Screening for rheumatoid arthritis-associated interstitial lung disease-a Delphi-based consensus statement

OBJECTIVE

Rheumatoid arthritis-associated interstitial lung disease (RA-ILD) is a major driver of premature mortality in patients with rheumatoid arthritis (RA). Detection of RA-ILD is crucial but requires awareness among the treating physicians. To date, however, there is no international recommendation concerning screening for ILD in RA patients.

METHODS

After a systematic literature review, the modified Delphi technique in combination with the nominal group technique was used to provide a Delphi consensus statement elaborated by an expert panel of pneumonologists, rheumatologists, and a radiologist. Based on the available evidence, several clusters of questions were defined and discussed until consent was reached.

RESULTS

A screening algorithm for ILD in patients with RA based on clinical signs, respiratory symptoms, and risk factors has been developed. Further, the recommendations address diagnostic tools for RA-ILD and the follow-up of RA patients qualifying for ILD screening.

[National consensus statement by the Austrian Societies for Rheumatology, Pulmonology, Infectiology, Dermatology and Gastroenterology regarding the management of latent tuberculosis and the associated utilization of biologic and targeted synthetic DMARDS (disease modifying antirheumatic drugs)]

This nationwide Austrian consensus statement summarizes the recommendations on the management of latent tuberculosis by treatment with biologic and targeted synthetic DMARDs. The essential questions with respect to screening and preventive treatment were discussed by experts from the disciplines of rheumatology, pneumology, infectious diseases, dermatology and gastroenterology, based on the available data, and then a joint consensus was formed by agreement. This involved a differentiated discussion on the various forms of treatment, and clear recommendations were formulated.

National consensus statement by the Austrian Societies for Rheumatology, Pulmonology, Infectiology, Dermatology and Gastroenterology regarding the management of latent tuberculosis and the associated utilization of biologic and targeted synthetic disease modifying antirheumatic drugs (DMARDs)

This publication provides a thorough analysis of the most relevant topics concerning the management of latent tuberculosis when using biologic and targeted synthetic Disease Modifying Antirheumatic Drugs (DMARDs) by a multidisciplinary, select committee of Austrian physicians. The committee includes members of the Austrian Societies for Rheumatology and Rehabilitation, Pulmonology, Infectiology, Dermatology and Gastroenterology. Consensus was reached on issues regarding screening and treatment of latent tuberculosis and includes separate recommendations for each biologic and targeted synthetic DMARD.

A mitochondrial unfolded protein response inhibitor suppresses prostate cancer growth in mice via HSP60

Mitochondrial proteostasis, regulated by the mitochondrial unfolded protein response (UPR^mt), is crucial for maintenance of cellular functions and survival. Elevated oxidative and proteotoxic stress in mitochondria must be attenuated by the activation of a ubiquitous UPR^mt to promote prostate cancer (PCa) growth. Here we show that the 2 key components of the UPR^mt, heat shock protein 60 (HSP60, a mitochondrial chaperonin) and caseinolytic protease P (ClpP, a mitochondrial protease), were required for the development of advanced PCa. HSP60 regulated ClpP expression via c-Myc and physically interacted with ClpP to restore mitochondrial functions that promote cancer cell survival. HSP60 maintained the ATP-producing functions of mitochondria, which activated the β-catenin pathway and led to the upregulation of c-Myc. We identified a UPR^mt inhibitor that blocked HSP60’s interaction with ClpP and abrogated survival signaling without altering HSP60’s chaperonin function. Disruption of HSP60-ClpP interaction with the UPR^mt inhibitor triggered metabolic stress and impeded PCa-promoting signaling. Treatment with the UPR^mt inhibitor or genetic ablation of Hsp60 inhibited PCa growth and progression. Together, our findings demonstrate that the HSP60-ClpP–mediated UPR^mt is essential for prostate tumorigenesis and the HSP60-ClpP interaction represents a therapeutic vulnerability in PCa.

Intestinal epithelial cell metabolism at the interface of microbial dysbiosis and tissue injury

The intestinal epithelium represents the most regenerative tissue in the human body, located in proximity to the dense and functionally diverse microbial milieu of the microbiome. Episodes of tissue injury and incomplete healing of the intestinal epithelium are a prerequisite for immune reactivation and account for recurrent, chronically progressing phenotypes of inflammatory bowel diseases (IBD). Mitochondrial dysfunction and associated changes in intestinal epithelial functions are emerging concepts in the pathogenesis of IBD, suggesting impaired metabolic flexibility of epithelial cells affects the regenerative capacity of the intestinal tissue. Next to rendering the intestinal mucosa susceptible to inflammatory triggers, metabolic reprogramming of the epithelium is implicated in shaping adverse microbial environments. In this review, we introduce the concept of "metabolic injury" as a cell autonomous mechanism of tissue wounding in response to mitochondrial perturbation. Furthermore, we highlight epithelial metabolism as intersection of microbiome, immune cells and epithelial regeneration.

Drug Screening, Oral Bioavailability and Regulatory Aspects: A Need for Human Organoids

The intestinal epithelium critically contributes to oral bioavailability of drugs by constituting an important site for drug absorption and metabolism. In particular, intestinal epithelial cells (IEC) actively serve as gatekeepers of drug and nutrient availability. IECs' transport processes and metabolism are interrelated to the whole-body metabolic state and represent potential points of origin as well as therapeutic targets for a variety of diseases. Human intestinal organoids represent a superior model of the intestinal epithelium, overcoming limitations of currently used in vitro models. Caco-2 cells or rodent explant models face drawbacks such as their cancer and non-human origin, respectively, but are commonly used to study intestinal nutrient absorption, enterocyte metabolism and oral drug bioavailability, despite poorly correlative data. In contrast, intestinal organoids allow investigating distinct aspects of bioavailability including spatial resolution of transport, inter-individual differences and high-throughput screenings. As several countries have already developed strategic roadmaps to phase out animal experiments for regulatory purposes, intestinal organoid culture and organ-on-a-chip technology in combination with in silico approaches are roads to go in the preclinical and regulatory setup and will aid implementing the 3Rs (reduction, refinement and replacement) principle in basic science.

Mitochondrial Metabolism in the Intestinal Stem Cell Niche-Sensing and Signaling in Health and Disease

Mitochondrial metabolism, dynamics, and stress responses in the intestinal stem cell niche play a pivotal role in regulating intestinal epithelial cell homeostasis, including self-renewal and differentiation. In addition, mitochondria are increasingly recognized for their involvement in sensing the metabolic environment and their capability of integrating host and microbial-derived signals. Gastrointestinal diseases such as inflammatory bowel diseases and colorectal cancer are characterized by alterations of intestinal stemness, the microbial milieu, and mitochondrial metabolism. Thus, mitochondrial function emerges at the interface of determining health and disease, and failure to adapt mitochondrial function to environmental cues potentially results in aberrant tissue responses. A mechanistic understanding of the underlying role of mitochondrial fitness in intestinal pathologies is still in its infancy, and therapies targeting mitochondrial (dys)function are currently lacking. This review discusses mitochondrial signaling and metabolism in intestinal stem cells and Paneth cells as critical junction translating host- and microbe-derived signals into epithelial responses. Consequently, we propose mitochondrial fitness as a hallmark for intestinal epithelial cell plasticity, determining the regenerative capacity of the epithelium.

Intestinal sodium/glucose cotransporter 3 expression is epithelial and downregulated in obesity

AIM

We aimed to determine whether the sodium/glucose cotransporter family member SGLT3, a proposed glucose sensor, is expressed in the intestine and/or kidney, and if its expression is altered in mouse models of obesity and in humans before and after weight-loss surgery.

MAIN METHODS

We used in-situ hybridization and quantitative PCR to determine whether the Sglt3 isoforms 3a and 3b were expressed in the intestine and kidney of C57, leptin-deficient ob/ob, and diabetic BTBR ob/ob mice. Western blotting and immunohistochemistry were also used to assess SGLT3 protein levels in jejunal biopsies from obese patients before and after weight-loss Roux-en-Y gastric bypass surgery (RYGB), and in lean healthy controls.

KEY FINDINGS

Sglt3a/3b mRNA was detected in the small intestine (duodenum, jejunum and ileum), but not in the large intestine or kidneys of mice. Both isoforms were detected in epithelial cells (confirmed using intestinal organoids). Expression of Sglt3a/3b mRNA in duodenum and jejunum was significantly lower in ob/ob and BTBR ob/ob mice than in normal-weight littermates. Jejunal SGLT3 protein levels in aged obese patients before RYGB were lower than in lean individuals, but substantially upregulated 6 months post-RYGB.

SIGNIFICANCE

Our study shows that Sglt3a/3b is expressed primarily in epithelial cells of the small intestine in mice. Furthermore, we observed an association between intestinal mRNA Sglt3a/3b expression and obesity in mice, and between jejunal SGLT3 protein levels and obesity in humans. Further studies are required to determine the possible role of SGLT3 in obesity.

Mitochondrial impairment drives intestinal stem cell transition into dysfunctional Paneth cells predicting Crohn's disease recurrence

OBJECTIVE

Reduced Paneth cell (PC) numbers are observed in inflammatory bowel diseases and impaired PC function contributes to the ileal pathogenesis of Crohn's disease (CD). PCs reside in proximity to Lgr5⁺ intestinal stem cells (ISC) and mitochondria are critical for ISC-renewal and differentiation. Here, we characterise ISC and PC appearance under inflammatory conditions and describe the role of mitochondrial function for ISC niche-maintenance.

DESIGN

Ileal tissue samples from patients with CD, mouse models for mitochondrial dysfunction (Hsp60^Δ/ΔISC) and CD-like ileitis (TNF^ΔARE), and intestinal organoids were used to characterise PCs and ISCs in relation to mitochondrial function.

RESULTS

In patients with CD and TNF^ΔARE mice, inflammation correlated with reduced numbers of Lysozyme-positive granules in PCs and decreased Lgr5 expression in crypt regions. Disease-associated changes in PC and ISC appearance persisted in non-inflamed tissue regions of patients with CD and predicted the risk of disease recurrence after surgical resection. ISC-specific deletion of Hsp60 and inhibition of mitochondrial respiration linked mitochondrial function to the aberrant PC phenotype. Consistent with reduced stemness in vivo, crypts from inflamed TNF^ΔARE mice fail to grow into organoids ex vivo. Dichloroacetate-mediated inhibition of glycolysis, forcing cells to shift to mitochondrial respiration, improved ISC niche function and rescued the ability of TNF^ΔARE mice-derived crypts to form organoids.

CONCLUSION

We provide evidence that inflammation-associated mitochondrial dysfunction in the intestinal epithelium triggers a metabolic imbalance, causing reduced stemness and acquisition of a dysfunctional PC phenotype. Blocking glycolysis might be a novel drug target to antagonise PC dysfunction in the pathogenesis of CD.

Organoids to Study Intestinal Nutrient Transport, Drug Uptake and Metabolism - Update to the Human Model and Expansion of Applications

Intestinal transport and sensing processes and their interconnection to metabolism are relevant to pathologies such as malabsorption syndromes, inflammatory diseases, obesity and type 2 diabetes. Constituting a highly selective barrier, intestinal epithelial cells absorb, metabolize, and release nutrients into the circulation, hence serving as gatekeeper of nutrient availability and metabolic health for the whole organism. Next to nutrient transport and sensing functions, intestinal transporters including peptide transporter 1 (PEPT1) are involved in the absorption of drugs and prodrugs, including certain inhibitors of angiotensin-converting enzyme, protease inhibitors, antivirals, and peptidomimetics like β-lactam antibiotics. Here, we verify the applicability of 3D organoids for in vitro investigation of intestinal biochemical processes related to transport and metabolism of nutrients and drugs. Establishing a variety of methodologies including illustration of transporter-mediated nutrient and drug uptake and metabolomics approaches, we highlight intestinal organoids as robust and reliable tool in this field of research. Currently used in vitro models to study intestinal nutrient absorption, drug transport and enterocyte metabolism, such as Caco-2 cells or rodent explant models are of limited value due to their cancer and non-human origin, respectively. Particularly species differences result in poorly correlative data and findings obtained in these models cannot be extrapolated reliably to humans, as indicated by high failure rates in drug development pipelines. In contrast, human intestinal organoids represent a superior model of the intestinal epithelium and might help to implement the 3Rs (Reduction, Refinement and Replacement) principle in basic science as well as the preclinical and regulatory setup.

Activated ATF6 Induces Intestinal Dysbiosis and Innate Immune Response to Promote Colorectal Tumorigenesis

BACKGROUND & AIMS

Activating transcription factor 6 (ATF6) regulates endoplasmic reticulum stress. We studied whether ATF6 contributes to the development of colorectal cancer (CRC) using tissue from patients and transgenic mice.

METHODS

We analyzed data from 541 patients with CRC in The Cancer Genome Atlas database for genetic variants and aberrant expression levels of unfolded protein response genes. Findings were validated in a cohort of 83 patients with CRC in Germany. We generated mice with intestinal epithelial cell-specific expression of the active form of Atf6 (nATF6IEC) from 2 alleles (homozygous), mice with expression of nATF6IEC from 1 allele (heterozygous), and nATF6IECfl/fl mice (controls). All nATF6IEC mice were housed under either specific-pathogen-free or germ-free conditions. Cecal microbiota from homozygous nATF6IEC mice or control mice was transferred into homozygous nATF6IEC mice or control mice. nATF6IEC mice were crossed with mice with disruptions in the myeloid differentiation primary response gene 88 and toll-like receptor adaptor molecule 1 gene (Myd88/Trif-knockout mice). Intestinal tissues were collected from mice and analyzed by histology, immunohistochemistry, immunoblots, gene expression profiling of unfolded protein response and inflammatory genes, array-based comparative genome hybridization, and 16S ribosomal RNA gene sequencing.

RESULTS

Increased expression of ATF6 was associated with reduced disease-free survival times of patients with CRC. Homozygous nATF6IEC mice developed spontaneous colon adenomas at 12 weeks of age. Compared with controls, homozygous nATF6IEC mice had changes in the profile of their cecal microbiota, increased proliferation of intestinal epithelial cells, and loss of the mucus barrier-all preceding tumor formation. These mice had increased penetration of bacteria into the inner mucus layer and activation of signal transducer and activator of transcription 3, yet inflammation was not observed at the pretumor or tumor stages. Administration of antibiotics to homozygous nATF6IEC mice greatly reduced tumor incidence, and germ-free housing completely prevented tumorigenesis. Analysis of nATF6IEC MyD88/TRIF-knockout mice showed that tumor initiation and growth required MyD88/TRIF-dependent activation of signal transducer and activator of transcription 3. Transplantation of cecal microbiota from nATF6IEC mice and control mice, collected before tumor formation, caused tumor formation in ex-germ-free nATF6IEC mice.

CONCLUSIONS

In patients with CRC, ATF6 was associated with reduced time of disease-free survival. In studies of nATF6IEC mice, we found sustained intestinal activation of ATF6 in the colon to promote dysbiosis and microbiota-dependent tumorigenesis.

The gut microbiota drives the impact of bile acids and fat source in diet on mouse metabolism

BACKGROUND

As the gut microbiota contributes to metabolic health, it is important to determine specific diet-microbiota interactions that influence host metabolism. Bile acids and dietary fat source can alter phenotypes of diet-induced obesity, but the interplay with intestinal microorganisms is unclear. Here, we investigated metabolic consequences of diets enriched in primary bile acids with or without addition of lard or palm oil, and studied gut microbiota structure and functions in mice.

RESULTS

In combination with bile acids, dietary lard fed to male C57BL/6N mice for a period of 8 weeks enhanced fat mass accumulation in colonized, but not in germ-free mice when compared to palm oil. This was associated with impaired glucose tolerance, lower fasting insulin levels, lower counts of enteroendocrine cells, fatty liver, and elevated amounts of hepatic triglycerides, cholesteryl esters, and monounsaturated fatty acids. Lard- and bile acid-fed mice were characterized by shifts in dominant gut bacterial communities, including decreased relative abundances of Lachnospiraceae and increased occurrence of Desulfovibrionaceae and the species Clostridium lactatifermentans and Flintibacter butyricus. Metatranscriptomic analysis revealed shifts in microbial functions, including lipid and amino acid metabolism.

CONCLUSIONS

Caution is required when interpreting data from diet-induced obesity models due to varying effects of dietary fat source. Detrimental metabolic consequences of a diet enriched with lard and primary bile acids were dependent on microbial colonization of the host and were linked to hepatic lipid rearrangements and to alterations of dominant bacterial communities in the cecum.

Inconclusive benefit of adjuvant 90Yttrium hydroxyapatite to radiosynovectomy for diffuse-type tenosynovial giant-cell tumour of the knee

Aims

Intra-articular 90Yttrium (90Y) is an adjunct to surgical treatment by synovectomy for patients with diffuse-type tenosynovial giant-cell tumour (dtTGCT) of the knee, with variable success rates. Clinical information is, however, sparse and its value remains unclear. We investigated the long-term outcome of patients who underwent synovectomy with and without adjuvant treatment with 90Yttrium.

Patients and Methods

All patients with dtTGCT of the knee who underwent synovectomy between 1991 and 2014 were included in the study. Group A patients underwent synovectomy and an intra-articular injection of 90Yttrium between six and eight weeks after surgery. Group B patients underwent surgery alone.

Results

There were 34 patients in group A and 22 in group B. Recurrence of dtTGCT was identified by MRI, which was undertaken in patients with further symptoms. At a mean follow-up of 7.3 years (2.5 to 25.4), there was residual disease in 15 patients in group A and 11 in group B (p < 0.363). The mean Musculoskeletal Tumor Society (MSTS) score at final follow-up was 85% and 83%, respectively (p < 0.91).

Conclusion

There were no significant differences in outcome between patients treated surgically for dtTGCT of the knee with or without an adjuvant intra-articular injection of 90Yttrium. We were unable to provide conclusive evidence of any benefits derived from the adjuvant treatment. Cite this article: Bone Joint J 2018;100-B:984–8.

Fractal analysis of subchondral bone changes of the hand in rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic and systemic inflammatory disorder. Conventional radiography, a widely available and cost-effective examination method, remains the standard of reference for the detection and quantification of joint involvement in RA. Fractal dimension (FD) of the trabecular bone structure has been proven to correlate with the bone's physical properties. The present study was designed to use fractal analysis to validate radiograph changes in the hand of RA patients.This study retrospectively evaluated the hand radiographs of 108 subjects. Fifty-four patients were suffering from RA, of which 18 were men and 36 were women. Their ages ranged from 25 to 90 years. The hand radiographs of 54 healthy patients, 18 men and 36 women (age range 23-88 years), were used as the control group. Bone structure value (BSV) is a critical parameter for the assessment and analysis of bone microarchitecture. The BSVs were calculated over the fractal dimension using the Brownian motion.The BSV calculated for ROI showed a significant difference in ROI5 (0.210 ± 0.045), ROI6 (0.186 ± 0.066), and ROI11 (0.201 ± 0.056) in patients with RA, in comparison to the CG (P < 0.05). A significant correlation was observed between anti-CCP and ROI4, ROI5, ROI6, ROI9, and ROI12 in seropositive RA patients (post hoc test (Bonferroni) P <0.001).This study demonstrates that the bone textural image analysis technique can be used to quantify the radiographic changes in RA hands, based on comparisons of FDs.

Role of Incretin Hormones in Bowel Diseases

Enteroendocrine cells (EEC) have been studied extensively for their ability to regulate gastrointestinal motility and insulin release by secretion of peptide hormones. In particular, the L cell-derived incretin glucagon-like peptide 1 has gained enormous attention due to its insulinotropic action and relevance in the treatment of type 2 diabetes. Yet, accumulating data indicates a critical role for EEC and incretins in metabolic adaptation and in orchestrating immune responses beyond blood glucose control. EEC actively sense the lamina propria and luminal environment including the microbiota via receptors and transporters, subsequently mediating signals by secreting hormones and cytokines. Data indicate that immune cells and cytokine-mediated signaling impacts EEC numbers and function during infection and chronic inflammation of the gut, suggesting EEC not only to play a role in these pathologies but also being a target of inflammatory processes. This review presents data on the interrelation of incretins and inflammatory signaling. It focuses on the impact of intestinal inflammation, in particular inflammatory bowel disease, on EEC and the potential role of EEC and incretins in these pathologies. Furthermore, it highlights endoplasmic reticulum unfolded protein response, cytokines and the intestinal microbiota as possible targets of inflammatory and EEC signaling.

Single minimal incision fasciotomy for the treatment of chronic exertional compartment syndrome: outcomes and complications

INTRODUCTION

Chronic exertional compartment syndrome (CECS) is a common injury in young athletes, causing pain in the involved leg compartment during strenuous exercise. The gold standard treatment is fasciotomy, but most of the reports on its effectiveness include relatively small cohorts and relatively short follow-up periods. This study reports the long-term results of a large cohort of young athletes who underwent single-incision fasciotomy for CECS.

MATERIALS AND METHODS

This a retrospective case-series study. All patients treated by fasciotomies performed for CECS between 2007 and 2011, in a tertiary medical institution. CECS was diagnosed following history taking and clinical evaluation, and confirmed by compartment pressure measurements. Ninety-five legs that underwent single-incision subcutaneous fasciotomy were included. Data on the numerical analog scale (NAS), Tegner activity score, and quality-of-life (QOL) as measured via the short form-12 (SF-12) were retrieved from all patients preoperatively and at the end of follow-up.

RESULTS

The average time to diagnosis was 22 months and the mean follow-up was 50.1 months. Sixty-three legs underwent anterior compartment fasciotomy (an additional 30 legs also underwent lateral compartment release), and two legs underwent lateral and peroneal compartment releases. The average change in Tegner score was an improvement of 14.6 points. Similarly, the patients reported a significant improvement in the SF-12 and NAS scores. Satisfaction rates were high (average 75.5 %). The main complications were wound infection (2 patients) and nerve injuries (4 patients). Eight patients had recurrence.

CONCLUSION

Single-incision fasciotomy leads to long-term improvement in the activity level and QOL of patients with CECS.

Inflammation Meets Metabolic Disease: Gut Feeling Mediated by GLP-1

Chronic diseases, such as obesity and diabetes, cardiovascular, and inflammatory bowel diseases (IBD) share common features in their pathology. Metabolic disorders exhibit strong inflammatory underpinnings and vice versa, inflammation is associated with metabolic alterations. Next to cytokines and cellular stress pathways, such as the unfolded protein response (UPR), alterations in the enteroendocrine system are intersections of various pathologies. Enteroendocrine cells (EEC) have been studied extensively for their ability to regulate gastrointestinal motility, secretion, and insulin release by release of peptide hormones. In particular, the L-cell-derived incretin hormone glucagon-like peptide 1 (GLP-1) has gained enormous attention due to its insulinotropic action and relevance in the treatment of type 2 diabetes (T2D). Yet, accumulating data indicate a critical role for EEC and in particular for GLP-1 in metabolic adaptation and in orchestrating immune responses beyond blood glucose control. EEC sense the lamina propria and luminal environment, including the microbiota via receptors and transporters. Subsequently, mediating signals by secreting hormones and cytokines, EEC can be considered as integrators of metabolic and inflammatory signaling. This review focuses on L cell and GLP-1 functions in the context of metabolic and inflammatory diseases. The effects of incretin-based therapies on metabolism and immune system are discussed and the interrelation and common features of metabolic and immune-mediated disorders are highlighted. Moreover, it presents data on the impact of inflammation, in particular of IBD on EEC and discusses the potential role of the microbiota as link between nutrients, metabolism, immunity, and disease.

Intestinal organoids for assessing nutrient transport, sensing and incretin secretion

Intestinal nutrient transport and sensing are of emerging interest in research on obesity and diabetes and as drug targets. Appropriate in vitro models are lacking that allow both, studies on transport processes as well as sensing and subsequent incretin hormone secretion including intracellular signaling. We here demonstrate that murine small-intestinal organoids are the first in vitro model system enabling concurrent investigations of nutrient and drug transport, sensing and incretin hormone secretion as well as fluorescent live-cell imaging of intracellular signaling processes. By generating organoid cultures from wild type mice and animals lacking different nutrient transporters, we show that organoids preserve the main phenotypic features and functional characteristics of the intestine. This turns them into the best in vitro model currently available and opens new avenues for basic as well as medical research.

Life-threatening acute pneumonitis in mixed connective tissue disease: a case report and literature review

Mixed connective tissue disease (MCTD) is a rare connective tissue disease frequently involving the lungs. The main characteristic is a systemic sclerosis-like picture of slowly progressing interstitial lung disease consistent with lung fibrosis, while pulmonary arterial hypertension is rare. Herein, we present a case of a newly diagnosed MCTD patient developing life-threatening acute pneumonitis similar to lupus pneumonitis. Previous literature on this exceptionally rare complication of MCTD is reviewed and differential diagnosis and management discussed.

Lateral epicondylitis treatment: international survey of surgeons' preferences and literature review

BACKGROUND

Lateral epicondylitis (LE) is a common cause of elbow pain. Despite a relatively high prevalence and morbidity, there is still no single effective ('gold standard') treatment for LE. We hypothesised that a surgeon's experience, country of origin and area of expertise would influence choices concerning patient management. The purpose of this survey was to describe the current trends and common practices in treating LE worldwide.

MATERIAL AND METHODS

A total of 291 orthopaedic surgeons of 12 subspecialties from 57 countries were surveyed on their choice of LE treatment modalities. Their preferences were analysed according to country of origin, field of expertise and seniority. The results were compared with current published level-1 evidence.

RESULTS

The most popular modalities of treatment among all of the surveyed orthopaedic surgeons were non-steroidal anti-inflammatory drugs (NSAIDs) and corticosteroid (CS) injection (38% of recommendations each). The most popular Modalities of treatment among the hand surgeons was NSAIDs (48%) and CS injection (30%). There was no significant difference in recommendations based on geography, seniority or specialisation (i.e., hand surgeons among others).

CONCLUSIONS

Neither geography, seniority nor medical specialty affects surgeons' preferences in the treatment of LE. There appears to be little correlation between scientific evidence and therapeutic choices for managing LE.

LEVEL OF EVIDENCE

Level V, Study.

C/EBP homologous protein inhibits tissue repair in response to gut injury and is inversely regulated with chronic inflammation

Loss of intestinal epithelial cell (IEC) homeostasis and apoptosis negatively affect intestinal barrier function. Uncontrolled activation of the unfolded protein response (UPR) in IEC contributes to an impaired barrier and is implicated in the pathogenesis of inflammatory bowel diseases. However, the contribution of the UPR target gene C/EBP homologous protein (CHOP), an apoptosis-associated transcription factor, to inflammation-related disease susceptibility remains unclear. Consistent with observations in patients with ulcerative colitis, we show that despite UPR activation in the epithelium, CHOP expression was reduced in mouse models of T-cell-mediated and bacteria-driven colitis. To elucidate the molecular mechanisms of IEC-specific CHOP expression, we generated a conditional transgenic mouse model (Chop(IEC Tg/Tg)). Chop overexpression increased the susceptibility toward dextran sodium sulfate (DSS)-induced intestinal inflammation and mucosal tissue injury. Furthermore, a delayed recovery from DSS-induced colitis and impaired closure of mechanically induced mucosal wounds was observed. Interestingly, these findings seemed to be independent of CHOP-mediated apoptosis. In vitro and in vivo cell cycle analyses rather indicated a role for CHOP in epithelial cell proliferation. In conclusion, these data show that IEC-specific overexpression impairs epithelial cell proliferation and mucosal tissue regeneration, suggesting an important role for CHOP beyond mediating apoptosis.

Helicobacter pylori γ-glutamyltranspeptidase impairs T-lymphocyte function by compromising metabolic adaption through inhibition of cMyc and IRF4 expression

Helicobacter pylori (H. pylori) is a human-specific pathogen that has evolved to cope with the immune response elicited against the infection. We previously reported that H. pylori γ-glutamyltranspeptidase (gGT) impairs T-lymphocyte proliferation and thus might act as immune regulatory factor. In this study, we analysed the underlying mechanism and its implications for H. pylori persistence. We found that H. pylori gGT compromised T-cell proliferation, activation and effector cytokine expression by specifically depriving the extracellular space of glutamine. When assessing signalling cascades and transcription factors affected by H. pylori gGT, we found that expression of cMyc and IRF4, both required for metabolic adaptation of T-lymphocytes, was highly sensitive to extracellular glutamine levels and downregulated upon gGT treatment. Moreover, we could confirm decreased IRF4 expression in T-lymphocytes infiltrating the stomach of infected individuals. Thus, our results suggest that H. pylori gGT-mediated glutamine deprivation in the gastric mucosa may suppress T-cell function thereby contributing to bacterial persistence.

Dual-energy computed tomography compared with ultrasound in the diagnosis of gout

OBJECTIVES

The aim of our study was to compare dual-energy CT (DECT) with US for the diagnosis of gouty arthritis and to correlate the imaging findings with results from synovial fluid aspiration whenever possible.

METHODS

We recruited 21 patients (17 male and 4 female) who presented with a clinical suspicion of acute or chronic gout in 37 joints. DECT scans of the hands, wrists, feet, ankles, knees and elbows were performed. For post-processing, a colour-coding gout software protocol was used. US examinations of the same joints were performed. In addition, joint fluid aspiration was performed in a total of 14 joints.

RESULTS

DECT images were positive for urate crystal deposits in 25 of 37 joints. US findings were positive in 24 of 37 examined joints. In 12 of 14 joints the synovial fluid aspiration was positive. CT and US findings correlated in 32 of 37 joints (86.5%; κ = 0.698, P < 0.001). CT and synovial fluid results correlated in 12 of 14 joints (85.7%; κ = 0.417, P = 0.119). US and cytology findings correlated in 14 of 14 joints (100%; κ = 1, P < 0.001).

CONCLUSION

DECT and US have comparable sensitivity for the detection of gouty arthritis in a clinical setting. However, DECT results should be interpreted carefully, as there could be some false-negative findings.

Abatacept (CTLA-4IG) treatment reduces the migratory capacity of monocytes in patients with rheumatoid arthritis

OBJECTIVE

The binding of abatacept (CTLA-4Ig) to the B7 ligands CD80 and CD86 prevents the engagement of CD28 on T cells and thereby prevents effector T cell activation. In addition, a direct effect of CTLA-4Ig on antigen-presenting cells (APCs) could contribute to the therapeutic effect. To further elucidate the mechanism of CTLA-4Ig, we performed phenotype and functional analyses of APCs in patients with rheumatoid arthritis (RA) before and after the initiation of CTLA-4Ig therapy.

METHODS

Peripheral blood mononuclear cells were analyzed before and at 2 and 4 weeks after the initiation of CTLA-4Ig therapy. Proportions of APCs were determined by flow cytometry. CD14+ monocytes were further analyzed for the expression of costimulatory and adhesion molecules and for their transendothelial migratory capacity in vitro. In addition, CD14+ monocytes from healthy controls were analyzed for their migratory and spreading capacity.

RESULTS

Proportions and absolute numbers of monocytes were significantly increased in RA patients treated with CTLA-4Ig. The expression of several adhesion molecules was significantly diminished. In addition, monocytes displayed a significant reduction in their endothelial adhesion and transendothelial migratory capacity upon treatment with CTLA-4Ig. Likewise, isolated monocytes from healthy controls revealed a significant reduction in their migratory and spreading activity after preincubation with CTLA-4Ig or anti-CD80 and anti-CD86 antibodies.

CONCLUSION

We describe direct effects of CTLA-4Ig therapy on phenotype and functional characteristics of monocytes in RA patients that might interfere with the migration of monocytes to the synovial tissue. This additional mechanism of CTLA-4Ig might contribute to the beneficial effects of CTLA-4Ig treatment in RA patients.

Induction of dsRNA-activated protein kinase links mitochondrial unfolded protein response to the pathogenesis of intestinal inflammation

OBJECTIVE

Inflammatory bowel diseases (IBDs) feature multiple cellular stress responses, including endoplasmic reticulum (ER) unfolded protein responses (UPRs). UPRs represent autoregulatory pathways that adjust organelle capacity to cellular demand. A similar mechanism, mitochondrial UPR (mtUPR), has been described for mitochondria. ER UPR in intestinal epithelial cells (IECs) contributes to the development of intestinal inflammation, and since mitochondrial alterations and dysfunction are implicated in the pathogenesis of IBDs, the authors characterised mtUPR in the context of intestinal inflammation.

METHODS

Truncated ornithine transcarbamylase was used to selectively induce mtUPR in a murine IEC line. Dextran sodium sulphate (DSS) was administered to PKR (double-stranded-RNA-activated protein kinase) knockout mice to induce IEC stress in vivo and to test for their susceptibility to DSS-induced colitis. Expression levels of the mitochondrial chaperone chaperonin 60 (CPN60) and PKR were quantified in IECs from patients with IBDs and from murine models of colitis using immunohistochemistry and Western blot analysis.

RESULTS

Selective mtUPR induction by truncated ornithine transcarbamylase transfection triggered the phosphorylation of eukaryotic translation initiation factor (eIF) 2α and cJun through the recruitment of PKR. Using pharmacological inhibitors and small inhibitory RNA, the authors identified mtUPR-induced eIF2α phosphorylation and transcription factor activation (cJun/AP1) as being dependent on the activities of the mitochondrial protease ClpP and the cytoplasmic kinase PKR. Pkr(-/-) mice failed to induce CPN60 in IECs upon DSS treatment at early time points and subsequently showed an almost complete resistance to DSS-induced colitis. Under inflammatory conditions, primary IECs from patients with IBDs and two murine models of colitis exhibited a strong induction of the mtUPR marker protein CPN60 associated with enhanced expression of PKR.

CONCLUSION

PKR integrates mtUPR into the disease-relevant ER UPR via eIF2α phosphorylation and AP1 activation. Induction of mtUPR and PKR was observed in IECs from murine models and patients with IBDs. The authors' results indicate that PKR might link mitochondrial stress to intestinal inflammation.

Mitochondria at the interface between danger signaling and metabolism: role of unfolded protein responses in chronic inflammation

Inflammatory bowel diseases (IBDs), like many other chronic diseases, feature multiple cellular stress responses including endoplasmic reticulum (ER) unfolded protein response (UPR). Maintaining protein homeostasis is indispensable for cell survival and, consequently, distinct signaling pathways have evolved to transmit organelle stress. While the ER UPR, aiming to restore ER homeostasis after challenges to ER function, has been extensively studied in the context of chronic diseases, only recently the related mitochondrial UPR (mtUPR), induced by disturbances of mitochondrial proteostasis, has drawn some attention. ER and mitochondria are in close contact and interact physically and functionally. Accumulating data have placed mitochondria at the center of diverse cellular functions and suggest mitochondria as integrators of signaling pathways such as autophagy and inflammation. Consequently, it is likely that mitochondrial stress and ER stress cannot be regarded separately and that mitochondrial stress, as well as ER stress, participates in the pathology of IBD. Protein homeostasis is particularly sensitive toward infections, oxidative stress, and energy deficiency. Thus, environmental disturbances impacting organelle function lead to the concerted activation of distinct UPRs. The metabolic status might therefore serve as an innate mechanism to sense the epithelial environment, including luminal-derived and host-derived factors. This review highlights mtUPR and its interrelation with ER UPR, focuses on recent studies identifying mitochondria as integrators of cellular danger signaling, and, furthermore, illustrates the importance ER UPR and mitochondrial dysfunction in IBD.

A dynamic real time in vivo and static ex vivo analysis of granulomonocytic cell migration in the collagen-induced arthritis model

Neutrophilic granulocytes and monocytes (granulomonocytic cells; GMC) drive the inflammatory process at the earliest stages of rheumatoid arthritis (RA). The migratory behavior and functional properties of GMC within the synovial tissue are, however, only incompletely characterized. Here we have analyzed GMC in the murine collagen-induced arthritis (CIA) model of RA using multi-photon real time in vivo microscopy together with ex vivo analysis of GMC in tissue sections.GMC were abundant as soon as clinical arthritis was apparent. GMC were motile and migrated randomly through the synovial tissue. In addition, we observed the frequent formation of cell clusters consisting of both neutrophilic granulocytes and monocytes that actively contributed to the inflammatory process of arthritis. Treatment of animals with a single dose of prednisolone reduced the mean velocity of cell migration and diminished the overall immigration of GMC.In summary, our study shows that the combined application of real time in vivo microscopy together with elaborate static post-mortem analysis of GMC enables the description of dynamic migratory characteristics of GMC together with their precise location in a complex anatomical environment. Moreover, this approach is sensitive enough to detect subtle therapeutic effects within a very short period of time.

Heme oxygenase-1 end-products carbon monoxide and biliverdin ameliorate murine collagen induced arthritis

OBJECTIVES

Heme oxygenase-1 (HO-1) which degrades Heme to free iron, biliverdin and carbon monoxide (CO) plays an important role in inflammation. There are, however, conflicting data concerning the role of HO-1 in rheumatoid arthritis (RA) and the therapeutic potential of individual heme degradation products remains to be determined. We therefore investigated the effect of CO and biliverdin upon therapeutic administration in the murine collagen induced arthritis (CIA) model of RA.

METHODS

CIA was induced in DBA/1 mice. Anti-CII antibody levels were determined by ELISA. Mice were scored for paw swelling and grip strength. After the first clinical signs of arthritis one group of animals was treated with biliverdin, the second group was treated with CO. After 60 days all animals were sacrificed and analysed for histomorphological signs of arthritis.

RESULTS

All animals immunised with CII developed serum anti-CII antibodies. Antibody levels were decreased in the CO-treated group. Both, Biliverdin and the CO-treated animals, showed an improvement in clinical disease activity. Histological analysis revealed significantly less inflammation, erosion and reduced numbers of osteoclasts in CO-treated animals only, whereas cartilage degradation was prevented in both biliverdin and CO-treated animals.

CONCLUSIONS

Our data demonstrate a beneficial effect of CO, in particular, and biliverdin, on inflammation and bone destruction in the CIA mouse model.

Adverse events and efficacy of TNF-alpha blockade with infliximab in patients with systemic lupus erythematosus: long-term follow-up of 13 patients

OBJECTIVE

To follow-up on all available infliximab-treated SLE patients for safety and long-term efficacy in order to extract information that is useful for planning appropriate controlled trials with infliximab in SLE.

METHODS

We analysed charts of six patients treated in an open-label safety trial and seven additional patients treated with infliximab on a compassionate care basis for uncontrolled SLE organ inflammation.

RESULTS

Out of nine patients with lupus nephritis, six had a long-term response after four infusions of infliximab in combination with AZA, lasting for up to 5 years. All five patients with lupus arthritis responded, but this response did not last for >2 months after the last infusion. One additional patient had a long-lasting improvement in SLE interstitial lung disease. No symptoms suggestive of infliximab-induced SLE flares occurred in any patients. Short-term treatment appeared relatively safe, but one patient developed deep-vein thrombosis and several infections. Under long-term therapy, two patients had life-threatening or fatal events, namely CNS lymphoma and Legionella pneumonia. Retreatment and treatment without concomitant immunosuppression led to drug reactions.

CONCLUSIONS

Short-term therapy with four infusions of infliximab in combination with AZA was relatively safe, and had remarkable long-term efficacy for lupus nephritis and, potentially, also interstitial lung disease. Long-term therapy with infliximab, however, was associated with severe adverse events in two out of three SLE patients, which may have been provoked by infliximab and/or by their long-standing refractory SLE and previous therapies.

Bracing in external rotation for traumatic anterior dislocation of the shoulder

We undertook a prospective study in 51 male patients aged between 17 and 27 years to ascertain whether immobilisation after primary traumatic anterior dislocation of the shoulder in external rotation was more effective than immobilisation in internal rotation in preventing recurrent dislocation in a physically active population. Of the 51 patients, 24 were randomised to be treated by a traditional brace in internal rotation and 27 were immobilised in external rotation of 15 degrees to 20 degrees. After immobilisation, the patients undertook a standard regime of physiotherapy and were then assessed clinically for evidence of instability. When reviewed at a mean of 33.4 months (24 to 48) ten from the external rotation group (37%) and ten from the internal rotation group (41.7%) had sustained a further dislocation. There was no statistically significant difference (p = 0.74) between the groups. Our findings show that external rotation bracing may not be as effective as previously reported in preventing recurrent anterior dislocation of the shoulder.

Phenotypic and functional analysis of CD4+ CD25- Foxp3+ T cells in patients with systemic lupus erythematosus

CD4(+)CD25(+)Foxp3(+) regulatory T cells (Treg) that specialize in the suppression of immune responses might be critically involved in the pathogenesis of autoimmune diseases. Recent studies have described increased proportions of CD4(+)Foxp3(+) T cells that lacked expression of CD25 in systemic lupus erythematosus (SLE) patients but the suppressive capacity of these cells has not been analyzed so far. We therefore performed combined phenotypic and functional analyses of CD4(+)CD25(-)Foxp3(+) T cells in patients with autoimmune diseases and healthy controls (HC). Phenotypic analysis revealed increased proportions of CD4(+)CD25(-)Foxp3(+) T cells in SLE patients as compared with patients with systemic sclerosis, rheumatoid arthritis, (RA), or HC. In addition, increased proportions of CD4(+)CD25(-)Foxp3(+) T cells correlated with the clinical disease activity and the daily cortisone dose. According to phenotypic analysis, CD4(+)CD25(-)Foxp3(+) T cells resembled regulatory T cells rather than activated T cells. For functional analysis, a surrogate surface marker combination to substitute for intracellular Foxp3 was defined: CD4(+)CD25(-)CD127(-) T cells from SLE patients were isolated by FACS sorting and analyzed for their suppressive capacity in vitro. CD4(+)CD25(-)CD127(-) T cells, that contained up to 53% Foxp3(+) T cells, were found to suppress T cell proliferation but not IFN-gamma production in vitro. In summary, CD4(+)CD25(-)Foxp3(+) T cells phenotypically and to a certain extent also functionally resemble conventional Treg. Despite increased proportions, however, their selective functional defects might contribute to the failure of Treg to control autoimmune dysregulation in SLE patients.

Lactobacillus reuteri 100-23 transiently activates intestinal epithelial cells of mice that have a complex microbiota during early stages of colonization

Monoassociations of germ-free animals with colitogenic and probiotic bacterial strains trigger intestinal epithelial cell (IEC) activation and host-derived feedback mechanisms. To characterize the impact of a single nonpathogenic bacterial strain on the intestinal epithelium in the presence of an established microbiota, we inoculated reconstituted Lacotobacillus-free (RLF) mice at 8 wk of age with Lactobacillus reuteri 100-23. Primary IEC from the small intestine of L. reuteri-inoculated and control RLF mice were isolated 2, 6, and 21 d after inoculation followed by gene expression analysis (real-time PCR; Affymetrix microarrays) as well as 2-dimensional-gel electrophoreses (2D SDS-PAGE) and peptide mass fingerprinting via matrix-assisted laser desorption/ionization time of flight MS. At d 6, gene expression of proinflammatory cytokines and chemokines including interleukin (IL)-1alpha, IL-6, interferon-gamma-inducible protein 10, and macrophage inflammatory protein 2 was transiently induced, whereas gene expression levels of regulatory proteins A20 and Toll-interacting protein decreased. In addition, 8 target proteins with changes in the steady-state protein expression levels were identified at d 2 and 6 of L. reuteri colonization. Consistent with the absence of histopathology, L. reuteri-induced activation of primary IEC returned to control levels by d 21 after inoculation of RLF mice. The capability of L. reuteri 100-23 to directly trigger epithelial cell activation was confirmed in small IEC cultures using the murine cell line Mode-K. These results clearly indicate that the intestinal epithelium is reactive toward environmental changes induced by the commensal bacterial strain L. reuteri even in the presence of an already-established microbiota. The induction of transient IEC activation may help to maintain mucosal homeostasis.

Meniscal allograft transplantation. Two- to eight-year results

We evaluated 18 of 23 patients who had undergone cryopreserved meniscal allograft transplantation for compartmental pain after total meniscectomy 2 to 8 years (mean, 5.4) after the operation. The Short Form-36 scores revealed a decrease in pain with a significant improvement in function, although function remained limited. There was no significant decrease in joint space on 45 degrees posteroanterior weightbearing radiographs through the duration of the study. Eight of 22 allograft menisci (36%) tore during the study period, necessitating 6 partial and 2 total meniscectomies. Two patients subsequently underwent reimplantation. Histologic examination of the removed tissue revealed reduced cellularity as compared with normal or torn native menisci. Four specimens also underwent detailed cytokine evaluation and demonstrated reduced cytokine expression compared with controls. While successful in alleviating compartmental pain that may be a late consequence of major meniscectomy, allograft menisci are repopulated with fewer cells than are present in normal or torn native menisci. These cells also demonstrate potentially reduced function, as measured by decreased growth factor production. This decreased biologic activity may be a factor that contributes to the high frequency of retears noted in this and prior studies.

The menisci: basic science and advances in treatment

Once described as a muscle remnant, and therefore treated with disrespect, the meniscus is now known to be a vital structure within the knee. Minimal partial meniscectomy performed arthroscopically, or meniscal repair when practical, have become the standard treatments. In spite of the advancements in understanding meniscal function and its preservation, much remains to be studied. In the future, availability of better repair techniques and the option of meniscal replacement with allograft or prosthetic menisci are expected to improve outcomes.

Is there a need for lumbar orthosis in mild compression fractures of the thoracolumbar spine?: A retrospective study comparing the radiographic results between early ambulation with and without lumbar orthosis

Compression fractures of the thoracolumbar spine are common in spinal trauma. Most patients are treated with early ambulation. Bracing is an option not always recommended by the treating team. There are no definite recommendations so far regarding the need for lumbar orthosis in this type of injury. The authors retrospectively compared two methods for treating patients with compression as great as 30%: early ambulation with and without lumbar orthosis. The results show that although demographic variables, type of injury, and cause of injury were similar between the groups, neither treatment emerged as superior. Thoracolumbar fractures with compression as much as 30% can be treated with early ambulation and no external support. Close clinical and radiographic follow-up is essential.

An operative technique for recurrent shoulder dislocations in older patients

Recurrent anterior shoulder dislocation in the elderly is not as exceptional as it was once thought to be. That anterior shoulder dislocation in older patients is caused by a rotator cuff tear through the posterior mechanism is well accepted. However, in the subset of patients who have multiple recurrent or intractable dislocations develop, there may be combined pathologic conditions at work: large or massive rotator cuff tears together with anterior capsulolabral injuries such as a Bankart lesion or fracture of the glenoid rim. These patients have multiple recurrences because of disruption of both the anterior and the posterior stability mechanisms. We suggest a procedure that provides anterior stabilization with the capsular shift technique and that is supplemented by Bankart repair as necessary. The capsule transfer is performed superiorly and posteriorly to close the defect in the cuff. In this way a capsulodesis effect can be achieved that displaces the humeral head downward and produces active centering of the head in the course of abduction. Use of only the anterior capsule for the shift, and not the subscapularis tendon, does not compromise subscapularis function. Between 1990 and 1996, we used this technique to treat 16 patients older than 55 years of age with multiple recurrent anterior shoulder dislocation and massive rotator cuff tear. We report the results for the first 10 patients with a minimum follow-up of 2 years (range 2 to 7 years) and an average follow-up of 52 months. There were 7 excellent results, 2 good results, and 1 fair result according to the Rowe criteria. None of the patients had a recurrence of the dislocation. All the patients regained full or functional range of motion with stable shoulders, and most of them could perform activities of daily living without limitation. The average Constant score was 83%. This procedure appears to be successful in treating older patients with recurrent shoulder dislocation.

[Vacuum phenomenon in the hip joint: diagnostic value]

Vacuum phenomenon is well known in degenerative spinal disease in the elderly, but is seldom seen in other joints, especially in children. The phenomenon does not represent a pathological finding, and can be used for imaging of the articular facets, mainly in the hip and knee joints. We report a patient with this phenomenon in the hip joint.

[Necrotizing soft tissue infection]

The dramatic course of necrotizing soft tissue infection represents a medical emergency, since it is limb- and life-threatening. Most necrotizing soft tissue infections are caused by mixed aerobic and anaerobic Gram-negative and Gram-positive organisms. Most case have been reported in immuno-compromised hosts after penetrating trauma or surgery. We describe a unique series of cases of necrotizing soft tissue infection. The mainstay of treatment is early and daily debridement of devitalized tissue and broad-spectrum antibiotics. Hyperbaric oxygen therapy should be considered.