Vitamin D3 in patients with various grades of chronic pancreatitis,according to morphological and functional criteria of the pancreas

There are still too few conclusive reports about conspicuous vitamin D deficiency in patients with chronic pancreatitis, or any connection of the deficiency to the severity of the disease. Between October 1999 and September 2000, we investigated 42 patients at an average age of 53 years, suffering from chronic pancreatits, as well as 20 healthy male controls at an average age of 49 years. Serum levels of D₃ vitamins, 1,25-(OH)₂-vitamin D₃ and 25-(OH)-vitamin D₃, as well as the concentration of fecal elastase 1 were determined in patients and controls. Furthermore, the severity of chronic pancreatitis in patients was determined via endoscopic retrograde cholangiopancreatography (ERCP) into 3 grades, based on the Cambridge classification. Elastase 1 in feces revealed sensitivities of 14%, 87%, and 95% for Cambridge-grades I, II, and III, respectively, and correlated significantly with this classification of severity of chronic pancreatitis (P < 0.01). In patients with Cambridge-grade II and III 1,25-(OH)₂-D₃ was markedly decreased (26.7 ± 7.7 pg/ml and 27.6 ± 9.0 pg/ml) compared to those with Cambridge-grade I (38.0 ± 10.5 pg/ml; between I and II P = 0.027, between I and III P = 0.033). 25-(OH)-D-₃ did not differ significantly within the various Cambridge-grade groups (P = 0.07). Nevertheless, vitamin D₃ and fecal elastase 1 in patients correlated significantly (P < 0.01) and, compared to controls, both were extremely low (means in patients: fecal elastase 1 140.7 ± 75.7 g/g, 1,25-(OH)₂-D₃ 29.9 ± 9.5 pg/ml, 25-(OH)-D₃ 26.7 ± 9.7 nmol/liter; controls: fecal elastase 1 694.9 ± 138.6 g/g, 1,25-(OH)₂-D₃ 67.5 ± 4.3 pg/ml, 25-(OH)-D₃ 69.5 ± 13.5 nmol/liter). The amounts of both D₃ vitamins in patients were significantly lower when the content of fecal elastase 1 was under 200 g/g compared to the others [for 1,25-(OH)₂-D₃ P < 0.01, for 25-(OH)-D₃ P < 0.05]. Therefore, ERCP and fecal elastase 1 verify the severity grade of a chronic pancreatitis, and thus show a vitamin D₃ deficiency, depending on the progress of the disease. There seems to be a connection between inflammatory pancreas destruction (Cambridge classification), exocrine insufficiency (fecal elastase 1), and perhaps even the characteristics of sterol-binding of pancreatic elastase 1, which seems to be relevant for vitamin D supply.     

Preferential accumulation in vivo of 24R,25-dihydroxyvitamin D(3) in growth plate cartilage of rats

Vitamin D₃ is metabolized in vivo through 25-(OH)D₃ (25D) to both 1α,25-(OH)₂D₃ (1,25D) and 24R,25-(OH)₂D₃ (24,25D). Whereas it is assumed that this metabolism occurs primarily in the kidney, recent studies show that there are extrarenal 1α-and 24R-hydroxylase activities as well, and in chondrocytes, these enzymes are regulated by hormones and growth factors. Furthermore, chondrocytes from the resting zone of growth plate cartilage are a target cell population for 24,25D action, suggesting that this vitamin D metabolite may be targeted to this tissue in vivo. To test this hypothesis, 30 normal male Sprague Dawley rats (120 ±20 g) were divided into three groups of eight animals each, and a control group of six animals, and fed ad libitum for 2 wk, a standard rat chow (Teklad LM-485), which contained 3 IU vitamin D₃/g. The rats were then injected im daily at 9:00am, for 4 consecutive d, with 0.1 mL of either [³H]-25D, [³H]-1,25D or [³H]-24,25D. Each dose contained 13 pmol of hormone (0.36 μCi/dose). The distribution of these metabolites was assessed in tibial bone (B) following ablation of the bone marrow, articular cartilage from the tibia (AC), costochondral growth plate cartilage (GC), serum (S), small intestine (I), and kidney (K). The use of high specific activity tritiated vitamin D metabolites facilitated determining tissue localization and further metabolism without perturbation of the body pools of each major metabolite. Accumulation of [³H]-1,25D or [³H]-24,25D in each tissue was compared to circulating serum levels. In rats dosed with [³H]-25D, the tissue:serum ratios for 1,25D were 4.1 (AC), 35.4 (GC), 1.3 (B), 0.7 (K), and 3.0 (I); and tissue:serum ratios for 24,25D were 1.6 (AC), 9.9 (GC), 0.04 (B), 0.2 (K), and 0.4 (I). In rats dosed with [³H]-24,25D alone, GC was the only tissue to accumulate the administered metabolite at a concentration significantly higher than that of serum. Similarly, in rats dosed with [³H]-1,25D alone, GC was the only tissue to accumulate 1,25D at a concentration higher than that of serum. These results demonstrate, for the first time, that under in vivo conditions, GC specifically accumulates 24,25D and 1,25D. This suggests that growth plate may be a target organ for these two hormones.     

Serum vitamin D_3 does not correlate with liver fibrosis in chronic hepatitis C

AIM: To investigate the relationship between serum vitamin D3 levels and liver fibrosis or inflammation in treatment-naive Chinese patients with chronic hepatitis C(CHC).METHODS: From July 2010 to June 2011, we enrolled 122 CHC patients and 11 healthy controls from Dingxicity, Gansu Province, China. The patients were infected with Hepatitis C virus(HCV) during blood cell retransfusion following plasma donation in 1992-1995, and had never received antiviral treatment. At present, all the patients except two underwent liver biopsy with ultrasound guidance. The Scheuer Scoring System was used to evaluate hepatic inflammation and the Metavir Scoring System was used to evaluate hepatic fibrosis. Twelve-hour overnight fasting blood samples were collected in the morning of the day of biopsy. Serum levels of alanine aminotransferase, aspartate aminotransferase, total bilirubin, direct bilirubin, cholineste rase, prothrom binactivity, albumin, γ-glutamyl transpeptidase, hemoglobin, calcium and phosphorus were determined. Serum HCV RNA levels were measured by real-time PCR. Serum levels of 25-hydroxyvitamin D3 [25(OH)D3] and 24,25-dihydroxyvitamin D3 [24,25(OH)2D3] were measured by high-performance liquid chromatography tandem mass spectrometry.R E S U LT S : Serumlevels of 2 5(OH) D3 but not 24,25(OH)2D3 were significantly lower in CHC patients than in control subjects. Serum 25(OH)D3 levels did not correlate with liver fibrosis, inflammation, patient age, or levels of alanine aminotransferase, aspartate aminotransferase, total bilirubin, direct bilirubin, prothrombin activity, cholinesterase or HCV RNA. However, serum 25(OH)D3 levels did correlate with serum 24,25(OH)2D3 levels. Serum 25(OH)D3 and 24,25(OH)2D3 levels, and the 25(OH)D3/24,25(OH)2D3 ratio, have no difference among the fibrosis stages or inflammation grades.CONCLUSION: We found that serum levels of 25(OH)D3 and its degradation metabolite 24,25(OH)2D3 did not correlate with liver fibrosis in treatment-naive Chinese patient with CHC.     

Effects of analogs of 1,25(OH)2 Vitamin D3 on the proliferation and differentiation of the human chronic myelogenous leukemia cell line,RWLeu-4

Summary We evaluated the proliferative and differentiative effects of analogs of 1,25(OH)₂ vitamin D₃ [1,25(OH)₂D₃] on a chronic myelogenous leukemia cell line, RWLeu-4, which is growth-inhibited and differentiates in response to 1,25(OH)₂D₃ (ED₅₀-3-10 nM). Side-chain-fluorinated analogs were more potent (ED₅₀=0.7–2 nM) while most of those with altered saturation of the D ring or side-chain carbon-carbon bonds were equally or less effective than 1,25(OH)₂D₃. However, the two analogs with either two additional double bonds or an extra double and triple bond in the D ring had greater antiproliferatiive activity [1,25(OH)₂-16,23-diene D₃ (ED₅₀=2.7 nM) and 1,25(OH)₂-16-ene-23-yne D₃ (ED₅₀=0.7 nM)]. Since the latter of these has been reported to be less potent at mobilizing calcium than 1,25(OH)₂D₃, it (or a similar compound) may be a candidate for clinical use as an antineoplastic agent.Abbreviations 1,25(OH)₂D₃ 1,25-(OH)₂ vitamin D₃ - CML chronic myelogenous leukemia - NBT nitroblue tetrazolium - ED₅₀ 50% effective dose - IC₅₀ 50% inhibitory concentration     

1α,25-Dihydroxyvitamin D(3) down-regulates pleiotrophin messenger RNA expression in osteoblast-like cells

Pleiotrophin (PTN)[heparin-binding-growth-associated molecule (HB-GAM), heparin-binding neurite-promoting factor (HBNF)] is a recently identified polypeptide that stimulates growth of fibroblasts and enhances neurite extension. PTN is expressed in many tissues but relatively high level of expression has been observed in brain and bone. We examined hormonal regulation of PTN mRNA expression in several osteoblast-like cell lines including MC3T3-E1 and ROS17/2.8. The levels of PTN mRNA in these cells was significantly reduced by treatment with 10⁻⁸ m 1α,25-dihydroxyvitamin D₃ (1,25(OH)₂D₃) for 24 h. However, PTN mRNA levels were increased when the non-osteoblastic cell line, ROS 25/1, was treated with 1,25(OH)₂D₃. These effects were observed in a dose-dependent manner in a dose range between 10⁻¹¹ m to 10⁻⁸ m. This effect was specific to 1,25(OH)₂D₃, since PTN mRNA levels were not affected by other steroids such as retinoic acid and dexamethasone in MC3T3-E1 or ROS17/2.8 cells. Similar 1,25(OH)₂D₃ down-regulation of PTN mRNA was also observed in primary cultures of osteoblast-enriched fetal rat calvaria cells as well as cultures of MC3T3-E1 and ROS17/2.8 cells. These observations suggest that PTN expression in osteoblasts is regulated by the calcitropic hormone, 1,25(OH)₂D₃, and that PTN may play a role in vitamin D-dependent regulation of bone metabolism.     

Tissue-specific expression and regulation by 1,25(OH)2D3 of chick protein kinase inhibitor (PKI) mRNA

The heat-stable protein kinase inhibitor (PKI) protein is a specific and potent competitive inhibitor of the catalytic subunit of cAMP-dependent protein kinase (PKA). Previously, it has been shown that vitamin D status affects chick kidney PKI activity: a 5- to 10-fold increase in PKI activity was observed in kidneys of chronically vitamin D-deficient chicks and treatment with 1,25-dihydroxyvitamin D₃ (1,25[OH]₂D₃) in cultured kidney cells resulted in a 95% decrease in PKI activity. The authors have recently cloned the cDNA for chick kidney PKI and have used the coding sequence to study the regulation of PKI mRNA. Northern analysis showed the expression of two PKI messages, which are 2.7 and 3.3 kb in size. These mRNAs are expressed in brain, muscle, testis, and kidney, but not in pancreas, liver, or intestine. PKI mRNA steady-state levels are downregulated by 47% in kidneys from vitamin D-replete chicks as compared to vitamin D-deficient chicks. PKI mRNA levels in brain, muscle, and testis are not affected by vitamin D status. Treatment of primary chick kidney cultures treated with 10⁻⁷ M, 1,25(OH)₂D₃ for 24 h resulted in a 20–30% decrease in PKI mRNA. 1,25(OH)₂D₃ treatment does not affect the stability of PKI mRNA as determined by treatment of cell cultures with actinomycin D. This study shows that 1,25(OH)₂D₃ directly and tissue-specifically downregulates PKI mRNA in the chick kidney.     

Treatment of resting zone chondrocytes with bone morphogenetic protein-2 induces maturation into a phenotype characteristic of growth zone chondrocytes by downregulating responsiveness to 24,25(OH)2D3 and upregulating responsiveness to 1,25-(OH)2D3

To determine if bone morphogenetic protein-2 (BMP-2) can induce the endochondral maturation of resting zone (RC) chondrocytes, confluent fourth-passage cultures of these cells were pretreated for 24, 36, 48, 72, or 120 h with recombinant human BMP-2. At the end of pretreatment, the media were replaced with new media containing 10⁻¹⁰–10⁻⁸ M 1,25-(OH)₂D₃ or 10⁻⁹–10⁻⁷ M 24,25-(OH₂)D₃, and the cells incubated for an additional 24 h. This second treatment was chosen, because prior studies had shown that the more mature growth zone (GC) chondrocytes and RC cells respond to 1,25-(OH)₂D₃ and 24,25-(OH)₂D₃ in distinctly different ways with respect to the parameters examined. The effect of BMP-2 pretreatment on cell maturation was assessed by measuring alkaline phosphatase specific activity (ALPase). In addition, changes in matrix protein production were assessed by measuring collagen synthesis, as well as [³⁵S]-sulfate incorporation into proteoglycans. When RC cells were pretreated for 72 or 120 h with BMP-2, treatment with 1,25-(OH)₂D₃ caused a dose-dependent increase in ALPase specific activity and collagen synthesis, with no effect on proteoglycan sulfation. RC cells pretreated with 1,25-(OH)₂D₃ responded like RC cells that had not received any pretreatment. RC cells normally respond to 24,25-(OH)₂D₃; however, RC cultures pretreated for 72 or 120 h with BMP-2 lost their responsiveness to 24,25-(OH)₂D₃. These results indicate that BMP-2 directly regulates the differentiation and maturation of RC chondrocytes into GC chondrocytes. These observations support the hypothesis that BMP-2 plays a significant role in regulating chondrocyte maturation during endochondral ossification.     

Demonstration of a high affinity receptor for 1,25-dihydroxyvitamin D3 in rat pancreas

The existence of a high affinity receptor for 1,25-dihydroxyvitamin D₃ (1,25(OH)₂D₃) in rat pancreas was biochemically demonstrated in this study. In order to study the properties of this putative receptor, we took advantage of the analysis of low ionic strength chromatin-localized 1,25(OH)₂D₃ receptor. Using this method, the susceptibility of receptor protein to enzymatic degradation was so decreased, and the contamination by plasma vitamin D binding protein (DBP) component was so efficiently eliminated that a specific, saturable binding for 1,25(OH)₂D₃ could be demonstrated in the saturation analysis and the peak for the receptor was consistently apparent in the sucrose density gradient analysis. The equilibrium dissociation constant (Scatchard K_d) was found to be 3.7 ± 1.5 × 10^-10 (M), and the concentration of specific binding sites was calculated to be 1.22 ± 0.40 (fmol/mg protein). The number of specific binding sites in the rat pancreas was only 0.44% of that present in rat intestine (277 ± 19 (fmol/mg protein)) and 6.7% of that in rat kidney (18.1 ± 1.0 (fmol/mg)). However, when a correction is made for the 1,25(OH)₂D₃ receptor distribution in the tissues and expressed as the receptor concentration per receptor-containing cells, the rat pancreatic receptor level was calculated to be about 30% of the rat intestine. Sucrose density gradient sedimentation of this receptor yielded a value of 3.2 ± 0.1 (S) for the sedimentation coefficient and this peak was displaceable by a 100-fold excess of nonradioactive 1,25(OH)₂D₃. These data provide evidence for the presence of a specific 1,25(OH)₂D₃ receptor in mammalian pancreas, and we suggest, in conjunction with the facts that vitamin D₃ and its active metabolites play a physiological role on insulin secretion from rat pancreatic β-cells, that this receptor might be involved in the mechanisms of action of vitamin D₃ on insulin secretion from rat pancreas via a genomic effect.     

Vitamin D receptor levels and binding are reduced in aged rat intestinal subcellular fractions

The hormonal form of vitamin D, 1α,25(OH)₂-vitaminD₃ [1α,25(OH)₂D₃], stimulates signal transduction pathways in intestinal cells. To gain insight into the relative importance of the vitamin D receptor (VDR) in the rapid hormone responses, the amounts and localization of the VDR were evaluated in young (3 months) and aged (24 months) rat intestinal cells. Immune-fluorescence and Western blot studies showed that VDR levels are diminished in aged enterocytes. Confocal microscopy assays revealed that the VDR and other immune-reactive proteins have mitochondrial, membrane, cytosol and perinuclear localization. Western blot analysis using specific antibodies detected the 60 and 50 kDa bands expected for the VDR in the cytosol and microsomes and, to a lesser extent, in the nucleus and mitochondria. Low molecular weight immune-reactive proteins were also detected in young enterocytes subcellular fractions. Since changes in hormone receptor levels appear to constitute a common manifestation of the ageing process, we also analyzed 1α,25(OH)₂D₃ binding properties and VDR levels in subcellular fractions from young and aged rats. In competition binding assays, employing [³H]-1α,25(OH)₂D₃ and 1α,25(OH)₂D₃, we have detected specific binding in all subcellular fractions, with maximum binding in mitochondrial and nuclear fractions. Both, VDR protein levels and 1α,25(OH)₂D₃ binding, were diminished with ageing. Age-related declines in VDR may have important consequences for correct receptor/effector coupling in the duodenal tissues and may explain age-related declines in the hormonal regulation of signal transduction pathways that we previously reported.     

Effects of 1α-hydroxy-vitamin D3 and 1,25-dihydroxy-vitamin D3 on calcium and phosphorus metabolism in hypoparathyroidism

The effects of 1α-OH D₃ or 1,25-(OH)₂D₃ on calcium and phosphorus metabolism have been evaluated in five hypoparathyroid patients to establish the direct effects of these compounds in adult humans, uncomplicated by compensatory changes in parathyroid hormone secretion. Doses of 1–2.5 μg/day in four patients (5 μg/day in a fifth patient on diphenyl-hydantoin and phenobarbital) caused a marked increase in serum calcium concentration and urinary calcium excretion, without significant changes in renal calcium clearance or urinary hydroxyproline excretion. These results suggest that the correction of hypocalcemia involved primarily a stimulation of intestinal calcium absorption rather than a stimulation of skeletal calcium resorption. Simultaneously, there were increases in urinary phosphorus excretion and variable changes in serum inorganic phosphate concentration.These effects were produced by doses of 1α-OH D₃ and 1,25-(OH)₂D₃ which approach the dose needed to prevent rickets, in contrast to the very large doses of vitamin D or 25-OH D₃ required for comparable effects in hypoparathyroid patients. The increased relative effectiveness of these one-hydroxylated forms of vitamin D reveals a deficiency of vitamin D one-hydroxylation in hypoparathyroidism. The rapidity of action of 1α-OH D₃ and 1,25-(OH)₂D₃ was also striking. Apart from its physiologic implications, the potency of the one-hydroxylated forms of vitamin D offers significant therapeutic advantages in some patients whose hypoparathyroidism is difficult to control with vitamin D itself.     

Stathmin levels in growth plate chondrocytes are modulated by vitamin D3 metabolites and transforming growth factor-beta1 and are associated with proliferation

Stathmin is a highly conserved, phosphorylated cytosolic protein that is found at decreased levels in all cells as they become more terminally differentiated, or when they decrease in their rate of proliferation. This study examined the hypothesis that stathmin levels in growth plate chondrocytes decreases as endochondral maturation increases. To test this hypothesis, we used a costochondral growth plate chondrocyte cell culture model. Cells derived from the resting zone (RC) express twice as much stathmin mRNA in culture and have twice as much stathmin protein as cells derived from the post proliferative growth zone ([GC];prehypertrophic and upper hypertrophic cell zones). Stathmin levels in vivo were assessed by immunohistochemistry. To assess the effects of agents that modulate proliferation and differentiation, RC and GC chondrocytes were cultured in the presence of 10⁻¹⁰ to 10⁻⁸ M 1α,25-(OH)₂D₃, which regulates proliferation in both cell types but affects differentiation of only GC cells, or 10⁻⁹ to 10⁻⁷ M 24R,25-(OH)₂D₃, which regulates differentiation and maturation of RC cells, but decreases proliferation of GC cells. In addition, RC cells were treated with 0.44 or 0.88 ng/mL of recombinant human transforming growth factor β1 (rhTGF-β1), which stimulates proliferation of RC cells and regulates proteoglycan production, but not alkaline phosphatase activity. Stathmin protein levels were determined using quantitative immunoblots, with recombinant human stathmin as a standard. The results show that stathmin levels are associated with proliferation. Proliferating chondrocytes in vivo exhibited higher levels of immunoreactive stathmin than either RC or GC cells in the growth plate. In culture, 1α,25-(OH)₂D₃ caused a dose-dependent de-crease in stathmin in RC and GC cells within 24 h. 24 R, 25-(OH)₂D₃ also reduced stathmin levels in GC cells within 24 h but only affected RC cells after prolonged exposures (96 h), at which time RC cells express a GC-like phenotype. rhTGF-β1 caused an increase in stathmin levels in RC cells. Stathmin levels are sensitive to protein kinase C (PKC) in other cells. Inhibition of PKC with chelerythrine had no effect on the response of RC cells to 1α,25-(OH)₂D₃ but it blocked the effect of rhTGF-β1, indicating that decreases in stathmin by vitamin D₃ metabolites may not be modulated by PKC, whereas increases in stathmin via rhTGF-β1 may be regulated via a PKC-dependent mechanism. These results support the hypothesis that constitutively expressed levels of stathmin are related to cell maturation state and that they are modulated by factors that regulate proliferation.     

Changes in vitamin D levels in patients with systemic lupus erythematosus: Effects on fatigue,disease activity,and damage

Objective

To analyze whether changes in serum 25‐hydroxyvitamin D (25[OH]D) levels affect activity, irreversible organ damage, and fatigue in systemic lupus erythematosus (SLE).

Methods

We performed an observational study of 80 patients with SLE included in a previous cross‐sectional study of 25(OH)D, reassessed 2 years later. Oral vitamin D₃ was recommended in those with low baseline 25(OH)D levels. The relationship between changes in 25(OH)D levels from baseline and changes in fatigue (measured by a 0–10 visual analog scale [VAS]), SLE activity (measured by the Systemic Lupus Erythematosus Disease Activity Index [SLEDAI]), and irreversible organ damage (measured by the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index [SDI]) were analyzed.

Results

Sixty patients took vitamin D₃. Mean 25(OH)D levels increased among all treated patients (P = 0.044), in those with baseline vitamin D levels <30 ng/ml (P < 0.001), and in those with baseline vitamin D levels <10 ng/ml (P = 0.005). Fifty‐seven patients (71%) still had 25(OH)D levels <30 ng/ml and 5 (6%) had 25(OH)D levels <10 ng/ml. Inverse significant correlations between 25(OH)D levels and the VAS (P = 0.001) and between changes in 25(OH)D levels and changes in the VAS in patients with baseline 25(OH)D levels <30 ng/ml (P = 0.017) were found. No significant correlations were seen between the variation of the SLEDAI or SDI values and the variation in 25(OH)D levels (P = 0.87 and P = 0.63, respectively).

Conclusion

Increasing 25(OH)D levels may have a beneficial effect on fatigue. Our results do not support any effects of increasing 25(OH)D levels on SLE severity, although they are limited by the insufficient 25(OH)D response to the recommended regimen of oral vitamin D₃ replacement.     

Vitamin D levels in women with systemic lupus erythematosus and fibromyalgia.

OBJECTIVE: Many patients with systemic lupus erythematosus (SLE) and fibromyalgia (FM) may spend less time exposed to the sun than healthy individuals and thus might have low vitamin D levels. It is known that hydroxychloroquine (HCQ) inhibits conversion of 25(OH)- to 1,25(OH)2-vitamin D both in vitro and in patients with sarcoidosis. We assessed winter serum 25(OH)- and 1,25(OH)2-vitamin D levels in patients with SLE and FM. METHODS: We recruited 25 consecutive female SLE and 25 female FM patients in London, Ontario, between January and March 2000. Subjects completed a brief questionnaire. Serum levels of 25(OH)-, 1,25(OH)2-vitamin D, and parathyroid hormone (PTH) were measured. RESULTS: In SLE patients mean 25(OH)-vitamin D was 46.5 nmol/l and mean 1,25(OH)2-vitamin D was 74.4 pmol/l. In FM patients these means were 51.5 nmol/l and 90.1 pmol/l, respectively. Serum 25(OH)-vitamin D levels did not significantly differ between SLE and FM patients, nor after adjusting for age and vitamin D, milk consumption, and sun block use. In 14 of the SLE patients and 12 of the FM patients 25(OH)-vitamin D levels < 50 nmol/l were found. SLE patients not using vitamin D supplements had lower 25(OH)-vitamin D levels than those who did. 1,25(OH)2-vitamin D tended to be lower in the SLE compared to the FM patients. This difference could be attributed to HCQ use: HCQ users (n = 17) had lower 1,25(OH)2-vitamin D levels than nonusers (n = 33); the mean adjusted difference was 24.4 pmol/l (95% CI 2.8-49.9). CONCLUSION: Half the SLE and FM patients had 25(OH)-vitamin D levels < 50 nmol/l, a level at which PTH stimulation occurs. Our data suggest that in SLE patients HCQ might inhibit conversion of 25(OH)-vitamin D to 1,25(OH)2-vitamin D.     

Role of vitamin D derivatives in intestinal tissue of patients with inflammatory bowel diseases

Background and aimThe adhesion molecule expression and matrix metalloproteinases (MMPs) are proposed to be major factors for intestinal injury mediated by T cells in (IBD) and are up-regulated in intestinal mucosa of IBD patients. To investigate the effect of vitamin D derivatives on adhesion molecules and MMPs in colonic biopsies of IBD patients.MethodsBiopsies from inflamed and non-inflamed tract of terminal ileum and colon and PBMC from the same IBD patients were cultured with or without vitamin D derivatives. MMP activity and adhesion molecule levels were determined.Results1,25(OH)₂D₃ and ZK 191784 significantly decrease ICAM-1 protein levels in the biopsies obtained only from the inflamed region of intestine of UC patients, while MAdCAM-1 levels decrease in the presence of 1,25(OH)₂D₃ in the non-inflamed region, and, in the presence of ZK, in the inflamed one. In CD patients 1,25(OH)₂D₃ and ZK decrease ICAM-1 and MAdCAM-1 in the biopsies obtained from the non-inflamed and inflamed regions, with the exception of ICAM-1 in the inflamed region in the presence of 1,25(OH)₂D₃. The expression of MMP-9, MMP-2, and MMP-3 decreases in the presence of vitamin D derivatives in UC and CD with the exception of 1,25(OH)₂D₃ that does not affect the levels of MMP-9 and MMP-2 in CD. Vitamin D derivatives always affect MMP-9, MMP-2 and ICAM-1 in PBMC of UC and CD patients.ConclusionsBased on the increased expression of ICAM-1, MAdCAM-1 and MMP-2,-9,-3 in IBD, our study suggests that vitamin D derivatives may be effective in the management of these diseases.     

Decreased expression of vitamin D receptor may contribute to the hyperimmune status of patients with acquired aplastic anemia

Acquired aplastic anemia (AA) is an immune‐mediated bone marrow failure syndrome. 1α,25‐Dihydroxyvitamin D₃ [1,25(OH)₂D₃], the biologically active metabolite of vitamin D, is a critical modulator of immune response via binding with vitamin D receptor (VDR). Previous studies have established that 1,25(OH)₂D₃ and VDR were involved in the pathogenesis of some autoimmune diseases. In this study, we evaluated the involvement of 1,25(OH)₂D₃ and VDR on T‐cell responses in AA. Plasma 25(OH)D₃ levels were comparable between patients with AA and healthy controls. Surprisingly, VDR mRNA was significantly lower in untreated patients with AA than in healthy controls. Subsequent in vitro experiments revealed that 1,25(OH)₂D₃ treatment suppressed the proliferation of lymphocytes and inhibited the secretion of interferon‐γ, tumor necrosis factor‐α, and interleukin‐17A, meanwhile promoting the production of transforming growth factor‐β1 in patients with AA. Moreover, 1,25(OH)₂D₃ inhibited the differentiation of type 1 and Th17 cells but induced the differentiation of type 2 and regulatory T cells. Interestingly, VDR mRNA was elevated in healthy controls after 1,25(OH)₂D₃ treatment, but not in patients with AA. In conclusion, decreased expression of VDR might contribute to the hyperimmune status of AA and appropriate vitamin D supplementation could partly correct the immune dysfunction by strengthening signal transduction through VDR in patients with AA.     

Serum concentration of vitamin D metabolites in rheumatoid arthritis

Summary One-hundred and two patients with rheumatoid arthritis (RA) were studied. They were divided into three groups according to treatment with gold salts, penicillamine or glucocorticoids. Blood samples were drawn between November and January and four different metabolites of vitamin D (25(OH)D₃, 24,25 (OH)₂D₃, 25,26 (OH)₂D and 1,25 (OH)₂D) were measured and compared to values from normal subjects. The mean serum concentrations of 25(OH)D₃ in all three patient groups were significantly lower than those of the controls (p<0.01–0.001). The mean serum concentrations of 24,25 (OH)₂D₃ and 25,26 (OH)₂D were not significantly different from the control values, whereas 1,25 (OH)₂D concentrations were significantly lower in the penicillamine and steroid groups (p<0.05–0.01). When patients were stratified according to functional classes, we found a significant inverse relation between serum concentrations of 25(OH) D₃, 24,25(OH)₂D₃, 25,26(OH)₂D and the functional class, but not between 1,25(OH)₂D and the functional class. We conclude that the decreased serum 25(OH)D₃ concentration found in patients with RA is likely to be caused by decreased exposure to sunlight due to decreased activity, and thus is a result of the disease rather than a pathogenetic factor. Whether the small decrease in serum 1,25(OH)₂D is of clinical significance and related to the development of osteoporosis in patients with RA is probably doubtful.     

Phosphate Transport Adaptation in Rat Jejunum and Plasma Level of 1,25-Dihydroxyvitamin D3

Intestinal absorption of inorganic phosphate (Pi) increases in response to a reduction in the dietary supply of Pi. In this work this adaptive response has been characterized in jejunal brush border membrane vesicles and studied in temporal relationship with the change in the plasma level of 1,25(OH)2D₃. The results indicate that in rat jejunal brush border membrane vesicles the activity of the sodium-dependent Pi transport system is stimulated by a low Pi diet. This adaptive response was the result of an increase in the V_max and a reduction in the K_m of the cotransport system. This change in Pi transport was correlated with an increase in the circulating level of 1,25(OH)2D₃ in a time-related fashion. In conclusion, these results are consistent with the notion that Pi restriction leads to an increase in Pi transport activity in the luminal membrane of the intestine. A time course study suggests that the elevation in plasma 1,25(OH)2D₃ might be involved in the adaptation of the intestinal Pi transport system to Pi restriction.     

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 D₃ (1,25[OH]₂D₃) 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)₂D₃, dexamethasone (DEX), and 1,25(OH)₂D₃ 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)₂D₃ reduced interleukin‐17A (IL‐17A) and interferon‐γ levels and increased IL‐4 levels in stimulated PBMCs from treatment‐naive patients with early RA. In addition, 1,25(OH)₂D₃ had favorable effects on tumor necrosis factor α (TNFα):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)₂D₃, in contrast to DEX, directly modulated human Th17 polarization, accompanied by suppression of IL‐17A, IL‐17F, TNFα, and IL‐22 production by memory T cells sorted by FACS from patients with early RA.

Conclusion

These data indicate that 1,25(OH)₂D₃ 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.