H. Brandt

Performance of referral recommendations in patients with chronic back pain and suspected axial spondyloarthritis

Background: Ankylosing spondylitis (AS) and its early form account for up to 5% of all patients with chronic back pain. Interest has recently focused on shortening the delay of 5–10 years between the appearance of first symptoms and the diagnosis of AS, particularly because effective treatments have now become available. Referral parameters that are easy for doctors in primary care to apply to patients presenting with possible AS could contribute to earlier diagnosis. Methods: Orthopaedists and primary-care doctors were requested to refer patients with (1) chronic low back pain (duration >3 months) and (2) onset of back pain before <45 years of age to a specialist rheumatology outpatient clinic for further diagnostic investigation if at least one of the following screening parameters was present: (1) inflammatory back pain, (2) positive human leucocyte antigen B27, and (3) sacroiliitis detected by imaging. The final diagnosis was made according to expert opinion. Results: In total, 350 referred cases were analysed. A diagnosis of definite axial spondyloarthritis (axial SpA), comprising established AS and pre-radiographic axial SpA, could be made in 45.4% of all referred patients (of which 50.3% were classified as AS and 49.7% as preradiographic axial SpA), whereas 45.4% were classified as non-SpA and 9.1% as possible SpA. A diagnosis of definite axial SpA could be made in 34.2% if only one referral parameter was positive, and in 62.6% if there was >1 positive referral parameter. Conclusions: The proposed referral parameters have proven useful when applied in primary care in identifying patients with AS/pre-radiographic axial SpA among young to middle-aged patients with chronic low back pain.

No efficacy of subcutaneous methotrexate in active ankylosing spondylitis: a 16-week open-label trial

Objective: To examine the potential therapeutic effect of methotrexate 20 mg given weekly as subcutaneous injections to 20 patients with ankylosing spondylitis refractory to non-steriodal antirheumatic drugs. Patients and methods: 20 patients with ankylosing spondylitis, a mean Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) score of 5.6 (range 4–9.3) and predominantly axial manifestations were treated with weekly 15 mg methotrexate subcutaneously for 4 weeks, which was then increased to 20 mg subcutaneously for the next 12 weeks. Clinical outcome assessments included, among others, BASDAI score physical function, spinal mobility, patients’ and physicians’ global assessment (visual analogue scale), peripheral joint assessment, quality of life (Short Form 36) and C reactive protein. The primary end point of the study was a 20% improvement on the ASsessments in Ankylosing Spondylitis (ASAS 20) scale. Results: Using an intention-to-treat analysis, ASAS 20 was achieved in only 25% of patients. An ASAS 40 response was achieved in 10% of patients, and no patient reached an ASAS 70 response or the ASAS criteria for partial remission. For the mean BASDAI score, no change was observed between baseline and week 16 (baseline 5.6 v week 16, 5.6). No improvement was observed in any of the clinical parameters or C reactive protein, except a small but non-significant decrease in the number of swollen joints. Conclusions: In this open study, methotrexate did not show any benefit for axial manifestations in patients with active ankylosing spondylitis beyond the expected placebo response.

The frequency of non-radiographic axial spondyloarthritis in relation to symptom duration in patients referred because of chronic back pain: results from the Berlin early spondyloarthritis clinic

Objective This study was aimed at investigating the frequencies of non-radiographic axial spondyloarthritis (nr-axSpA) and ankylosing spondylitis (AS) diagnoses and their ratios in relation to symptom duration in patients referred because of chronic back pain and suspicion of axial SpA. Methods In this monocentre study, orthopaedists and primary care physicians were requested to refer patients with chronic low back pain (duration >3 months) and onset of back pain before 45 years of age to a SpA-specialised rheumatology outpatient clinic for further diagnostic investigation, if proposed screening parameters were present. The ratio of nr-axSpA to AS was analysed in relation to the duration of symptoms. Results A diagnosis of definite axial SpA was made in 43.7% of the referred patients (n=522). Axial SpA was diagnosed in a similar percentage of about 50% if back pain duration was <9 years but decreased to 36% if symptom duration was >9 years. Nr-axSpA represented the majority of patients (67.3%) only if duration of back pain was 1 year and less at the time of referral. Between 1 and 6 years of back pain duration the probability of nr-axSpA and AS was nearly equal (1–3 years: 52.5% and 47.5%, respectively; 3–6 years: 53.7% and 46.3%, respectively). In patients with back pain duration of 6–9 years, AS was more likely (61.1%) to be diagnosed than nr-axSpA (38.9%), and this increased further over time. Conclusions Non-radiographic axial SpA represents an important differential diagnosis of back pain, especially in patients with recent symptom onset.

Limited Diagnostic Value of Unilateral Sacroiliitis in Scintigraphy in Assessing Axial Spondyloarthritis

Objective. To assess the diagnostic value for axial spondyloarthritis (SpA) of unilateral sacroiliitis in scintigraphy in daily clinical practice. Methods. In 207 patients with chronic back pain, the diagnostic value of scintigraphy was assessed retrospectively. The diagnosis made by the rheumatologist (axial SpA vs no axial SpA) was the standard. Results. Sensitivities of scintigraphy for any (unilateral or bilateral), bilateral, and isolated unilateral sacroiliitis were 64.9%, 40.2%, and 24.7%, respectively. Respective specificities were 50.5%, 57.7%, and 92.8%, resulting in likelihood ratios of 1.3, 1.0, and 3.4. Conclusion. Scintigraphy of the sacroiliac joints is of limited value for the diagnosis of axial SpA. Unilateral compared to bilateral sacroiliitis is slightly superior, but is associated with a low sensitivity.

Bildgebende Diagnostik bei Verdacht auf entzündlich rheumatische Achsenskeletterkrankungen (Sakroiliitis)

Zusammenfassung Die entzündliche Beteiligung der Sakroiliakalgelenke ist das Schlüsselsymptom der Spondylarthropathien, vor allem bei der ankylosierenden Spondylitis. Die konventionelle bildgebende Diagnostik der Sakroiliitis gilt in den Frühstadien als problematisch, da die Sensitivität konventioneller Röntgenaufnahmen hier sehr gering ist. Die Magnetresonanztomographie der Sakroiliakalgelenke ist in der Lage, sowohl akut entzündliche als auch chronische Veränderungen in allen Stadien zu erfassen. Mögliche Nachteile dieser Methode sind Untersucherabhängigkeit, bislang fehlende Standardisierung sowie die noch relativ hohen Kosten. Deshalb hat der „Arbeitskreis bildgebende Diagnostik in der Rheumatologie des Regionalen Rheumazentrums Berlin“, welcher sich aus erfahrenen Rheumatologen, Skelettradiologen und Orthopäden zusammensetzt, eine Übersicht der bildgebenden Diagnostik der Sakroiliitis erarbeitet, in welcher neben dem klinischen Hintergrund auch technische Details ausgeführt und Strahlenexposition und Kosteneffektivität berücksichtigt werden.Summary Involvement of the sacroiliac joints is a hallmark of the spondyloarthropathies, especially in ankylosing spondylitis. The conventional diagnostic imaging of sacroiliitis in early stages might cause problems, because sensitivity of conventional radiographic methods is known to be too low in early stages of the disease. Magnetic resonance imaging of the sacroiliac joints certainly enables one to detect acute as well as chronic inflammatory changes in all stages of the disease. The potential disadvantages of this method are the dependency on the examiner, the lack of standardization, and the relatively high costs. Therefore, the „Workgroup of Diagnostic Imaging in Rheumatology of the Regional Center of Rheumatology of Berlin“ including experienced rheumatologists, skeletal radiologists, and orthopedists acquired an imaging graduation for detection of sacroiliitis in consideration of the clinical background, the technical details of the methods, questions of ionizing radiation exposure, and cost effectiveness.