Assessment of fatigue in the management of patients with ankylosing spondylitis.

BACKGROUND: Pain, stiffness, functional impairment, range of motion and quality of life are the main conventional domains used in studies evaluating ankylosing spondylitis (AS). However, fatigue has been reported as the major complaint of AS patients. OBJECTIVES: To evaluate fatigue as a potential independent domain in comparison with the 'conventional' ones and to evaluate the sensitivity to change after non-steroidal anti-inflammatory drug (NSAID) therapy. METHODS: Patients were classified as having painful AS (modified New York criteria). The following variables were recorded at baseline and after 6 weeks of therapy (either placebo or NSAIDs): pain (VAS), function (Bath Ankylosing Spondylitis Functional Index), patient's global assessment (VAS), inflammation (night pain), morning stiffness, metrology (Schober test, finger-to-floor) and fatigue using 0-100 VAS scale. Analysis consisted of (i) the prevalence of fatigue (VAS value of at least 50 mm), (ii) the independence of the information evaluated using a regression model, and (iii) the sensitivity to change, by calculating the standardized response mean (mean change/s.d. change) (SRM) between placebo and NSAID group. RESULTS: Fatigue was considered important in 401 patients (out of 639: 63%). The information provided by the variables 'pain', 'function' and 'global assessment' explained only 44% of the variability of the variable 'fatigue' (similar analyses considering 'pain' on the one hand and 'function' on the other hand as the dependent variables showed an R2 value of 34 and 60%, respectively). The NSAID treatment effect (SRM) was higher for the variables 'pain' and 'function' (0.76 and 0.71, respectively) than for the variable 'fatigue' (0.34). CONCLUSION: This study strongly suggests that fatigue should be considered as an independent domain to be systematically evaluated in AS patients and that conventional therapy such as NSAIDs have a lower effect on this domain than on pain or functional impairment.

Inducible nitric oxide synthase attenuates chronic colitis in human histocompatibility antigen HLA-B27/human beta2 microglobulin transgenic rats.

Rats transgenic for HLA-B27/human beta2-microglobulin develop a spontaneous multisystem inflammatory disorder that closely mimics human spondyloarthropathies. Prominent features of this disorder are gut inflammation that predominates in the colon, and arthritis. Several mediators such as IFN-gamma, IL-1beta, TNF-alpha, and inducible nitric oxide synthase (iNOS) have been found increased in the inflamed colonic mucosa. In the colon of HLA-B27 transgenic rats, iNOS is predominantly expressed by epithelial cells, and iNOS transcripts are detected in the hip cartilage of those rats, but not in nontransgenic littermates. The role of iNOS in this disorder was evaluated by administering the corticosteroid dexamethasone, or the NOS inhibitor L-N6-(1-iminoethyl)lysine (L-NIL) to HLA-B27 transgenic rats with established disease. Treatment with dexamethasone attenuated some aspects of gut inflammation, although it had no effect on iNOS expression. In contrast, treatment with L-NIL effectively inhibited iNOS activity, and resulted in an increase in colitis. Cytokine transcripts in the colon were modified by these treatments: IFN-gamma and IL-1beta were decreased after dexamethasone treatment, whereas administration of L-NIL resulted in decreased IFN-gamma, and TNF-alpha. A trend towards increased IL-1b expression was observed which could have contributed to the L-NIL pro-inflammatory effect. These results suggest that iNOS exerts a protective effect on colitis, in the inflammatory disorder of HLA-B27 transgenic rats.

Phenotypic diversity is not determined by independent genetic factors in familial spondylarthropathy.

OBJECTIVE: To analyze the segregation of manifestations belonging to the spectrum of spondylarthropathy (SpA) among patients and unaffected siblings within SpA multiplex families. METHODS: Ninety-five multiplex families have been investigated. The diagnosis of SpA was made according to European Spondylarthropathy Study Group criteria. The prevalence of SpA manifestations was determined in unaffected siblings and compared with their prevalence in patients. RESULTS: We compared 241 SpA patients with 259 unaffected siblings. The prevalence of skeletal and extraarticular features not used as diagnostic criteria, i.e., radiographic sacroiliitis, peripheral enthesitis, uveitis, psoriasis, and inflammatory bowel disease, was significantly increased in patients compared with unaffected siblings. This result was not accounted for by sex or HLA-B27 distribution differences. CONCLUSION: In familial SpA, skeletal and extraarticular manifestations tend to segregate together, implying that all subsets are predominantly determined by a shared component, and that accessory factors must be responsible for phenotype diversity.

Nitric oxide in rheumatology.

Nitric oxide (NO) is attracting considerable interest because it mediates many functions. This gas is ubiquitously produced in the body by three enzymes, called NO synthases. Two NO synthases are constitutively expressed, one in the nervous system and the other in the blood vessels, where it regulates tissue perfusion. The third NO synthase can be induced by several stimuli (bacterial endotoxins, cytokines), most notably in inflammatory cells and chondrocytes. The effects of NO produced by the inducible NO synthase range from T-cell response modulation to formation of free radicals responsible fortissue damage and cartilage matrix degradation. Administration of NO synthase inhibitors in animal models of arthritis yields ambiguous effects, often with prevention of arthritis, but sometimes with worsening of established arthritis. The data available to date do not support the use of such inhibitors in the treatment of human arthritis.

Animal models of the spondyloarthropathies.

Several lines of rats transgenic for human leukocyte antigen (HLA)-B27 spontaneously develop a multisystemic inflammatory disease resembling human spondyloarthropathies. This disease is mediated by cells of the immune system and is dependent on the presence of a normal bacterial flora. Both antigen-presenting cells expressing high levels of HLA-B27 and T cells appear to be of importance in the pathogenesis of this model. HLA-B27 transgenic/b2- microglobulin deficient mice also develop arthritis, under the influence of the bacterial flora. In both types of model, CD8+ T cells appear to be unnecessary, arguing against the "arthritogenic peptide" hypothesis.

The familial form of spondylarthropathy: a clinical study of 115 multiplex families. Groupe Français d'Etude Génétique des Spondylarthropathies.

OBJECTIVE: To investigate the interrelationships among different phenotypes, and their relationship to the HLA-Blocus, in multiplex families with spondylarthropathy (SpA). METHODS: We recruited 115 white French families, each of which had at least 2 members with SpA. Pedigrees were established. Clinical data and pelvic radiographs were collected. The HLA-B27 status of all patients was determined. Analysis was performed to determine the prevalence of SpA manifestations according to sex, disease duration, and HLA-B status, and to examine clustering of specific manifestations in subsets of families. RESULTS: We identified 329 SpA patients. Mean +/-SD age at onset was 24+/-9.4 years. The male:female ratio was 186:143, or 1.3, with few sex differences in disease expression. Axial manifestations and HLA-B27 were each present in 97% of the patients. Inflammatory bowel disease and HLA-B35 were overrepresented in the 7 families containing HLA-B27-negative patients. The frequency of radiographic sacroiliitis increased in parallel with disease duration. Peripheral enthesitis, radiographic sacroiliitis, and psoriasis were evenly distributed in the families. Clustering independent of age was only observed for peripheral arthritis, suggesting that specific factors may predispose individuals to this manifestation. CONCLUSION: Familial SpA appears to be homogeneous, based on the high frequencies of axial skeletal involvement and HLA-B27. The lack of clustering of most manifestations in families suggests that a predominant shared component, including HLA-B27, predisposes individuals to all forms of familial SpA, and that ubiquitous genetic or environmental factors contribute to phenotype diversity.