Demonstration of type II latency in T lymphocytes of Epstein–Barr Virus‐associated hemophagocytic lymphohistiocytosis

Epstein–Barr virus (EBV) is the most common infectious cause of non‐genetic hemophagocytic lymphohistiocytosis (HLH). To investigate EBV‐infected lymphocytes and immune dysfunction in EBV‐associated HLH, blood samples from a 6‐year‐old boy were longitudinally analyzed using molecular techniques. EBV‐positive lymphocytes were detected as CD5 + , CD8 + , and/or HLA DR + lymphocytes on Day 25 of the disease, mostly disappearing thereafter. CD8 + cells specific for lytic antigen BRLF1 were detected, but cells specific for latent antigens EBNA3 and LMP2 were not. EBV genes EBNA1, LMP1, LMP2, EBER1, BARTs were detected, suggesting a latency type II gene expression pattern in this case. Pediatr Blood Cancer 2013;60:326–328. © 2012 Wiley Periodicals, Inc.