A 44-year-old man has progressive symmetric distal sensory-motor neuropathy, gynaecomastia, hepatosplenomegaly, and papilloedema. X-ray shows a solitary osteosclerotic lesion in the left iliac bone. Serum protein electrophoresis reveals a small lambda-restricted M-protein; bone marrow plasma cells are under 5%. Which cytokine mediates the neuropathy and vascular abnormalities in this condition?

• A Vascular endothelial growth factor ✓
• B Interleukin-6
• C Tumour necrosis factor alpha
• D Beta-2 microglobulin

Explanation

This is POEMS syndrome (polyneuropathy, organomegaly, endocrinopathy, M-protein, skin changes), typically associated with osteosclerotic rather than lytic lesions and low-volume marrow plasmacytosis. Serum VEGF is characteristically markedly elevated, produced by the clonal plasma cells, and drives vascular permeability, oedema, ascites and possibly the demyelinating neuropathy; it also serves as a response marker after local radiotherapy to the sclerotic lesion. IL-6 elevation is nonspecific, and beta-2 microglobulin is a myeloma staging marker.

Reference: Harrison's Principles of Internal Medicine, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.