EBV Infection in XLP1 Manifested Solely by BehavioralAggression and Effective Treatment Using Rituximab

Patients with X-linked lymphoproliferative disease 1 (XLP1) are exquisitely susceptible to Epstein-Barr virus (EBV), with the firstEBV infection often resulting in rapid death. In a manner not previously described, a 5-year-old patient with XLP1 presented solelywith behavioral aggression, with no laboratory evidence of organ dysfunction or inflammation. Although EBV-IgM was negative,PCR confirmed the presence of EBV in both the blood and cerebrospinal fluid. MRI of the brain showed frontal lobe foci. Afterfailure to eradicate his viremia with ganciclovir, rituximab was administered. EBV was eradicated from the blood after the secondrituximab infusion and remained absent for 5 months, at which time he underwent hematopoietic stem cell transplant. AlthoughEBV classically produces fulminant infection in patients with XLP1, this case demonstrates that EBV infection may be initiallysubtle. Acute change in behavior should prompt evaluation. This case also demonstrates the possible effectiveness of rituximab inthe treatment of acute EBV infection.