Saliva Polymerase Chain Reaction Assay for Detection and Follow-up of Herpesvirus Reactivation in Patients With Drug Reaction With Eosinophilia and Systemic Symptoms (DRESS)

IMPORTANCE: Reactivations of human herpesviruses (HHVs) contribute to the development of drug reaction with eosinophilia and systemic symptoms (DRESS). Diagnosis of HHV reactivation is conventionally based on quantitative real-time polymerase chain reaction (PCR) analysis of blood samples, but these viruses are present in the oropharynx and are shed in saliva. OBJECTIVE: To evaluate the use of a saliva PCR assay for demonstrating HHV shedding in patients with DRESS. DESIGN: Shedding of HHV in saliva was prospectively studied in patients with DRESS. Reactivations of HHV, including HHV-6, HHV-7, cytomegalovirus (CMV), and Epstein-Barr virus (EBV), were studied by performing quantitative real-time PCR analysis of blood samples obtained at admission) and serial samples of saliva obtained within the first 2 weeks of DRESS; saliva samples from controls were compared. PARTICIPANTS: The study included 5 patients who met definite criteria for DRESS and 15 controls (5 immunosuppressed patients and 10 healthy adults). MAIN OUTCOME MEASURES: DNA viral loads of HHV, including HHV-6, HHV-7, CMV, and EBV as measured with real-time PCR in blood and saliva samples from patients with DRESS and saliva samples from immunosuppressed and healthy controls. RESULTS: The PCR assay demonstrated shedding of HHV-7, EBV, HHV-6, and CMV, listed by order of magnitude. The DNA viral loads in blood and saliva samples, also measured with real-time PCR, were found to be close. In 1 patient, reactivations in saliva preceded clinical manifestations of CMV disease. Significant production of HHV-7 and EBV was demonstrated in saliva samples from the controls, but neither HHV-6 nor CMV were detected. CONCLUSIONS AND RELEVANCE: The saliva PCR assay is a useful tool for demonstration and follow-up of HHV reactivation. The interpretation of HHV viral loads in saliva differs according to HHV type.