Hello, my daughter was found to have a high percentage of lymphocytes upon a routine full blood count test, at the age of 10.5 years. Our paediatrician asked for anti-EBV IgM&IgG antibodies. The results were IgG >400 U/ml, IgM negative. This high titre more or less remained upon all subsequent testing during the next 1.5 years (i.e. until now), the most recent lymphocyte count being 53,8% (3,18x1000/μl), and also she presents a high B12 level (984 pg/ml, normal values 211-911). Is this high anti-EBV titre common, and how long is it expected to last? Could the high lymphocyte percentage be related to the EBV infection and for how long is it expected to last? Thank you, Asimina Mataftsi, Associate Professor in Ophthalmology, Thessaloniki, Greece.