Incidentally, one of the male patients followed in the study is hospitalized with right knee pain and swelling. A sample of his synovial fluid shows negatively birefringent crystals under polarized light microscopy. To achieve rapid improvement in this patient's symptoms, therapy should be directed toward inhibiting which of the following types of cells?

Question

Incidentally, one of the male patients followed in the study is hospitalized with right knee pain and swelling.  A sample of his synovial fluid shows negatively birefringent crystals under polarized light microscopy.  To achieve rapid improvement in this patient's symptoms, therapy should be directed toward inhibiting which of the following types of cells?

Quizplus · Accepted Answer

11ec160b_36f8_f787_9249_c19a2e3e5f49_MD0001_00 This patient's synovial fluid analysis shows negatively birefringent crystals (ie, monosodium urate crystals) under polarized light, which is diagnostic for gouty arthritis. Neutrophils are the primary cells responsible for the intense inflammatory response seen in patients with gout. Phagocytosis of urate crystals by neutrophils causes the release of various cytokines and inflammatory mediators that lead to further neutrophil activation and chemotaxis, resulting in a positive feedback loop that amplifies the inflammatory response. Nonsteroidal anti-inflammatory drugs (NSAIDs) are first-line therapy for treating acute gouty arthritis. They inhibit prostanoid biosynthesis (eg, prostaglandins, prostacyclin, thromboxanes), exerting a broad anti-inflammatory effect that includes inhibition of neutrophils. Patients with contraindications to NSAIDs (eg, peptic ulcer disease, renal impairment) are often treated with colchicine, which impairs neutrophil migration and phagocytosis by interfering with microtubule formation. Colchicine also decreases tyrosine phosphorylation in response to monosodium urate crystals, resulting in decreased neutrophil activation. (Choice A) Eosinophils function in defense against parasitic infections and are also pathogenic in patients with asthma, allergy, hypereosinophilic syndromes, and vasculitides such as Churg-Strauss syndrome. (Choice B) Lymphocytes produce delayed-type hypersensitivity reactions that do not play a role in gout. (Choice D) Synovial cells and macrophages play a role in initiating the inflammatory response in gouty arthritis. However, targeting these cells would not eliminate the inflammatory amplification caused by neutrophils, which is the central mechanism involved in precipitating an acute gouty attack. (Choice E) Mast cell degranulation can be inhibited by medications such as cromolyn sodium, which is used in conditions such as asthma and allergic rhinitis. Educational objective: Nonsteroidal anti-inflammatory drugs (NSAIDs) are first-line therapy for treating acute gouty arthritis. They inhibit cyclooxygenase and exert a broad anti-inflammatory effect that includes inhibition of neutrophils. When NSAIDs are contraindicated (eg, peptic ulcer disease, renal impairment), colchicine is useful in the acute management of gout as it inhibits neutrophil chemotaxis and phagocytosis by preventing microtubule formation. __________ References: Crystal-induced neutrophil activation. III. Inflammatory microcrystals induce a distinct pattern of tyrosine phosphorylation in human neutrophils. (http://www.ncbi.nlm.nih.gov/pubmed/8386191) Prevention of neutrophil apoptosis by monosodium urate crystals. (http://www.ncbi.nlm.nih.gov/pubmed/9106933) Colchicine: its mechanism of action and efficacy in crystal-induced inflammation. (http://www.ncbi.nlm.nih.gov/pubmed/18638431)

Incidentally, One of the Male Patients Followed in the Study