THE PARAMETERS AFFECTING THE FUNCTIONAL AND CLINICAL STATUS IN PATIENTS WITH ANKYLOSING SPONDYLITIS

Aims: In this study we aimed to clarify the effects of gender, HLA-B27 positivity and articular involvement extensity (axial alone or axial and peripheral articular involvements both) to the functional and clinical status in patients with AS (Ankylosing Spondylitis). Materials and methods: Eighty one consecutive patients with AS were enrolled in this study. The demographic, clinical and laboratory data including erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and HLA-B27 of patients were recorded. Functional disability was evaluated using Bath Ankylosing Spondylitis Functional Index (BASFI). Clinical status was evaluated with Bath Ankylosing Spondylitis Metrology Index (BASMI). The global disease assessments of physician and patients were measured on Visual Analog Scala (VAS). The patients were divided into two groups according to HLA-B27 positivity, gender and articular involvement extensity. Results: The mean age of 81 patients was 42.4+12.3 years and the mean duration of the disease was 97.2+101.2 months. HLA-B27 was positive in 53 patients (65.4%). BASMI score was significantly lower in female patients than male and patients who had HLA-B27 compared to patients who are HLA-B27 negative (p<0.05 for both). BASFI score was determined to be significantly lower in patients who had axial involvement (p<0.05). BASFI score was found to be correlated with age, duration of the disease, duration since the onset of first symptom, BASMI, patient’s global assessment and physician’s global assessment of the disease on VAS (p values were 0.008, 0.028, 0.013, <0.001 <0.001 and <0.001 respectively). The existence of axial and peripheral articular involvements, age, duration of AS and duration since the onset of first symptom were found to contribute to the BASFI scores (p<0.05 for all). The predictive parameters for the BASMI scores were age, sex, HLA B27 and duration since the onset of first symptom (p<0.05 for all). Discussion: Physicians should be more careful in male AS patients who are HLA B27 negative and who has both axial and peripheral articular involvements, because of being prone to have worse functional or clinical status. Received May 18, 2014; Accepted September 02, 2014 cal and functional status of AS patients are conflicting. In this study we aimed to explore the effects of gender, HLA-B27 positivity and articular involvement extensity (axial alone or axial and peripheral involvements both) to the functional and clinical status in patients with AS in Turkish population. Patients and methods Eighty-one consecutive patients with AS who admitted to our outpatient clinic were enrolled in this study. All the patients have fulfilled the modified New York criteria. Informed consents of the patients were obtained before attending to study. The study was approved by Ethics Committee of Süleyman Demirel University Medical School. We have included the patients with AS in this study. The patients having another rheumatic or chronic disease such as DM or chronic infectious diseases which may affect the functional or clinical status were excluded. The demographic data of the patients including age and sex, duration of the disease, duration since onset of first symptom and since the start of medication were recorded. The articular involvement including current or previous arthritis of any peripheral joints was also noted as absent or present. The laboratory evaluation comprised erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and HLA B27. The global disease assessment of patients and physician was measured on 0-10 cm. horizontal Visual Analog Scale (VAS). Functional disability was evaluated using the Turkish version of BASFI. BASFI consists of eight questions on daily activities and two additional questions to assess patients’ ability to cope with everyday life. The patients assessed each question by using a 0-10 cm horizontal VAS reflecting the status over previous month. The VAS have no distinguishing marks except the words ‘easy’ and ‘impossible’ at either end of the line to indicate the direction of severity. BASFI score is the mean of ten scores, with higher scores indicating more severe impairment. Clinical status was evaluated with Bath Ankylosing Spondylitis Metrology Index (BASMI). BASMI was calculated with the measurements of wall to tragus distance, lumbar flexion, cervical rotation, lumbar lateral flexion and intermalleolar distance. Lateral flexion of lumbar spine was measured bilaterally and the mean of right and left flexion values were accepted as a single value. Each measurement received either 0 (mild disease involvement), 1 (moderate disease involvement), or 2 (severe disease involvement) points. The sum of five scores is 0-10 with higher scores indicating higher disease involvement. The patients were divided into two groups based on HLA B27 positivity, on gender and on involvement extensity as axial alone or axial and peripheral both. Statistical analysis Data were analyzed using the Statistical Package for Social Sciences (SPSS) software version 15.0 for Windows (SPSS Inc., Chicago, IL). Frequencies and percentages were used for categorical data. For parametric variables, Student’s t test and for non-parametric variables Mann-Whitney U test were used for two group comparisons. For evaluation of categorical variables, chi-square (X2) test and if needed, Fisher’s exact test were used. Pearson and Spearman correlation coefficients were used to investigate correlations between variables. p<0.05 was accepted as significant for all statistical analysis. The significant variables that seem to be independent determinants of BASFI and BASMI in correlation model and other categorical variables seem to be related were put in multivariate regression analysis. Regression analysis was performed with backward method with 95 % confidence interval and the final significant models are presented.