Ankylosing spondylitis in associated with:

SERONEGATIVE SPONDYLOAHROPATHIES Feature HLA B-27 positive/presence of uveitis Onset usually before 45 years age Inflammatory ahritis of spine/large peripheral joints Absence of autoantibodies (e.g. rheumatoid factor) in serum so known as seronegative -Other diseases associated with HLA-B27 positivity Mnemonic: PEARS (HLA-B27 Positive) P- Psoriatic ahritis E- Enteropathic ahritis A- Ankylosing spondylitis(>90%) R- Reiter's syndrome/ Reactive ahritis S- SAPHO Syndrome OTHER OPTIONS: HLA-DW4/DR4- A/W rheumatoid ahritis. HLA-DR3 - A/W Type 1 diabetes mellitus HLA-B47- A/W 21 hydroxylase deficiency