WBR0542
| Author | [[PageAuthor::Rim Halaby, M.D. [1], Alison Leibowitz [2] (Reviewed by Alison Leibowitz)]] |
|---|---|
| Exam Type | ExamType::USMLE Step 1 |
| Main Category | MainCategory::Pathology |
| Sub Category | SubCategory::Neurology |
| Prompt | [[Prompt::A 42-year-old man, with a medical history of coronary artery disease, hypertension, hyperlipidemia, and type 2 diabetes mellitus, is brought to the emergency department with acute flaccid paralysis. The patient recently had bloody diarrhea and cerebrospinal fluid (CSF) analysis demonstrates high levels of proteins and a normal cell count. Which of the following pathologies corresponds to a similar immunological reaction?]] |
| 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 type a II and 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), an auto-immune disease, is characterized by a type IV hypersensitivity caused by antibodies against Schwann cells in the peripheral nervous system. GBS frequently manifests with a symmetric paralysis that usually starts in the distal lower extremities and gradually becomes more proximal. Upon physical examination, patients with GBS often have areflexia in the lower extremities. CSF demonstrates 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 positive prognosis, 20% of affected patients remain severely disabled with a death rate reaching 5%.
GBS frequently develops following diarrhea or upper respiratory tract infection. The most common organism associated with GBS is Campylobacter jejuni in 30% of the cases, followed by cytomegalovirus (CMV) in 10%. Less common infectious agents associated with GBS are Epstein-Barr virus (EBV), varicella-zoster virus (VZV), and Mycoplasma pneumoniae. GVHD is a type IV hypersensitivity reaction, similar to GBS. |
| Approved | Approved::Yes |
| Keyword | WBRKeyword::guillain-barre syndrome, WBRKeyword::campylobacter jejuni, WBRKeyword::albuminocytologic dissociation, WBRKeyword::CSF, WBRKeyword::cerebrospinal fluid, WBRKeyword::flaccid paralysis, WBRKeyword::areflexia, WBRKeyword::hypersensitivity, WBRKeyword::infection, WBRKeyword::microbiology |
| Linked Question | Linked:: |
| Order in Linked Questions | LinkedOrder:: |