Profile of HLA-B27-related 'unclassifiable' seronegative spondyloarthropathy in females and its comparison with the profile in males

Identifying patients with axial spondyloarthritis in primary care: how useful are items indicative of inflammatory back pain?

Background

The value of clinical items defining inflammatory back pain to identify patients with axial spondyloarthritis (SpA) in primary care is unclear.

Objective

To identify predictive clinical parameters for a diagnosis of axial SpA in patients with chronic back pain presenting in primary care.

Methods

Consecutive patients aged <45 years (n=950) with back pain for >2 months who presented to orthopaedic surgeons (n=143) were randomised based on four key questions for referral to rheumatologists (n=36) for diagnosis.

Results

The rheumatologists saw 322 representative patients (mean age 36 years, 50% female, median duration of back pain 30 months). 113 patients (35%) were diagnosed as axial SpA (62% HLA B27+), 47 (15%) as ankylosing spondylitis (AS) and 66 (21%) as axial non-radiographic SpA (nrSpA). Age at onset ≤35 years, improvement by exercise, improvement with non-steroidal anti-inflammatory drugs, waking up in the second half of the night and alternating buttock pain were identified as most relevant for diagnosing axial SpA by multiple regression analysis. Differences between AS and nrSpA were detected. No single item was predictive, but ≥3 items proved useful for good sensitivity and specificity by receiver operating characteristic modelling.

Conclusion

This study shows that a preselection in primary care of patients with back pain based on a combination of clinical items is useful to facilitate the diagnosis of axial SpA.

Undifferentiated Spondyloarthropathy in Chinese Patients

BACKGROUND

Undifferentiated spondyloarthropathy (USpA) is a unique group in spondyloarthropathy (SpA). This study will investigate the clinical and laboratory characteristics of USpA in the Chinese population.

METHODS

Forty two patients with USpA were enrolled from our rheumatology outpatient facility in this retrospective study. SpA was diagnosed according to the European Spondyloarthropathy Study Group (ESSG) criteria. Patients were considered having USpA when they had SpA but did not meet the criteria for the diagnosis of ankylosing spondylitis (AS), Reiter's syndrome or reactive arthritis (ReA), psoriatic arthritis (PsA), and inflammatory bowel diseases (IBD)-related arthritis, etc. Laboratory tests included erythrocyte sedimentation rate (ESR), serum C-reactive protein (CRP), immunoglobulin A (IgA), and human leukocyte antigen B27 (HLA-B27).

RESULTS

Among the 42 USpA patients, the ratio of men to women was 1.47:1, and the age at onset was 32.33 +/- 10.83 years old. Approximately 61.9% of patients had peripheral arthritis, 30.95% had uveitis, and 64.29% had positive HLA-B27. Among these female USpA patients, compared to males, there is a trend of older age at disease onset, higher percentage of HLA-B27 positive, more peripheral arthritis and uveitis, longer disease duration, and higher level of ESR, and IgA and CRP in serum. The items reaching significant difference between males and females were longer disease duration (p < 0.001), higher level of ESR (p < 0.001), and serum IgA (p = 0.03). There was no significant difference in clinical and laboratory characteristics between HLA-B27-positive and -negative groups.

CONCLUSIONS

Studies on USpA patients have not been reported in the Chinese population. In this study, we demonstrate the unique demographic characteristics, clinical and laboratory data of USpA in the Chinese population. These findings should be confirmed by analyzing larger number of patients and longer time for further follow-up. Such studies are crucial to understand the pathogenesis of USpA and evaluate its prognosis.

Ankylosing spondylitis and undifferentiated spondyloarthritis in Kuwait: a comparison between Arabs and South Asians

The objectives of this study were to describe and compare the clinical characteristics of ankylosing spondylitis (AS) and undifferentiated spondyloarthritis (USpA) in Middle East Arab (MEA) and South Asian (SA) patients diagnosed in our unit. Fifty-eight consecutive patients diagnosed with SpA were studied after classifying them into MEA and SA. They were further classified as per disease diagnosis. Excluding three patients with miscellaneous ethnicity, there were 29 MEA and 26 SA patients. Seventy-two percent of MEA patients were males (vs 92% of SA patients). Of the 29 patients with MEA ethnicity, 17 had AS and 9 had USpA. Of the 26 patients with SA ethnicity, 10 had AS and 14 had USpA. Fifty-nine percent of MEA patients had AS (vs 39% of SA patients). Mean age at onset in AS patients was similar in the two ethnic groups. However, in patients with USpA, mean age at onset was somewhat lower at 21.8 years in the MEA group compared with 29.4 years in the SA group. Family history in first-degree relatives was significantly more common in MEA patients. Weight loss, inflammatory spinal pain, gluteal pain, and enthesopathy were equally common in both ethnic groups. Knee, ankle, and metatarsophalangeal joint involvement was less common in MEA patients. There were no significant differences in the occurrence of syndesmophytes, bamboo spine, and sacroiliitis in the two ethnic groups. HLA-B27 positivity rates in MEA patients were 87% for AS and 67% for USpA compared to 75 and 71%, respectively, in SA patients. It is concluded that some significant new findings have arisen from this study: the majority of MEA patients presented with AS, whereas the majority of SA patients had a picture of USpA. Family history was more common in MEA patients. Peripheral arthritis was less common in MEA patients. Worldwide, this is the first study to show that there are significant differences in the clinical expression of the various SpA in MEA patients compared to SA patients.

Can some cases of 'possible' spondyloarthropathy be classified as 'definite' or 'undifferentiated' spondyloarthropathy? Value of criteria for spondyloarthropathies. Spanish Spondyloarthropathy Study Group

OBJECTIVES

When evaluating patients for spondyloarthropathy, clinicians use the 'possible spondyloarthropathy' category to indicate that they are unsure about the diagnosis. We sought to determine whether Amor's criteria or the European Spondyloarthropathy Study Group (ESSG) criteria could lift thi uncertainty.

PATIENTS AND METHODS

During a Spanish study designed to validate criteria for spondyloar thropathies, 102 patients were classified in the 'possible spondyloarthropathy' category. We divided these patients into subgroups based on whether or not they met criteria for spondyloarthropathy. We compare baseline characteristics (N = 102) and five-year outcomes (N = 52) in these subgroups.

RESULTS

The following features were significantly more common in the subgroups of patients who met Amor's criteria for spondyloarthropathy: oligoarthritis, heel pain, uveitis, balanitis, family history of spondyloarthropathy, an presence of the HLA B27 antigen. No differences were found for age at symptom onset, disease duration, buttock pain, gender, dactylitis, diarrhea, or psoriasis. Of the 52 patients followed up for five years, 17 me Amor's criteria at baseline and 13 were subsequently found to have definite spondyloarthropathy, whic was undifferentiated in six cases. There were only three cases of spondyloarthropathy among the 2 patients who did not meet Amor's criteria at baseline. Of the 28 patients who met ESSG criteria at baseline, 13 had spondyloarthropathy versus three of the 17 patients who did not meet ESSG criteria at baseline

CONCLUSION

Amor's criteria or the ESSG criteria allow early classification of most patients with 'possible spondyloarthropathy' and early identification of undifferentiated spondyloarthropathy corresponding to minimal-symptom or incipient disease. In this study, Amor's criteria performed better than the ESSG criteria.

Studying patients with inflammatory back pain and arthritis of the lower limbs clinically and by magnetic resonance imaging: many, but not all patients with sacroiliitis have spondyloarthropathy

OBJECTIVE

Clinical and magnetic resonance imaging (MRI) data of 170 consecutive patients with inflammatory back pain (IBP) and/or oligoarthritis of the lower limbs were evaluated in a retrospective study. The aim was to determine the frequency of sacroiliitis and spondyloarthropathy (SpA) in this population, and to assess the significance of HLA B27 measurements for diagnosis in early disease.

METHODS

Pelvic X-rays were performed in all IBP patients and dynamic MRI of the sacroiliac joints in patients with IBP who had indefinite results on sacroiliac X-rays (n = 32).

RESULTS

European Spondyloarthropathy Study Group criteria for SpA were fulfilled by 106/170 patients (62.4%); eight additional patients had symptoms suggestive of SpA (4.7%). The most frequent SpA subset was undifferentiated SpA (uSpA), diagnosed in 46/106 patients (43.4%). Sacroiliitis was detected by MRI in 21/32 patients with IBP and unclear X-rays (65.6%). Of those, 14 were diagnosed as SpA and seven females with moderate unilateral sacroiliitis, but no features of SpA, also not on follow-up (at least 1 yr), were classified as undifferentiated sacroiliitis (US). Ten of the 14 SpA (71.4%) and none of the seven US patients were HLA B27 positive.

CONCLUSION

HLA B27 positivity in IBP patients with MRI-proven sacroiliitis positively predicts SpA. uSpA is a frequent SpA subset. There are HLA B27-negative non-SpA patients with moderate unilateral sacroiliitis whom we propose to be classified as US.

Radiologic diagnosis and pathology of the spondyloarthropathies

Five different subtypes of spondyloarthropathy (SpA) are now recognized. Clinical and radiologic involvement of the sacroiliac joint is an outstanding feature of the SpA, especially ankylosing spondylitis (AS). In this partly debilitating form of SpA a unique type of inflammatory axial involvement is observed which is characterized by inflammation and new bone formation at different spinal sites. In longstanding disease sacroiliitis, spondylitis and spondylodiscitis are easily recognized by conventional radiography and even better by computed tomography--especially when bony changes have already taken place. The advantage of dynamic magnetic resonance imaging (MRI) is to visualize morphologic changes and inflammation at the same time. This facilitates detection of sacroiliitis and spondylitis/spondylodiscitis at early time points. Hopefully, this will lead to other forms of therapy to prevent ankylosis of the spine. The origin of the granulation tissue infiltrating cartilage and bone in AS might be the synovium, the subchondrium or the bone marrow itself. T cells and macrophages seem to play an important role in this inflammatory process in which TNF-alpha is present in severe cases. The mechanisms responsible for the increased bone formation observed in the course of AS are unknown.