A 20-year-old female presents with a 5-day history of fatigue, lowgrade fever, and sore throat. Physical examination reveals bilateral enlarged, tender cervical lymph nodes, an exudative tonsillitis, and an enlarged spleen. A complete blood cell count reveals the hemoglobin and platelet counts to be within normal limits. The total white blood cell count is increased to 9200 cells per uL. Examination of the peripheral blood reveals the presence of atypical mononuclear cells with abundant cytoplasm. These cells have peripheral condensation of the cytoplasm, which gives them a "ballerina ski" appearance. Which one of the listed findings is most likely to be present in this individual?
Infectious mononucleosis is a benign lymphoproliferative disorder caused by infection with the Epstein-Barr virus (EBV). It typically occurs in young adults and presents with systemic symptoms, lymphadenopathy, and pharyngitis. Hepatosplenomegaly may be present. Peripheral blood shows an absolute lymphocytosis, and many lymphocytes are atypical with irregular nuclei and abundant basophilic vacuolated cytoplasm. These represent CD8+ T killer cells induced by EBV-transformed B lymphocytes. These atypical lymphocytes are usually adequate for diagnosis, along with a positive heterophil or monospot test (increased sheep red cell agglutinin). Administration of ampicillin for a mistaken diagnosis of streptococcal pharyngitis results in a rash in many patients. Reference: Robbins & Cotran Pathologic Basis of Disease, 9edition.
Aggregates of mononuclear cells with cytoplasmic Birbeck granules in the liver
Elevated levels of d-ALA in the urine
Group A streptococcus on culture of the tonsillar exudate
Heterophil antibodies in the serum
miscellaneous