Lymphocytosis with atypical lymphocytes are seen in infection with -

Ans. is 'c' i.e., EBV o In IMN, there is predominantly lymphocytosis with a presence of 20% or more atypical lymphocytes, o These atypical lymphocytes are activated T-lymphocytes which have round or irregularly shaped nuclei, with abundant flowing cytoplasm that characteristically has a dark-staining periphery. o Burkitt's lymphoma is caused by EBV. Epstein - Barr Virus (EBV) o Belongs to Herpes viruses family. o Infection is most common in early childhood, with a second peak during late adolescence. o Infectious mononucleosis (IM) is usually a disease of young adults. o EBV is transmitted by saliva (oral secretions) of an infected person. o Intimate oral contact, as in kissing is the predominant mode of transmission - causes kissing disease. o The virus enters the pharyngeal epithelial cells and B cells through (CR 2/or CD21) receptors, o Memory B Cells are the reservoir of FBI. Clinical Manifestations: o Most primary infections are asymptomatic o Causes an acute self-limited illness - Infectious mononucleosis (Glandular fever) o Incubation period - 4-8 weeks o Age groups - young adults o The most common symptom of IMN is sore throat o Most common sign is lymphadenopathy o Most common complication - meningitis/encephalitis EBV associated malignancies * Burkitt's lyrijphoma # Nasopharyngeal carcinoma * Hodgkin's disease (mixed cellularity type) # Tonsillar Carcinoma * T Cell lymphoma # Thymoma * Gastric carcinoma # CNS lymphoma in AIDS and transplant recipient * Angiocentric nasal NK/T cell immunoproliferative lesions # Leiomyosarcoma * Angio-immunoblastic lymphadenopathy Other associated non-malignant conditions Oral hairy leukoplakia in AIDS patients Chronic fatigue syndrome X-linked lymphoproliferative syndrome (Duncan's disease)