Long-term efficacy and safety of etanercept after readministration in patients with active ankylosing spondylitis

OBJECTIVES

Treatment of ankylosing spondylitis (AS) with the tumour necrosis factor alpha (TNF-alpha) receptor fusion protein etanercept has shown efficacy in patients with active disease in randomized controlled trials (RCTs) for limited periods. The objective of the study was to assess the long-term efficacy and safety of etanercept over 1 yr, including discontinuation and readministration.

METHODS

In this 54-week open observational study, 26 AS patients received 25 mg etanercept subcutaneously twice weekly after several months of discontinuation following a 6-month RCT with the same agent. All patients who developed high disease activity after cessation of etanercept, defined as a Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) > or = 4 and pain > or = 4 on a numerical rating scale, entered the study. Standard assessment tools, such as the Bath Ankylosing Spondylitis functional index (BASFI), were used. An intention-to-treat (ITT) and a completer analysis were performed. The results were compared with the baseline values of the open study.

RESULTS

Out of the initial 30 patients, 26 (87%) were eligible for the open extension study after a mean of about 27 weeks. At week 54, 23/26 patients (88%) were still on treatment with etanercept. The ITT analysis showed that 58% (95% confidence interval 39-74%) of the patients achieved a 50% improvement of BASDAI at week 54. According to the Assessments in Ankylosing Spondylitis working group criteria, 8/26 patients (31%) were in partial remission at week 54. Function, metrology and quality of life improved significantly. Only one patient had a serious adverse event that resulted in discontinuation.

CONCLUSIONS

This study shows that treatment with etanercept is efficacious and safe after readministration over 1 yr in patients with active AS not taking DMARDs or steroids.

Outcome of patients with active ankylosing spondylitis after two years of therapy with etanercept: Clinical and magnetic resonance imaging data

OBJECTIVE

To examine the long-term outcome of patients with active ankylosing spondylitis (AS) clinically and by magnetic resonance imaging (MRI) after continuous treatment with the tumor necrosis factor (TNF) receptor fusion protein etanercept over 2 years.

METHODS

Overall, 26 patients with active AS were treated with etanercept 25 mg twice daily subcutaneously, twice weekly with no concomitant disease-modifying antirheumatic drugs (DMARDs) or steroids. The clinical response was assessed by standardized parameters. Inflammatory spinal lesions were quantified by the ASspiMRI-a rating gadolinium-enhanced (T1-weighted gadolinium diethylenetriaminepentaacetic acid) and STIR MRI sequences. The primary outcome was a Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) improvement > or =50% after 2 years of etanercept therapy compared with the baseline value of the study.

RESULTS

Overall, 21 (70%) of 30 patients completed year 2. In the intent-to-treat analysis, 54% of the patients showed a 50% improvement according to the BASDAI and a 40% improvement according to the Assessment in Ankylosing Spondylitis (ASAS) criteria. In the completer analysis, 9 (43%) of 21 patients were in partial remission according to ASAS criteria. Mean +/- SD BASDAI scores, which were elevated at baseline (6.3 +/- 1.6), remained low: 2.7 +/- 2.4 after 2 years compared with 2.6 +/- 2.2 at week 54. In accordance, all other clinical parameters showed sustained improvement during year 2. The majority of patients had no disease activity flares. MRI evaluation showed a 75% improvement of active spinal lesions, but minor spinal inflammation was still present in 64% of the patients after 2 years. There were 2 serious adverse events leading to discontinuation of etanercept.

CONCLUSION

The clinical efficacy and safety of etanercept in patients with active AS without simultaneous administration of DMARDs or steroids over 2 years of continuous treatment is confirmed. Spinal inflammation as depicted by MRI decreased significantly, but a few patients still had some spinal inflammation even after long-term anti-TNF therapy.

Impact of anti-tumour necrosis factor alpha treatment on admissions to hospital and days of sick leave in patients with ankylosing spondylitis

OBJECTIVE

To analyse the impact of infliximab treatment on the number of hospital inpatient days and days of sick leave in patients with active ankylosing spondylitis (AS).

METHODS

The data of a 2 year open extension study of a 12 week, double blind, randomised, placebo controlled trial, in which all patients with AS were treated with 5 mg/kg infliximab, were used to investigate the effect of anti-TNF treatment on admissions to hospital and days of sick leave. All patients were interviewed at baseline and at regular intervals during the study to collect this information by questionnaires. Patients who completed 2 years of treatment (n = 49) and those who did not (n = 20) were analysed separately. Sick leave analysis was restricted to currently employed patients (n = 38).

RESULTS

During the 12 months before the screening visit, 20/49 (41%) completers had been admitted to hospital. After 1 and 2 years of treatment this percentage was reduced to 5/49 (10%; p<0.01), corresponding to a significant decrease in the mean number of inpatient days: from 11.1 to 0.6 after 1 year (p<0.01) and 2.9 after 2 years (p<0.01), respectively. No changes were seen in the dropout group.

CONCLUSION

The use of infliximab in patients with active AS reduces some important costs of AS, but additional studies with detailed cost calculations are needed.

Nutzen der station�ren Therapie in der Versorgung von Patienten mit Rheumatoider Arthritis

Our aim was to analyze the existing body of evidence about inpatient care of patients suffering from rheumatoid arthritis (RA). The report was induced by the executive board of the German Society of Rheumatology which assigned the "Oliver-Sangha committee" to dissect and point out the tasks of inpatient care during the next few years. A systemic search of the literature was performed covering the years 1966 to 2001. A total of 16 studies were selected and thoroughly appraised in a systematic way. Four randomized controlled trials addressing the question could be identified. All of them included only patients in a clinical condition allowing outpatient care as well. Two studies indicate some advantage of inpatient care in comparison to outpatient treatment. Two studies, both equivalence studies from design, reveal that RA patients do not generally experience additional benefit from hospitalization. Consideration of two additional cohort studies demonstrates the increased need of inpatient care in RA patients. None of the studies was derived from the German health care system. Emergency cases were not the subject of any of these trials. General statements about the value of inpatient care of RA patients can not be drawn from the analyzed studies. The committee makes suggestions for future investigations that may help to answer this important question considering the special circumstances of the German health care system.

Inflammation in ankylosing spondylitis: a systematic description of the extent and frequency of acute spinal changes using magnetic resonance imaging

BACKGROUND

Magnetic resonance imaging (MRI) is increasingly used to detect inflammation in the spine of patients with ankylosing spondylitis (AS).

OBJECTIVES

To detect differentially the presence and extent of inflammation in the three spinal segments of patients with AS by MRI.

METHODS

In 38 patients with active AS, acute spinal lesions were assessed by T(1) weighted, gadolinium enhanced, spin echo MRI (T(1)/Gd-DTPA) and short tau inversion recovery (STIR) sequences. MRI was quantified by the validated scoring system ASspiMRI-a. Acute spinal lesions were detected in the whole spine and in each spinal segment. One vertebral unit (VU) was defined as the region between two virtual lines drawn through the middle of each vertebral body.

RESULTS

A greater number of inflammatory spinal lesions were found by the STIR sequence than by Gd-DTPA: inflammation was present in 30.6% of the VUs as assessed by STIR, compared with 26.8% of the same VUs assessed by T(1)/Gd-DTPA. Inflammation was found more commonly in the thoracic spine (TS) than in the cervical (CS) or the lumbar spine (LS) with both techniques. When STIR was used, spinal inflammation in the CS, the TS, and LS was detected in 10/38 (26%), 28/38 (74%), and 9/38 (24%) patients, respectively. The VU T7/8 was found to be the VU most often affected by both techniques (27.8% by T(1)/Gd-DTPA and 34.5% by STIR).

CONCLUSIONS

Spinal inflammation is a common manifestation in patients with AS, and appears more frequently in the TS. The scoring system ASspiMRI-a can be used for evaluation of acute spinal changes in AS.

Two year maintenance of efficacy and safety of infliximab in the treatment of ankylosing spondylitis

OBJECTIVE

To obtain results of the second year extension of an original 3 month randomised, placebo controlled trial (and the 1 year extension study) assessing the use of infliximab, a monoclonal antibody to tumour necrosis factor alpha, for the treatment of patients with ankylosing spondylitis (AS).

METHODS

Of the 54 patients with AS who completed the first year of the study, 52 continued to receive infliximab 5 mg/kg every 6 weeks up to week 102. The primary end point was the proportion of patients achieving at least 50% improvement from baseline in the Bath AS Disease Activity Index (BASDAI) at week 102. Other assessments included patient and physician global assessments, quality of life as assessed by Short Form-36, Bath AS Functional Index, Bath AS Metrology Index, and C reactive protein (CRP).

RESULTS

Improvement in signs and symptoms of AS seen during the first year of the study was sustained during the second year. Forty nine patients (71% of 69 enrolled patients and 49/52 (94%) patients who started year 2) completed the study up to week 102. Thirty (58%) patients achieved at least 50% improvement from baseline in the BASDAI score at week 102. Scores for other efficacy assessments were similar at weeks 54 and 102. Median CRP levels remained low at weeks 54 and 102 (3.9 and 4.3 mg/l, respectively). Side effects during the second year of the study were similar to those of the first year of treatment with infliximab.

CONCLUSIONS

Patients with AS treated for 2 years with infliximab 5 mg/kg exhibited a good and durable clinical response.

The burden of ankylosing spondylitis and the cost-effectiveness of treatment with infliximab (Remicade(R))

OBJECTIVES

In the past, treatment options for ankylosing spondylitis (AS) have been limited, and the introduction of new treatments such as infliximab will have a noticeable impact on health-care budgets. The objective of this study was therefore to assess the current burden of the disease and estimate the cost-effectiveness of infliximab treatments.

METHODS

A cross-sectional retrospective observational study of resource consumption and utility related to disease severity was performed in patients who had participated in a population survey between 1992 and 1994 at the University of Bath and patients regularly followed at the Royal National Hospital for Rheumatic Diseases in Bath for up to 9 years. Mean costs and utility were estimated using a regression model including age, gender, disease duration, disease activity and functional status, and disease development was expressed as annual progression of functional disability. Cost-effectiveness of infliximab was modelled using a 3-month placebo-controlled clinical trial with open 1-yr extension in 70 patients, over a total time frame of 2 yr. In the model, costs and utility controlled for disease severity and age from the observational study were assigned to individual patients. The effect of long-term treatment was evaluated in a hypothetical model over 30 yr.

RESULTS

Fifty-seven per cent of patients answered the questionnaires. The mean age was 57 (s.d. 11.2) yr, 74% were male and mean disease duration was 30.2 (11.7) yr. Mean total costs were estimated at pound 6765 (s.d. pound 166). Indirect costs represented 57.9% and non-medical costs such as investments and informal care accounted for 16.5% of total costs. Mean utility was 0.67 (0.21). In the main model, mean costs for untreated patients are estimated at pound 25,128. For the infliximab group, mean costs (excluding treatment) are estimated at pound 17,240, a reduction of 31%. Thus, part of the treatment cost was offset by savings in other resources ( pound 7888), leaving an incremental cost of pound 6214. Treatment increased the number of quality-adjusted live years (QALYs) by 0.175 QALYs, leading to a cost per QALY gained of pound 35,400 for the first year of treatment. When treatment is assumed to continue for the full 2 yr, the cost per QALY is pound 32,800. When infliximab infusions are given every 8 weeks instead of every 6 weeks, the cost per QALY is reduced to pound 17,300. In the long-term model, the cost per QALY is estimated at pound 9600.

CONCLUSIONS

Non-medical costs and production losses dominate costs in AS, and economic evaluation must therefore adopt a societal perspective. The cost of treatment with infliximab is partly offset by reductions in the cost of the disease and patients' quality of life is increased, leading to a cost per QALY gained in the vicinity of pound 30,000 to pound 40,000 in the short term, but potentially below pound 10,000 in the long term.

Biological therapies in the spondyloarthritides--the current state

Therapeutic options for patients suffering from the more severe spondyloarthritides (SpA) have been rather limited in the last decades. Evidence is now accumulating that anti-tumour necrosis factor (TNF) therapy is highly effective in SpA, especially in ankylosing spondylitis (AS) and psoriatic arthritis (PsA). Based on the data recently published concerning more than 1000 patients with AS and PsA, this treatment seems to be even more effective than in rheumatoid arthritis (RA). The anti-TNFalpha agents currently available, infliximab (Remicade), etanercept (Enbrel) and adalimumab (Humira), are approved for the treatment of RA in the USA and Europe. The situation for SpA is different from RA because there is an unmet medical need, especially in AS, since no therapies with disease-modifying anti-rheumatic drugs (DMARDs) are available for severely affected patients, especially those with spinal disease. Thus, TNF blockers may even be considered a first-line treatment in a patient with active AS and PsA whose condition is not sufficiently controlled with non-steroidal anti-inflammatory drugs (NSAIDs) in the case of axial disease, and sulphasalazine or methotrexate in the case of peripheral arthritis. For infliximab, a dose of 5 mg/kg is required, and intervals of between 6 and 12 weeks are necessary to constantly suppress disease activity-also a major aim for long-term treatment. The standard dosage of etanercept is 2 x 25 mg subcutaneously per week. There are almost no studies yet on adalimumab (standard dose in RA, 20-40 mg subcutaneously every 1-2 weeks) in SpA. Infliximab and etanercept are now both approved for AS in Europe. The efficacy of etanercept was first demonstrated in PsA, and it is now approved for this indication in the USA and Europe. There is preliminary evidence that both agents also work in other SpA, such as undifferentiated SpA (uSpA). Studies should be performed to document the long-term efficacy of this treatment. There is hope that ankylosis may be preventable, but it remains to be shown whether patients benefit from long-term anti-TNF therapy and whether radiological progression and ankylosis can be stopped. Severe adverse events have remained rare. Complicated infections including tuberculosis have been reported. These can largely be prevented by appropriate screening. As it stands now, the benefits of anti-TNF therapy in AS seem to outweigh these shortcomings.

How to diagnose axial spondyloarthritis early

BACKGROUND

Chronic low back pain (LBP), the leading symptom of ankylosing spondylitis (AS) and undifferentiated axial spondyloarthritis (SpA), precedes the development of radiographic sacroiliitis, sometimes by many years.

OBJECTIVE

To assign disease probabilities and to develop an algorithm to help in the early diagnosis of axial SpA.

METHODS

Axial SpA comprises AS and undifferentiated SpA with predominant axial involvement. Clinical features include inflammatory back pain (IBP), alternating buttock pain, enthesitis, arthritis, dactylitis, acute anterior uveitis, a positive family history, psoriasis, inflammatory bowel disease, and good response to NSAIDs. Associated laboratory findings include raised acute phase reactions, HLA-B27 association, and abnormalities on skeletal imaging. Sensitivities, specificities, and likelihood ratios (LRs) of these parameters were determined from published studies. A 5% prevalence of axial SpA among patients with chronic LBP was used. The probability of the presence of axial SpA, depending on the presence or absence of the above clinical features of SpA, was determined. A probability of > or = 90% was used to make a diagnosis of axial SpA.

RESULTS

The presence of inflammatory back pain features increased the probability of axial SpA from the background 5% prevalence to 14%. The presence of 2-3 SpA features was necessary to increase the probability of axial SpA to 90%. The highest LRs were obtained for HLA-B27 and MRI. Diagnostic algorithms to be used in daily practice were suggested.

CONCLUSIONS

This approach can help clinicians to diagnose with a high degree of confidence axial SpA at an early stage in patients with IBP who lack radiographic sacroiliitis.

How to diagnose axial spondyloarthritis early

BACKGROUND

Chronic low back pain (LBP), the leading symptom of ankylosing spondylitis (AS) and undifferentiated axial spondyloarthritis (SpA), precedes the development of radiographic sacroiliitis, sometimes by many years.

OBJECTIVE

To assign disease probabilities and to develop an algorithm to help in the early diagnosis of axial SpA.

METHODS

Axial SpA comprises AS and undifferentiated SpA with predominant axial involvement. Clinical features include inflammatory back pain (IBP), alternating buttock pain, enthesitis, arthritis, dactylitis, acute anterior uveitis, a positive family history, psoriasis, inflammatory bowel disease, and good response to NSAIDs. Associated laboratory findings include raised acute phase reactions, HLA-B27 association, and abnormalities on skeletal imaging. Sensitivities, specificities, and likelihood ratios (LRs) of these parameters were determined from published studies. A 5% prevalence of axial SpA among patients with chronic LBP was used. The probability of the presence of axial SpA, depending on the presence or absence of the above clinical features of SpA, was determined. A probability of > or = 90% was used to make a diagnosis of axial SpA.

RESULTS

The presence of inflammatory back pain features increased the probability of axial SpA from the background 5% prevalence to 14%. The presence of 2-3 SpA features was necessary to increase the probability of axial SpA to 90%. The highest LRs were obtained for HLA-B27 and MRI. Diagnostic algorithms to be used in daily practice were suggested.

CONCLUSIONS

This approach can help clinicians to diagnose with a high degree of confidence axial SpA at an early stage in patients with IBP who lack radiographic sacroiliitis.

Aktueller Stand der Therapie mit TNF?-Antagonisten bei ankylosierender Spondylitis und undifferenzierter Spondyloarthritis

The Spondyloarthritides (SpA) comprise a group of inflammatory rheumatic diseases which mostly affect the spine and the larger peripheral joints. The most common entities in this group are ankylosing spondylitis (AS) and undifferentiated spondyloarthritis (uSpA). Treatments with disease-modifying or remission-inducing properties for patients with AS are so far not available. However, in the light of relevant individual and socioeconomic consequences this is an unmet medical need. Recently, etanercept in addition to infliximab has shown substantial efficacy which might even be disease controlling. For both TNFalpha blocking agents, large randomized placebo-controlled trials have proven their efficacy with an acceptable profile of adverse events. In open trials these drugs also work in patients with uSpA. There is some hope now that the TNFalpha blocking agents could stop the development of AS in patients starting with uSpA.

Besonderheiten der Osteoporose-Therapie bei entz�ndlich-rheumatischen Erkrankungen*

The therapeutic specialties of osteoporosis in inflammatory rheumatic diseases has gained mounting interest in the last year. The paper describes special aspects of osteoporosis in rheumatoid arthritis, ankylosing spondylitis and systemic lupus erythematodes. The problems of glucocorticoid therapy are discussed intensively with regard to the recently published recommendations for glucocorticoid-induced osteoporosis. Risk factors of osteoporosis and the therapeutic implications are demonstrated intensively as well as the modifications of the recommendations.

In vivo 1 H magnetic resonance spectroscopy of rat brain after valproate administration

Previous studies have shown that valproate is detectable in vitro by 1H magnetic resonance spectroscopy (MRS) at 1.5 T, whereas in patients on valproate monotherapy, no significant dose-dependent valproate signal could be seen. To investigate whether an increased signal-to-noise ratio as provided by higher valproate doses and increased magnetic field strength would enable detection of valproate in vivo, six Wistar rats were examined using volume-selective 1H MRS at 2.34 T. The spectra were analyzed by fitting a linear superposition of the basis spectra of valproate, brain metabolites, and simulated lipid signals. The analysis revealed no significant signal contributions after valproate administration of up to 330 mg/kg body weight. To analyze how underlying mechanisms, such as potential drug interactions with macromolecules, may affect the valproate signal, additional in vitro spectra of valproate were measured before and after adding albumin. The spectra exhibited a strong decrease of the valproate signal with increasing albumin concentration. The results support the hypothesis that in vivo valproate is bound to a high degree to macromolecules and will therefore not be detectable by 1H MRS.

Morphology of canine cumulus-oocyte complexes in pre-pubertal bitches

The morphology of canine cumulus-oocyte complexes (COCs) before puberty is still unknown. Therefore, the aim of our study was to elucidate the morphological characteristics of pre-pubertal oocytes and cumulus cells by light microscopy, scanning electron microscopy and transmission electron microscopy. The pre-pubertal oocyte was characterized by accumulation of lipid yolk droplets in the cytoplasm as well as high energy metabolism, low protein synthesis and high transcriptional activity of the cumulus cells. The cumulus cells, which revealed a prominent nucleus and few cytoplasm, communicated with each other by few short processes and exhibited merely a small amount of processes reaching the oocyte. Our studies imply that both the oocyte and the cumulus cells of canine COCs before puberty reveal characteristic morphological features which are correlated with changes in oocyte metabolism and cumulus cell communication.

Analysing chronic spinal changes in ankylosing spondylitis: a systematic comparison of conventional x rays with magnetic resonance imaging using established and new scoring systems

OBJECTIVES

To compare conventional radiography and magnetic resonance imaging (MRI) for detection of chronic changes in the spine of patients with ankylosing spondylitis (AS).

METHODS

Assessment of chronic lesions in conventional x rays and T1 weighted MRI turbo spin echo sequences was performed with the established x ray scores BASRI and SASSS, the new Berlin score, and the MRI scoring system ASspiMRI-c All images were read twice and "blindly" by two readers. One vertebral unit (VU) was defined as the region between two virtual lines drawn through the middle of each vertebra. Definite involvement was defined as a score > or =2 in a spinal segment.

RESULTS

Thirty nine patients with AS were examined (25 (64%) male, mean age 40.9 years, 33/36 (92%) HLA-B27 positive). The Berlin score correlated with the BASRI (r = 0.73, p = 0.01). The ASspiMRI-c correlated well with the BASRI and the Berlin score (r = 0.66 and r = 0.51, respectively, p = 0.01). The Berlin x ray score showed that 12/35 (34.3%), 13/35 (37.1%), and 12/28 (31.6%) patients had definite involvement of the cervical spine (CS), thoracic spine (TS), and lumbar spine (LS), respectively. The ASspiMRI-c showed that 10/36 (27.8%), 21/36 (58.3%), and 9/35 (25.7%) patients had definite involvement of the CS, TS, and LS, respectively. Syndesmophytes were found in 14.4% of all VUs with 90% agreement between the SASSS and Berlin score.

CONCLUSIONS

T1 weighted MRI can detect chronic lesions in AS. The two new scoring systems proved valid in comparison with established scoring systems and based on aspects of the OMERACT filter. The thoracic spine is most commonly affected in AS. This part of the spine is best assessed by MRI.

Development and preselection of criteria for short term improvement after anti-TNF alpha treatment in ankylosing spondylitis

OBJECTIVE

To develop and compare candidate improvement criteria for anti-TNFalpha treatment in ankylosing spondylitis with optimal discriminating capacity between treatment and placebo.

METHODS

Data from two randomised controlled trials which included 99 patients treated with infliximab or etanercept were used to evaluate 50 candidate improvement criteria. These were developed on the basis of pain, patient's global assessment, function, morning stiffness, spinal mobility, and C reactive protein. Different levels of improvement in each domain (20-60%) were used to define Boolean type criteria. These criteria were compared with different percentages of improvement on the BASDAI and with modified ASAS improvement criteria. Bootstrap methods were applied to calculate 95% confidence intervals (CI) of the chi(2) test values to select the best candidate improvement criteria.

RESULTS

The best performing improvement criteria were "20% improvement in five of six domains" (chi(2) = 31.9 (95% CI, 18.0 to 46.9)) with a low placebo response of 2.9% and a high response to infliximab of 67.7%; and "ASAS 40% improvement" (chi(2) = 26.5 (13.3 to 41.1)), with response to placebo of 5.7% and response to infliximab of 64.7%. The good discriminating capacity of the two improvement criteria was confirmed by the combined dataset of the infliximab and etanercept trial.

CONCLUSIONS

The "five of six" improvement criterion has the advantage of including the objective domains spinal mobility and acute phase reactants, but requires only 20% improvement. The ASAS 40% improvement criterion has the advantage of setting a high threshold, but only in patient reported outcomes. The choice between these improvement criteria needs to be based on further validation from upcoming trials.

Prediction of a major clinical response (BASDAI 50) to tumour necrosis factor alpha blockers in ankylosing spondylitis

BACKGROUND

TNFalpha blockers have been shown to be highly efficacious in patients with active ankylosing spondylitis (AS).

OBJECTIVE

To identify parameters predicting the clinical response to TNF blockers in AS.

METHODS

Patients with active AS participated in two placebo controlled, randomised trials conducted in Germany with infliximab (n = 69) and etanercept (n = 30), respectively. For inclusion in either trial patients had to have high disease activity (BASDAI >or=4) and a spinal pain score (numerical rating scale 0-10) >or=4 despite treatment with NSAIDs. A major clinical response was defined as a 50% improvement of the initial BASDAI (BASDAI 50) after 12 weeks' treatment with active drug. Logistic regression likelihood ratio tests (univariate and multivariate), Student's t test, and chi(2) tests were performed.

RESULTS

Univariate analysis showed the following to be predictors of a major response (BASDAI 50) to treatment: shorter disease duration (p = 0.003); lower BASFI (p = 0.007); younger age (p = 0.009); raised ESR (p = 0.033); raised CRP (p = 0.035). After adjustment for disease duration, BASFI, ESR, and CRP, but not age, remained significantly associated. After adjustment for disease duration and for BASFI, ESR, CRP, and in addition, a higher BASDAI were significantly associated with response. The best multivariate model built by stepwise regression contained the covariables disease duration, BASFI, BASDAI, and CRP.

CONCLUSION

A shorter disease duration, younger age, and a lower BASFI are predictors of a major clinical response to TNF blockers in active AS. Raised CRP and a higher BASDAI may also be valuable predictors. These data need to be confirmed in further studies.