Pediatric Divisions

Pediatric Pulmonology & Sleep Medicine


Pediatric Faculty

Dr. Hector Gutierrez
Director | Professor

Dr. Guillermo Beltran Ale
Assistant Professor

Dr. Ammar Saadoon Alishlash
Assistant Professor

Dr. Miles Fowler
Assistant Professor

Dr. Jennifer Guimbellot
Associate Professor

Dr. Tom Harris
Associate Professor

Dr. Wyn Hoover

Claire Lenker, LICSW
Associate Professor

Dr. Isabel Lowell

Dr. Mary Halsey Maddox
Associate Professor

Dr. Terri Magruder
Associate Professor

Dr. Anis Nourani
Assistant Professor

Dr. Gabriela Oates
Assistant Professor

Dr. Spencer Poore
Assistant Professor

Dr. Ryne Simpson
Assistant Professor

Valerie Tarn, MS, RD, LD
Associate Professor

Dr. Brad Troxler
Associate Professor

Dr. Brett Turner
Assistant Professor

Featured Research

The UAB Division of Pediatric Pulmonology and Sleep Medicine maintains a broad research portfolio that complements the clinical programs, with focus areas in aerodigestive disorders, asthma, bronchopulmonary dysplasia (BPD), cystic fibrosis (CF), neuromuscular disorders (NMD), sleep medicine and sickle cell disease (SCD).

Aerodigestive Disorders

Founded in 2012 by Tom Harris, M.D., the Children's of Alabama Aerodigestive Program was one of the first in the region. Now it is one of the largest in the country with three pediatric pulmonologists, three gastroenterology physicians, two ENT physicians, three speech and swallow therapists, two nurse coordinators, one nutritionist and one social worker. The goal of the Aerodigestive Program is to provide comprehensive multidisciplinary care for children with feeding and respiratory issues. Guillermo Beltran Ale, M.D., joined the program in 2020, and Ryne Simpson, M.D., joined in 2021, bringing global expertise to the program. Both are experts in airway disease management and intervention. Current clinical research projects include investigating the optimal medical management of dysphagia, surgical correction of laryngeal defects, etiology and clinical improvement of severe dysphagia with no safe liquid consistency, and quantifying the prevalence of eosinophilic esophagitis in children with chronic cough. Over the last year they have started a quarterly Genetics-Aerodigestive Combined clinic to expedite diagnosis of genetic conditions in patients with dysphagia, a “no safe swallow protocol” in close collaboration with the Speech Language Department with the goal of promoting shared decision-making in management of severe dysphagia and a research collaboration with the Children’s Hospital of Colorado Aerodigestive group with focus in standardizing scoring for pediatric dysphagia.


The Asthma Program is led by Terri Magruder, M.D., MPH, and Isabel Virella-Lowell, M.D. It oversees the care of over 3,000 patients, many of them with severe or difficult to treat asthma. 
Dr. Magruder, in collaboration with UAB Division of Pulmonary and Critical Care Medicine, is an investigator on the recently funded NIH P42 Grant Impact of Airborne Heavy Metals on Lung Disease and the Environment. This project focuses on investigating asthma in children exposed to heavy metals in north Birmingham. She is also collaborating with UAB School of Public Health faculty to investigate the health care utilization patterns of pediatric Alabama Medicaid recipients who have asthma. 

Dr. Magruder works in collaboration with Division of Pediatric Hospital Medicine to lead the inpatient asthma clinical pathway at Children's of Alabama. This quality improvement initiative is entering its 10th year and has shown sustained improvement in reducing asthma length of stay and improved care consistency for children requiring hospitalization. 

Dr. Lowell is the pediatric principal investigator for the American Lung Association's Airways Clinic Research Center (ACRC) at UAB. The ACRC is a network of 35 clinical research centers around the nation dedicated to asthma and chronic obstructive pulmonary disease (COPD) research. Dr. Lowell works with the other network members to help design and implement asthma clinical trials to advance our understanding and management of this prevalent airway disease. She is currently the principal investigator on an ACRC study looking at improving adherence to treatment in asthma utilizing telehealth care medication therapy management.

Drs. Lowell and Magruder have also helped design a comprehensive database to track the division's pediatric asthma patients. This database is used to track individual and collective patient outcomes, provide data for quality improvement projects and identify potential subjects for clinical research trials.

Bronchopulmonary Dysplasia

The Bronchopulmonary Dysplasia Program is led by Brett Turner, M.D., and Miles Fowler, M.D. The mission of this academic clinical initiative is to provide the highest quality evidence-based, interdisciplinary, family-centered care for infants and children with bronchopulmonary dysplasia (BPD) and other chronic lung diseases of infancy and improve their health and developmental outcomes. The program continues to grow and serves between 175 and 200 unique patients per year, referred locally from the neonatal intensive care units at UAB and Children’s of Alabama, along with community nurseries around the state. Most recently, the interdisciplinary team has expanded to include a speech and language pathologist with specialty in neonatal feeding and dysphagia, further optimizing the comprehensive care of these patients. Specific quality improvement initiatives aimed at improving transition success from the inpatient to outpatient settings and reducing nutritional failure are ongoing and focus on enhancing caregiver education surrounding the child's disease and their specific needs. Over the past year, enhanced collaboration with the NICU has led to consistent consultation for infants with chronic respiratory failure in the NICU with targeted strategies for weaning from long-term use of systemic steroids. Evaluation of infants’ long-term pulmonary outcomes in the program is achieved through a robust clinical database of more than 1,100 infants and over 4,500 individual clinical encounters.

Cystic Fibrosis

Jennifer Guimbellot, M.D., Ph.D., studies personalized medicine for CF. Her CFF and NIH K23-supported research involves individualized pharmacokinetic analysis and pharmacogenomics approaches to gain insights into tailoring modulator therapy to provide maximal therapeutic benefit for every CF patient. Her team has also developed multiple personalized models for predicting the effectiveness of CFTR modulators in CF patients and those with acquired CFTR dysfunction. Using cells from the nose, lower airway and sweat gland, her laboratory continues to develop minimally invasive, personalized models for individuals with pulmonary disease. She has support from the CFF, NIH and the Kaul Pediatric Research Institute to develop these models.

Hector Gutierrez, M.D., leads the CF Clinical Center. His research objectives are to implement and investigate quality improvement, outcomes measurement and management of clinical and non-clinical processes using CF as a model to improve the quality and value of clinical care, which ultimately results in greater survival. His current work involves training clinical CF teams in low and middle-income countries (LMICs) by transferring the know-how to become centers of care excellence. In addition, he is working on establishing a functional database to serve as a registry for CF in LMICs. Lastly, in collaboration with Dr. Gabriela Oates, he is working on implementing mobile health (mHealth) solutions for better patient self-management and patient-centered care. Grants from the CFF support his work.

Tom Harris, M.D., investigates novel targets for therapeutic intervention in CF. He currently focuses on microRNA (miRNA), which are small (~22 base pair) non-coding nucleotide sequences that destabilize messenger RNA transcripts and inhibit protein translation. Dr. Harris discovered that miR-145 impedes CFTR expression and response to CFTR directed therapeutics. miR-145 antagonists improve efficacy of CFTR modulators. With the miR-145 binding sequence on CFTR known, Dr. Harris is now pursuing the refined approach of utilizing antisense oligonucleotides (ASOs) to block the miR-145 target on F508del CFTR. He is now extending these investigations to additional genotypes and therapeutic approaches, including nonsense mutations for which no FDA-approved therapies are currently available. His work in CF-related miRNA recently has attracted support from the CFF and NIH to trial miRNA antagonists and miRNA target site blockers in CF animal models. Dr. Harris has also led several pharmaceutical trials of CFTR correction at UAB that have led to FDA approval in the pediatric population.

Isabel Lowell, M.D., is the pediatric director of the CF Therapeutics Development Network (TDN) and the Airways Clinical Research Center at UAB. She is a PI on a number of large multi-clinical trials in CF looking at new therapies, the expansion of highly effective modulator therapies and the simplification of CF respiratory care. She also is involved in smaller trials looking at adherence in asthma, self-efficacy in CF, infection control measures in CF and the relationship between oral disease and lung disease in CF. Dr. Lowell serves on the TDN protocol review board evaluating protocols submitted by pharma and independent investigators for implementation by the TDN centers. Dr. Lowell also serves as a coach for the TDN eQUIP Program, which is instrumental in educating the research teams at different centers in quality improvement processes.

Gabriela Oates, Ph.D., conducts research on the social determinants of health in cystic fibrosis (CF) and other chronic diseases. She integrates measures of the socioeconomic environment with clinical data for health services and outcomes research. Dr. Oates investigates the contribution of tobacco smoke exposure for CF disease progression and the effect of smoke exposure on clinical benefit from cystic fibrosis transmembrane conductance regulator (CFTR) modulators. She leads a CF-specific smoking cessation intervention project, Clinical Effort Against Smoke Exposure in CF (CEASE-CF), and the Alabama Youth Tobacco Prevention Program. She leads research on screening for and addressing food insecurity across CF centers in the US. She also leads studies on CF self-management and patient-centered care using mobile health (mHealth) tools. She is the site principal investigator of the Success with Therapies Research Consortium (STRC). Her work is supported by grants from the Cystic Fibrosis Foundation (CFF), the National Institutes of Health (NIH), the Kaul Pediatric Research Institute and the Alabama Department of Public Health.

T. Spencer Poore, M.D., MSCS, is an assistant professor who recently completed his fellowship and master’s degree at the University of Colorado. His main area of focus is clinical and translational research in CF. He focuses both of his clinical and basic science studies on fungal infections, aspergillus and pseudomonas co-infection, allergic bronchopulmonary aspergillosis, airway inflammation, thoracic imaging and disease modeling in tissue culture and animals. He is supported by the CFF and is a part of the NIH Loan Repayment Program from the National Heart, Lung, and Blood Institute (NHLBI). As a former chief resident of UAB, he is involved in the pediatrics residency program and a mentor for the UAB Pediatric Residency Program’s Research Academic Pathway.

Neuromuscular Disorders

Bradley Troxler, M.D., leads the Muscular Dystrophy Care Center and the CureSMA Care Center. These centers provide care to greater than 300 patients annually and provide the latest disease-modifying therapies, including gene therapy, risdiplam, nusinersen and exon-skipping therapy. The care centers have been active in advocacy to start newborn screening for spinal muscular atrophy (SMA) in Alabama in 2021–2022. Our center presented original research regarding quality of life and parental perception for patients with SMA who have experienced disease-modifying therapies at the annual CureSMA conference. This multi-specialty program offers exemplary care to these complex patients.

Sickle Cell Disease

Ammar Saadoon Alishlash, M.D., in collaboration with the UAB Division of Pediatric Hematology/Oncology, launched the Sickle Cell Pulmonary Program at Children’s of Alabama, which encompasses both basic research and clinical components. Dr. Alishlash’s lab investigates the pathogenesis and management of pulmonary complications of sickle cell disease (SCD). He uses SCD mouse model to investigate the mechanisms and therapeutic approaches of acute chest syndrome and SCD-associated pulmonary hypertension. The clinical component involves screening, developing protocols and treating SCD patients for pulmonary complications such as asthma, pulmonary hypertension, acute chest syndrome and sleep disordered breathing. Dr. Alishlash has a designated clinic for SCD patients with pulmonary disorders. He obtained funding from Obesity Health Disparities Research Center to investigate the effects of growth disturbances on pulmonary complications of children with SCD.

Pediatric Pulmonary Hypertension

Ammar Saadoon Alishlash, M.D., and Brett Turner, M.D., represent the pulmonary division in the Pediatric Pulmonary Hypertension Program at Children’s of Alabama. The program aims to improve the quality of care of children with pulmonary hypertension through a multidisciplinary approach, and it spans both inpatient and outpatient care of these children. In addition to the pulmonary division, the program currently includes the cardiology, neonatology, intensive care and hematology divisions.

Sleep Medicine

Bradley Troxler, M.D., is the medical director of the Children's of Alabama Sleep Disorder Center. This center annually performs around 2,000 pediatric sleep studies and provides clinical care to hundreds of patients each year. The Sleep Center faculty (Drs. Krizstina Harsanyi, Mary Halsey Maddox, Pedro Anis Nourani and Brad Troxler) are involved in several research endeavors, including NIH-funded research to ascertain the impact of sleep-disordered breathing in the development of chronic lung injury in premature infants with Dr. Ambalavanan (UAB Neonatology).

Mary Halsey Maddox, M.D., is working with the Department of Neurosurgery to evaluate the impact of sleep-disordered breathing on patients with Chiari malformations and spina bifida. In addition, the sleep faculty maintain a robust sleep medicine fellowship program, one of the few in the country housed in a department of pediatrics.

Other Research

Hector Gutierrez, M.D., is a co-investigator on Dr. Akila Subramaniam's (PI, UAB Division of Maternal-Fetal Medicine) NIH-funded study Childhood Pulmonary and Related Outcomes after Perinatal Exposure to Adjunctive Azithromycin Prophylaxis for Cesarean Delivery: C/SOAP Follow-up Study. The study hypothesizes that perinatal exposure to adjunctive azithromycin compared to standard cesarean prophylaxis alone is not associated with increased childhood pulmonary morbidity by age seven.

Gabriela Oates, Ph.D., conducts COVID-19 research funded by the National Institutes of Health. This includes the Alabama Community-Engagement Research Alliance Against COVID-19 (Alabama CEAL); the COVID-19 Testing Model among Vulnerable Populations, which implements a mobile community-based COVID-19 testing model and evaluates its impact for improved access, acceptance, uptake and follow-up to testing; and a project that aims to understand and address the social, ethical and behavioral factors surrounding COVID-19 testing in vulnerable urban and rural African American communities in Alabama. Dr. Oates also leads a project that links clinical data with area-level measures of social determinants of health to develop clinically useful risk stratification tools for chronic diseases.

Quality Improvement and Collaboratives

Hector Gutierrez, M.D., and Gabriela Oates, Ph.D., are co-PIs of the CFF funded CF Training Network: Latin America, a quality improvement initiative. It is aimed to train multidisciplinary CF teams in Latin America in three critical aspects: delivery of evidence-based CF care adapted to local healthcare settings, the establishment of a CF patient registry and data infrastructure to support such care, and engagement and education of the local CF patient community and stakeholders. The network is developing and implementing a structured, sustainable training program for CF centers in Latin America, starting with teams from Chile, Argentina and Mexico. Teams from other Latin American countries have started collaborative work with CFTN-LA member centers.

Dr. Gutierrez is the site PI for the CFF Cystic Fibrosis Learning Network (CFLN), a 30+ academic CF clinical center consortium. This initiative is a network-based learning health system. It aims to share purposes and outcomes, build community, facilitate the effective use of technology (with enhanced registries, commons, social media) and enriches a learning system combining science, quality improvement, outcomes and clinical research. During 2020, the consortium has worked extensively in developing an effective and impactful telemedicine care management process.

Wyn Hoover, M.D., served as a member of the CFF Online Education Advisory Board from 2017 to date. The board participates in authorship, editing and review of online learning modules and publishes content in collaboration with the University of Indiana Online Continuing Medical Education Portal. This program provides interdisciplinary education to CF providers and distributed to all Pediatric CFF Care Centers in the United States. The goal of this collaborative is to improve diagnostic accuracy of CF and promote evidence-based standardized care that is consistent with previously published CFF care guidelines. The program has published five modules targeting care providers across all medical disciplines that comprise the CFF Center Care Team. To date, more than 1,300 unique learners have completed modules.

Dr. Oates serves as the site PI, and Jennifer Guimbellot, M.D., Ph.D., as a co-investigator, of the CFF Success with Therapies Research Consortium, which tests interventions that enhance adherence to therapies and self-management of CF.

Dr. Oates is also the site PI of the CFF/Boston Children’s Hospital study, Feasibility of a Mobile Medication Plan Application in CF Patient Care.

2021 Publications

High-Impact Publications

Am J Physiol Lung Cell Mol Physiol. 2021. CFTR Function and Clinical Response to Modulators Parallel Nasal Epithelial Organoid Swelling. Anderson, JD, Liu, Z, Kersh, L, Guimbellot, JS.

N Engl J Med. 2021 Aug 26;385(9):815-825. Triple Therapy for Cystic Fibrosis Phe508del-Gating and -Residual Function Genotypes. Peter J Barry, Marcus A Mall, Antonio Álvarez, Carla Colombo, Karin M de Winter-de Groot, Isabelle Fajac, Kimberly A McBennett, Edward F McKone, Bonnie W Ramsey, Sivagurunathan Sutharsan, Jennifer L Taylor-Cousar, Elizabeth Tullis, Neil Ahluwalia, Lucy S Jun, Samuel M Moskowitz, Valentin Prieto-Centurion, Simon Tian, David Waltz , Fengjuan Xuan, Yaohua Zhang, Steven M Rowe, Deepika Polineni, VX18-445-104 Study Group.

Redox Biol. 2021 May 17;44:102009. Chlorine inhalation induces acute chest syndrome in humanized sickle cell mouse model and ameliorated by postexposure hemopexin. Ammar Saadoon Alishlash, Muna Sapkota, Israr Ahmad, Kelsey Maclin, Noor A Ahmed, Adam Molyvdas, Stephen Doran, Carolyn J Albert, Saurabh Aggarwal, David A Ford, Namasivayam Ambalavanan, Tamas Jilling, Sadis Matalon.

Extramural Awards, Recognition & Leadership Roles

Jennifer Guimbellot, M.D., Ph.D.

  • Dr. Guimbellot continues to serve as a member of the American Academy of Pediatrics Section on Clinical Pharmacology and Therapeutics (SOCPT) Executive Committee. Her three-year term began on November 1, 2019, and runs through 2022.
  • She is the 2021 workshop chair, W28—GMS-NT: Systems for Developing & Testing Therapeutic Strategies for the North American CF Conference.
  • She was on the 2021 North American CF Conference Abstract Review Committee.

Tom Harris, M.D.

  • Dr. Harris was invited to present his research at the 2021 North American CF Conference.
  • He was also invited to discuss his clinical expertise at the 2021 American Thoracic Society International Meeting.

Wyn Hoover, M.D.

  • Dr. Hoover serves on the CFF Advisory Board and CF Foundation Professional Education Committee.

Hector Gutierrez, M.D.

  • Dr. Gutierrez is the co-chair of the CFF Global Advisory Committee.
  • He is also a member of the CFF's task force for an International Minimal Dataset in CF Registries.
  • He is part of a research group examining the COVID-19 data in CF Registries, a combined effort of the CFF, The UK CF Trust and the European Cystic Fibrosis Society.

Gabriela Oates, Ph.D.

  • Dr. Oates was invited to chair the CFF Food Insecurity Committee and to serve as Advisor in the CFF Racial Justice Working Group.
  • She also serves on the CFF Mobile Health Working Group.
  • Dr. Oates was invited to chair the Social Determinants of Health workgroup of the NIH Rapid Acceleration of Diagnostics Underserved Populations (RADx-UP).
  • She also serves on the CF Foundation Racial Justice workgroup.

New Faculty 2021

Christopher Miles Fowler, M.D.
Assistant Professor

Thomas Spencer Poore, M.D.
Assistant Professor

Ryne Simpson, M.D.
Assistant Professor

Pediatric Pulmonology Fellowship Program

The UAB Pediatric Pulmonary Fellowship Program strives to train highly competent physician-educators and scientists. Our program provides the clinic knowledge necessary to diagnose and manage pediatric patients with acute and chronic respiratory disorders, including those that are life-threatening. Training in our program is complemented by our UAB Pediatric Pulmonary Center, which is one of five educational programs funded through a competitive federal grant through MCHB and HRSA that focuses on building leadership skills and promotes awareness of childhood respiratory disease. Clinical training is designed to develop the subspecialty resident’s competence in the clinical diagnosis, pathophysiology and medical treatment of respiratory disorders in pediatric patients within an interprofessional healthcare team. Clinical care is provided for children with a remarkable variety of lung diseases and breathing disorders, such as asthma, sleep-disordered breathing, apnea, central hypoventilation, cystic fibrosis, ciliopathies, bronchiectasis, interstitial lung diseases, bronchopulmonary dysplasia, bronchiolitis, pneumonia, chronic respiratory insufficiency, thoracic tumors and congenital lung anomalies. A significant portion of training consists of scholarly activity, during which fellows develop and hone skills necessary to be successful as effective subspecialists, advocates, clinical investigators and pulmonary scientists.

2021–2022 Fellows

Christopher Mertens, M.D.
First-Year Fellow
Residency: University of Tennessee, Memphis

Kyle Bliton, M.D.
Second-Year Fellow
Residency: University of Alabama at Birmingham

Mohini Gunnett, M.D.
Third-Year Fellow
Residency: Children’s Hospital at Ascension Sacred Heart

Program Directors

Wynton Hoover, M.D.
Program Director

Brett Turner, M.D.
Associate Program Director

Jennifer Guimbellot, M.D.
Assistant Program Director

Program Coordinator

Leslie Jones

Pediatric Sleep Medicine Fellowship Program

The UAB Sleep Medicine Fellowship Program offers fellows clinical teaching and formal didactics provided by faculty with diverse backgrounds and expertise, evenly spanning faculty with primary training in adult/pediatric pulmonary medicine and adult/pediatric neurology. The sleep disorder centers of UAB and Children’s of Alabama attract patients with a broad spectrum of sleep disorders from the state and beyond, offering fellows the opportunity of firsthand experience with common and rare disorders.

2021–2022 Fellows

Robert Murray, D.O.
First-Year Fellow
Residency: Methodist Hospital

Vignesh Nayak, M.D.
First-Year Fellow
Residency: University of Florida, Ascension Sacred Heart

Program Director

Krisztina Harsanyi-Jilling, M.D.

Program Coordinator

Leslie Jones

Pediatric Pulmonary Center

The UAB Division of Pediatric Pulmonology and Sleep Medicine is the proud to have one of six Pediatric Pulmonary Centers (PPCs) in the nation. The purpose of the PPC is to develop leaders who will improve the health of children with respiratory conditions through the provision of family-centered care. This is accomplished through interprofessional training, patient and family care and education, research, consultation, and the provision of continuing education and technical assistance. The project is in year two of a five-year cycle with funding from the Maternal and Child Health Bureau. The project provides interdisciplinary training to students in nursing, nutrition, social work, respiratory therapy, family leaders and medical fellows. In February 2021, the UAB PPC was selected by the national steering committee to present the projects’ first interprofessional case study to a national audience, led by first-year fellow Kyle Bliton.

2021–2022 Trainees

Abigail Cheek
Social Work Trainee

Kelvin Dam
Nutrition Trainee

Sarah Minor
Family Leader Trainee

Taylor Noah
Nursing Trainee

Angelia Stanton
Respiratory Therapy Trainee

Program Directors

Brad Troxler, M.D.

Claire V. Lenker, LICSW, CCM, PIP

Valerie Tarn, MS, RD
Training Director

Education Coordinator

Leslie Jones