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

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.
 ...
PMID:Rationale for treatment of involutional osteoporosis in women and for prevention and treatment of corticosteroid-induced osteoporosis with alfacalcidol. 1048 85

The effect of alfacalcidol therapy on bone mineral density at the spine and proximal femur was evaluated in 112 transplant recipients (59 heart, 26 liver and 27 lung); 45 transplant cases served as controls (included in a randomised way in a placebo group) and in 42 rheumatoid arthritis cases. Liver and lung transplantation cases had before transplantation a lower bone density at the spine and femur compared to heart transplant cases. Heart transplant cases lost considerably more bone immediately after transplantation than liver and lung transplant recipients. A positive effect of 2 years alfacalcidol treatment (0.5-1 microgram/day) on bone loss was observed in all treated groups. Alfacalcidol was particularly effective against trabecular bone loss at the spine in rheumatoid arthritis patients and transplant recipients. There is a manifest difference in evolution between organ transplant groups and bone sites measured. Liver and lung transplant recipients respond better to therapy than cardiac recipients.
 ...
PMID:Transplantation osteoporosis and corticosteroid-induced osteoporosis in autoimmune diseases: experience with alfacalcidol. 1076 38

Alfacalcidol (1-alpha-hydroxyvitamin D3) is a non-endogenous analog of vitamin D which can bypass the renal and intestinal regulatory mechanisms that control the production of calcitriol (1,25-hydroxyvitamin D3, the active form of vitamin D, D-Hormone). Alfacalcidol may be metabolized into calcitriol with a limited risk of hypercalcemia. Alfacalcidol and calcitriol have been evaluated in animal and human studies assessing their effects on bone mineral density and fracture rates. More recently, they have been shown to produce beneficial effects in muscle, immune system, and autoimmune diseases, including rheumatoid arthritis. This paper discusses the therapeutic efficacy of alfacalcidol in reports in which it has been proposed as an interesting alternative to vitamin D or calcitriol. Some recent findings about general metabolism and regulation of vitamin D and its analogs are discussed. The biological and clinical effects of alfacalcidol in post-menopausal osteoporosis are reviewed, followed by critical appraisal of its efficacy in preventing bone loss and falls in the elderly. The last two sections discuss the role of D analogs in regulating the immune system, with particular regard to rheumatoid arthritis. The main results of this review show that alfacalcidol may have a wider range of therapeutic applicability, beyond simply restricting it to patients in hemodialysis or peritoneal dialysis with high serum levels of intact PTH.
 ...
PMID:D-hormone analog alfacalcidol: an update on its role in post-menopausal osteoporosis and rheumatoid arthritis management. 1597 52

Inflammatory diseases lead to systemic osteoporosis. Causal factors include increased circulating concentrations of inflammatory cytokines such as interleukin 6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha), glucocorticoid medication, and reduced physical activity. In addition, disturbances of vitamin D metabolism play an important role for the development of inflammation induced osteoporosis. Therefore, D-hormone analogs offer an important treatment option. 1,25-dihydroxyvitamin D (D-hormone) prevented bone loss in the rat model of inflammation mediated osteopenia and in an arthritis model. One explanation is that animals and humans with inflammatory diseases exhibit markedly reduced circulating concentrations of D-hormone, partly the result of inhibition of renal 1-alpha-hydroxylase by TNF-alpha. In addition, the number of vitamin D receptors is reduced by glucocorticoids. Moreover, D-hormone has pleiotropic effects not only on calcium homoeostasis but also on muscle (improving power), the nervous system, and the immune system. D-hormone inhibits the release of cytokines (IL-1, IL-6, TNF-alpha) from macrophages and stimulates osteoprotegerin secretion in vitro and improves arthritis in animal models. This article reviews the interaction between inflammatory disease and vitamin D metabolism, summarizes the rationale for the therapeutic use of alfacalcidol, and provides recent data from controlled clinical trials comparing the effect of alfacalcidol versus plain vitamin D in secondary osteoporosis. Alfacalcidol, but not plain vitamin D, has pleiotropic effects improving bone and muscle metabolism and clinical symptoms in patients with rheumatoid arthritis.
 ...
PMID:Alfacalcidol versus plain vitamin D in inflammation induced bone loss. 1614 48

Vitamin D metabolism has an important role in the pathogenesis of osteoporosis. Vitamin D deficiency is very common in elderly people in central Europe. This leads to secondary hyperparathyroidism and to increased bone resorption, resulting in osteoporosis. Combined with the elevated risk of falling that results from vitamin D deficiency, this increases the frequency of bone fractures. Severe vitamin D deficiency also causes impaired bone mineralization (osteomalacia). Controlled intervention trials with native vitamin D (and calcium) yielded no consistent results in terms of the prevention of extravertebral fractures. It appears likely that treatment with plain vitamin D is effective only in populations with vitamin D deficiency. Treatment with active vitamin D (1-alpha-hydroxylated metabolites such as alfacalcidol) has to be considered a pharmacological intervention that exerts pleiotropic effects on the gut (calcium absorption), bone (stimulation of formation), muscle (decreasing of the risk of falling), and immune system. Target groups are patients with disturbed vitamin D metabolism (renal insufficiency, glucocorticoid therapy, inflammatory disease such as rheumatoid arthritis). Alfacalcidol can prevent glucocorticoid-induced bone loss (high-grade evidence). In comparative studies alfacalcidol was superior to plain vitamin D.
 ...
PMID:[Relative value of plain vitamin D and of biologically active vitamin D in the prevention and treatment of osteoporosis]. 1694 81