CD40LG and Epstein-Barr virus infection: On the other hand, IPAH patients with negative results of the EBV DNA test as well as all healthy controls had the anti-EBV status suggesting a past EBV infection (anti-VCA IgM negative; anti-VCA IgG positive; anti-EBNA-1 IgG positive; anti-EA IgM, IgG, and IgA negative; anti-VCA IgA negative; and anti-EBNA-1 IgA and IgM negative).