Sections View Full Chapter Figures Tables Videos Full Chapter Figures Tables Videos Supplementary Content ++ DEFINITION ++ Infectious mononucleosis is defined as any blood lymphocytosis induced in response to an infectious agent. Usually greater than 50 percent of the circulating white cells are lymphocytes, more than 10 percent of which have the morphology of reactive lymphocytes (see Fig. 53–1). Table 53–1 lists the etiologic agents that produce mononucleosis. Pharyngeal form: — Sore throat preceded by 1 to 2 weeks of lethargy. — Epstein-Barr virus (EBV) generally is the cause. Glandular form without pharyngitis: — Lymph node enlargement. — Usually caused by agents other than EBV, e.g., Toxoplasma gondii. Typhoidal form: — Lethargy with fever or diarrhea without pharyngitis, usually as a consequence of cytomegalovirus (CMV). ++ FIGURE 53–1 A–D. Blood films from patients with EBV-induced mononucleosis. These reactive lymphocytes exhibit the characteristic changes seen in patients with infectious mononucleosis: large lymphocytes with abundant cytoplasm. The cytoplasmic margin often spreads around (is indented by) neighboring red cells and the margin may take on a densely basophilic coloration. This type of reactive T lymphocyte may be seen a variety of diseases and is not specific changes but are characteristic. (Reproduced with permission from Lichtman's Atlas of Hematology, www.accessmedicine.com.) (Source: Williams Hematology, 8th ed, Chap. 84, Fig. 84–1, p. 1202.) Graphic Jump LocationView Full Size|Favorite Figure|Download Slide (.ppt) ++Table Graphic Jump LocationTABLE 53–1ETIOLOGIC AGENTS ASSOCIATED WITH MONONUCLEOSIS SYNDROMEView Table|Favorite Table|Download (.pdf) TABLE 53–1 ETIOLOGIC AGENTS ASSOCIATED WITH MONONUCLEOSIS SYNDROME Epstein-Barr virus Hepatitis A Cytomegalovirus Adenovirus Human immunodeficiency virus Toxoplasma gondii Human herpes virus-6 Bartonella henselae Metapneumovirus Brucella abortus Rubella Source: Williams Hematology, 8th ed, Chap. 84, Table 84–1, p. 1200. ++ ETIOLOGY AND PATHOGENESIS ++ Caused by two members of the herpes virus family: EBV or CMV. After the early phase of fever, which lasts for 3 to 7 days, laboratory abnormalities include a blood lymphocyte proportion greater than 50 percent, often with greater than 10 percent reactive lymphocytes. Table 53–2 lists other complications of EBV and CMV mononucleosis. ++Table Graphic Jump LocationTABLE 53–2COMPLICATIONS IN PATIENTS WITH EBV OR CMV MONONUCLEOSISView Table|Favorite Table|Download (.pdf) TABLE 53–2 COMPLICATIONS IN PATIENTS WITH EBV OR CMV MONONUCLEOSIS EBV CMV Hemolytic anemia ++ + Thrombocytopenia + + Aplastic anemia + - Splenic rupture + - Jaundice (> age 25 years) ++ ++ Guillain-Barré* + ++ Encephalitis* ++ +/- Pneumonitis* +/- + Myocarditis* + - B-cell lymphoma + - Agammaglobulinemia + - *Can occur without mononucleosis syndrome. ++, common; +, infrequent; +/-, uncommon; -, not observed.Source: Williams Hematology, 8th ed, Chap. 84, Table 84–2, p. 1200. ++ FEATURES OF MONONUCLEOSIS CAUSED BY EACH ETIOLOGIC AGENT ++ Table 53–3 list the signs and symptoms associated with EBV and CMV mononucleosis. Target cell for EBV mononucleosis is the B lymphocyte. Target cell for CMV mononucleosis is the macrophage.... GET ACCESS TO THIS RESOURCE Sign In Username Error: Please enter User Name Password Error: Please enter Password Forgot Username? Forgot Password? Sign in via OpenAthens Sign in via Shibboleth Get Free Access Through Your Institution Contact your institution's library to ask if they subscribe to McGraw-Hill Medical Products. What is MyAccess? Create a FREE MyAccess profile to: Use this site remotely Bookmark your favorite content Track your self-assessment progress and more!