<prompt> Ankylosing spondylitisHLA-B27HLA-DR-4HLA-B-8HLA-DR-3  <response>: A HLA B27 1093 - Davidson 21stANKYLOSING SPONDYLITIS JOINTS AND SPINE Predominating effecting the sacroiliac joints and spine HLA-B27 positive Increased facel carriage of Klebsiella aerogens occurs in patients with established as and may relate to exacerbation of both joint and eye disease. Low back pain and marked stiffness Symptoms are more marked in the early morning and after inactivity, and are relieved by movement. Although the lumbosacral area is usually the first and worst affected region. Planter fasciitis, achilis tendinitis and tenderness over bony prominences. Such as the iliac crest and greater trochanter are common reflecting inflammation at the sites of tendon insertion Enthesitis or Osteitis The modified Schober test is a useful measure of lumber spine flexion. Most serious complication of the spinal disease is spinal fracture. Most common extraarticular manifestation is acute anterior uveitis.EXTRA ARTICULAR FEATURES OF AS Anterior uveitis and conjunctivitis Prostatitis usually asymptomatic Cardiovascular disease Aortic incompetence Mitral incompetence Cardiac conduction defects Pericarditis Amyloidosis, psoriasis Atypical upper lobe pulmonary fibrosis Retroperitoneal fibrosis Cauda equina syndromeRadiographic features: Sacroilitis is often first abnormality. Earliest changes by standard radiography are blurring of the cortical margins of the subchondral bone. Anterior squaring of vertebrae due to erosion and sclerosis of the anterior comers and periositis of the waist. Bamboo Spine Bridging the adjacent vertebral bodies. Osteoporosis and atlanto-axial dislocation can occur as late features.HLA - B 27 is associated with1. Ankylosing spondylitis2. Reiters syndrome3. Reative arthritis Yersinia, salmonella, Shigella, Chlamydia4. Psoriatic spondylitis5. Acute anterior uveitisOther conditions associated with HLAsHLA B-8 - M. gravisHyperthyroidismDW-4 DR4- Rheumatoid arthritis P. VulgarisHLA DR 3 - Glutein sensitive enteropathyDiabetes mellitus type IM. gravis chromic active hepatitisHLA - B5 - Bechets syndromeHLA - DR2 - Narcolepsy, Good pastures syndrome Multiple selerosis 