Background Ankylosing spondylitis is a potentially limitating rheumatic disease, moreover because it affects adolescents and young adults. Sometimes it can be incapacitating, not only because of its spondylitic features but also because of the associated complications and extra-spondylarthropathy manifestations. It is a well known association with the histocompatibility antigen HLA B27, but the exact nature of this association remains hypothetic.

Objectives To apply disease indexes and measures to our Unit´s patients population and correlate them with the presence of HLA B27. To apply a psychometric test to this population and correlate the results with some parameters of disease measurement.

Methods We describe and characterise our Unit´s ankylosing spondylitis patients population in terms of demographis parameters and presence of HLA B27. In a single visit we measured some disease indexes (Schober value, Mander index, BASFI and BASDAI indexes) and applied the Scl-90 questionnaire.

Results From our baseline population of 34 patients, 14 were evaluated until now with these parameters. We found 5 women (36%) and 9 men (64%), with mean age 49,8 ± 7 SD years old and 47,8 ± 15,4 SD years old, respectively. Almost all patients (n = 12, 86%) were white, being one yellow and one black. Mean age at diagnostic was 43,6 ± 7,8 SD years old for women and 32,9 ± 12,2 SD years old for men, which seems to confirm the more benign course in women. Ten (71,4%) of these patients had extra-spondylarthropathy manifestations. In eight (57%) HLA B27 was positive, in four (28,6%) it was unknown and in two (14,3%) it was negative. Six patients had a Schober value between 0 and 1 cm, five between 1,5 and 3 cm and three between 3,5 and 4,5 cm. From this last group, two were thw ones with negative HLA B27. Mander index was between 0 and 10 in nine patients, between 11 and 20 in three and between 21 and 30 in two. Only 13 from the 14 patients answered the BASFI and BASDAI indexes and Scl-90 questionnaire. In six patients BASFI score was between 0 and 3, in five between 3,1 and 5 and in two between 5,1 and 8. BASDAI score was between 0 and 3 in four patients, between 3,1 and 5 in six and between 5,1 and 8 in three. Scl-90 test revealed psychologic pathology in eight of thirteen patients: four in the range of obsessive-compulsive, four with interpersonal sensitivity, three with somatization, three with hostility, two with paranoid ideas and one with psycoticism. We will evaluate the rest of the patients to finish this study.

Conclusion As is commonly described, we found in our ankylosing spondylitis population a majority of males, in a 2:1 rate; age at diagnosis was more advanced in women, probably due to a more benign and/or slow progression of disease. Patients without HLA B27 antigen had better Schober measures, probably signifying a more benign disease. The majority of patients revealed different types of psychopathology by Scl 90, which may be associated with bad coping with the disease.