A 35-year-old man with obesity, metabolic syndrome, and renal failure presents with excruciating joint pain associated with localized hyperemia and warmth involving ankles, heels, and knees. Aspirate from the joint shows dense neutrophilic infiltrate and crystals are seen under polarised light are as shown below. What is the most likely diagnosis?
- Ans.D. Gout
- The most likely diagnosis is gout. Aspirate from the joint shows dense neutrophilic infiltrate and crystals which are long, slender, needle-shaped, and negatively birefringent.
- Gout is marked by transient attacks of acute arthritis initiated by crystallization of monosodium urate within and around joints.
- Gout can be classified into primary and secondary forms.
- The inflammation in gout is triggered by precipitation of monosodium urate (MSU) crystals into the joints, which results in the production of cytokines that recruit leukocytes.
- Macrophages phagocytose the MSU and the inflammasome activates caspase-1, which is involved in the production of some biologically active cytokines.
- IL-1 is pro-inflammatory and promotes the accumulation of neutrophils and macrophages in the joint.