WBR0542

Author	[[PageAuthor::Rim Halaby, M.D. [1]]]
Exam Type	ExamType::USMLE Step 1
Main Category	MainCategory::Pathology
Sub Category	SubCategory::Neurology
Prompt	[[Prompt::A 42 year old patient with a past medical history significant for coronary artery disease, hypertension, hyperlipidemia, and type 2 diabetes mellitus, is brought to the emergency department with acute flaccid paralysis. The family explains that the patient has had a recent bloody diarrhea. Cerebrospinal fluid (CSF) analysis shows high levels of proteins and normal cell count. Which of the following pathologies corresponds to a similar immunological reaction as that observed in the patient?]]
Answer A	AnswerA::Autoimmune hemolytic anemia (AIHA)
Answer A Explanation	AnswerAExp::AIHA is a type II hypersensitivity.
Answer B	AnswerB::Systemic lupus erythematosus (SLE)
Answer B Explanation	AnswerBExp::SLE is a type III hypersensitivity.
Answer C	AnswerC::Goodpasture's syndrome
Answer C Explanation	AnswerCExp::Goodpasture's syndrome is a type II hyersensitivity.
Answer D	AnswerD::Graft vs. host disease (GVHD)
Answer D Explanation	AnswerDExp::GVHD is a type IV hypersensitivity, similar to Guillain-Barre syndrome.
Answer E	AnswerE::Post-streptococcal glomerulonephritis (PSGN)
Answer E Explanation	AnswerEExp::PSGN is a type III hypersensitivity.
Right Answer	RightAnswer::D
Explanation	[[Explanation::Guillain-Barre syndrome (GBS) is an auto-immune disease characterized by a type IV hypersensitivity caused by antibodies against Schwann cells in the peripheral nervous system. The most common presentation of GBS is a symmetric paralysis that usually starts in the distal lower extremities and gradually becomes more proximal. On physical examination, patients with GBS generally have areflexia in the lower extremities. CSF shows albuminocytologic dissociation, defined as a high level of CSF proteins and normal cell counts. Although GBS is generally regarded as a benign condition with a good prognosis, recent research has shown that GBS prognosis is not as good as first believed. 20% of affected patients remain severely disabled with a death rate reaching 5%. GBS is believed to be a pathology that subsequently develops following a recent diarrhea or upper respiratory tract infection. The most common organism associated with GBS is Campylobacter jejune in 30% of the cases, followed by cytomegalovirus (CMV) in 10%. Other less common infectious agents associated with GBS are: Epstein-Barr virus (EBV), varicella-zoster virus (VZV), and mycoplasma pneumoniae. Among the list of possible options, only GVHD is a type IV hypersensitivity reaction, similar to GBS. Educational Objective: Guillain-Barre syndrome is a type IV hypersensitivity that usually follows a diarrhea or upper respiratory tract infection following C. jejuni infection. It is characterized by flaccid paralysis with areflexia on physical examination and albuminocytologic dissociation on CSF analysis. Reference: Yuki N, Hartung HP. Guillain-Barre syndrome. N Eng J Med. 2012; 366:2294-304 Educational Objective: References: ]]
Approved	Approved::No
Keyword	WBRKeyword::guillain, WBRKeyword::barre, WBRKeyword::syndrome, WBRKeyword::guillain barre syndrome, WBRKeyword::guillain-barre syndrome, WBRKeyword::c. jejuni, WBRKeyword::campylobacter, WBRKeyword::jejuni, WBRKeyword::campylobacter jejuni, WBRKeyword::albuminocytologic, WBRKeyword::dissociation, WBRKeyword::albuminocytologic dissociation, WBRKeyword::CSF, WBRKeyword::cerebrospinal fluid, WBRKeyword::flaccid, WBRKeyword::paralysis, WBRKeyword::flaccid paralysis, WBRKeyword::areflexia
Linked Question	Linked::
Order in Linked Questions	LinkedOrder::