Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0003873 (rheumatoid arthritis)
 53,068 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In several studies on patients with rheumatoid arthritis, an association of bone loss with a persistently high disease activity has been found. The aim of our study was to investigate the relation between disease activity and serum levels of vitamin D metabolites, parathyroid hormone (PTH), and parameters of bone turnover in patients with rheumatoid arthritis. A total of 96 patients (83 women and 13 men) were divided into three groups according to disease activity measured by serum levels of C-reactive protein (CRP). In the whole group, serum levels of 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) (P < 0.001) and PTH (P < 0.05) were negatively correlated to disease activity. The urinary excretion of collagen crosslinks--pyridinoline (Pyd) (P < 0.001) and deoxypyridinoline (Dpd) (P < 0.05)--showed a positive correlation with disease activity. The inverse correlation between serum 1,25(OH)2D3 and disease activity was separately evident in patients with (P < 0.001) and without (P < 0.01) glucocorticoid treatment, in pre- (P < 0.01) and postmenopausal (P < 0.001) women, and in men (P < 0.01). 1,25(OH)2D3 and PTH serum levels were positively correlated to serum bone alkaline phosphatase (ALP) (P < 0.01). The results indicate that high disease activity in patients with rheumatoid arthritis is associated with an alteration in vitamin D metabolism and increased bone resorption. The decrease of 1,25(OH)2D3 levels in these patients may contribute to a negative calcium balance and inhibition of bone formation. Furthermore, low levels of 1,25(OH)2D3 as an endogenous immunomodulator suppressing activated T cells and the proliferation of cells may accelerate the arthritic process in rheumatoid arthritis.
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PMID:Relationship between disease activity and serum levels of vitamin D metabolites and PTH in rheumatoid arthritis. 950 50

The vitamin D hormone, 1,25-dihydroxyvitamin D3, functions by way of a nuclear receptor (vitamin D receptor [VDR]) in a manner analogous to the other members of the steroid-thyroid hormone superfamily. Although the vitamin D receptor has been cloned, its three-dimensional structure remains unknown. The VDR binds to the direct repeat response elements called DR-3 in the promoter region of target genes to stimulate or suppress transcription of those genes encoding for proteins that carry out a wide variety of functions. The binding of the VDR to a DR-3 requires the presence of its ligand and a companion protein, namely the RXR group of retinoid receptors. The RXR binds to the 5' arm of the response element while the VDR binds to the 3' arm. In addition, the transcription factor TFIIB has been shown to bind VDR but there is currently no evidence that a co-repressor or co-activator of VDR is also involved. Phosphorylation of VDR in the transcription complex occurs as does bending of the DNA prior to the initiation or suppression of transcription. As VDR has been detected in cells not previously thought to be target organs, scientists continue to discover new functions of vitamin D. Among these new functions are those noted in the immune system. Experiments in mice have illustrated that the autoimmune diseases of multiple sclerosis and rheumatoid arthritis can be successfully treated with the vitamin D hormone and its analogs. New experiments illustrating the use of the vitamin D hormone and its analogs in suppressing transplant rejection indicate that these compounds may be superior to cyclosporin and may not have the side effects attributed to the cyclosporin immunosuppression therapies.
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PMID:Mechanisms and functions of vitamin D. 956 71

Increased cytokine release and increased activity of osteoclasts (reduced osteoclast apoptosis) due to a fall in estrogen is of causal significance in postmenopausal bone loss as well as malfunction of the vitamin D activation and concomitant calcium (Ca) malabsorption. Alfacalcidol prevents rapid postmenopausal bone loss by elimination of Ca malabsorption and by blocking resorbing cytokines. Established osteoporosis in older patients of both sexes is characterized by decoupled bone remodeling induced by sex hormone deficits and by a so-called somatopause (insulin-like growth factor [IGF]-deficit), but also by lack of vitamin D and, very importantly, by reduced synthesis of D-hormone (Calcitriol) in kidneys and bone as well as by a lack of receptors or receptor affinity for D-hormone in the target organs. As a consequence of these facts, a rise in parathormone (PTH) frequently occurs. The lack of D-hormone and IGF-1 evidently causes a reduction in muscle strength as well and reinforces the risk of falling and, thus, the risk of a fracture. Alfacalcidol, a prodrug of D-hormone, is a specific antiosteoporotic therapy. In alfacalcidol therapy, D-hormone is provided to the body in circumvention of its own regulation, by means of which much higher hormone concentrations can be achieved in the target tissues than by administration of plain vitamin D. Chances have been significantly improved of reducing and frequently preventing the real osteoporosis complication for older male and female patients, i. e., bone fractures, by alfacalcidol. A clear distinction should be made between supplementation with low-dosed plain vitamin D and calcium as base supply in elderly housebound subjects or as adjuvant to antiosteoporotic drugs and the specific antiosteoporotic therapy with alfacalcidol in patients with osteoporosis. The expanded understanding of the pathogenesis of corticosteroid-induced osteoporosis with its disturbed Ca homeostasis and the pharmacological effects of alfacalcidol, counteracting such iatrogenic bone loss, explain the particularly good clinical efficacy in this most frequent form of secondary osteoporosis. Normalizing de-coupled bone remodeling due to cytokine modulation and the potential influence on deteriorated bone quality in patients with rheumatoid arthritis and Crohn's disease predestine this form of therapy for prevention and treatment of osteoporosis as a result of chronic inflammatory diseases as well as of transplantation osteoporosis cases in particular.
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PMID:Rationale for treatment of involutional osteoporosis in women and for prevention and treatment of corticosteroid-induced osteoporosis with alfacalcidol. 1048 85

Besides localised osteopenia, patients with rheumatoid arthritis (RA) with or without corticosteroids develop in 30-50% osteoporosis induced by several factors and thus a higher risk of fractures. Bone loss appears very early and correlates directly with disease activity and also later with the negative effects of restrictive mobility. Corticosteroids reduce as a pathogenetic co-factor intestinal calcium absorption and increase renal calcium excretion resulting in compensatory increased PTH-release and increased sensitivity of bone to PTH. In addition, corticosteroids inhibit osteoblast function as well as the favourable effects of growth factors and sex hormones on bone. It has recently been recognised that the expression of D-hormone receptors (VDRs) is suppressed by these medications and that corticosteroids probably induce VDR disorders. The negative influence of corticosteroids on muscle strength (indirectly--via increased PTH-levels, lowered IGF-1-levels or reduced D-hormone activity) is a feature which has been underestimated. The demonstrated drop in 1,25(OH)2D3 (D-hormone) levels in patients with RA in correlation with C-reactive protein (CRP) is of significance in the pathogenesis of RA-induced osteoporosis and could further promote the process of inflammation. There is a general consensus that cytokines (e.g. IL-1, IL-6, IL-12, TNF-alpha) induce bone resorption in inflammatory rheumatic diseases. There are, however, new findings which show that cytokines like TNF-alpha also interfere with bone formation by promoting apoptosis of osteoblasts and reduce the muscle strength, too. D-hormone preparations (alfacalcidol, calcitriol) possess immunoregulatory effects in vitro and in vivo by inhibiting the cytokines IL-1, IL-6, TNF-alpha and particularly IL-12. At the cellular level, D-hormone reduces the expression of Th1 helper cells directly or indirectly by inhibition of IL-12 from monocytes. Therapy with alfacalcidol or calcitriol results in increased production of Th2 helper cells which produce bone protective cytokines like IL-4 and IL-10. It is important to know that D-hormone protects osteoblasts against TNF-alpha-induced cell death. After conversion to D-hormone in the liver and bone, alfacalcidol antagonises the above described pathogenetic factors of the corticosteroids. D-hormone is one of the body's own immunoregulators, which is produced in macrophages in cases of need to reduce immunological overreactions in a feed-back loop. Improved understanding of the pathogenesis of corticosteroid-induced osteoporosis and of the pharmacological effects of alfacalcidol in this type of iatrogenic bone loss as well as the results of specific animal models simulating bone loss in inflammatory diseases explain the favourable effects of alfacalcidol in this indication. Various clinical studies have demonstrated clearly that alfacalcidol retards corticosteroid-induced bone loss in contrast to plain vitamin D. Due to its immunomodulating properties, alfacalcidol is particularly suitable for RA-induced bone loss and for the prevention of transplantation osteoporosis, and an adjuvant contribution to the disease-modifying therapy of RA and to the immunosuppressive therapy after transplantation can not be excluded.
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PMID:[Osteoporosis in rheumatoid arthritis--significance of alfacalcidol in prevention and therapy]. 1076 29

Active vitamin D metabolites are not only involved in the regulation of bone metabolism but exerts immunomodulatory effects important in the regulation of inflammatory processes. The purpose of the present study was to evaluate the effects of a short-time treatment with 1 alpha-hydroxycholecalciferol on both disease activity and bone metabolism in patients with rheumatoid arthritis (RA). The effects of an adjuvant therapy with 1 microgram 1 alpha-hydroxycholecalciferol over eight weeks on conventional parameters of disease activity (Ritchie index, duration of morning stiffness, C-reactive protein, ESR), serum levels of cytokines and soluble cytokine receptors (TNF-alpha, IL-6, IL-4, sIL-2R, sIL-6R) and parameters of bone metabolism (bone-specific alkaline phosphatase, osteocalcin, renal excretion of pyridinolin- and desoxypyridinolin-collagen-crosslinks, serum levels of parathormon, 1,25-dihydroxycholecalciferol and calcium, daily urinary calcium excretion) were investigated in 20 patients with RA. The treatment with 1 alpha-hydroxycholecalciferol resulted in an insignificant decrease in the number of swollen and tender joints, morning stiffness, CRP and ESR. Furthermore, a non-significant decrease in serum levels of TNF-alpha and IL-6 and an increase in IL-4 was observed. The treatment led to a significant decrease of bone-specific alkaline phosphatase (p = 0.001), osteocalcin (p = 0.04) and renal excretion of pyridinolin-crosslinks (p = 0.022) and to an increase of both serum calcium (p = 0.01) and daily urinary calcium excretion (p = 0.004). The results of this pilot study in a small group of RA patients indicate that an adjuvant therapy with active vitamin D metabolites may not only have preventive effects on systemic bone loss but also may inhibit the inflammatory and destructive process in RA in a limited degree.
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PMID:[Vitamin D metabolites in rheumatoid arthritis: findings--hypotheses--consequences]. 1076 32

Glucocorticoid- (GC-) induced osteoporosis and an increased risk of fractures are one of the most serious problems for patient using long-term GC therapy, such as those with rheumatoid arthritis, autoimmune diseases, inflammatory bowel diseases, bronchial asthma, and chronic lung diseases. GCs are known to affect both bone formation and resorption. In rheumatoid arthritis, the etiology of bone loss is multifactorial, including local inflammation around joints, release of bone-absorbing cytokines, physical inactivity, and malnutrition, in addition to the use of GC. Two guidelines have been published, by the American College of Rheumatology Task Force in 1966 and by the UK Consensus Group in 1998. Both guidelines recommend that patients 'receiving GC therapy at doses of 7.5 mg/day of prednisolone or more for 6 months or longer should have their bone mineral density measured and begin preventive therapies. Calcium and vitamin D supplements, sex hormone replacement, and weight-bearing exercise are the first-line therapies. For patients who are unable to take sex hormone replacement therapy (HRT), bisphosphonates are recommended by both guidelines. In this article, we briefly summarize the pathogenesis of GC-induced osteoporosis and its prevention and treatment.
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PMID:Glucocorticoid-induced osteoporosis: pathogenesis and management. 1105 69

The presence of certain vitamin D receptor (VDR) genotypes has been associated with low bone mineral density (BMD) in elderly populations as well as with accelerated bone loss in patients with rheumatoid arthritis (RA). In the present study, VDR genotypes from 120 Spanish patients with RA were investigated. Three VDR gene polymorphisms (BsmI, ApaI and TaqI) were investigated using polymerase chain reaction followed by enzymatic digestion. The distributions of VDR allelic frequencies were similar in patients and controls and therefore no influence of VDR polymorphisms on rheumatoid arthritis susceptibility could be demonstrated. However, in an analysis of the clinical features of the different VDR-related genetic subgroups, the BB/tt genotype, defined by the BsmI and TaqI restriction site polymorphisms, was identified to be weakly associated with an early onset RA in female patients. This VDR genotype has been associated with a low BMD level in various studies. When patients were stratified according to the presence of the shared HLA epitope SE, it was found that SE + female patients bearing the BB/tt genotype showed the earliest disease onset. The mechanisms by which the VDR polymorphism is associated with RA is unknown, but they could be related to the immunoregulatory properties of vitamin D.
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PMID:Association of vitamin D receptor genotypes with early onset rheumatoid arthritis. 1125 90

Patients with rheumatic diseases frequently ask the physician for diet recommendations. Although much has been written about this subject, scientifically validated studies investigating the impact of certain diets on rheumatoid arthritis are scant and often inconclusive. Elimination diets or total fasting is believed to eliminate food ingredients that cause or aggravate arthritis. In contrast, supplementation with fish oil, gamma-linoleic acid or vitamin E is directed at anti-oxidative and anti-inflammatory effects of these food compounds. So far, both approaches have failed to reveal a significant benefit with respect to objective signs of inflammation. Supplementation with other vitamins such as vitamin A and C, or with trace elements like selenium and zinc are of no proven influence on the disease activity as well. There is a higher request for calcium and vitamin D in patients with active RA under steroid treatment to prevent osteoporosis. In addition, patients with active RA have a slightly increased risk for cardiovascular events. Therefore, cholesterol-lowering diets and drugs should be applied early.
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PMID:[Are there effective dietary recommendations for patients with rheumatoid arthritis?]. 1126 11

Induced apoptosis of autoreactive T-lymphocyte precursors in the thymus is crucial for the prevention of autoimmune disorders. IGF-I and prolactin, which are lymphocyte growth factors, may have the potential to suppress apoptosis in thymocytes and thus encourage autoimmunity; conversely, dietary fish oil rich in omega-3 fats appears to upregulate apoptosis in lymphocytes. Since whole-food vegan diets may downregulate systemic IGF-I activity, it is proposed that such a diet, in conjunction with fish oil supplementation and treatment with dopamine agonists capable of suppressing prolactin secretion, may have utility for treating and preventing autoimmune disorders. This prediction is consistent with the extreme rarity of autoimmune disorders among sub-Saharan black Africans as long as they followed their traditional quasi-vegan lifestyles, and with recent ecologic studies correlating risks for IDDM and for multiple sclerosis mortality with animal product and/or saturated fat consumption. Moreover, there is evidence that vegan or quasi-vegan diets are useful in the management of rheumatoid arthritis, multiple sclerosis, and possibly SLE. The dopamine agonist bromocryptine exerts anti-inflammatory effects in rodent models of autoimmunity, and there is preliminary evidence that this drug may be clinically useful in several human autoimmune diseases; better tolerated D2-specific agonists such as cabergoline may prove to be more practical for use in therapy. The moderate clinical utility of supplemental fish oil in rheumatoid arthritis and certain other autoimmune disorders is documented. It is not unlikely that extra-thymic anti-inflammatory effects contribute importantly to the clinical utility of vegan diets, bromocryptine, and fish oil in autoimmunity. The favorable impact of low latitude or high altitude on autoimmune risk may be mediated by superior vitamin D status, which is associated with decreased secretion of parathyroid hormone; there are theoretical grounds for suspecting that parathyroid hormone may inhibit apoptosis in thymocytes. Androgens appear to up-regulate thymocyte apoptosis, may be largely responsible for the relative protection from autoimmunity enjoyed by men, and merit further evaluation for the management of autoimmunity in women. It will probably prove more practical to prevent autoimmune disorders than to reverse them once established; a whole-food vegan diet, coupled with fish oil and vitamin D supplementation, may represent a practical strategy for achieving this prevention, while concurrently lowering risk for many other life-threatening 'Western' diseases.
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PMID:Upregulation of lymphocyte apoptosis as a strategy for preventing and treating autoimmune disorders: a role for whole-food vegan diets, fish oil and dopamine agonists. 1146 Nov 85

Receptor activator of nuclear factor (NF-kappaB) ligand (RANKL), its cellular receptor, receptor activator of NF-kappaB (RANK), and the decoy receptor osteoprotegerin (OPG) constitute a novel cytokine system. RANKL produced by osteoblastic lineage cells and activated T lymphocytes is the essential factor for osteoclast formation, fusion, activation, and survival, thus resulting in bone resorption and bone loss. RANKL activates its specific receptor, RANK located on osteoclasts and dendritic cells, and its signaling cascade involves stimulation of the c-jun, NF-kappaB, and serine/threonine kinase PKB/Akt pathways. The effects of RANKL are counteracted by OPG which acts as a soluble neutralizing receptor. RANKL and OPG are regulated by various hormones (glucocorticoids, vitamin D, estrogen), cytokines (tumor necrosis factor alpha, interleukins 1, 4, 6, 11, and 17), and various mesenchymal transcription factors (such as cbfa-1, peroxisome proliferator-activated receptor gamma, and Indian hedgehog). Transgenic and knock-out mice with excessive or defective production of RANKL, RANK, and OPG display the extremes of skeletal phenotypes, osteoporosis and osteopetrosis. Abnormalities of the RANKL/OPG system have been implicated in the pathogenesis of postmenopausal osteoporosis, rheumatoid arthritis, Paget's disease, periodontal disease, benign and malignant bone tumors, bone metastases, and hypercalcemia of malignancy, while administration of OPG has been demonstrated to prevent or mitigate these disorders in animal models. RANKL and OPG are also important regulators of vascular biology and calcification and of the development of a lactating mammary gland during pregnancy, indicating a crucial role for this system in extraskeletal calcium handling. The discovery and characterization of RANKL, RANK, and OPG and subsequent studies have changed the concepts of bone and calcium metabolism, have led to a detailed understanding of the pathogenesis of metabolic bone diseases, and may form the basis of innovative therapeutic strategies.
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PMID:Role of receptor activator of nuclear factor-kappaB ligand and osteoprotegerin in bone cell biology. 1148 16


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