Research News from the Department of Pediatrics

October 13, 2009

Allergy-immunology fellow research projects published

Ownby DR, Partridge ME, Wegienka GR et al. Influence of dose and frequency of antigen injection on IgE development in young children: a comparison of fire ant stings and tetanus immunizations. Ann Allergy Asthma Immunol 2009;103:337.

Perry LM, Ownby DR, Wegienka GR et al. Differences in total and allergen specific IgE during pregnancy compared with 1 month and 1 year post partum. Ann Allergy Asthma Immunol 2009;103:342.

September 30, 2009

Tracking Ambulatory Blood Pressure

Li Z, Snieder H, Harshfield GA, Treiber FA, Wang X. A 15-year longitudinal study on ambulatory blood pressure tracking from childhood to early adulthood. Hypertens Res. 2009; 32:404-10.

This study evaluates the tracking stability of office blood pressure (BP), ambulatory BP (ABP), BP variability (BPV) and nocturnal BP drops (dipping) from childhood to early adulthood, and their dependence on ethnicity, gender and family history (FH) of essential hypertension (EH). Generalized estimating equations (GEEs) were used to estimate tracking coefficients for 295 European Americans and 252 African Americans, with a maximum of 12 measurements over a 15-year period. Office BP and ABP had moderate-to-relatively high tracking coefficients (r= 0.30-0.59; P =0.001). Twenty-four hour readings tracked better than office readings for diastolic BP (DBP; 0.57 vs. 0.46, P=1.72 x 10(-6)) and pulse pressure (PP) (0.59 vs. 0.51, P=2.70 x 10(-4)), and equally well for systolic BP (SBP; 0.55 vs. 0.54, P=0.805). Daytime readings tracked better than their night-time counterparts for SBP (0.50 vs. 0.37, P=7.62 x 10(-13)), DBP (0.49 vs. 0.30, P=7.98 x 10(-32)) and PP (0.55 vs. 0.50, P=0.0061). All BPV (r=0.08-0.28; P=0.001) and dipping measures (r=0.07-0.12; odds ratio, 1.60-1.73; P=0.001) had low tracking coefficients. Males had significantly higher tracking stability for office SBP, DBP and ambulatory PP than females (P < 0.01). Subjects with a positive FH of EH had significantly higher tracking stability for daytime and night-time DBP and dipping indexed by continuous variables than those with a negative FH (P < 0.001). No significant ethnic differences were observed. The high tracking stability of 24-h ABP highlights the importance of using ambulatory BP monitoring in both research and clinical settings.

September 11, 2009

Allergy-Immunology Fellows Prepare for Presentations at Meetings

Augusta, Ga. - Fellows in the allergy-immunology program are hard at work preparing for presentations at upcoming regional, national, and international meetings.

Dr. Crocker

Dr. Deidre Crocker is a first-year fellow who was a staff epidemiologist at the Centers for Disease Control (CDC) in Atlanta before beginning training in July, 2009. While at the CDC, she investigated a cluster of asthma deaths in Augusta. Her paper has been accepted for oral presenation at the XXI World Allergy Congress in Buenos Aires, December 6-10, 2009.

An Investigation of a Cluster of Pediatric Asthma Deaths—Augusta, Georgia, USA 2006

In January 2007, the Georgia Division of Public Health and Centers for Disease Control and Prevention conducted an investigation of a cluster of four pediatric asthma deaths in Augusta, GA occurring from September 2006-November 2006. The investigation consisted of an assessment of available data to confirm evidence of a cluster, case evaluation to verify the diagnosis and locate any additional cases, and a descriptive case study using information from medical chart abstractions and interviews. Four pediatric asthma deaths within a three-month period is a substantial increase over the previous mean baseline of 0.4 deaths per year during the years 1999-2005. There were multiple risk factors contributing to the significant increase in asthma mortality. Preventable risk factors included underuse of inhaled corticosteroids, overuse of beta-agonists, lack of asthma action plans, and exposure to asthma triggers. Recommendations for preventing future asthma deaths included emphasizing appropriate use of controller and rescue medications, frequent monitoring of asthma symptoms, recognizing and avoiding asthma triggers, and regular use of asthma action plans.

Dr. Krishnan

Dr. Karthik Krishnan is a second-year fellow who was a medical student at MCG, did his pediatric residency training at MCG, and who was a faculty member working as a hospitalist at MCG prior to beginning fellowship training in July, 2008. Karthik's paper has been accepted for oral presentation at the annual meeting of the American College of Allergy, Asthma, and Immunology. Moreover, it has won a prestigious von Pirquet award, which will be presented at the meeting. He will also present at the Southeastern Allergy, Asthma, and Immunology Society annual meeting.

Endothelin receptor A activity contributes to increased T-cells in the renal cortex in angiotensin II-dependent hypertension

Increasing evidence indicates the etiology of hypertension includes an immune mediated inflammatory process. T cells and endothelin contribute to the mechanism of hypertension; however, the exact interrelationships of these factors have not been established. The aim of our study was to determine whether there is an increase in renal T-cell numbers in angiotensin II (AngII)-dependent hypertension and if this increase is mediated through the endothelin pathway. Results support the hypothesis that AngII-dependent hypertension increases renal cortical T-cell numbers. This increase appears to be mediated through ETA receptor activation. Understanding the specific interactions between T-cells and endothelin in the kidney may facilitate development of novel therapeutic strategies for treating hypertension and preventing end organ damage.
Dr. Potter

Dr. Lance Potter is a first-year fellow who has been a Navy pediatrician. The US Navy has sent him for fellowship training at MCG. Dr. Potter's paper has been accepted for presentation at the annual meeting of the American College of Allergy, Asthma, and Immunology.

A Case of NEMO

A 5 year old male child was diagnosed with NEMO immunodeficiency syndrome. Mutations of the nuclear factor kappa beta essential modulator gene are inherited in an X-linked manner. Mutations are defined based on function of the regulator gene and may be hypermorphic, hypomorphic or amorphic. This patient has a hypomorphic mutation in the NEMO regulatory gene found after an exhaustive preliminary immune deficiency evaluation was normal. Recent studies report patients with similar mutations who have ectodermal dysplasia and evidence of mycobacterial infection. Accordingly, once the diagnosis was known, the patient was begun on prophylactic dosing of azithromycin in addition to Septra. This patient does not have ectodermal dysplasia or mycobacterial infection currently. It is unknown if he will develop such an infection in the future. This presentation emphasizes the need to consider rare immunodeficiency disorders, especially in male children with a normal preliminary evaluation.


Revised October 13, 2009 .  Please send comments, suggestions or questions about this page to Bill Dolen, bdolen@mcg.edu .