Edgar M. Colin

Th17 cells, but not Th1 cells, from patients with early rheumatoid arthritis are potent inducers of matrix metalloproteinases and proinflammatory cytokines upon synovial fibroblast interaction, including autocrine interleukin‐17A production

OBJECTIVE Both Th1 cells and Th17 cells have been recognized in rheumatoid arthritis (RA); however, it remains unclear whether Th1 cells and/or Th17 cells are involved in driving disease chronicity and destructiveness. The aim of this study was to identify and characterize the functional role of Th17 cells in early RA. METHODS Flow cytometry analysis was performed on peripheral blood mononuclear cells (PBMCs) from treatment-naive patients with early RA and age-matched healthy volunteers. PBMCs from these patients, naive T cells, and primary CCR6- Th1 cells and CCR6+ Th17 cells were sorted and cultured in the absence or presence of synovial fibroblasts from patients with early RA (RASFs), and cytokine expression and gene transcription were analyzed. In addition, tumor necrosis factor α (TNFα)- and interleukin-17A (IL-17A)-blocking experiments were performed. RESULTS In the PBMCs of treatment-naive patients with early RA, an increased fraction of IL-17A-and TNFα-producing CCR6+ Th17 cells was observed. When cocultured with RASFs, these primary Th17 cells were potent inducers of IL-6 and IL-8 and the tissue-destructive enzymes matrix metalloproteinase 1 (MMP-1) and MMP-3, whereas primary Th1 cells or naive T cells were not. Importantly, specific up-regulation of IL-17A but not TNFα or interferon-γ was observed in RASF/Th17 cell cocultures. In addition to TNFα blocking, IL-17A neutralization was required to further down-regulate Th17 activity in RASF/Th17 cell cocultures. CONCLUSION Th17 cells, but not Th1 cells, cooperated with RASFs in a proinflammatory feedback loop, revealing a potential mechanism by which human Th17 cells drive chronic destructive disease in patients with RA. Furthermore, the neutralization of IL-17A activity is essential in current anti-TNF therapies to suppress Th17 cell activity in patients with early RA and potentially other Th17 cell-mediated disorders.

1,25-Dihydroxyvitamin D3 modulates Th17 polarization and interleukin-22 expression by memory T cells from patients with early rheumatoid arthritis

OBJECTIVE To examine the immunologic mechanism by which 1,25-dihydroxyvitamin D(3) (1,25[OH](2)D(3)) may prevent corticosteroid-induced osteoporosis in patients with early rheumatoid arthritis (RA), with a focus on T cell biology. METHODS Peripheral blood mononuclear cells (PBMCs) and CD4+CD45RO+ (memory) and CD4+CD45RO- (non-memory) T cells separated by fluorescence-activated cell sorting (FACS) from treatment-naive patients with early RA were stimulated with anti-CD3/anti-CD28 in the absence or presence of various concentrations of 1,25(OH)(2)D(3), dexamethasone (DEX), and 1,25(OH)(2)D(3) and DEX combined. Levels of T cell cytokines were determined by enzyme-linked immunosorbent assay and flow cytometry. RESULTS The presence of 1,25(OH)(2)D(3) reduced interleukin-17A (IL-17A) and interferon-gamma levels and increased IL-4 levels in stimulated PBMCs from treatment-naive patients with early RA. In addition, 1,25(OH)(2)D(3) had favorable effects on tumor necrosis factor alpha (TNFalpha):IL-4 and IL-17A:IL-4 ratios and prevented the unfavorable effects of DEX on these ratios. Enhanced percentages of IL-17A- and IL-22-expressing CD4+ T cells and IL-17A-expressing memory T cells were observed in PBMCs from treatment-naive patients with early RA as compared with healthy controls. Of note, we found no difference in the percentage of CD45RO+ and CD45RO- cells between these 2 groups. Interestingly, 1,25(OH)(2)D(3), in contrast to DEX, directly modulated human Th17 polarization, accompanied by suppression of IL-17A, IL-17F, TNFalpha, and IL-22 production by memory T cells sorted by FACS from patients with early RA. CONCLUSION These data indicate that 1,25(OH)(2)D(3) may contribute its bone-sparing effects in RA patients taking corticosteroids by the modulation of Th17 polarization, inhibition of Th17 cytokines, and stimulation of IL-4.

Evidence for Involvement of 17β-Estradiol in Intestinal Calcium Absorption Independent of 1,25-Dihydroxyvitamin D3 Level in the Rat

The sex steroid 17β‐estradiol (17β‐E2) has a broad range of actions, including effects on calcium and bone metabolism. This study with 3‐month‐old Brown Norway rats was designed to investigate the role of 17β‐E2 in the regulation of calcium homeostasis. Rats were divided in four groups, sham‐operated, ovariectomized (OVX), and OVX supplemented with either a 0.025‐mg or 0.05‐mg 17β‐E2 pellet implanted subcutaneously. After 4 weeks, in none of the groups was serum calcium, phosphate, or parathyroid hormone altered compared with the sham group, while only in the OVX rats was a significant reduction in urinary calcium found. Bone mineral density and osteocalcin were modified, as can be expected after OVX and 17β‐E2 supplementation. OVX resulted in a nonsignificant increase in serum 1,25‐dihydroxyvitamin D3 (1,25(OH)2D3). Supplementation with either one of the 17β‐E2 dosages resulted in an 80% reduction of 1,25(OH)2D3 and only a 20% reduction in 25‐hydroxyvitamin D3 levels. OVX, as well as supplementation with 17β‐E2, did not affect serum levels of vitamin D binding protein. As a consequence, the estimated free 1,25(OH)2D3 levels were also significantly decreased in the 17β‐E2‐supplemented group compared with the sham and OVX groups. Next, the consequences for intestinal calcium absorption were analyzed by the in situ intestinal loop technique. Although the 1,25(OH)2D3 serum level was increased, OVX resulted in a significant decrease in intestinal calcium absorption in the duodenum. Despite the strongly reduced 1,25(OH)2D3 levels (18.1 ± 2.1 and 16.4 ± 2.2 pmol/l compared with 143.5 ± 29 pmol/l for the OVX group), the OVX‐induced decrease in calcium absorption could partially be restored by supplementation with either 0.025 mg or 0.05 mg of 17β‐E2. None of the treatments resulted in a significant change in calcium handling in the jejunum, although the trends were similar as those observed in the duodenum. 17β‐E2 did not change the VDR levels in both the intestine and the kidney. In conclusion, the present study demonstrates that 17β‐E2 is positively involved in intestinal calcium absorption, and the data strengthen the assertion that 17β‐E2 exerts this effect independent of 1,25(OH)2D3. In general, 17β‐E2 not only affects bone turnover but also calcium homeostasis via an effect on intestinal calcium absorption.

Does anti-mutated citrullinated vimentin have additional value as a serological marker in the diagnostic and prognostic investigation of patients with rheumatoid arthritis? A systematic review

Objective: To review the diagnostic and prognostic value of anti-mutated citrullinated vimentin (MCV) in rheumatoid arthritis, taking into account the already available serology. Methods: Medline was searched via PubMed (1966 to May 2008) for anti-MCV and related terms, arthritis and arthropathies. Studies with anti-MCV, arthritis/arthropathy, and primary data on diagnosis and/or prognosis were included. Their methodological quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS) instrument for diagnostic studies and the modified Hayden list for prognostic studies. Results: Of 14 eligible studies, 11 included diagnostic data and 3 included prognostic data. No study evaluated anti-MCV as an added diagnostic test to the already available anti-cyclic citrullinated peptide (CCP) and rheumatoid factor serology. One study included the optimal patient spectrum resulting in a sensitivity of 0.59 and specificity of 0.98. A total of 10 diagnostic case-control studies using the same anti-MCV kit showed a sensitivity of 0.64–0.84 and a specificity of 0.79–0.96. This almost equalled the performance of anti-CCP in the same studies. The prognostic evaluation of anti-MCV was limited by differences in study methodology, outcome and statistical modelling. Individual studies showed moderate associations for anti-MCV and radiological progression with the strength of the association comparable to that of anti-CCP. Conclusions: Study heterogeneity, choice of study population and methodological limitations limited overall conclusions about the true diagnostic and prognostic test performance of anti-MCV. Evidence from the diagnostic case-control studies suggests that anti-MCV may be used as an alternative for anti-CCP.

Vitamin D in Autoimmunity: Molecular Mechanisms and Therapeutic Potential

Over the last three decades, it has become clear that the role of vitamin D goes beyond the regulation of calcium homeostasis and bone health. An important extraskeletal effect of vitamin D is the modulation of the immune system. In the context of autoimmune diseases, this is illustrated by correlations of vitamin D status and genetic polymorphisms in the vitamin D receptor with the incidence and severity of the disease. These correlations warrant investigation into the potential use of vitamin D in the treatment of patients with autoimmune diseases. In recent years, several clinical trials have been performed to investigate the therapeutic value of vitamin D in multiple sclerosis, rheumatoid arthritis, Crohn’s disease, type I diabetes, and systemic lupus erythematosus. Additionally, a second angle of investigation has focused on unraveling the molecular pathways used by vitamin D in order to find new potential therapeutic targets. This review will not only provide an overview of the clinical trials that have been performed but also discuss the current knowledge about the molecular mechanisms underlying the immunomodulatory effects of vitamin D and how these advances can be used in the treatment of autoimmune diseases.

Emergency department visits due to vertebral fractures in the Netherlands, 1986-2008: Steep increase in the oldest old, strong association with falls

BACKGROUND Vertebral fractures are a common consequence of osteoporosis in older persons. With the ageing of the population, numbers are expected to rise. OBJECTIVE To determine trends in health care demand due to vertebral fracture related emergency department (ED) visits and hospitalizations in the older Dutch population. DESIGN AND SETTING Secular trend analysis of vertebral fracture related ED visits between 1986 and 2008, using the Dutch Injury Surveillance System. All ED visits with a primary diagnosis of a vertebral fracture in persons aged ≥65 years were extracted from this database. MAIN OUTCOME MEASURE Numbers, age-specific and age-adjusted incidence rates (per 100,000 population) of ED visits and hospitalization rates due to vertebral fractures in the older Dutch population were calculated for each year of the study. RESULTS The total number of ED visits due to a vertebral fracture increased from 913 in 1986 to 2502 in 2008 (174% increase). The majority of fractures were caused by a low-energetic fall incident (83%). The overall age-adjusted incidence rate increased from 51.6 per 100,000 population in 1986 to 103.6 in 2008. Incidence rates increased with age and were higher in females than in males. The hospitalization rate remained stable at about 50-55%, in both females and males. CONCLUSION Vertebral fracture related ED visits and hospitalizations are increasing rapidly in the older Dutch population, especially in the oldest-old. Most vertebral fractures were associated with falls. These findings indicate that a pro-active approach in the diagnosis and treatment of osteoporosis and in the prevention of falls in both men and women is warranted.

Periarticular osteoporosis: a useful feature in the diagnosis of early rheumatoid arthritis? Reliability and validity in a cross-sectional diagnostic study using dual-energy X-ray absorptiometry

OBJECTIVES To identify regions of interest (ROIs) relevant to periarticular osteoporosis in RA with low precision error and sufficient inter-rater reliability and to test diagnostic validity for RA. METHODS Periarticular BMD was measured using dual-energy X-ray absorptiometry (DXA). Five ROIs were defined around MCP and/or PIP joints II-V, II-IV and mid-metacarpal to mid-phalangeal. They were evaluated for precision using the root mean square coefficient of variation (RMS-CV) and the intra-class correlation coefficient (ICC) for inter-reader reliability. To test validity, established RA patients (n = 25) and early arthritis patients (n = 25) were compared with healthy controls (n  = 37) matched on sex, age and menopausal status using paired t-tests, ROC curves and scatterplots. RESULTS The RMS-CV was 0.45-1.07%. The ICC was 0.99. Mean BMDs of the five ROIs ranged from 0.321 to 0.372 g/cm(2) in established RA, from 0.321 to 0.382 g/cm(2) in early arthritis and from 0.342 to 0.401 g/cm(2) in healthy controls. Mean differences ranged from 0.012 to 0.032 g/cm(2) for established RA and from 0.023 to 0.033 g/cm(2) for early arthritis patients compared with matched controls, with P < 0.05 for ROIs 1-5 in early arthritis and the whole hand in established RA. ROC curves indicated low discriminative power, with an area under the curve (AUC) of 0.61-0.64, and scatterplots showed great overlap between BMD values of patients and controls. CONCLUSIONS Periarticular BMD measured with DXA seems not to be a useful diagnostic feature due to strong overlap of BMD values between healthy controls, established RA patients and early arthritis patients.

Vitamin D suppresses the pathogenic behaviour of primary Th17 cells from patients with early rheumatoid arthritis

Background and objectives Recently, the authors showed that CCR6+ Th17 cells from early rheumatoid arthritis (RA) patients are potent inducers of a pro-inflammatory feed-back loop upon RA synovial fibroblast (RASF) interaction, including autocrine interleukin (IL)-17A production. In this study, the effect of vitamin D on this pathogenic behaviour of Th17 cells was investigated. Materials and methods Peripheral CCR6+ Th17 cells of patients with early RA, CCR6+ Th17/RASF co-cultures and synovial biopsies of patients with established RA, were cultured in the absence or presence of 1,25(OH)2D3, the active vitamin D metabolite and/or Etanercept. Intracellular cytokine expression was detected by flow cytometry. Cytokine and matrix metalloprotease (MMP) expression was determined by ELISA. Transcription of factors involved in Th differentiation and function was analysed by quantitative PCR analysis. Results In Th17 cultures and Th17/RASF co-cultures vitamin D suppressed the expression of IL-17A, IL-22 and IFN-γ. Furthermore, in Th17/RASF co-cultures, vitamin D induced IL-4 and IL-10 expression, which was accompanied with reduced Rorγt and induced Gata3 transcription. Moreover, vitamin D suppressed IL-6, IL-8, MMP-1 and MMP-3 expression in the Th17/RASF co-cultures and synovial biopsies. Interestingly, the enhanced autocrine production of IL-17A in Th17/RASF co-cultures was inhibited by vitamin D, but not with tumour necrosis factor (TNF)-α neutralisation. Vitamin D in combination with TNF-α neutralisation has an additive effect on the suppression of Th17 activity as indicated by a significant further reduction in IL-6, IL-8, MMP-1 and MMP-3 expression in the co-cultures and IL-6 and IL-8 in the synovial biopsy cultures. Conclusions These data show that vitamin D modulates the pathogenic behaviour of Th17 cells and may have additional therapeutic potential when used in combination with TNF treatment in RA and potentially other Th17-mediated inflammatory diseases.

Better knowledge on vitamin D and calcium in older people is associated with a higher serum vitamin D level and a higher daily dietary calcium intake

Objective: The objective of the present study was to examine knowledge on vitamin D and calcium in a cohort of older adults and to test the association between health knowledge, vitamin D status and dietary calcium intake. Methods: The participants of this cross-sectional survey consisted of 426 individuals (≥65 years), living in residential homes. Participants were tested for their knowledge on vitamin D and calcium using a standardized questionnaire. Serum 25-hydroxyvitamin D3 (25(OH)D3) levels and dietary calcium intake were measured. Results: The mean serum 25(OH)D3 level was 39.1 (±21.4) nmol/l and the mean daily dietary calcium intake was 826 (±242) mg/day. Of the participants, only 38 per cent indicated that they knew or had heard of vitamin D. Participants overestimated their daily calcium intake. Better knowledge on vitamin D and calcium was associated with both higher vitamin D levels (P < 0.0001) and a higher daily dietary calcium intake (P < 0.0001). Conclusion: Given the poor knowledge on vitamin D and calcium and the observed associations, improving health knowledge could be a possible intervention to improve vitamin D status and calcium intake in older people. Further studies are needed to assess whether education will indeed lead to improvement of vitamin D levels and calcium intake in this age group.

Stopping Tumor Necrosis Factor Inhibitor Treatment in Patients With Established Rheumatoid Arthritis in Remission or With Stable Low Disease Activity

Tumor necrosis factor inhibitor (TNFi) biologic agents are an effective treatment for rheumatoid arthritis (RA). It is unclear whether patients whose disease is in remission or who have stable low disease activity need to continue use of TNFi or can stop this treatment. This study was undertaken to assess whether patients with established RA who are in remission or have stable low disease activity can effectively and safely stop their TNFi therapy.