Psoriatic arthritis (PsA) develops in approximately 30% of patients with psoriasis. The HLA association that strongly predisposes to PsA (particularly the axial/spondyloarthropathy pattern) is:
- A HLA-Cw6
- B HLA-DR4
- C HLA-B27 ✓
- D HLA-A2
Correct answer: C. HLA-B27
Explanation
HLA-B27 is strongly associated with the axial (spondyloarthropathy) pattern of psoriatic arthritis and with sacroiliitis/spondylitis in PsA. HLA-Cw6 is the primary genetic association with plaque psoriasis itself (skin disease) and is present in approximately 65% of patients with early-onset psoriasis. HLA-DR4 is associated with rheumatoid arthritis. Thus a PsA patient with predominant spinal/axial involvement is more likely to carry HLA-B27, while the skin disease associates with HLA-Cw6.
Reference: Neena Khanna Illustrated Synopsis of Dermatology & STD, 6th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.