Lisa Hiskey, DO

Accurate, reliable, and rapid diagnostic tests remain limited for many infectious agents. Up to 40% of children undergoing hematopoietic cell transplant develop bloodstream infections post-transplant, which can lead to increased morbidity and mortality. Gram stains and blood cultures provide useful treatment information but take time. By improving available diagnostics for bacterial infections, clinicians can expedite treatment with appropriate antibiotics and reduce unnecessary antibiotic use.  

We are also exploring how to improve our diagnostic tests for human herpesvirus 6 (HHV-6). HHV-6 is a double-stranded DNA virus that can cause encephalitis in immunocompromised children. A few treatment options are available, but early detection is key. To optimize diagnostics, we are involved in a project which aims to determine how HHV-6 is best diagnosed in whole blood samples or plasma. 

Systemic viruses can have lifelong impacts for our patients, but available treatments for many of these microbes are limited. For example, adenovirus, which can cause disseminated infections post-transplant, has one available antiviral. Human polyomavirus 1 (BK virus) causes hemorrhagic cystitis and nephritis, both clinically significant illnesses. However, no antivirals have been approved to treat it. Clinicians can only offer supportive care for a virus that can sometimes impact health for months on end. Lastly, Epstein-Barr Virus (EBV), which can lead to secondary cancers in post-transplant patients, is without antiviral options; certain monoclonal antibodies can be used but those destroy B cells and can usher in another set of health issues for our patients. My work is focused on expanding and optimizing treatment options for these conditions. 

Cytomegalovirus (CMV) is the most common systemic virus impacting children after undergoing hematopoietic stem cell transplant. This virus can cause retinitis, pneumonitis and gastroenteritis — conditions which complicate treatment and recovery. Compared to other systemic infectious agents, we have more diagnostics and treatments available for CMV, but we must continue to optimize our preventative measures. We have introduced the antiviral letermovir as a preventive measure in our post-HCT patients who have a history of pre-transplant CMV infection. Future endeavors are focused on the evaluation of our post-transplant patients’ CMV-specific immune-reconstitution. These data will help us determine which patients require ongoing prophylaxis, monitoring or even treatment for CMV. 

Infectious disease prevention and education go hand in hand. Educating care teams about infectious diseases concerns post-transplant increases awareness, allowing for better patient care. In association with the Pediatric Infectious Diseases Program at University of Tennessee Health Sciences Center and St. Jude Children’s Research Hospital, I am working to create a transplant curriculum for the pediatric infectious diseases fellows. I also lecture and provide educational insights to the hematology/oncology fellows, focusing on infection education in immunocompromised children, such as those who have undergone transplantation.