Clinical rheumatology, 1992, 11, N ~ 2 239-242 HLA B27 and Clinical Features in Reiter's Syndrome T. TUNCER*, M.I. ARMAN*, A. AKYOKUS*, B. BIOTQN*, S. ONAL** Summary HLA B27 and other clinical findings were investigated in 18 Turkish patients with Reiter's syndrome (mean age 35.8 _ 8.09). Male/female ratio was 2/1. All 18 patients were seronegative, 12 (66.6%) presenting with an asymmetrical oli- goarticular arthritis. Radiologicai sacroiliitis and enthesopathy was found in 9 (50%) and 7 (45.6%) patients respectively. HLA B27 was present in 11 (61.1%) pa- tients. Key words : Reiter's Syndrome, HLA B27, Sacroiliitis. INTRODUCTION Since Hans Reiter's description of the triad consisting of polyarthritis, urethritis and conjunctivitis, other dis- criminating clinical features have been added that may aid one in the diagnosis of this disorder. These include oligoarticular, asymmetrical arthritis, enthesitis or peri- ostitis, sausage digits, inflammation of the axial skeleton, the mucocutaneous manifestations, an antecedent histo- ry of a dysenteric illness or venereal exposure (1). With the awareness of genetic and microbiologic factors, the term "reactive arthritis" is generally becoming accepted as more precise than Reiter's syndrome (RS) and the two initiating causes of the arthritis are included in the nomenclature as "sexually acquired reactive arthritis" and "enteric reactive arthritis" (2). The interrelation- ship between the environment and genetics is crucial in the pathogenesis of RS. How these two features - sev- eral different relevant infective agents (salmonella, yers- inia, shigella, campylobacter, ureaplasma, chlamydia) and a specific genetic background (HLA-B27) - inter- act in the pathogenesis of the disease remains unclear, but the problem forms the center of much interest. Several studies in different populations have been made to determine the clinical findings and the frequen- cy of HLA B27 in RS. The results were found to be dif- ferent from each other. This study was planned to in- vestigate the characteristic clinical findings and the fre- quency of HLA B27 in Turkish patients with RS who live in the southwest part of Turkey. *Department of Physical Medicine and Rehabilitation ; ** Department of Immunology;Akdeniz University, School of Medicine, Antalya, Turkey. MATERIAL AND METHOD Eighteen RS patients diagnosed in a 2-year period at the Department of Physical Medicine and Rehabilita- tion, Akdeniz University were included in this study. A clinical diagnosis of RS was based upon the char- acteristic articular pattern and other accepted discrim- inating clinical findings. The patients were subdivided into 3 categories : 1) Classical triad of urethritis, con- junctivitis, and arthritis; 2) Urethritis or conjunctivitis with arthritis; 3) Discriminating clinical features of RS without urethritis or conjunctivitis (oligoarticular asym- metrical arthritis, enthesitis, diffuse swelling of the dig- its, mucocutaneous lesions or an antecedent history of dysenteric illness). Rheumatoid factor was negative in all patients. Ankyl- osing spondylitis, psoriatic arthritis, enteropathic arthri- tis, gout, brucellosis, Behcet's disease were considered in the differential diagnosis and were eliminated with clinical or laboratory findings. HLA B27 was tested in all patients with NIH tech- nique. Microorganisms mentioned above could not be investigated due to incomplete technical requirements; only chlamydia and yersinia antibodies could be tested in 5 and 2 patients respectively. Chi-square tests were used for the statistical analysis. RESULTS Eighteen patients (12 males and 6 females) with a mean age of 35.8_+ 8.09 and age range from 18 to 45 years were evaluated. Male/female ratio was 2/1 ; 12 pa- tients admitted a history of antecedent dysentery. The disease duration was changed from 4 months to 12 years.