Nepal Cancer Hospital & Research Center, Nepal
Anjali Pandit is a Pediatric Hematology-Oncology & Bone Marrow Transplant Specialist at Nepal Cancer Hospital & Research Center. Her research interests include stem cell transplants, pediatric hematology and cancer.
BACKGROUND: Patients who undergo allo-HSCT are more prone to viral infections or reactivations. HHV-6 infection in post allo-HSCT patients has a varied presentation which include fever, gastrointestinal, respiratory and central nervous system symptoms and myelosuppression. Classically described rash like exanthema subitum may or may not be present. We aimed to find out the prevalence and clinical manifestations of the HHV-6 reactivation and/or disease in pediatric allo-HSCT patients.
METHODS: Between January 2017 and June 2018, 54 patients (male-33, female 21) underwent HSCT at our center. Demographic and transplant related details of patients were captured from hospital database. HHV-6 DNA viral load was tested if patient had relevant signs/symptoms. The HHV-6 DNAemia was measured with whole-blood and/or CSF real-time quantitative polymerase chain reaction (PCR) technique.
A total of 54 consecutive patients underwent allogeneic HSCT during the study period. Donors were HLA-matched related-30, haploidentical-17 and matched unrelated-7. The source of stem cells was peripheral blood in 50 patients and bone marrow in 4 patients. Three patients (5.5%) had HHV-6 reactivation. One patient had persistent fever and pancytopenia from D+20. Second patient presented with generalized tonic clonic seizure on D+60. Third patient had persistent fever with maculopapular rash over extremities and face from D+30. Median time of detection was day 30 (range, 15-60 days). Two patient had HHV 6 viremia detected in blood and one in CSF. Out of these 1 patient had coexistent cytomegalovirus (CMV) reactivation. All these patients were treated with intravenous (IV) gancyclovir (GCV) at the dose of 5 mg/kg every 12 hours. Two patients showed resolution of symptoms in 3 to 4 days. HHV-6 became undetectable in 1 week after initiation of treatment. The patient who had coexisting CMV and HHV-6 developed severe aplastic bone marrow post IV GCV which required discontinuation of treatment and the patient eventually died.
CONCLUSION: Our findings point out that HHV 6 infection is rare but dreaded complication in post allo-HSCT patients. Clinicians need to have high index of suspicion as the presentation can be varied. Early diagnosis and treatment can lead to better outcomes in this patient population.