Phase 1 study of the pharmacokinetics and clinical proof-of-concept activity of a biofilm-disrupting human monoclonal antibody in patients with chronic prosthetic joint infection of the knee or hip.

We report the results of a first-in-human phase 1 clinical study to evaluate TRL1068, a native human monoclonal antibody that disrupts bacterial biofilms with broad-spectrum activity against both Gram-positive and Gram-negative species. The study population consisted of patients with chronic periprosthetic joint infections (PJIs) of the knee or hip, including both monomicrobial and polymicrobial infections, that are highly resistant to antibiotics due to biofilm formation. TRL1068 was administered via a single pre-surgical intravenous infusion in three sequentially ascending dose groups (6, 15, and 30 mg/kg). Concomitant perioperative antibiotics were pathogen-targeted as prescribed by the treating physician. In this double-blinded study, 4 patients were randomized to receive placebo and 11 patients to receive TRL1068 on day 1, as well as targeted antibiotics for 7 days prior to the scheduled removal of the infected implant and placement of an antibiotic-eluting spacer as the first stage of the standard of care two-stage exchange arthroplasty. No adverse events attributable to TRL1068 were reported. TRL1068 serum half-life was 15-18 days. At day 8, the concentration in synovial fluid was approximately 60% of the blood level and thus at least 15-fold above the threshold for biofilm-disrupting activity in vitro. Explanted prostheses were sonicated to release adherent bacteria for culture, with elimination of the implant bacteria observed in 3 of the 11 patients who received TRL1068, which compares favorably to prior PJI treatments. None of the patients who received TRL1068 had a relapse of the original infection by the end of the study (day 169). CLINICAL TRIALS: This study is registered with ClinicalTrials.gov as NCT04763759.

High-Throughput CAMP Assay (HiTCA): A Novel Tool for Evaluating the Vitamin D-Dependent Antimicrobial Response.

Vitamin D is known to modulate human immune responses, and vitamin D deficiency is associated with increased susceptibility to infection. However, what constitutes sufficient levels or whether vitamin D is useful as an adjuvant therapeutic is debated, much in part because of inadequate elucidation of mechanisms underlying vitamin D's immune modulatory function. Cathelicidin antimicrobial peptide (CAMP) has potent broad-spectrum activity, and the CAMP gene is regulated in human innate immune cells by active 1,25(OH)2D3, a product of hydroxylation of inactive 25(OH)D3 by CYP27B1-hydroxylase. We developed a CRISPR/Cas9-edited human monocyte-macrophage cell line containing the mCherry fluorescent reporter gene at the 3' end of the endogenous CAMP gene. The High Throughput CAMP Assay (HiTCA) developed here is a novel tool for evaluating CAMP expression in a stable cell line that is scalable for a high-throughput workflow. Application of HiTCA to serum samples from a small number of human donors (n = 10) showed individual differences in CAMP induction that were not fully accounted for by the serum vitamin D metabolite status of the host. As such, HiTCA may be a useful tool that can advance our understanding of the human vitamin D-dependent antimicrobial response, which is being increasingly appreciated for its complexity.

REsCue trial: Randomized controlled clinical trial with extended-release calcifediol in symptomatic COVID-19 outpatients.

OBJECTIVES: This double-blind randomized controlled trial investigated raising serum 25-hydroxyvitamin D (25D) with extended-release calcifediol (ERC) on time to symptom resolution in patients with mild to moderate COVID-19. METHODS: COVID-19 outpatients received oral ERC (300 mcg on days 1-3 and 60 mcg on days 4-27) or placebo (NCT04551911). Symptoms were self-reported daily. Primary end points were raising 25D to ≥50 ng/mL and decreasing resolution time for five aggregated symptoms (three respiratory). RESULTS: In all, 171 patients were randomized, 160 treated and 134 (65 ERC, 69 placebo) retained. The average age was 43 y (range 18-71), 59% were women. The mean baseline 25D was 37 ± 1 (SE) ng/mL. In the full analysis set (FAS), 81% of patients in the ERC group achieved 25D levels of ≥50 ng/mL versus 15% in the placebo group (P < 0.0001). In the per-protocol (PP) population, mean 25D increased with ERC to 82 ± 4 (SE) ng/mL (P < 0.0001) by day 7; the placebo group trended lower. Symptom resolution time was unchanged in the FAS by ERC (hazard ratio [HR], 0.983; 95% confidence interval [CI], 0.695-1.390; P = 0.922). In the PP population, respiratory symptoms resolved 4 d faster when 25D was elevated above baseline level at both days 7 and 14 (median 6.5 versus 10.5 d; HR, 1.372; 95% CI, 0.945-1.991; P = 0.0962; Wilcoxon P = 0.0386). Symptoms resolved in both treatment groups to a similar extent by study end. Safety concerns including hypercalcemia were absent with ERC treatment. CONCLUSION: ERC safely raised serum 25D to ≥50 ng/mL in outpatients with COVID-19, possibly accelerating resolution of respiratory symptoms and mitigating the risk for pneumonia. These findings warrant further study.

Alternative splicing diversifies the skeletal muscle transcriptome during prolonged spaceflight.

BACKGROUND: As the interest in manned spaceflight increases, so does the requirement to understand the transcriptomic mechanisms that underlay the detrimental physiological adaptations of skeletal muscle to microgravity. While microgravity-induced differential gene expression (DGE) has been extensively investigated, the contribution of differential alternative splicing (DAS) to the plasticity and functional status of the skeletal muscle transcriptome has not been studied in an animal model. Therefore, by evaluating both DGE and DAS across spaceflight, we set out to provide the first comprehensive characterization of the transcriptomic landscape of skeletal muscle during exposure to microgravity. METHODS: RNA-sequencing, immunohistochemistry, and morphological analyses were conducted utilizing total RNA and tissue sections isolated from the gastrocnemius and quadriceps muscles of 30-week-old female BALB/c mice exposed to microgravity or ground control conditions for 9 weeks. RESULTS: In response to microgravity, the skeletal muscle transcriptome was remodeled via both DGE and DAS. Importantly, while DGE showed variable gene network enrichment, DAS was enriched in structural and functional gene networks of skeletal muscle, resulting in the expression of alternatively spliced transcript isoforms that have been associated with the physiological changes to skeletal muscle in microgravity, including muscle atrophy and altered fiber type function. Finally, RNA-binding proteins, which are required for regulation of pre-mRNA splicing, were themselves differentially spliced but not differentially expressed, an upstream event that is speculated to account for the downstream splicing changes identified in target skeletal muscle genes. CONCLUSIONS: Our work serves as the first investigation of coordinate changes in DGE and DAS in large limb muscles across spaceflight. It opens up a new opportunity to understand (i) the molecular mechanisms by which splice variants of skeletal muscle genes regulate the physiological adaptations of skeletal muscle to microgravity and (ii) how small molecule splicing regulator therapies might thwart muscle atrophy and alterations to fiber type function during prolonged spaceflight.

Pilot Trial of Vitamin D3 and Calcifediol in Healthy Vitamin D Deficient Adults: Does It Change the Fecal Microbiome?

CONTEXT: Experimental studies suggest that vitamin D receptor signaling may benefit the gut microbiome. In humans, whether vitamin D supplementation directly alters the gut microbiome is not well studied. OBJECTIVE: To determine whether correcting vitamin D deficiency with cholecalciferol (vitamin D3, D3) or calcifediol (25-hydroxyvitamin D3, 25(OH)D3) changes gut microbiome composition. METHODS: 18 adults with vitamin D deficiency (25-hydroxyvitamin D [25(OH)D] <20 ng/mL) received 60 µg/day of D3 or 20 µg/day of 25(OH)D3 for 8 weeks. Changes in serum 25(OH)D, 1,25-diydroxyvitamin D (1,25(OH)2D), and 24,25-dihydroxyvitamin D (24,25(OH)2D) were assessed. We characterized composition of the fecal microbiota using 16S rRNA gene sequencing, and examined changes in α-diversity (Chao 1, Faith's Phylogenetic Diversity, Shannon Index), ß-diversity (DEICODE), and genus-level abundances (DESeq2). RESULTS: Vitamin D3 and 25(OH)D3 groups were similar. After 8 weeks of vitamin D3, mean 25(OH)D and 24,25(OH)2D increased significantly, but 1,25(OH)2D did not (25(OH)D: 17.8-30.1 ng/mL, P = .002; 24,25(OH)2D: 1.1 to 2.7 ng/mL, P =0.003; 1,25(OH)2D: 49.5-53.0 pg/mL, P = .9). After 8 weeks of 25(OH)D3, mean 25(OH)D, 24,25(OH)2D, and 1,25(OH)2D increased significantly (25(OH)D: 16.7-50.6 ng/mL, P < .0001; 24,25(OH)2D: 1.3-6.2 ng/mL, P = .0001; 1,25(OH)2D: 56.5-74.2 pg/mL, P = .05). Fecal microbial α-diversity and ß-diversity did not change with D3 or 25D3 supplementation. Mean relative abundance of Firmicutes increased and mean relative abundance of Bacterioidetes decreased from baseline to 4 weeks, but returned to baseline by study completion. DESeq2 analysis did not confirm any statistically significant taxonomic changes. CONCLUSION: In a small sample of healthy adults with vitamin D deficiency, restoration of vitamin D sufficiency with vitamin D3 or 25(OH)D3 did not lead to lasting changes in the fecal microbiota.

Vitamin D metabolites and the gut microbiome in older men.

The vitamin D receptor is highly expressed in the gastrointestinal tract where it transacts gene expression. With current limited understanding of the interactions between the gut microbiome and vitamin D, we conduct a cross-sectional analysis of 567 older men quantifying serum vitamin D metabolites using LC-MSMS and defining stool sub-Operational Taxonomic Units from16S ribosomal RNA gene sequencing data. Faith's Phylogenetic Diversity and non-redundant covariate analyses reveal that the serum 1,25(OH)2D level explains 5% of variance in α-diversity. In ß-diversity analyses using unweighted UniFrac, 1,25(OH)2D is the strongest factor assessed, explaining 2% of variance. Random forest analyses identify 12 taxa, 11 in the phylum Firmicutes, eight of which are positively associated with either 1,25(OH)2D and/or the hormone-to-prohormone [1,25(OH)2D/25(OH)D] "activation ratio." Men with higher levels of 1,25(OH)2D and higher activation ratios, but not 25(OH)D itself, are more likely to possess butyrate producing bacteria that are associated with better gut microbial health.

CCN1/Cyr61 Is Required in Osteoblasts for Responsiveness to the Anabolic Activity of PTH.

CCN1/Cyr61 is a dynamically expressed matricellular protein that serves regulatory functions in multiple tissues. Previous studies from our laboratory demonstrated that CCN1 regulates bone maintenance. Using an osteoblast and osteocyte conditional knockout mouse model (Ccn1OCN ), we found a significant decrease in trabecular and cortical bone mass in vivo, in part through suppression of Wnt signaling since the expression of the Wnt antagonist sclerostin (SOST) is increased in osteoblasts lacking CCN1. It has been established that parathyroid hormone (PTH) signaling also suppresses SOST expression in bone. We therefore investigated the interaction between CCN1 and PTH-mediated responses in this study. We find that loss of Ccn1 in osteoblasts leads to impaired responsiveness to anabolic intermittent PTH treatment in Ccn1OCN mice in vivo and in osteoblasts from these mice in vitro. Analysis of Ccn1OCN mice demonstrated a significant decrease in parathyroid hormone receptor-1 (PTH1R) expression in osteoblasts in vivo and in vitro. We investigated the regulatory role of a non-canonical integrin-binding domain of CCN1 because several studies indicate that specific integrins are critical to mechanotransduction, a PTH-dependent response, in bone. These data suggest that CCN1 regulates the expression of PTH1R through interaction with the αvß3 and/or αvß5 integrin complexes. Osteoblasts that express a mutant form of CCN1 that cannot interact with αvß3/ß5 integrin demonstrate a significant decrease in mRNA and protein expression of both PTH1R and αv integrin. Overall, these data suggest that the αvß3/ß5-binding domain of CCN1 is required to endow PTH signaling with anabolic activity in bone cells. © 2020 American Society for Bone and Mineral Research (ASBMR).

Comparative Morpho-Anatomical and HPTLC Profiling of Tinospora Species and Dietary Supplements.

Overlapping geographical occurrence, history of traditional use, confusion in species identification, and morphological resemblances among various species are some considerations that necessitate the importance of qualitative analysis for efficient quality control and safer botanical products. This paper provides detailed morpho-anatomies of the leaves and stems of Tinospora cordifolia, Tinospora crispa, and Tinospora sinensis, and stems of Tinospora baenzigeri. Microscopy studies of the selected Tinospora species revealed key diagnostic features that can help distinguish the closely related species of Tinospora as well as to detect any adulteration or substitution in the raw materials. HPTLC profiles of the authenticated plant materials, as well as commercial products claiming to contain Tinospora, were compared to distinguish T. crispa from other closely related species and to establish an efficient method to assess the identity and quality of the products using qualified chemical markers. HPTLC chromatograms of both plant samples and dietary supplements were compared with six reference marker compounds. The analysis revealed that borapetoside B and C were useful to identify T. crispa while tinosineside A was found to be characteristic to authenticate the T. sinensis products.

Preoperative Vitamin D Repletion in Total Knee Arthroplasty: A Cost-Effectiveness Model.

BACKGROUND: Recent studies have identified vitamin D deficiency (serum 25-hydroxyvitamin D [25(OH)D] < 20 ng/L) as a potentially modifiable risk factor for prosthetic joint infection (PJI) in arthroplasty. The purpose of this study is to determine whether implementation of preoperative 25(OH)D repletion is cost-effective for reducing PJI following total knee arthroplasty (TKA). METHODS: A cost estimation predictive model was generated to determine the utility of both selective and nonselective 25(OH)D repletion in primary TKA to prevent PJI. Input data on the incidence of 25(OH)D deficiency, relative complication rates, and costs of serum 25(OH)D repletion and 2-stage revision for PJI were derived from previously published literature identified using systematic review and publicly available data from Medicare reimbursement schedules. Mean, lower, and upper bounds of 1-year cost savings were computed for nonselective and selective repletion relative to no repletion. RESULTS: Selective preoperative 25(OH)D screening and repletion were projected to result in $1,504,857 (range, $215,084-$4,256,388) in cost savings per 10,000 cases. Nonselective 25(OH)D repletion was projected to result in $1,906,077 (range, $616,304-$4,657,608) in cost savings per 10,000 cases. With univariate adjustment, nonselective repletion is projected to be cost-effective in scenarios where revision for PJI costs ≥$10,636, incidence of deficiency is ≥1.1%, and when repletion has a relative risk reduction ≥4.2%. CONCLUSION: This predictive model supports the potential role of 25(OH)D repletion as a cost-effective mechanism of reducing PJI risk in TKA. Given the low cost of 25(OH)D repletion relative to serum laboratory testing, nonselective repletion appears to be more cost-effective than selective repletion. Further prospective investigation to assess this modifiable risk factor is warranted.

Vitamin D Binding Protein and the Biological Activity of Vitamin D.

Vitamin D has a long-established role in bone health. In the last two decades, there has been a dramatic resurgence in research interest in vitamin D due to studies that have shown its possible benefits for non-skeletal health. Underpinning the renewed interest in vitamin D was the identification of the vital role of intracrine or localized, tissue-specific, conversion of inactive pro-hormone 25-hydroxyvitamin D [25(OH)D] to active 1,25-dihydroxyvitamin D [1,25(OH)2D]. This intracrine mechanism is the likely driving force behind vitamin D action resulting in positive effects on human health. To fully capture the effect of this localized, tissue-specific conversion to 1,25(OH)2D, adequate 25(OH)D would be required. As such, low serum concentrations of 25(OH)D would compromise intracrine generation of 1,25(OH)2D within target tissues. Consistent with this is the observation that all adverse human health consequences of vitamin D deficiency are associated with a low serum 25(OH)D level and not with low 1,25(OH)2D concentrations. Thus, clinical investigators have sought to define what concentration of serum 25(OH)D constitutes adequate vitamin D status. However, since 25(OH)D is transported in serum bound primarily to vitamin D binding protein (DBP) and secondarily to albumin, is the total 25(OH)D (bound plus free) or the unbound free 25(OH)D the crucial determinant of the non-classical actions of vitamin D? While DBP-bound-25(OH)D is important for renal handling of 25(OH)D and endocrine synthesis of 1,25(OH)2D, how does DBP impact extra-renal synthesis of 1,25(OH)2D and subsequent 1,25(OH)2D actions? Are their pathophysiological contexts where total 25(OH)D and free 25(OH)D would diverge in value as a marker of vitamin D status? This review aims to introduce and discuss the concept of free 25(OH)D, the molecular biology and biochemistry of vitamin D and DBP that provides the context for free 25(OH)D, and surveys in vitro, animal, and human studies taking free 25(OH)D into consideration.

Mental Illness Among Youth With Chronic Physical Conditions.

BACKGROUND AND OBJECTIVES: Youth with chronic physical conditions (CPCs) may be at greater risk for developing chronic mental health conditions (MHCs), and limitations in the ability to engage in developmentally appropriate activities may contribute to the risk of MHCs among youth with CPCs. We compared the risk of incident MHCs in youth with and without CPCs and explored whether activity limitations contribute to any such association. METHODS: The 2003-2014 Medical Expenditure Panel Survey provided a nationally representative cohort of 48 572 US youth aged 6 to 25 years. We calculated the 2-year cumulative incidence of MHCs overall and by baseline CPC status. Cox proportional hazard models were used to estimate the association between CPCs and incident MHCs, adjusting for sociodemographic characteristics. Stepwise models and the Sobel test evaluated activity limitations as a mediator of this relationship. RESULTS: The 2-year cumulative incidence of MHCs was 7.8% overall, 11.5% in youth with CPCs (14.7% of sample), and 7.1% in those without. The adjusted risk of incident MHCs was 51% greater (adjusted hazard ratio 1.51; 95% confidence interval 1.30-1.74) in youth with CPCs compared with those without. Activity limitations mediated 13.5% of this relationship (P < .001). CONCLUSIONS: This nationally representative cohort study supports the hypotheses that youth with CPCs have increased risk for MHCs and that activity limitations may play a role in MHC development. Youth with CPCs may benefit from services to bolster their ability to participate in developmentally important activities and to detect and treat new onset MHCs.

Serum and synovial fluid vitamin D metabolites and rheumatoid arthritis.

Vitamin D-deficiency has been linked to inflammatory diseases including rheumatoid arthritis (RA). Studies to date have focused on the impact of serum 25-hydroxyvitamin D3 (25(OH)D3), an inactive form of vitamin D, on RA disease activity and progression. However, anti-inflammatory actions of vitamin D are likely to be mediated at sites of RA disease, namely the inflamed joint, and may involve other vitamin D metabolites notably the active form of vitamin D, 1,25-dihydroxyvitamin D3 (1,25(OH)2D3). In the current study serum and synovial fluid samples from n = 20 patients with persistent RA and n = 7 patients with reactive arthritis (ReA) were analysed for multiple vitamin D metabolites. Serum data for RA and ReA patients were compared to healthy controls (HC). There was no significant difference between RA or ReA patients relative to HC for 25(OH)D3, 24,25(OH)2D3, 1,25(OH)2D3 or 25(OH)D2. However, 3-epi-25(OH)D3 was significantly lower in RA and ReA patients compared to HC (p < 0.05). All vitamin D metabolites, apart from 25(OH)D2, were lower in SF compared to serum, and SF 1,25(OH)2D3 was unquantifiable in 13/20 RA and 4/7 ReA samples. SF 25(OH)D3, 3-epi-25(OH)D3 and DBP correlated inversely with swollen joint score, and serum 25(OH)D2 and SF DBP correlated directly with C-reactive protein levels. These data indicate that serum 25(OH)D3 provides only limited insight into the role of vitamin D in RA. Alternative serum metabolites such as 3-epi-25(OH)2D3, and SF metabolites, notably lack of SF 1,25(OH)2D3, may be more closely linked to RA disease severity and progress.

Intrinsic activation of the vitamin D antimicrobial pathway by M. leprae infection is inhibited by type I IFN.

Following infection, virulent mycobacteria persist and grow within the macrophage, suggesting that the intrinsic activation of an innate antimicrobial response is subverted by the intracellular pathogen. For Mycobacterium leprae, the intracellular bacterium that causes leprosy, the addition of exogenous innate or adaptive immune ligands to the infected monocytes/macrophages was required to detect a vitamin D-dependent antimicrobial activity. We investigated whether there is an intrinsic immune response to M. leprae in macrophages that is inhibited by the pathogen. Upon infection of monocytes with M. leprae, there was no upregulation of CYP27B1 nor its enzymatic activity converting the inactive prohormone form of vitamin D (25-hydroxyvitamin D) to the bioactive form (1,25α-dihydroxyvitamin D). Given that M. leprae-induced type I interferon (IFN) inhibited monocyte activation, we blocked the type I IFN receptor (IFNAR), revealing the intrinsic capacity of monocytes to recognize M. leprae and upregulate CYP27B1. Consistent with these in vitro studies, an inverse relationship between expression of CYP27B1 vs. type I IFN downstream gene OAS1 was detected in leprosy patient lesions, leading us to study cytokine-derived macrophages (MΦ) to model cellular responses at the site of disease. Infection of IL-15-derived MΦ, similar to MΦ in lesions from the self-limited form of leprosy, with M. leprae did not inhibit induction of the vitamin D antimicrobial pathway. In contrast, infection of IL-10-derived MΦ, similar to MΦ in lesions from patients with the progressive form of leprosy, resulted in induction of type I IFN and suppression of the vitamin D directed pathway. Importantly, blockade of the type I IFN response in infected IL-10 MΦ decreased M. leprae viability. These results indicate that M. leprae evades the intrinsic capacity of human monocytes/MΦ to activate the vitamin D-mediated antimicrobial pathway via the induction of type I IFN.

CIRM Alpha Stem Cell Clinics: Collaboratively Addressing Regenerative Medicine Challenges.

The California Institute for Regenerative Medicine (CIRM) Alpha Stem Cell Clinic (ASCC) Network was launched in 2015 to address a compelling unmet medical need for rigorous, FDA-regulated, stem cell-related clinical trials for patients with challenging, incurable diseases. Here, we describe our multi-center experiences addressing current and future challenges.

Associations Between Change in Total and Free 25-Hydroxyvitamin D With 24,25-Dihydroxyvitamin D and Parathyroid Hormone.

Context: The physiologic role of free 25-hydroxyvitamin D [25(OH)D] in humans is unclear. Objective: To assess whether rise in total vs free 25(OH)D is associated with change in downstream biomarkers of 25(OH)D entry into target cells in kidney and parathyroid: 24,25-dihyroxyvitamin D [24,25(OH)2D] and PTH, respectively. Design: 16-week randomized controlled trial. Intervention: 60 µg (2400 IU)/d of D3 or 20 µg/d of 25(OH)D3. Setting: Academic medical center. Participants: 35 adults age ≥18 years with 25(OH)D levels < 20 ng/mL. Main Outcome Measures: 24,25(OH)2D, 1,25-dihyroxyvitamin D [1,25(OH)2D] and PTH. Results: At baseline, participants [D3 and 25(OH)D3 groups combined] were 35.1 ± 10.6 years. Mean total 25(OH)D, free 25(OH)D, 24,25(OH)2D, and PTH were 16.6 ng/mL, 4.6 pg/mL, 1.3 ng/mL, and 37.2 pg/mL, respectively. From 0 to 4 weeks, rise in only free 25(OH)D was associated with a concurrent 24,25(OH)2D increase [P = 0.03, adjusted for change in 1,25(OH)2D and supplementation regimen] and PTH decrease (P = 0.01, adjusted for change in calcium and supplementation regimen). Between 4 and 8 weeks, and again from 8 to 16 weeks, rises in free and total 25(OH)D were associated with 24,25(OH)2D increase; in contrast, rise in neither total nor free 25(OH)D was associated with PTH decrease during these time periods. Conclusions: Early rise in free 25(OH)D during treatment of vitamin D deficiency was more strongly associated with changes in biomarkers of 25(OH)D entry into target kidney and parathyroid cells, suggesting a physiologic role of free 25(OH)D in humans.

Preoperative Vitamin D Deficiency Is Associated With Higher Postoperative Complication Rates in Total Knee Arthroplasty.

The purpose of this study was to determine the relative incidence of postoperative complications in 25-hydroxyvitamin D (25D)-deficient and -sufficient patients undergoing total knee arthroplasty (TKA). Patients who were either serum 25D deficient (25D <20 ng/mL) or 25D sufficient (25D ≥20 ng/mL) 90 days prior to primary TKA from 2007 to 2016 were identified using the Humana administrative claims registry. The incidence of postoperative medical and surgical complications was determined by querying for relevant International Classification of Diseases, Ninth Revision and Current Procedural Terminology codes. Risk-adjusted odds ratios (ORs) were calculated using multivariate logistic regression with age, sex, and Charlson Comorbidity Index as covariates. In total, 868 of 6593 patients who underwent TKA from 2007 to 2016 were 25D deficient, corresponding to a 13.2% prevalence rate. On adjustment for age, sex, and Charlson Comorbidity Index, 25D-deficient patients had a higher incidence of postoperative stiffness requiring manipulation under anesthesia (OR, 1.69; 95% confidence interval [CI], 1.39-2.04; P<.001), surgical site infection requiring irrigation and debridement (OR, 1.76; 95% CI, 1.25-2.48; P=.001), and prosthesis explantation (OR, 2.97; 95% CI, 2.04-4.31; P<.001) at 1 year. Patients who were 25D deficient also had higher rates of postoperative deep venous thrombosis (OR, 1.80; 95% CI, 1.36-2.38; P<.001), myocardial infarction (OR, 2.11; 95% CI, 1.41-3.15; P<.001), and cerebrovascular accident (OR, 1.73; 95% CI, 1.17-2.57; P=.006). Thus, serum 25D levels below 20 ng/mL are associated with a higher incidence of postoperative complications and may be a perioperative modifiable risk factor in TKA. [Orthopedics. 2018; 41(4):e489-e495.].

Single-Dose, Preoperative Vitamin-D Supplementation Decreases Infection in a Mouse Model of Periprosthetic Joint Infection.

BACKGROUND: Despite recent advances, infection remains the most common etiology of arthroplasty failure. Recent work suggests that 25-hydroxyvitamin D (25D) deficiency correlates with the frequency of periprosthetic joint infection (PJI). We endeavored to examine whether 25D3 deficiency leads to increased bacterial burden in vivo in an established mouse model of PJI and, if so, whether this effect can be reversed by preoperative 25D3 supplementation. METHODS: Mice (lys-EGFP) possessing fluorescent neutrophils were fed a vitamin D3-sufficient (n = 20) or deficient (n = 40) diet for 6 weeks. A group of 25D3-deficient mice (n = 20) were "rescued" with 1 intraperitoneal dose of 25D3 at 3 days before surgery. A stainless steel implant was inserted into the knee joint and the joint space was inoculated with bioluminescent Staphylococcus aureus (1 × 10 colony forming units [CFUs]). In vivo imaging was used to monitor bacterial burden and neutrophil infiltration. Blood was drawn to confirm 25D3 levels 3 days before surgery and on postoperative days (PODs) 0 and 14. Mice were killed at POD 21, and CFUs were quantified after culture. Myeloperoxidase (MPO) and ß-N-acetylglucosaminidase (NAG) were assayed to look at neutrophil infiltration and activated tissue macrophage recruitment, respectively. RESULTS: Serum values confirmed 25D3 deficiency and repletion of the 25D3-rescued group. Bacterial bioluminescence and neutrophil fluorescence were significantly greater (p < 0.05) in the 25D3-deficient group. CFU counts from the joint tissue and implant were also significantly greater in this group (p < 0.05). Rescue treatment significantly decreased bacterial burden and neutrophil infiltration (p < 0.05). Compared with the 25D3-sufficient and 25D3-rescued groups, MPO activity was higher (p < 0.02) and NAG activity was lower (p < 0.03) in the 25D3-deficient group. CONCLUSIONS: This study demonstrated in vivo in a mouse model of PJI that (1) 25D3 deficiency results in increased bacterial burden and neutrophil infiltration, and (2) this effect can be reversed with preoperative repletion of 25D3. CLINICAL RELEVANCE: Considering that >65% of patients undergoing arthroplasty have insufficient or low levels of total 25D and that 25D levels can be replenished with ease using a U.S. Food and Drug Administration (FDA)-approved, oral 25D3 product, 25D deficiency may be an important modifiable risk factor in humans undergoing joint replacement.

Outpatient treatment of osteomyelitis with telavancin.

Telavancin is a lipoglycopeptide antibiotic with bactericidal activity against Gram-positive pathogens including Staphylococcus aureus, the most frequent cause of osteomyelitis. Treatment is often challenging due to needs for surgical intervention along with prolonged administration of intravenous antimicrobials, frequently in an outpatient setting. This was a retrospective analysis of the efficacy and safety of telavancin for treatment of osteomyelitis provided as outpatient parenteral antimicrobial therapy (OPAT) in physician office infusion centres. Medical records of 60 patients receiving telavancin for osteomyelitis in 22 physician office infusion centres from 2010 to 2011 and 2013 to 2015 were reviewed. Of these, 60% were treated without hospitalisation, 37% had orthopaedic hardware and 56% had concurrent infections. Staphylococcus aureus was the most common pathogen (78%), primarily methicillin-resistant. The median duration of telavancin treatment in the outpatient setting was 21 days (range 3-105 days). Telavancin was used as first-line therapy in 32% of cases, following prior antibiotic failure in 47% and due to intolerance to previous agents in 22%, predominantly daptomycin or vancomycin. The telavancin dose was 10 mg/kg/day, adjusted for renal function in 25% of patients. The majority of patients self-administered telavancin at home via an elastomeric infusion pump. Overall clinical success was 73%. No significant differences in outcomes were observed with the presence of hardware, concurrent infection, concomitant therapies or type of osteomyelitis. Telavancin-associated adverse events occurred in 57%, with discontinuation in three patients (5%). These data demonstrate the effective and safe OPAT use of telavancin, providing an alternative for successful treatment of patients with osteomyelitis.