Ossification of the posterior longitudinal ligament in three geographically and genetically different populations of ankylosing spondylitis and other spondyloarthropathies

STUDY DESIGN

Cross sectional.

RESEARCH QUESTIONS

(a) Is any clinical variable of ankylosing spondylitis (AS) associated with the presence of ossification of the posterior longitudinal ligament (OPLL)? and (b) Is OPLL present in patients with AS from different geographical or genetic backgrounds?

METHODS

Three groups were assembled: (1) a prospective group of 103 consecutive AS patients from two community based rheumatology clinics from Guadalajara, who were evaluated using: a questionnaire with disease characteristics variables; clinical assessment by a neurologist; lateral radiographic views of the cervical spine and somatosensory evoked potentials (SSEP). (2) Fifty one spondyloarthropathies (SpA) patients from Mexico city whose cervical spine films were retrospectively reviewed. (3) Thirty nine AS patients from Edmonton, Canada whose cervical spine films were retrospectively reviewed and compared with 72 controls.

RESULTS

Group 1: 74% of the 103 patients were men and 86% were HLA-B27 positive. The mean age was 35 years, and mean (SD) disease duration 10 (8) years. OPLL was reported in 16 patients (15.5%; 95% CI 9, 22). OPLL was statistically associated with older age (p = 0.001), longer disease duration (p = 0.001), clinical myelopathy (p = 0.03), worst functional index (p = 0.042), restricted axial movement measurements (all p < 0.001), radiological sacroilitis (p < 0.001 for linear association), osteitis pubis (p = 0.009), hip involvement (p = 0.006 for linear association), and abnormal SSEP (p = 0.008). Group 2: 92% of 51 patients were men; the mean age was 30 years and the mean (SD) disease duration 11 (7) years. OPLL was reported in 15 (29%, 95% CI 17, 41) patients (nine AS, two psoriatic arthritis, three juvenile AS, and one Reiter's syndrome). Group 3: 95% of the 39 patients were men; the mean of age was 46 years and disease duration of 18 (10) years. OPLL was reported in nine (23%; 95% CI 10, 36) patients, including one with psoriatic arthritis, and two with Crohn's disease. OPLL was observed in two of the control group.

CONCLUSIONS

The prevalence of OPLL in AS and SpA is higher than previously recognised and seems to be associated with variables identifying more severe axial disease.

Temporomandibular joint osseous morphology in a consecutive sample of ankylosing spondylitis patients

OBJECTIVE

To evaluate temporomandibular joint (TMJ) osseous morphology in a consecutive sample of Mexican patients with ankylosing spondylitis.

METHODS

Consecutive patients with a diagnosis of ankylosing spondylitis who attended two secondary care outpatient rheumatology clinics were included in the study. Patients had a rheumatological assessment using a structured questionnaire and examination. Recorded variables included demographic data, disease characteristics, TMJ symptoms, and axial mobility measurements. Hypocycloidal tomography of the TMJ was obtained on all subjects. Radiographic variables included condyle position, superior joint space, range of movement, condylar osseous changes, and temporal osseous changes. Patients also underwent standard cervical spine radiography. A control group of normal people without either TMJ symptoms or systemic rheumatic disease was obtained.

RESULTS

65 subjects were studied (65 right sided and 63 left sided tomograms). The control group consisted of 22 individuals. Both groups were similar in age [33 (SD 11) v 34 (9) years, P = 0.8]. Patients with ankylosing spondylitis had more variability in TMJ mobility than controls (P < 0.05) and showed increased frequency of condylar erosions (P < 0.01), flattening (P < 0.01), sclerosis (P < 0.01), and temporal flattening (P < 0.01). Condylar erosions were associated with longer duration of ankylosing spondylitis (P < 0.05), neck complaints (P < 0.05), and atlantoaxial subluxation (P < 0.05).

CONCLUSIONS

TMJ involvement is frequent in this population of patients with ankylosing spondylitis and is associated with variables that suggest more severe disease.

Inactivation of GABAA receptor is related to heat shock stress response in organism model Caenorhabditis elegans

The mechanisms underlying oxidative stress (OS) resistance are not completely clear. Caenorhabditis elegans (C. elegans) is a good organism model to study OS because it displays stress responses similar to those in mammals. Among these mechanisms, the insulin/IGF-1 signaling (IIS) pathway is thought to affect GABAergic neurotransmission. The aim of this study was to determine the influence of heat shock stress (HS) on GABAergic activity in C. elegans. For this purpose, we tested the effect of exposure to picrotoxin (PTX), gamma-aminobutyric acid (GABA), hydrogen peroxide, and HS on the occurrence of a shrinking response (SR) after nose touch stimulus in N2 (WT) worms. Moreover, the effect of HS on the expression of UNC-49 (GABAA receptor ortholog) in the EG1653 strain and the effect of GABA and PTX exposure on HSP-16.2 expression in the TJ375 strain were analyzed. PTX 1 mM- or H2O2 0.7 mM-exposed worms displayed a SR in about 80 % of trials. GABA exposure did not cause a SR. HS prompted the occurrence of a SR as did PTX 1 mM or H2O2 0.7 mM exposure. In addition, HS increased UNC-49 expression, and PTX augmented HSP-16.2 expression. Thus, the results of the present study suggest that oxidative stress, through either H2O2 exposure or application of heat shock, inactivates the GABAergic system, which subsequently would affect the oxidative stress response, perhaps by enhancing the activity of transcription factors DAF-16 and HSF-1, both regulated by the IIS pathway and related to hsp-16.2 expression.

Two year followup of anterior and vertical atlantoaxial subluxation in ankylosing spondylitis

OBJECTIVE

To describe the clinical and radiological 2-yr followup of 22 patients with anterior atlantoaxial subluxation (AAS) from a prospective cohort of patients with ankylosing spondylitis.

METHODS

The 2-yr assessment included a structured questionnaire for rheumatologic and neurologic complaints and lateral cervical radiographs in maximal flexion view. Initial and 2-yr radiographs were assessed blind to patient data. The course of anterior AAS was classified as unchanged (< 1 mm), progression (> or = 1 mm) or regression (> or = 1 mm) at 2 yrs compared with baseline. Vertical AAS was classified using the Sakaguchi-Kauppi method. Magnification factor was corrected using the ratio of C3 width.

RESULTS

Anterior AAS was detected in 22 patients at baseline examination. Two patients also had vertical AAS; 86% were male. Mean age was 33 +/- 9 yrs and mean disease duration was 12 +/- 7 yrs. At followup, one patient had died of acquired immunodeficiency syndrome, 3 could not be reached, and 2 had undergone surgical fusion due to severe myelopathy and now showed complete neurological recovery. Of the remaining 16 patients, 7 (32%) showed progression and 9 (41%) showed no change in the C1-odontoid distance. Vertical AAS developed in one patient. After the 2-yr assessment, 3 additional patients had surgical fusion because of notable progression of AAS, despite absence of neurological signs.

CONCLUSION

Anterior AAS progressed in a number of these patients in the 2 yrs following its detection, and with or without neurological signs, surgical management was thought appropriate in a considerable number of them.