons using semi-automated software and compared them using statistical shape modeling methods. Then we calculated a logistic regression model using lung and airway shape to differentiate NEHI from controls, and we compared shape model parameters to lung function measurements. RESULTS: Airway and lung shapes were statistically different between children with NEHI and controls. We noted a broad lung apex in the children with NEHI and a significantly increased apical anterior-posterior lung diameter. A logistic regression model including lung shape was 90% accurate in differentiating children with NEHI from controls. Correlation coefficients were significant between lung function values and lung and airway shape. CONCLUSION: Lung and airway shapes were different between children with NEHI and control children in this cohort. Children with NEHI had an increased anteroposterior diameter of their lungs that might be useful in the diagnostic criteria.

Pediatric Pulmonary Hypertension: Guidelines From the American Heart Association and American Thoracic Society.

Pulmonary hypertension is associated with diverse cardiac, pulmonary, and systemic diseases in neonates, infants, and older children and contributes to significant morbidity and mortality. However, current approaches to caring for pediatric patients with pulmonary hypertension have been limited by the lack of consensus guidelines from experts in the field. In a joint effort from the American Heart Association and American Thoracic Society, a panel of experienced clinicians and clinician-scientists was assembled to review the current literature and to make recommendations on the diagnosis, evaluation, and treatment of pediatric pulmonary hypertension. This publication presents the results of extensive literature reviews, discussions, and formal scoring of recommendations for the care of children with pulmonary hypertension.

Unsedated transnasal esophagoscopy for monitoring therapy in pediatric eosinophilic esophagitis.

BACKGROUND AND AIMS: Unsedated transnasal endoscopy (TNE) is safer and less costly than sedated EGD. The aim of this study was to evaluate the performance of TNE with biopsies in monitoring the esophageal mucosa of pediatric patients with eosinophilic esophagitis. METHODS: Patients between 8 and 17 years of age with eosinophilic esophagitis and their parents were enrolled. Unsedated TNE was performed. A 2.8-mm (1.2-mm channel) or a 4-mm flexible bronchoscope (2-mm channel) was used, and esophageal biopsy specimens were obtained. Biopsy specimen analysis, duration, adverse events, and billing charges of TNE were assessed. Immediately after TNE and a minimum of 2 weeks later, a modified Group Health Association of America 9 survey and a preference questionnaire were completed, respectively. RESULTS: Twenty-one of 22 enrolled patients underwent TNE. TNE was performed with no serious adverse events. Histopathological analysis revealed 0 eosinophils per high-power field (n = 12), fewer than 15 eosinophils per high-power field (n = 4), and more than 15 eosinophils per high-power field (n = 5). The total epithelial surface area of mucosal biopsy samples from either TNE Forceps (1.2 mm or 2 mm biopsy channel forceps) compared with those obtained during the subject's previous EGD by using standard endoscopic forceps was not statistically different (P = .308 [1.2 mm]/P = .492 [2 mm]). All parents and 76.2% of subjects would undergo the TNE again. TNE was preferred over EGD by 85.7% of parents and 52.4% of subjects. The modified Group Health Association of America 9 survey revealed a high degree of satisfaction (average, 43.19 ± 2.6; maximum score, 45). Charges associated with TNE were 60.1% lower than for previous EGDs. CONCLUSIONS: Unsedated TNE is an effective, lower-cost procedure for monitoring the esophageal mucosa of children with eosinophilic esophagitis.

The relationship of circulating proteins in early pregnancy with preterm birth.

BACKGROUND: Preterm birth (PTB) (< 37 completed weeks' gestation) is a pathological outcome of pregnancy and a major global health problem. Babies born preterm have an elevated risk for long-term adverse medical and neurodevelopmental sequelae. Substantial evidence implicates intrauterine infection and/or inflammation in PTB. However, these are often relatively late findings in the process, when PTB is inevitable. Identification of earlier markers of PTB may make successful intervention possible. Although select proteins, notably those related to the inflammatory pathways, have been associated with PTB, there has been a lack of research into the role of other protein pathways in the development of PTB. The purpose of this study was to investigate, using a previously described biomarker discovery approach, a subset of circulating proteins and their association with PTB focusing on samples from early pregnancy. OBJECTIVES: The objectives of the study were as follows: (1) to perform a large-scale biomarker discovery, utilizing an innovative platform to identify proteins associated with preterm birth in plasma taken between 10 and 15 weeks' gestation and, (2) to determine which protein pathways are most strongly associated with preterm birth. To address these aims, we measured 1129 proteins in a plasma sample from early pregnancy using a multiplexed aptamer-based proteomic technology developed in Colorado by SomaLogic. STUDY DESIGN: Using a nested case-control approach, we measured proteins at a single time point in early pregnancy in 41 women who subsequently delivered preterm and 88 women who had term uncomplicated deliveries. We measured 1129 proteins using a multiplexed aptamer-based proteomic technology developed by SomaLogic. Logistic regressions and random forests were used to compare protein levels. RESULTS: The complement factors B and H and the coagulation factors IX and IX ab were the highest-ranking proteins distinguishing cases of preterm birth from term controls. The top 3 pathways associated with preterm birth were the complement cascade, the immune system, and the clotting cascade. CONCLUSION: Using a discovery approach, these data provide further confirmation that there is an association of immune- and coagulation-related events in early pregnancy with preterm birth. Thus, plasma protein profiles at 10-15 weeks of gestation are related to the development of preterm birth later in pregnancy.