A 23-year-old woman is brought to the emergency department due to one day of fever, vomiting, diarrhea, and muscle pains. The symptoms developed rapidly over the course of the day. The patient is confused and unable to answer questions. She has no known medical problems and takes no medications. She lives with her boyfriend. The patient's temperature is 39.1 C (102.4 F), blood pressure is 88/50 mm Hg, pulse is 120/min, and respirations are 20/min. A diffuse, erythematous, macular rash resembling a sunburn is noted on dermatologic examination; pelvic examination reveals a tampon in the vagina. Laboratory results are as follows: A pregnancy test is negative. Activation of which of the following cells is most likely primarily responsible for this patient's condition?

Question

A 23-year-old woman is brought to the emergency department due to one day of fever, vomiting, diarrhea, and muscle pains.  The symptoms developed rapidly over the course of the day.  The patient is confused and unable to answer questions.  She has no known medical problems and takes no medications.  She lives with her boyfriend.  The patient's temperature is 39.1 C (102.4 F), blood pressure is 88/50 mm Hg, pulse is 120/min, and respirations are 20/min.  A diffuse, erythematous, macular rash resembling a sunburn is noted on dermatologic examination; pelvic examination reveals a tampon in the vagina.  Laboratory results are as follows:  A pregnancy test is negative.  Activation of which of the following cells is most likely primarily responsible for this patient's condition?

Quizplus · Accepted Answer

11ec160b_37d7_2328_9249_c78002c8e478_MD0001_00 Fever, vomiting, diarrhea, muscle pains, and erythroderma (diffuse macular rash resembling a sunburn) are manifestations of toxic shock syndrome (TSS). TSS can rapidly progress to severe hypotension and multisystem dysfunction (eg, elevated creatinine, elevated transaminases). Desquamation, particularly on the palms and soles, can occur 1-2 weeks after the onset of illness. TSS has been associated with the use of tampons and nasal packing. Staphylococcus aureus strains producing toxic shock syndrome toxin (TSST) are responsible for most cases of TSS. TSST acts as a superantigen that activates large numbers of helper T cells (compared to a regular antigen, which activates few helper T cells). Superantigens interact with major histocompatibility complex molecules on antigen-presenting cells (eg, macrophages) and with the variable region of the T lymphocyte receptor to cause a nonspecific, widespread activation of T lymphocytes. Activation of T cells is responsible for the release of interleukin (IL)-2 from the T cells and IL-1 and tumor necrosis factor from macrophages. These ILs cause capillary leakage, circulatory collapse, hypotension, shock, fever, skin findings, and multiorgan failure. (Choice A) Basophils are not involved in TSS. Basophilia can be seen with some myeloproliferative disorders and, rarely, certain parasitic infections. (Choices C and E) Eosinophil activation is associated with reactions to allergens and parasites, hypersensitivity reactions to drugs, and some hematologic malignancies. Mast cells, when stimulated (due to antigen-induced cross-linking of IgE on their cell membrane), release histamine, prostaglandins, leukotrienes, and other inflammatory mediators; they are active in allergic reactions and anaphylaxis. (Choice D) B lymphocytes respond to activation by replicating and synthesizing antibodies specific for the antigen with which they were presented; they are not responsible for TSS. Neutrophilia is commonly seen with TSS. Educational objective: Superantigens (eg, toxic shock syndrome toxin) interact with major histocompatibility complex molecules on antigen-presenting cells and the variable region of the T lymphocyte receptor to cause nonspecific, widespread activation of T cells. This results in the release of interleukin (IL)-2 from the T cells and IL-1 and tumor necrosis factor from macrophages. This immune cascade is responsible for the manifestations of toxic shock syndrome.

A 23-Year-Old Woman Is Brought to the Emergency Department Due