Dr. Bettina Ault
Associate Professor of Pediatrics

Dr. Ault completed her fellowship at the UTHSC in 1989 and continued her laboratory research training as an Instructor in Pediatrics at Washington University in St. Louis. In Dr. Harvey Colten's laboratory she was the first to delineate the molecular basis for a deficiency of factor H in a patient with collagen type III glomerulopathy. Factor H is the major regulatory protein for the alternate complement pathway. In 1997 she returned to Memphis to join the division of pediatric nephrology.

Dr. Ault has focused her research on the hemolytic-uremic syndrome (HUS), which consists of severe anemia, thrombocytopenia (low platelets), and kidney failure. In this country, the most common type of HUS is that associated with infection by a toxin-producing strain of E. coli, O157:H7. Outbreaks of infection with this bacterium have been associated with contaminated meat, and a number of children who have contracted disease from this strain of E. coli have developed HUS. A few have even died from this disease. The hemolytic-uremic syndrome may also result from infection with pneumococcus (a bacterium that causes pneumonia and meningitis), or it may follow bone marrow transplantation. There are also cases of HUS which are idiopathic (not associated with any known infection). Many of these cases appear to have a genetic cause. One gene associated with idiopathic HUS is the gene for factor H, a gene of the complement system (a group of blood proteins which protect the body from infection). Dr. Ault has been studying the factor H gene of several individuals with idiopathic HUS to see if mutations in this gene could be responsible for their disease.

The angiotensin converting enzyme (ACE) gene regulates levels of angiotensin II, a hormone involved in control of blood pressure. Previous studies have suggested that individuals who inherit a certain form of the ACE gene are more likely to develop kidney failure, if they have a variety of kidney diseases. Dr. Ault’s laboratory has screened more than 70 pediatric patients with IgA nephropathy, the most common form of chronic inflammation of the kidney in this country. She has found that pediatric patients with IgA nephropathy who have a particular mutation of the ACE gene progress more quickly to kidney failure. Dr. Ault’s work in understanding the role of factor H in the development of HUS and the ACE gene in the development of IgA nephropathy will have an important impact on predicting both the development and severity of these diseases in children and will likely lead to better therapies for these diseases, as these findings are translated into the clinical arena.

Dr. Ault's clinical research is related to pediatric transplantation. She published one of the initial case series on the use of Thymoglobulin for induction in pediatric allograt recipients.

Dr. Ault is a member of the UTHSC Institutional Review Board and the College of Medicine Radiation Safety Committe.