Effect of chronic hepatitis C virus infection on bone disease in postmenopausal women

Pegylated interferon α/ribavirin therapy enhances bone mineral density in children with chronic genotype 4 HCV infection

BACKGROUND

The impact of chronic hepatitis C (CHC) on bone mineral density (BMD) has been well studied in adults with a relative paucity of data in children, especially concerning effect of treatment with pegylated interferon (PEG-IFN) plus ribavirin (RV). In the current work, we assessed prospectively changes in BMD in children with CHC before, during, and after treatment.

METHODS

Forty-six consecutive children with noncirrhotic genotype 4 CHC were subjected to dual-energy X-ray absorptiometry at baseline, 24 weeks, 48 weeks of therapy and 24 weeks after treatment. BMD, bone mineral content (BMC), and Z score of lumbar spine (L2-L4) were reported. Tanner pubertal stage, viral load, liver function tests, serum calcium, phosphorus, alkaline phosphatase, parathyroid hormone, and liver histopathology were assessed in all included children.

RESULTS

Thirty (65.2%) patients had normal BMD, 10 (21.7%) were at risk for low BMD, and 6 (13.1%) had low BMD for chronological age. Patients with low BMD were significantly older (P=0.001), with higher frequency of delayed puberty than other groups (P=0.002). Baseline densitometric parameters (BMD & BMC) were significantly positively correlated with patients' age, weight, height, body mass index and hemoglobin level; while they were insignificantly correlated with basal viral load, histopathology activity index and fibrosis score. Densitometric parameters improved significantly on PEG-IFN plus RV treatment, this improvement was found to be sustainable 24 weeks after therapy.

CONCLUSIONS

Low BMD is detectable in a proportion of CHC children. Antiviral therapy leads to a sustainable increase in BMD.

Relation Between Hepatitis C Virus Exposure and Risk of Osteoporosis: A Nationwide Population-Based Study

The effect of hepatitis C virus (HCV) exposure on bone mineral density without advanced liver disease remains debated. Thus, we assessed the relation between HCV exposure and the risk of osteoporosis.From 2000 to 2011, patients aged >20 years with HCV exposure were identified from the Longitudinal Health Insurance Database 2000. Of the 51,535 sampled patients, 41,228 and 10,307 patients were categorized as the comparison and the HCV exposure cohorts, respectively.The overall incidence of osteoporosis in the HCV exposure cohort was higher than in the comparison cohort (8.27 vs 6.19 per 1000 person-years; crude hazard ratio = 1.33, 95% confidence interval = 1.20-1.47). The incidence of osteoporosis, higher in women than in men, increased with age and comorbidity of hypertension, hyperlipidemia, and heart failure. The risk of developing osteoporosis was significantly higher in the HCV exposure cohort than in the comparison cohort after adjusting for age, sex, diabetes, hypertension, hyperlipidemia, heart failure, stroke, and cirrhosis. However, the risk of osteoporosis contributed by HCV decreased with age and the presence of comorbidity. Furthermore, the risk of osteoporotic fracture did not differ significantly between patients exposed to HCV and the comparison cohorts.HCV increases the risk of osteoporosis, but no detrimental effect on osteoporotic fracture was observed in this study. Furthermore, HCV may be less influential than other risk factors, such as hypertension, hyperlipidemia, and heart failure, in contributing to the development of osteoporosis.

Fracture risk in hepatitis C virus infected persons: results from the DANVIR cohort study

BACKGROUND & AIMS

The association between Hepatitis C virus (HCV)-infection and fracture risk is not well characterized. We compared fracture risk between HCV-seropositive (HCV-exposed) patients and the general population and between patients with cleared and chronic HCV-infection.

METHODS

Outcome measures were time to first fracture at any site, time to first low-energy and first non-low-energy (other) fracture in 12,013 HCV-exposed patients from the DANVIR cohort compared with a general population control cohort (n=60,065) matched by sex and age. Within DANVIR, 4500 patients with chronic HCV-infection and 2656 patients with cleared HCV-infection were studied.

RESULTS

Compared with population controls, HCV-exposed patients had increased overall risk of fracture [adjusted incidence rate ratio (aIRR) 2.15, 95% Confidence Interval (CI) 2.03-2.28], increased risk of low-energy fracture (aIRR 2.13, 95% CI: 1.93-2.35) and of other fracture (aIRR 2.18, 95% CI: 2.02-2.34). Compared with cleared HCV-infection, chronic HCV-infection was not associated with increased risk of fracture at any site (aIRR 1.08, 95% CI: 0.97-1.20), or other fracture (aIRR 1.04, 95% CI: 0.91-1.19). The aIRR for low-energy fracture was 1.20 (95% CI: 0.99-1.44).

CONCLUSIONS

HCV-exposed patients had increased risk of all fracture types. In contrast, overall risk of fracture did not differ between patients with chronic vs. cleared HCV-infection, although chronic HCV-infection might be associated with a small excess risk of low-energy fractures. Our study suggests that fracture risk in HCV-infected patients is multi-factorial and mainly determined by lifestyle-related factors associated with HCV-exposure.

Network-based study reveals potential infection pathways of hepatitis-C leading to various diseases

Protein-protein interaction network-based study of viral pathogenesis has been gaining popularity among computational biologists in recent days. In the present study we attempt to investigate the possible pathways of hepatitis-C virus (HCV) infection by integrating the HCV-human interaction network, human protein interactome and human genetic disease association network. We have proposed quasi-biclique and quasi-clique mining algorithms to integrate these three networks to identify infection gateway host proteins and possible pathways of HCV pathogenesis leading to various diseases. Integrated study of three networks, namely HCV-human interaction network, human protein interaction network, and human proteins-disease association network reveals potential pathways of infection by the HCV that lead to various diseases including cancers. The gateway proteins have been found to be biologically coherent and have high degrees in human interactome compared to the other virus-targeted proteins. The analyses done in this study provide possible targets for more effective anti-hepatitis-C therapeutic involvement.

Hungry bone syndrome and normalisation of renal phosphorus threshold after total parathyroidectomy for tertiary hyperparathyroidism in X-linked hypophosphataemia: a case report

INTRODUCTION

This is the first report of which the authors are aware to describe this c.2166delinsGG mutation in X-linked hypophosphataemia and to describe normalisation of renal threshold for phosphate excretion after parathyroidectomy for tertiary hyperparathyroidism in X-linked hypophosphataemia.

CASE PRESENTATION

We present the case of a 34-year-old Caucasian woman with X-linked hypophosphataemia. She developed tertiary hyperparathyroidism with markedly high bone turnover requiring total parathyroidectomy and had prolonged requirement for intravenous calcium infusion after surgery. She had a novel mutation in her phosphate-regulating gene with homologies to endopeptidases on the X-chromosome and had an unusual degree of dependence on phosphate supplementation. Prior to operative intervention she had a trial of cinacalcet that improved bone turnover markers when used in isolation but which led to a paradoxical rise in parathyroid hormone levels when given with phosphate supplementation. After correction of hungry bone syndrome, the renal phosphorus threshold normalised as a manifestation of hypoparathyroid state despite marked elevation in level of fibroblast growth factor 23.

CONCLUSIONS

This case illustrates the risk of tertiary hyperparathyroidism as a complication of treatment for hypophosphataemia; it highlights the morbidity associated with hungry bone syndrome and provides novel insight into renal handling of phosphorus.

Serum sclerostin in hepatitis C virus infected patients

Background

Sclerostin inhibits osteoblast functions, differentiations, and survival rates. As an endogenous inhibitor of the Wnt/β-catenin pathway, the sclerostin should be related to decreased bone masses, although several studies indicate opposite results. In addition, it may be related to insulin resistances and carbohydrate metabolisms, a relation shared with other markers of bone metabolisms, such as osteocalcin. Hepatitis C virus (HCV) infected patients may present osteoporosis, and frequently show liver steatosis, which is a consequence of insulin resistance. The behaviour of sclerostin in these patients is yet unknown. The aim of this work is to analyse the relationships between serum sclerostin and osteocalcin levels and bone mineral density (BMD), liver functions, the intensity of liver steatosis and biochemical markers of bone homeostasis and insulin resistance in HCV-infected patients.

Methods

Forty HCV patients with 20 years of age and gender-matching controls were included in this study and underwent bone densitometry. Serum sclerostin, osteocalcin, collagen telopeptide, adiponectin, leptin, insulin, resistin, tumor necrosis factor (TNF)-α, and interleukin (IL)-6 were determined. Liver fat was histomorphometrically assessed.

Results

Sclerostin levels were slightly higher in patients than in controls, and were directly related to BMD at different parts of the skeleton, also to the serum telopeptide, and to the liver steatosis and TNF-α. On the contrary, osteocalcin showed a significant direct relationship with serum adiponectin, and an inverse one with IL-6.

Conclusions

Serum sclerostin levels were within the normal range in HCV patients, and correlated directly with BMD and serum telopeptide. In addition, the relationships of sclerostin and osteocalcin with variables associated with insulin resistance suggested the role of bones for intermediary metabolisms.

Low-dose hydrocortisone replacement therapy is associated with improved bone remodelling balance in hypopituitary male patients

OBJECTIVE

Glucocorticoid (GC) therapy is associated with adverse effects on bone metabolism, yet the effects of different GC physiological replacement regimens in hypopituitarism are not well characterised. We aimed to assess the effect of three hydrocortisone (HC) replacement dose regimens on bone turnover.

STUDY DESIGN

An open cross-over study randomising ten hypopituitary men with severe acth deficiency to three commonly used HC dose regimens: dose A (20 mg mane and 10 mg tarde), dose B (10 mg mane and 10 mg tarde) and dose C (10 mg mane and 5 mg tarde).

METHODS

Following 6 weeks of each regimen, the participants underwent 24-h serum cortisol sampling and measurement of bone turnover markers: bone-specific alkaline phosphatase, procollagen type I N-propeptide (PINP), intact osteocalcin (OC(1-49)), C-terminal cross-linking telopeptide (CTX-I) and tartrate-resistant acid phosphatase 5b (TRACP5b). Bone remodelling balance was estimated as an absolute ratio (PINP:CTX-I) and as an index using standardised scores derived from the matched controls.

RESULTS

There were significant increases in the concentrations of the formation markers PINP (P=0.045) and OC(1-49) (P=0.006) and in the PINP:CTX-I ratio (P=0.015), and a more positive bone remodelling balance index (P=0.03) was observed in patients on the lowest dose C than in those on the highest dose A. Mean 24-h cortisol concentrations correlated negatively with CTX-I (r=-0.66 and P=0.04) and TRACP5b (r=-0.74 and P=0.01) in patients on dose B and with OC(1-49) (r=-0.66 and P=0.04) and CTX-I (r=-0.81 and P<0.01) in patients on dose C. In patients receiving the lower-dose regimen, trough cortisol concentrations correlated with increased bone formation and resorption.

CONCLUSION

Low-dose HC replacement (10 mg mane and 5 mg tarde) is associated with increased bone formation and a positive bone remodelling balance. This may have a long-term beneficial effect on bone health.

In HIV/hepatitis C virus co-infected patients, higher 25-hydroxyvitamin D concentrations were not related to hepatitis C virus treatment responses but were associated with ritonavir use

BACKGROUND

Among patients with hepatitis C virus (HCV) monoinfection, 25-hydroxyvitamin D [25(OH)D] concentrations are positively associated with a response to peg-interferon/ribavirin. Data on the relation between 25(OH)D concentrations and HCV treatment response in HIV-infected patients are limited.

OBJECTIVE

The objective was to determine whether baseline 25(OH)D concentrations predict virologic response in HIV/HCV co-infected patients and to examine variables associated with 25(OH)D concentrations ≥30 ng/mL.

DESIGN

Data and samples from 144 HCV genotype 1, treatment-naive patients from a completed HCV treatment trial were examined in this retrospective study. Early virologic response (EVR) was defined as ≥2 log10 reduction in HCV RNA and/or HCV RNA <600 IU/mL at week 12 of peg-interferon/ribavirin treatment. Baseline 25(OH)D was measured by liquid chromatography/tandem mass spectrometry.

RESULTS

Compared with the non-EVR control group (n = 68), the EVR group (n = 76) was younger, had fewer cirrhotic subjects, had a higher proportion with the IL28B CC genotype, had a higher albumin concentration, and had a lower HCV viral load at baseline (P ≤ 0.05). The difference in baseline 25(OH)D concentrations between EVR and non-EVR patients was not statistically significant (median: 25 ng/mL compared with 20 ng/mL; P = 0.23). Similar results were found for sustained virologic response (SVR). In multivariable analysis, white and Hispanic race-ethnicity (OR: 6.26; 95% CI: 2.47, 15.88; P = 0.0001) and ritonavir use (OR: 2.68; 95% CI: 1.08, 6.65; P = 0.033) were associated with higher 25(OH)D concentrations (≥30 ng/mL).

CONCLUSION

Baseline 25(OH)D concentrations did not predict EVR or SVR. Because ritonavir impairs the conversion of 25(OH)D to the active metabolite, utilization of 25(OH)D may have been impaired in subjects taking ritonavir. This trial was registered at www.clinicaltrials.gov as NCT00078403.

Limited utility of tartrate-resistant acid phosphatase isoform 5b in assessing response to therapy in osteoporosis

BACKGROUND

Tartrate-resistant acid phosphatase isoform 5b (TRACP5b) is a serum bone resorption marker. Our aim was to investigate its utility in monitoring metabolic bone disease.

METHODS

Serum TRACP5b, C-terminal cross-linking telopeptide of type I collagen, urine N-terminal cross-linking telopeptide of type I collagen and free deoxypyridinoline were measured pre- and post-treatment with a parathyroid hormone analogue [PTH (1-34)] (n = 14) or a bisphosphonate (N-BP) (n = 8). TRACP5b, bone alkaline phosphatase (bone ALP), 25-hydroxyvitamin D (25OHD) and parathyroid hormone (PTH) were measured in 100 osteoporosis patients on prolonged bisphosphonate therapy.

RESULTS

Changes in TRACP5b were smaller in magnitude but mimicked those of other bone resorption markers. Absolute changes in TRACP5b and the other resorption markers correlated significantly (p < 0.001). In patients on long-term bisphosphonates, TRACP5b and bone ALP levels were not suppressed. Vitamin D status was consistent with the level of supplementation.

CONCLUSION

TRACP5b has limited utility as a single marker of metabolic bone disease treatment.

Periarticular bone gain at proximal interphalangeal joints and changes in bone turnover markers in response to tumor necrosis factor inhibitors in rheumatoid and psoriatic arthritis

OBJECTIVE

Rheumatoid arthritis (RA) and psoriatic arthritis (PsA) are characterized by periarticular bone erosion; periarticular bone formation is a feature in PsA. The effect of anti-tumor necrosis factor-α (TNF-α) on periarticular bone remodeling is unclear in both diseases. Our aim was to assess the response of bone turnover markers (BTM) and hand bone mineral density (BMD) to anti-TNF over 3 years in RA and PsA.

METHODS

We measured serum bone-specific alkaline phosphatase (bone ALP), procollagen type-I N-propeptide (PINP), intact osteocalcin, C-terminal cross-linking telopeptides (CTX-I), urinary N-terminal cross-linking telopeptide of type-I collagen (NTX-I), and free deoxypyridinoline crosslinks (fDPD) at baseline, 1, 12, and 36 months. BMD measurements (hands/spine/hip) were obtained at 3 timepoints.

RESULTS

We recruited 62 patients (RA 35; PsA 27). BTM correlated significantly with hand BMD but not with central BMD. Low hand BMD was associated with RA and increased BTM. Following anti-TNF therapy, hip BMD declined while spine and hand BMD were unchanged. Periarticular BMD at proximal interphalangeal (PIP) joints increased while it decreased at metacarpophalangeal joints. Bone ALP increased steadily and was always higher in PsA. PINP and intact osteocalcin increased to a lesser extent, but resorption markers did not change.

CONCLUSION

At baseline, hand BMD was inversely associated with BTM. Bone formation rather than resorption markers better showed the bone response to anti-TNF. Despite a lack of effect on central BMD, the modest effect of anti-TNF on PIP BMD may provide evidence that BTM reflect specifically bone remodeling activity at periarticular sites of inflammation in RA and PsA.

Vitamin D for your patients with chronic hepatitis C?

Vitamin D is increasingly becoming recognized as an important physiological regulator with pleiotropic functions outside of its classical role in skeletal homeostasis. A growing body of clinical evidence highlights the prevalence and risks of vitamin D deficiency in patients suffering from chronic hepatitis C infection, and vitamin D supplementation has been proposed as an adjunct to current standards of care. This review considers the experimental evidence for the anti-inflammatory, antifibrotic and antiviral effects of vitamin D, and discusses the therapeutic potential of vitamin D supplementation to protect against liver disease progression and improve responses to treatment.

Bone alterations in hepatitis C virus infected patients

BACKGROUND AND AIMS

Most studies have shown that patients with chronic hepatitis C virus (HCV) infection are affected by osteoporosis. However, liver function impairment and deranged nutrition may both play a role in the bone alterations observed. In some works no osteoporosis was found, and some cases of osteosclerosis have been reported. The aim of the study is to assess bone alterations in treatment-naïve, well-nourished HCV patients, in order to discern whether or not HCV infection causes osteoporosis.

METHODS

Whole-body bone densitometry and assessment of T-score at lumbar spine and hip were performed to 40 patients and 40 age- and sex-matched controls, with a Lunar Prodigy Advance (General Electric, Piscataway, NJ, USA). All the patients underwent liver biopsy. Nutritional evaluation was performed by subjective nutritional assessment, body mass index (BMI), and densitometric assessment of total lean mass and total fat mass. Serum osteocalcin, osteoprotegerin, RANKL, PTH, crosslaps, vitamin D3, testosterone, IGF-1, and estradiol were determined.

RESULTS

Patients did not show differences in total bone mineral density (BMD) or T-score with controls. On the contrary, about a third of them showed positive T scores. Patients showed lower IGF-1, vitamin D3 and testosterone, but higher telopeptide levels, and a trend to higher osteoprotegerin levels. Multivariate analyses disclosed that age, sex, and total lean mass were the only parameters independently related with BMD.

CONCLUSIONS

Therefore, chronic HCV infection in well nourished patients with preserved liver function does not cause osteoporosis.

Association between chronic hepatitis C virus infection and bone mineral density

Whether chronic hepatitis C virus (HCV) infection is a risk factor for the development of bone disease has long been controversial. For this reason, chronic HCV-infected participants (n = 69) were recruited into a prospective cohort study and underwent dual-energy X-ray absorptiometry for determination of bone mineral density (BMD). Fibrosis staging was evaluated according to the noninvasive index FIB-4. T scores at the femoral neck and lumbar spine were used as the primary outcome variables to assess the association between degree of liver disease and BMD. The study cohort was 41 % male with a mean age of 53.6 years. The mean BMD, Z score, and T score values of lumbar spine in chronic hepatitis C (CHC) patients were significantly lower than those in healthy controls (p < 0.001). The rate of osteoporosis for CHC patients aged 45-54 years was significantly higher than that of the control group (p = 0.011). Bone alkaline phosphatase and C-terminal cross-linking telopeptide of type I collagen levels were also significantly higher in CHC patients with reduced BMD. Patients with more advanced liver fibrosis had significantly lower BMD. In conclusion, reduced BMD is common in this population of chronic HCV-infected patients and associated with liver disease severity. This extrahepatic manifestation is probably secondary to increased bone turnover in osteodystrophy pathogenesis.

Fractures after antiretroviral initiation

BACKGROUND

Bone mineral density declines by 2-6% within 1-2 years after initiation of antiretroviral therapy (ART); however, it is uncertain whether this results in an immediate or cumulative increase in fracture rates.

METHODS

We evaluated the incidence and predictors of fracture in 4640 HIV-positive participants from 26 randomized ART studies followed in the AIDS Clinical Trials Group (ACTG) Longitudinal-Linked Randomized Trial study for a median of 5 years. Fragility and nonfragility fractures were recorded prospectively at semiannual visits. Incidence was calculated as fractures/total person-years. Cox proportional hazards models evaluated effects of traditional fracture risks, HIV disease characteristics, and ART exposure on fracture incidence.

RESULTS

Median (interquartile range) age was 39 (33, 45) years; 83% were men, 48% white, and median nadir CD4 cell count was 187 (65, 308) cells/μl. Overall, 116 fractures were reported in 106 participants with median time-to-first fracture of 2.3 years. Fracture incidence was 0.40 of 100 person-years among all participants and 0.38 of 100 person-years among 3398 participants who were ART naive at enrollment into ACTG parent studies. Among ART-naive participants, fracture rates were higher within the first 2 years after ART initiation (0.53/100 person-years) than subsequent years (0.30/100 person-years). In a multivariate analysis of ART-naive participants, increased hazard of fracture was associated with current smoking and glucocorticoid use but not with exposure to specific antiretrovirals.

CONCLUSION

Fracture rates were higher within the first 2 years after ART initiation, relative to subsequent years. However, continuation of ART was not associated with increasing fracture rates in these relatively young HIV-positive individuals.

Proton pump inhibitors increase the incidence of bone fractures in hepatitis C patients

BACKGROUND

While proton pump inhibitors (PPI) may increase the risk of bone fractures, the incidence of new bone fractures in a chronic hepatitis C virus (HCV) infected cohort, with or without PPI exposure, has not been explored.

METHODS

A retrospective cohort study of the incidence of bone fractures over 10 years in 9,437 HCV antibody positive patients in the Dallas VA Hepatitis C Registry was performed. The study endpoint was the incidence of verified new bone fractures per patient-years (pt-yrs) in PPI users compared to non-PPI users. PPI use was defined as those taking a PPI for ≥360 days. Pt-yrs of exposure for PPI users began on the first PPI prescription date, and pt-yrs of exposure for non-PPI users began with first date of any non-PPI prescription. For both HCV groups, the final date of patients' study duration was defined by end of PPI exposure, bone fracture occurrence, death or end of study evaluation period. Exclusion criteria included use of bone health modifying medications ≥30 days. Statistical differences in fracture incidence between groups were determined by multivariate regression analysis.

RESULTS

Among the total study population analyzed (n = 2,573), 109 bone fractures occurred. Unadjusted bone fracture incidences were 13.99/1,000 pt-yrs vs. 5.86/1,000 pt-yrs in PPI and non-PPI users, respectively. The adjusted hazard ratio for new bone fractures was 3.87 (95 % CI 2.46-6.08) (p < 0.001) in PPI users.

CONCLUSIONS

In patients with chronic HCV, use of PPI for >1 year increased the risk of new bone fractures by more than threefold.

Elevated circulating osteoprotegerin and reduced matrix-metalloprotease-9 in post-menopausal women with chronic Hepatitis C virus infection

The failure of the immune response to clear the Hepatitis C virus (HCV) results in chronic inflammation that leads to liver cirrhosis. In general, women have a better prognosis than men and this may be associated with increased levels of anti-inflammatory mediators that are positively regulated by female sex hormones. Our aim was to determine if a cohort of Irish women who acquired infection through administration of HCV genotype 1b-contaminated anti-D immunoglobulin from a single source, had altered levels of circulating cytokine levels compared to women who spontaneously resolved infection, men with HCV infection or age-matched healthy controls. Twenty post-menopausal women and 20 men with chronic HCV infection (genotype 1), 20 post-menopausal women who resolved infection and age and sex-matched controls were recruited for the study. Levels of circulating cytokines were assessed by ELISA. Circulating IL-6, Oncostatin-M, TNF-α, CXCL10, CCL18, VEGF and GM-CSF did not differ between groups. Both men and women with HCV had significantly elevated levels of circulating Osteoprotegerin (OPG). However, male but not female HCV patients had elevated levels of circulating Matrix Metalloprotease-9 (MMP-9). An increased OPG: MMP-9 ratio in the circulation of females compared to males with chronic HCV may help protect against HCV-associated liver disease and explain the slow progress of liver disease in this cohort.

Immunomodulators for multiple sclerosis may ameliorate spinal bone loss

BACKGROUND

The effect of immunomodulator therapy (IMT) for multiple sclerosis (MS) on bone turnover is unknown.

AIM

The aim of this study was to assess bone turnover in MS patients on IMT.

METHODS

MS patients (n = 29) on maintenance IMT had repeat measurement of bone mineral density (BMD) after a 4.0 ± 0.4 years; bone turnover markers (BTM) were measured at the time of repeat BMD.

RESULTS

BMD was unchanged at the spine but declined at the hip. BTMs, both resorption and formation, were reduced compared to normative range that may indicate an anti-resorptive action of IMT. Significant negative correlations were noted between BTMs and changes in BMD at spine but not hip.

CONCLUSION

These observations suggest that IMT may have a beneficial effect on spinal bone by an antiresorptive action. A prospective study of the effect of IMT on BMD and bone turnover is warranted.

Review article: the extra-skeletal effects of vitamin D in chronic hepatitis C infection

BACKGROUND

Recent interest has focused on the extra-skeletal effects of vitamin D, in particular, in patients with chronic hepatitis C.

AIMS

To review data in the literature regarding the extra-skeletal effects of vitamin D in patients with chronic hepatitis C, with and without liver transplantation.

METHODS

A Medline search was performed for relevant studies up to August 2011 using the terms 'vitamin D' 'chronic liver disease' and 'hepatitis C'.

RESULTS

Vitamin D deficiency is very frequent before liver transplantation ranging between 51% and 92%, whereas, in the liver transplantation setting, the prevalence of vitamin D deficiency is also high. Severe liver disease may increase the risk of vitamin D deficiency and vice versa, as there may be a relationship between vitamin D deficiency and fibrosis. In patients with chronic hepatitis C and those with recurrent of hepatitis C after liver transplantation, recent clinical data shows that a higher serum vitamin D level is an independent predictor of sustained virological response (SVR) following anti-viral therapy, and that a higher SVR is achieved with vitamin D supplementation.

CONCLUSIONS

Larger randomised clinical studies with adequate statistical power are needed to confirm these potentially very important nonskeletal effects of vitamin D in patients with chronic hepatitis C.

Chronic hepatitis C infection blocks the ability of dendritic cells to secrete IFN-α and stimulate T-cell proliferation

Dendritic cells (DCs) are likely to play a key role in the compromised T-cell function associated with hepatitis C Virus (HCV) infection. However, studies of DC function in HCV-infected patients to date have yielded conflicting findings possibly because of patient and virus heterogeneity. Here, we report the characterization of monocyte-derived DCs obtained from a homogenous cohort of women who were infected with HCV genotype 1b following exposure to contaminated anti-D immunoglobulin from a single donor source. Patients included in the study had not received anti-viral therapy and all had mild liver disease. We show that phenotypically normal monocyte-derived dendritic cells (MDDCs) (CD11c(+) HLA(-) DR(+) CD1a(+) CD14(lo) ) can be obtained from these patients. These cells respond to both Poly(I:C) and LPS, by up-regulating expression of CD86. They secrete high levels of IL-8 and CCL5 in response to LPS, an indication that the MyD88-dependent and MyD88-independent signalling pathways downstream of TLR4 ligation are functioning normally. However, these cells are poor stimulators of T-cell proliferation in allogeneic mixed lymphocyte reactions. Furthermore, patient MDDCs fail to secrete IFN-α in response to poly(I:C) or IFN-β stimulation. Altered DC function may contribute to impaired cellular immune responses and chronicity of disease following HCV infection in this cohort. An effective therapeutic vaccine for chronic HCV infection will most likely need to target DCs to elicit an appropriate cellular response; therefore, it is important to resolve how the DCs of different patient cohorts respond to stimulation via TLRs.

Informational value and bias of videos related to orthodontics screened on a video-sharing Web site

OBJECTIVE

To assess the informational value, intention, source, and bias of videos related to orthodontics screened by the video-sharing Internet platform YouTube.

METHODS

YouTube (www.youtube.com) was scanned in July 2010 for orthodontics-related videos using an adequately defined search term. Each of the first 30 search results of the scan was categorized with the system-generated sorts "by relevance" and "most viewed" (total: 60). These were rated independently by three assessors, who completed a questionnaire for each video. The data were analyzed statistically using Friedman's test for dependent samples, Kendall's tau, and Fleiss's kappa.

RESULTS

The YouTube scan produced 5140 results. There was a wide variety of information about orthodontics available on YouTube, and the highest proportion of videos was found to originate from orthodontic patients. These videos were also the most viewed ones. The informational content of most of the videos was generally judged to be low, with a rather poor to inadequate representation of the orthodontic profession, although a moderately pro-orthodontics stance prevailed. It was noticeable that the majority of contributions of orthodontists to YouTube constituted advertising. This tendency was not viewed positively by the majority of YouTube users, as was evident in the divergence in the proportions when sorting by "relevance" and "most viewed."

CONCLUSION

In the light of the very large number of people using the Internet as their primary source of information, orthodontists should recognize the importance of YouTube and similar social media Web sites in the opinion-forming process, especially in the case of adolescents.

Fracture incidence in HIV-infected women: results from the Women's Interagency HIV Study

BACKGROUND

The clinical importance of the association of HIV infection and antiretroviral therapy (ART) with low bone mineral density (BMD) in premenopausal women is uncertain because BMD stabilizes on established ART and fracture data are limited.

METHODS

We measured time to first new fracture at any site with median follow-up of 5.4 years in 2391 (1728 HIV-infected, 663 HIV-uninfected) participants in the Women's Interagency HIV Study (WIHS). Self-report of fracture was recorded at semiannual visits. Proportional hazard models assessed predictors of incident fracture.

RESULTS

At baseline, HIV-infected women were older (40 ± 9 vs. 36 ± 10 years, P < 0.0001), more likely to report postmenopausal status and be hepatitis C virus-infected, and weighed less than HIV-uninfected women. Among HIV-infected women, mean CD4(+) cell count was 482 cells/μl; 66% were taking ART. Unadjusted incidence of fracture did not differ between HIV-infected and uninfected women (1.8 vs. 1.4/100 person-years, respectively, P = 0.18). In multivariate models, white (vs. African-American) race, hepatitis C virus infection, and higher serum creatinine, but not HIV serostatus, were statistically significant predictors of incident fracture. Among HIV-infected women, older age, white race, current cigarette use, and history of AIDS-defining illness were associated with incidence of new fracture.

CONCLUSION

Among predominantly premenopausal women, there was little difference in fracture incidence rates by HIV status, rather traditional risk factors were important predictors. Further research is necessary to characterize fracture risk in HIV-infected women during and after the menopausal transition.

New treatments for chronic hepatitis C

Treatments for chronic hepatitis C has evolved significantly in the past 15 years. The standard of care (SOC) is peginterferon alfa-2a/-2b with ribavirin for 48 weeks or 24 weeks in patients infected with HCV genotype 1 or 2/3, respectively. The treatment duration can be individualized based on the baseline viral load and the speed of the virologic response during treatment. However, current therapies are associated with side effects, complications, and poor patient tolerability. Therefore, there is an urgent need to identify better strategies for treating this disease. An improved sustained virologic response (SVR) can be achieved with new HCV-specific inhibitors against NS3/4A and NS5B polymerases. Recent trials have found SVR rates in patients with HCV genotype 1 infection of 61~68% and 67~75% for combining the SOC with the protease inhibitors telaprevir and boceprevir, respectively. Several new HCV-specific inhibitors such as protease inhibitors and nucleoside and non-nucleoside polymerase inhibitors as well as non-HCV-specific compounds with anti-HCV activity are currently in clinical evaluation. In this review we discuss these new treatments for chronic hepatitis C.

Liver and bone

Osteoporosis is a frequent complication in patients with chronic liver disease, especially in end-stages and in cases with chronic cholestasis, hemochromatosis and alcohol abuse. The problem is more critical in transplant patients when bone loss is accelerated during the period immediately after transplantation, leading to a greater incidence of fractures. Advanced age, low body mass index and severity of the liver disease are the main risk factors for bone disease in patients with cholestasis. Mechanisms underlying osteoporosis in chronic liver disease are complex and poorly understood, but osteoporosis mainly results from low bone formation, related to the effects of retained substances of cholestasis, such as bilirubin and bile acids, or to the effects of alcohol on osteoblastic cells. Increased bone resorption has also been described in cholestatic women with advanced disease. Although there is no specific treatment, bisphosphonates associated with supplements of calcium and vitamin D are effective for increasing bone mass in patients with chronic cholestasis and after liver transplantation. The outcome in reducing the incidence of fractures has not been adequately demonstrated essentially because of the low number of patients included in the therapeutic trials. Randomized studies assessing bisphosphonates in larger series of patients, the development of new drugs for osteoporosis and the improvement in the management of liver transplant recipients may change the future.

Variant in CD209 promoter is associated with severity of liver disease in chronic hepatitis C virus infection

CD209, a c-type lectin expressed by dendritic cells (DCs), acts as a pathogen recognition receptor. A single nucleotide polymorphism (SNP) in the promoter region of CD209 (-336 A/G; rs4804803) affects transcription and is associated with the severity of tuberculosis and dengue fever. Because CD209 binds hepatitis C virus (HCV) glycoprotein-E2, we investigated this SNP in the context of chronic HCV infection. A total of 131 Irish women who had received HCV-contaminated anti-D-immunoglobulin and 79 healthy control subjects were genotyped. We found no association between rs4804803 and the risk of HCV chronicity. However, of those with chronic infection, possession of at least one g-allele was associated with more advanced liver disease, with significantly higher liver fibrosis scores and levels of alanine transaminase (ALT) observed. We conclude that rs4804803, an SNP in the CD209 promoter, contributes to severity of liver disease in chronic HCV infection.

Targeting host factors: a novel rationale for the management of hepatitis C virus

Hepatitis C is recognized as a major threat to global public health. The current treatment of patients with chronic hepatitis C is the addition of ribavirin to interferon-based therapy which has limited efficacy, poor tolerability, and significant expense. New treatment options that are more potent and less toxic are much needed. Moreover, more effective treatment is an urgent priority for those who relapse or do not respond to current regimens. A major obstacle in combating hepatitis C virus (HCV) infection is that the fidelity of the viral replication machinery is notoriously low, thus enabling the virus to quickly develop mutations that resist compounds targeting viral enzymes. Therefore, an approach targeting the host cofactors, which are indispensable for the propagation of viruses, may be an ideal target for the development of antiviral agents because they have a lower rate of mutation than that of the viral genome, as long as they have no side effects to patients. Drugs targeting, for example, receptors of viral entry, host metabolism or nuclear receptors, which are factors required to complete the HCV life cycle, may be more effective in combating the viral infection. Targeting host cofactors of the HCV life cycle is an attractive concept because it imposes a higher genetic barrier for resistance than direct antiviral compounds. However the principle drawback of this strategy is the greater potential for cellular toxicity.