Answer by
darla (94)
High lymphocytes can be cused by a number of things. One such thing is a blood transfusion. There are other possible reasons as well, ranging from common sicknesses such as the flu or chicken pox. But also more serious and rare sicknesses like tuberculosis, mumps, rubella, varicella, whooping cough. However high levels of lymphocytes can also be caused by leukemia.