Hypothalamic-pituitary-adrenal axis function in ankylosing spondylitis

Serum markers associated with clinical improvement in patients with ankylosing spondylitis treated with golimumab

Objective

Identify serum biomarkers modulated by golimumab treatment and associated with clinical response in patients with ankylosing spondylitis (AS).

Methods

Sera were collected at weeks 0, 4 and 14 from 100 patients with active AS in the GO–RAISE study. Patients were randomly assigned subcutaneous injections of placebo, golimumab 50 mg, or golimumab 100 mg every 4 weeks. Samples were tested for select inflammatory, bone and cartilage markers, and protein profiling was also performed.

Results

Golimumab treatment resulted in significant decreases in several serum proteins at weeks 4 and 14 compared with placebo. Patients who achieved clinical response at week 14, as assessed by a ≥20% improvement in the Assessment in SpondyloArthitis international Society response criteria (ASAS 20), demonstrated a distinct biomarker profile with lower levels of acute phase reactants and inflammatory biomarkers compared with patients who did not. Notably, combinations of two or three biomarkers assessed at baseline were predictive of various clinical outcomes (ASAS 20, Bath ankylosing spondylitis disease activity index 50 or Bath ankylosing spondylitis functional index) using a logistic regression analysis, and the overall predictive values for these combined biomarkers were greater than observed for C-reactive protein (CRP) alone.

Conclusion

Golimumab modulated acute phase reactants and inflammatory markers in patients with active AS. Specific combinations of biomarkers at baseline demonstrated a stronger prediction for clinical efficacy than CRP alone. These data provide insights into the mechanism of golimumab on inflammatory processes driving AS pathology, and may have utility in managing the treatment of patients with AS.

More Night Than Day — Circadian Rhythms in Polymyalgia Rheumatica and Ankylosing Spondylitis

The circadian rhythm of symptoms in patients with chronic inflammatory diseases is well known. Circadian rhythms could be used to identify targets for time-adapted antiinflammatory therapies, which are administered prior to the flare of cytokine synthesis and inflammatory activity. In recent years, the diurnal variations in rheumatoid arthritis have been described precisely for pain, stiffness, and functional disability, as well as the underlying cyclic variations in hormone levels and cytokine concentrations. This review summarizes the current knowledge on circadian rhythms in other rheumatic diseases, focusing on polymyalgia rheumatica and ankylosing spondylitis.

Impaired hypothalamo-pituitary-adrenal axis in patients with ankylosing spondylitis

BACKGROUND

To investigate the hypothalamic-pituitary- adrenal (HPA) axis in patients with ankylosing spondylitis (AS) and healthy controls.

METHODS

Forty-nine AS patients and 20 healthy controls were included. Lowdose ACTH test (LDST) was used to assess the HPA axis. Basal cortisol, stimulated peak cortisol levels, and acutephase reactants [C-reactive protein (CRP), erythrocyte sedimentation rate, and fibrinogen] were studied. Bath Ankylosing Spondylitis Functional Index, Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), and Bath Ankylosing Spondylitis Metrology Index were also evaluated.

RESULTS

Patient and control groups were not different regarding age, sex, body mass index and waist circumference (WC). Basal cortisol levels did not show a significant difference between groups. However, cortisol increment after low-dose ACTH was significantly impaired in AS subjects with respect to controls (20.0+/-4.4 vs 24+/-2.2 microg/dl, p<0.001). Eleven AS patients had impaired cortisol peak after LDST when a cortisol cut-off is accepted as 500 nmol/l (18 microg/dl) and none of the controls exhibited a peak cortisol responses to LDST<500 nmol/l. Comparison of AS subjects who were receiving anti-tumor necrosis factor (TNF) (no.=23), and conventional therapy (no.=26) yielded similar basal and peak cortisol concentrations. Peak cortisol concentrations were associated with basal cortisol, impaired cortisol response, CRP, and fibrinogen. Impaired cortisol response (subjects with peak cortisol levels <18 microg/dl) was significantly correlated with basal and peak cortisol concentrations and BASDAI.

CONCLUSION

Our results indicate an increased prevalence of subclinical glucocorticoid deficiency in AS patients. Anti-TNF treatment seems not to have effect on HPA axis.

Increased expression of Toll-like receptor 4 in peripheral blood leucocytes and serum levels of some cytokines in patients with ankylosing spondylitis

Toll-like receptor 4 (TLR4) is a member of the Toll-like receptor family, which can bridge innate and adaptive immune responses. Activation of the TLR4 signalling pathway may induce the release of proinflammatory cytokines such as tumour necrosis factor (TNF)-alpha and interleukin (IL)-12, which was considered to play an important role in pathogenesis of immune-mediated diseases. Ankylosing spondylitis (AS) is an immune-mediated disease whose aetiology remains unknown. The aim of the study was to investigate the expression of TLR4 and serum TNF-alpha, IL-12 and soluble tumour necrosis factor-related apoptosis-inducing ligand (sTRAIL) level in AS patients. The results indicated that TLR4 protein and mRNA levels were significantly higher in AS patients than in healthy controls; however, there was no significant difference between human leucocyte antigen (HLA)-B27-positive and -negative AS patients, as well as serum levels of TNF-alpha, IL-12 and sTRAIL. In addition, in HLA-B27-positive AS patients, TLR4 level showed close associations with the cytokines and laboratory parameters of disease activity [erythrocyte sedimentation rate (ESR) and plasma C-reactive protein (CRP)], respectively. Similarly, the strong associations between the cytokines or between IL-12 and ESR or CRP were observed in HLA-B27-positive AS patients. Interestingly, in HLA-B27-positive AS patients, TNF-alpha correlated significantly with ESR, but did not with CRP. In contrast, sTRAIL correlated with CRP, but did not with ESR. Among HLA-B27-negative patients, no close correlation was found. In our study, it was suggested that the abnormal activation of TLR4 signalling and serum TNF-alpha, IL-12 and sTRAIL may play a key role in the development and progression of AS, which may be dependent on the status of HLA-B27 antigen.

Hypoglycemia, an Old Tool for New Findings in the Adrenomedullary Hormonal System in Patients with Rheumatic Diseases

Over the past decades, research in patients with rheumatic disorders showed enormous progress in detecting various perturbations of the neuroendocrine system including those affecting autonomic nervous function. There is, however, a substantial lack of data on adrenomedullary hormonal system (AMHS) function in those patients. Insulin-induced hypoglycemia (IIH) represents a metabolic stressor, which elicits a counterregulatory stress response not only of the hypothalamic-pituitary axis but also of the AMHS. Therefore, in addition to traditional testing of hypothalamic-pituitary function, IIH can be used as a well-controlled functional test of the AMHS. Our recent studies showed, for the first time, attenuated epinephrine and norepinephrine responses to IIH in premenopausal females with rheumatoid arthritis (RA) and systemic sclerosis (SSc). These findings are suggestive of downregulation, or possibly defects, of the AMHS in those patients. This article reviews mechanism of the AMHS activation during IIH and demonstrates applications of the test in neuroendocrine-immune research.