WBR0466

Author	[[PageAuthor::Yazan Daaboul, M.D. (Reviewed by Yazan Daaboul, M.D. and Alison Leibowitz [1])]]
Exam Type	ExamType::USMLE Step 1
Main Category	MainCategory::Immunology
Sub Category	SubCategory::Neurology, SubCategory::Renal
Prompt	[[Prompt::A 35-year-old woman presents to the physician's office for an episode of double vision. The patient had a similar episode 4 weeks prior to presentation that self-resolved. Physical examination and neurological exam appear to be normal, but a cranial MRI demonstrates several periventricular plaques. Which disease share the same HLA subtype association as the patient's condition?]]
Answer A	AnswerA::Pencil-in-cup deformity of end joints
Answer A Explanation	[[AnswerAExp::Psoriatic arthritis is frequently characterized by pencil-in-cup deformity of end joints. Psoriatric arthritis affects approximately 10-15 % of patients with psoriasis. Psoriatic arthritis is associated with the HLA-B27 subtype. Other seronegative arthropaties, namely ankylosing spondylitis, arthritis of inflammatory bowel disease (IBD), and reactive arthritis (Reiter syndrome), are also associated with the HLA-B27 subtype.]]
Answer B	AnswerB::Skip lesions and granulomatous inflammation of a bowel section
Answer B Explanation	[[AnswerBExp::Crohn's disease is frequently characterized by skip lesions and granulomatous inflammation of a bowel section. Arthritis of crohn's disease is associated with HLA-B27 subtype.]]
Answer C	AnswerC::Lymphocytic infiltratoin with germinal centers of the thyroid gland
Answer C Explanation	[[AnswerCExp::Hashimoto thyroidis is characterized by lymphocytic infiltratoin with germinal centers of the thyroid gland. Hashimoto thyroiditis and pernicious anemia (vitamin B12 deficiency due to auto-antibodies against gastric parietal cells) are associated with HLA-DR5 subtype.]]
Answer D	AnswerD::Antibodies against glomerular basement membrane
Answer D Explanation	[[AnswerDExp::Goodpasture syndrome is characterized by auto-antibodies against glomerular basement membrane (anti-GBM). It is considered a pulmorenal syndrome because it affects the lungs and the kidneys' basement membranes. Goodpasture syndrome, similar to MS, is associated with HLA-DR2 subtype. Other diseases associated with HLA-DR2 subtype are hay fever and systemic lupus erythematosus (SLE).]]
Answer E	AnswerE::Antibodies against gastric parietal cells
Answer E Explanation	[[AnswerEExp::Pernicious anemia is characterized by auto-antibodies against gastric parietal cells. Pernicious anemia is a cause of vitamin B12 because parietal cells normally produce intrinsic factor (IF), a glycoprotein that binds to vitamin B12 and allows its migration along the GI tract before it is absorbed in the terminal ileum. Pernicious anemia and Hashimoto thyroiditis are associated with HLA-DR5.]]
Right Answer	RightAnswer::D
Explanation	[[Explanation::Multiple sclerosis (MS) is a chronic autoimmune disorder of the CNS. MS is a demyelinating inflammatory disease that usually involves the white matter of the cervical region. It features asymmetric lesions due to the autoimmune myelin and axonal destruction. Although the etiology of the disease is still unknown, it is believed that MS may be caused by environmental triggers in genetically predisposed individuals. It commonly affects women aged between 20-45 years. In the majority of cases, manifestations of MS are reversible neurological deficits in the early stages of the diseases with progression to irreversible deterioration. MS is generally suspected by history and physical examination. Classical signs and symptoms include scanning speech, loss of vision due to optic neuritis, diplopia, and bilateral trigeminal neuralgia. Other common signs and symptoms include spasticity of the extremities, paresthesias, dysesthesias, ataxia, vertigo, and urinary dysfunction. The diagnosis is often confirmed by brain MRI that shows multiple periventricular plaques at various levels, and lumbar puncture that shows evidence of inflammation and oligoclonal bands. Multiple sclerosis is associated with HLA-DR2 subtype. Other diseases associated with HLA-DR2 subtype include hay fever, systemic lupus erytheromatosus (SLE), and Goodpasture syndrome. The following table illustrates the association between HLA subtypes and diseases: Educational Objective: The HLA-DR2 subtype is associated with MS, hay fever, systemic lupus erytheromatosus (SLE), and Goodpasture syndrome. References: First Aid 2014 page 199]]
Approved	Approved::Yes
Keyword	WBRKeyword::HLA subtype, WBRKeyword::HLA-DR2, WBRKeyword::Multiple sclerosis, WBRKeyword::MS, WBRKeyword::Periventricular plaques, WBRKeyword::HLA
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