sbryant6Atypical lymphocytes are CD8+ T cells, not CD4+. Remember that.+17
mangotangoI remember this because Infectious Mononucleosis is caused by a virus (mostly EBV, sometimes CMV) and MHC Class I functions to present endogenous antigens (e.g. viral or cytosolic proteins) to CD8+ T cells. In comparison, MHC Class II is more involved with presenting exogenous antigens (e.g. bacterial proteins) to CD4+ T cells. // FA 2019, pg 100+3
amyI get the atypical T cell idea, but can someone help me understand why monocyte is not elevated in mononucleosis????
BTW, there are both heterophil positive(EBV) AND heterophil negative(CMV) mononucleosis, so patient can have - monospot test and still have mononucleosis...+
drdoom@amy mononucleosis ≠ monocytes. Mono-nucleosis refers to the increase of mono-nuclear cells (lymphocytes) in the blood, as opposed to polymorpho-nuclear or “segmented” white blood cells like neutrophils, basophils, or eosinophils—which all have their nuclei divided into 2 or more “lobes” (multilobar cells). “Mono-nucleosis” just refers to an increase in the blood of those cells with a “single, unlobulated/unsegmented” nucleus = lymphocytes.+1
submitted by ∗pparalpha(93)
EBV (HHV-4) infects B cell through CD21.
Atypical lymphocytes on peripheral blood smear (not infected B cells, but reactive cytotoxic T cells).
"Mononucleosis": + monospot test (antibodies detected by agglutination of sheep or horse RBCs)