<prompt> Atypical lymphocytes in infectious mononucleosis are made up of: E. REPEAT 2006CD4 T cellsCD8 T cellsPlasma cellsNK cells  <response>: Ref: Harrisons 18th edition, Page 1467 and Robbins Pathologic Basis of Disease, 8th edition. Pages 355-7Explanation:The atypical lymphocytes seen in the blood, so characteristic of this disease, are mainly Ell V-specific CD8 cytotoxic T cells, but also include CD 16 NK cells. Ref: RobbinsThe atypical lymphocytes seen in infectious mononucleosis are T lymphocytes of CD8 subset, with a smaller contribution from CD4 cells. Ref: Encyclopedia of Molecular Mechanisms of Disease: Volume 3, Page 1346INFECTIOUS MONONUCLEOSISIt is caused by EBV.Clinical Featureso Fever.o Cervical nodeso Hepatosplenomegalvo Rash.Lymphocytosis with atypical lymphocytes CD 8.The peripheral blood shows absolute lymphocytosis.More than 60 of white blood cells are lymphocytes.Atypical lymphocytes account for 5 - 80 of lymphocytes.o 12 to 16 mm in diametero Abundant cytoplasmo Multiple clear vacuolationso Oval, indented, or folded nucleuso Scattered cytoplasmic azurophilic granuleso Express CDS. Abnormal LFT.CNS complications: o Meningitis.o Encephalitiso Cranial nerve palsieso GBS.o Transverse myelitis.Other complications:o Splenic rupture.o Upper airway obstructiono Bacterial superinfection. 