Derotational distal femoral osteotomy corrects excessive femoral anteversion in patients with patellofemoral instability: A systematic review.

PURPOSE: Patellofemoral instability (PFI) is a common condition that can be caused from multiple factors, including lower limb rotational malalignments. Determining precise criteria for performing corrective torsional osteotomy can be a daunting task due to the lack of consensus on normal and excessive values and the limited evidence-based data in the postoperative results. The purpose was to assess the clinical, functional and imaging outcomes following derotational distal femoral osteotomy (DDFO) in patients with PFI and/or anterior knee pain (AKP) associated with lower limb rotational malalignments. METHODS: Searches were conducted on PubMed, EMBASE and Web of Science databases up to October 2023. Studies reporting outcomes after DDFO in patients with PFI and/or AKP were eligible for the systematic review. The primary outcome was imaging metrics, especially femoral anteversion. Secondary outcomes included the patient-reported outcome measures (PROMs) (clinical and functional). Quantitative synthesis involved the use of weighted averages to calculate pre- to postoperative mean differences (MD) and compare them against the minimal clinically important difference (MCID). RESULTS: Ten studies (309 knees) were included with a mean follow-up of 36.1 ± 11.7 months. Imaging outcomes consistently indicated the correction of femoral anteversion (MD = -19.4 degrees, 95% confidence interval: -20.1 to -18.7) following DDFO. PROMs showed significant improvements in most studies, exceeding the MCID. Patient satisfaction with the DDFO was high (93.3%). CONCLUSIONS: The DDFO was an effective treatment option for correcting excessive femoral anteversion in patients with PFI associated with clinically relevant functional and clinical improvement and a high satisfaction rate. LEVEL OF EVIDENCE: Level IV, systematic review of level II-IV studies.

Women show a positive response to platelet-rich plasma despite presenting more painful knee osteoarthritis than men.

PURPOSE: The purpose of this study was to evaluate the impact of gender on the efficacy of platelet-rich plasma (PRP) in patients with knee osteoarthritis (KOA), comparing their short-term response between men and women. METHODS: Four hundred-eighteen patients (529 knees) were included. Patients were treated with three injections of PRP on a weekly basis. Blood and PRP samples were randomly tested. Patients were asked to complete the knee injury and osteoarthritis outcome score (KOOS) and 12-item short form survey (SF-12), at baseline and 6 months. Success rates were calculated according to a reduction in the pain score of at least 9.3 points [minimal clinically important improvement (MCII)]. Comparative tests and multivariate regression were performed. RESULTS: The PRP had a platelet concentration factor of 2.0X compared to blood levels, with no leucocytes or erythrocytes. KOOS scores showed an increase from baseline to 6 months (p < 0.0001). There was an increase in the physical component summary (PCS) (p < 0.0001) and mental component summary (MCS) (p < 0.01) of the SF-12. The number of knees of women with MCII was 156 out of 262 (59.6%), whereas the number of knees of men was 136 out of 267 (50.9%) (p = 0.0468). Women had worse baseline scores on pain (p = 0.009), PCS (p < 0.0001) and MCS (p < 0.0001). CONCLUSION: Although the symptomatology generated by KOA was worse in women when compared to men, treatment with repeated injections of PRP was effective, ultimately achieving a higher improvement in women providing comparable final follow-up outcomes between men and women. LEVEL OF EVIDENCE: Level IV.

A Novel Fibrin Matrix Derived from Platelet-Rich Plasma: Protocol and Characterization.

Although fibrin matrices derived from Platelet-Rich Plasma (PRP) are widely used in regenerative medicine, they have some limitations that can hinder their application. Modifying the composition of the PRP-derived fibrin matrix may improve its properties, making it suitable for certain medical uses. Three types of fibrin matrices were obtained: a PRP-derived fibrin matrix (FM), a PRP-derived fibrin matrix with a high fibrinogen content and platelets (FM-HFP) and a PRP-derived fibrin matrix with a high fibrinogen content (FM-HF). The fibrinogen levels, biomechanical properties and cell behavior were analyzed. The presence of platelets in the FM-HFP generated an inconsistent fibrin matrix that was discarded for the rest of the analysis. The fibrinogen levels in the FM-FH were higher than those in the FM (p < 0.0001), with a concentration factor of 6.86 ± 1.81. The values of clotting and swelling achieved using the FM-HF were higher (p < 0.0001), with less clot shrinkage (p < 0.0001). The FM had a significantly higher stiffness and turned out to be the most adherent composition (p = 0.027). In terms of cell viability, the FM-HF showed less cell proliferation but higher live/dead ratio values (p < 0.01). The increased fibrinogen and platelet removal in the FM-HF improved its adhesion and other biomechanical properties without affecting cell viability.

Donor and recipient human leukocyte antigen-G polymorphisms modulate the risk of adverse immunologic events following lung transplantation.

The long-term benefits of lung transplantation (LTx) are limited by pathogenic alloimmune responses that drive injury, inflammation, and chronic dysfunction. Human leukocyte antigen-G (HLA-G) plays a key role in the modulation of these pathways. This study assesses the impact of the HLA-G genotype on immunologic risk and survival following LTx. This retrospective cohort study included 289 bilateral LTx. Recipient and donor HLA-G genotypes were analyzed to identify associations with de novo donor-specific antibodies, acute rejection, chronic lung allograft dysfunction, and allograft survival. We further assessed these associations, both individually and in paired analysis, based on a grouped haplotype classification of HLA-G expression. Donor HLA-G single nucleotide polymorphisms were associated with allograft injury, the onset of chronic lung allograft dysfunction following injury, and allograft survival. Recipient HLA-G single nucleotide polymorphisms were associated with allograft injury, cellular rejection, and donor-specific antibody formation. "Low HLA-G expression" donor haplotypes were associated with impaired allograft survival, as were "low HLA-G expression" donor-recipient haplotype pairs. This study provides compelling evidence for the role of HLA-G in modulating immunologic risk after LTx. Our results highlight the importance of both donor and recipient HLA-G genotypes on the overall risk profile and underscore the lasting influence of donor genotype on lung transplant outcomes.

The effect of short-term cryopreservation on the properties and functionality of platelet-rich plasma.

Platelet Rich Plasma (PRP) is a biological treatment which, thanks to its enhanced growth factors content, is widely used in the field of regenerative medicine for its reparative effects. Although it is usually used fresh immediately after preparation, its freezing for preservation for future usage could be key in increasing its versatility and new applications. To assess the suitability of freezing, after collecting PRP and platelet lysates (PL) from 6 patients, they were preserved for 1 or 3 months at temperatures of -20ºC and -80°C. Measurements were then made on platelet number and integrity, growth factor levels, biomechanical properties of the clot and its bioactivity on cultured cells. Fresh PRP and PL were used as controls. The results showed an increase in platelet size (p < .01) and clot elasticity (p < .01), as well as decrease in levels of PDGF (P < .05) and VEGF (p < .05), though the overall bioactivity was not affected as culture cells showed the same responsiveness to both frozen and fresh PRP and PL in terms of cell viability. Based on these results, it could be assumed that preservation of PRP by freezing is a feasible and suitable option for its further use.

What is the context? Platelet-Rich Plasma (PRP) is a biological treatment widely used in regenerative medicine as a result of its high content of growth factors.In its routine use, PRP has autologous character, since it is obtained from the same patient and its infiltration in the affected area takes place immediately after it is obtained.Its storability would give PRP versatility in use, which could enable a potential allogeneic use and even significantly reduce the number of blood draws for each patient.It is necessary to establish a PRP storage protocol where its properties are not affected.What is new? PRP was stored at two time points (1 and 3 months) and temperatures (−20ºC and −80ºC) in activated and unactivated states. Afterwards, platelet number, size and activation were measured. Furthermore, the biomechanical properties of the resulting clot, the growth factor content and PRP's impact on cell viability were analyzed.The limiting factor was not having used aggregometry or other techniques that measure other cellular processes, as well as the limited sample size.The results showed that freezing affected platelet size, the levels of platelet-derived GFs and the biomechanical properties of the clot. However, plasmatic levels of growth factors or its capacity to boost cellular proliferation were not affected.What is the impact?The clinical impact of this work is the ability to preserve PRP by freezing. This is especially relevant as it allows a possible use of PRP as an allogeneic treatment. Moreover, its preservation significantly reduces the number of blood draws for each patient, especially in those with puncture difficulties or with apprehension.

High survival rate after the combination of intrameniscal and intraarticular infiltrations of platelet-rich plasma as conservative treatment for meniscal lesions.

PURPOSE: To evaluate the efficacy of applying a combination of intrameniscal and intraarticular infiltrations of Platelet-Rich Plasma (PRP) in patients with meniscal tears, analyzing its failure rate and clinical evolution, as well as factors that may influence the positive response to this treatment. METHODS: Three hundred and ninety-two cases out of 696 met the inclusion criteria and were included in this work. Survival and patient-reported outcome measure (PROM) were collected and analyzed. Survival rate was defined as the percentage of patients who did not undergo meniscus surgery during their follow-up time. Patients were asked to complete the Knee injury and Osteoarthritis Outcome Score (KOOS) at baseline, 6 months and 18 months. Other patient- and pathology-related variables were collected. Blood and PRP samples were randomly tested as a quality control measure. Survival and comparative statistical tests, and multivariate regression were performed for the analysis of the variables. RESULTS: The PRP applied had a platelet concentration factor of 1.9X in respect to blood levels, with no leukocytes or erythrocytes. Thirty-eight patients required surgical intervention after treatment reaching a survival rate of 90.3% with an estimated mean survival time of 54.4 months. The type of injury (P = 0.002) and the presence of chondropathy were risk factors for surgical intervention after PRP treatment (P = 0.043). All KOOS scores showed a significant statistical increase from baseline to 6 months (N = 93) and 18 months (N = 66) (P < 0.0001). The number of cases with minimal clinically important improvement (MCII) at 6 months and 18 months post-treatment was 65 (69.9%) and 43 (65.2%), respectively. CONCLUSION: The combination of intrameniscal and intraarticular PRP infiltrations is a valid conservative treatment for meniscal injuries avoiding the need for surgical intervention. Its efficacy is higher in horizontal tears and decreases when joint degeneration is present. LEVEL OF EVIDENCE: Level IV.

Action of Platelet-Rich Plasma on In Vitro Cellular Bioactivity: More than Platelets.

Platelet-rich plasma (PRP) is a biological therapy in which one of the mechanisms of action is the stimulation of biological processes such as cell proliferation. The size of PRP's effect depends on multiple factors, one of the most important being the composition of PRP. The aim of this study was to analyze the relationship between cell proliferation and the levels of certain growth factors (IGF-1, HGF, PDGF, TGF-ß and VEG) in PRP. First, the composition and effect on cell proliferation of PRP versus platelet-poor plasma (PPP) were compared. Subsequently, the correlation between each growth factor of PRP and cell proliferation was evaluated. Cell proliferation was higher in cells incubated with lysates derived from PRP compared to those cultured with lysates derived from PPP. In terms of composition, the levels of PDGF, TGF-ß, and VEGF were significantly higher in PRP. When analyzing the PRP growth factors, IGF-1 was the only factor that correlated significantly with cell proliferation. Of those analyzed, the level of IGF-1 was the only one that did not correlate with platelet levels. The magnitude of PRP's effect depends not only on platelet count but also on other platelet-independent molecules.

New Formulation of Platelet-Rich Plasma Enriched in Platelet and Extraplatelet Biomolecules Using Hydrogels.

Platelet-rich plasma (PRP) is an autologous biologic product used in several fields of medicine for tissue repair due to the regenerative capacity of the biomolecules of its formulation. PRP consists of a plasma with a platelet concentration higher than basal levels but with basal levels of any biomolecules present out of the platelets. Plasma contains extraplatelet biomolecules known to enhance its regenerative properties. Therefore, a PRP containing not only a higher concentration of platelets but also a higher concentration of extraplatelet biomolecules that could have a stronger regenerative performance than a standard PRP. Considering this, the aim of this work is to develop a new method to obtain PRP enriched in both platelet and extraplatelet molecules. The method is based on the absorption of the water of the plasma using hydroxyethyl acrylamide (HEAA)-based hydrogels. A plasma fraction obtained from blood, containing the basal levels of platelets and proteins, was placed in contact with the HEAA hydrogel powder to absorb half the volume of the water. The resulting plasma was characterized, and its bioactivity was analyzed in vitro. The novel PRP (nPRP) showed a platelet concentration and platelet derived growth factor (PDGF) levels similar to the standard PRP (sPRP), but the concentration of the extraplatelet growth factors IGF-1 (p < 0.0001) and HGF (p < 0.001) were significantly increased. Additionally, the cells exposed to the nPRP showed increased cell viability than those exposed to a sPRP in human dermal fibroblasts (p < 0.001) and primary chondrocytes (p < 0.01). In conclusion, this novel absorption-based method produces a PRP with novel characteristics compared to the standard PRPs, with promising in vitro results that could potentially trigger improved tissue regeneration capacity.

Canadian Guidelines for Hereditary Transthyretin Amyloidosis Polyneuropathy Management.

Hereditary transthyretin-mediated (hATTR) amyloidosis is a progressive disease caused by mutations in the TTR gene leading to multisystem organ dysfunction. Pathogenic TTR aggregation, misfolding, and fibrillization lead to deposition of amyloid in multiple body organs and frequently involve the peripheral nerve system and the heart. Common neurologic manifestations include: sensorimotor polyneuropathy (PN), autonomic neuropathy, small-fiber PN, and carpal tunnel syndrome. Many patients have significant progression due to diagnostic delays as hATTR PN is not considered within the differential diagnosis. Recently, two effective novel disease-modifying therapies, inotersen and patisiran, were approved by Health Canada for the treatment of hATTR PN. Early diagnosis is crucial for the timely introduction of these disease-modifying treatments that reduce impairments, improve quality of life, and extend survival. In this guideline, we aim to improve awareness and outcomes of hATTR PN by making recommendations directed to the diagnosis, monitoring, and treatment in Canada.

Lignes directrices sur la prise en charge de l'amylose héréditaire à transthyrétine, accompagnée de polyneuropathie, au Canada.L'amylose héréditaire à transthyrétine (ATTRh) est une maladie évolutive, causée par des mutations du gène de la transthyrétine (TTR), qui entraînent un dysfonctionnement plurisystémique. L'agrégation, le mauvais repliement et la fibrillisation pathogènes de la TTR aboutissent au dépôt de protéines amyloïdes dans plusieurs organes, et affectent souvent le système nerveux périphérique et le cœur. Les troubles neurologiques fréquents comprennent une polyneuropathie sensorimotrice (PN), une neuropathie autonome, une polyneuropathie des petites fibres et le syndrome du canal carpien. Chez bon nombre de patients, la maladie a connu une évolution importante en raison de la pose tardive du diagnostic, la PN-ATTRh ne faisant pas l'objet d'un diagnostic différentiel. Santé Canada a approuvé, depuis peu, deux nouveaux médicaments modificateurs de la PN-ATTRh et efficaces contre l'affection, soit l'inotersen et le patisiran. La pose précoce du diagnostic revêt une importance cruciale dans l'instauration, en temps opportun, de ces tout nouveaux traitements qui atténuent les troubles, améliorent la qualité de vie et prolongent la survie. Les auteurs, par l'élaboration de la nouvelle ligne directrice, espèrent sensibiliser la communauté médicale à la PN-ATTRh, et améliorer les résultats cliniques qui y sont associés, en formulant des recommandations sur le diagnostic et le traitement de la maladie au Canada ainsi que sur la surveillance de son évolution.

Isolation of Platelet-Derived Exosomes from Human Platelet-Rich Plasma: Biochemical and Morphological Characterization.

Platelet-Rich Plasma (PRP) is enriched in molecular messengers with restorative effects on altered tissue environments. Upon activation, platelets release a plethora of growth factors and cytokines, either in free form or encapsulated in exosomes, which have been proven to promote tissue repair and regeneration. Translational research on the potential of exosomes as a safe nanosystem for therapeutic cargo delivery requires standardizing exosome isolation methods along with their molecular and morphological characterization. With this aim, we isolated and characterized the exosomes released by human PRP platelets. Western blot analysis revealed that CaCl2-activated platelets (PLT-Exos-Ca2+) released more exosomes than non-activated ones (PLT-Exos). Moreover, PLT-Exos-Ca2+ exhibited a molecular signature that meets the most up-to-date biochemical criteria for platelet-derived exosomes and possessed morphological features typical of exosomes as assessed by transmission electron microscopy. Array analysis of 105 analytes including growth factors and cytokines showed that PLT-Exos-Ca2+ exhibited lower levels of most analytes compared to PLT-Exos, but relatively higher levels of those consistently validated as components of the protein cargo of platelet exosomes. In summary, the present study provides new insights into the molecular composition of human platelet-derived exosomes and validates a method for isolating highly pure platelet exosomes as a basis for future preclinical studies in regenerative medicine and drug delivery.

Correlation between the analysis of the dentoalveolar square and the photometric clinical diagnosis of smile.

AIM: Increased vertical growth of the maxilla is a condition that affects a large part of the population. The condition reveals a skeletal alteration of the cranio-masticatory system. One of the effects generated by the excessive vertical growth of the maxilla is a gingival smile pattern that can affect esthetic patterns as well as alter the masticatory biomechanics, which is a primary etiologic factor in temporomandibular dysfunction (TMD). Contemporary imaging aids help to optimize diagnostic analysis; perform treatment; and make an evaluation before, during, and after treatment. The present study aims to compare the clinical diagnosis of gingival smile with the dimensions of the dentoalveolar square, digitally calculated in the panoramic projection of the CBCT. MATERIALS AND METHODS: In a sample of 37 patients, an analysis was performed of the correlation between the dimensions of the dentoalveolar square of the Tatis panoramic cephalometry and the clinical photometry, applying the Tjan gingival smile analysis. RESULTS: The results show that there is high correlation and agreement between the cephalometric measurement method of the dentoalveolar square and Tjan's photometric measurement method. Both methods can be used to classify the smile type as high, medium or low. CONCLUSIONS: Analysis of the dentoalveolar square of the panoramic cephalometry provides an accurate diagnosis of the anterior vertical dimension of the maxilla as it relates to the clinical diagnosis of smile.

Platelet-rich plasma injections delay the need for knee arthroplasty: a retrospective study and survival analysis.

PURPOSE: The biological action of platelet-rich plasma (PRP) could slow down the osteoarthritis progression, resulting in a delay of joint replacement. This work aims to evaluate the ability of PRP to postpone and even avoid knee replacement in patients with knee osteoarthritis (KOA) analyzing, on the one hand, the time of delay and on the other hand the percentage of patients without undergoing total knee arthroplasty (TKA). METHODS: A retrospective analysis and a survival analysis were conducted. KOA patients who underwent knee replacement between 2014 and 2019 and previously received PRP infiltrations were included in the retrospective analysis. Regarding survival analysis, KOA patients who received PRP treatment during 2014 and with follow-up until 2019 were included. The dates of PRP treatment and TKA, KOA severity, age of the patients, number of PRP cycles, and administration route were analyzed. RESULTS: This work included 1084 patients of which 667 met the inclusion criteria. 74.1% of the patients in the retrospective study achieved a delay in the TKA of more than 1.5 years, with a median delay of 5.3 years. The survival analysis showed that 85.7% of the patients did not undergo TKA during the five year follow-up. The severity degree, age, PRP cycles, and administration route had a statistically significant influence on the efficacy of PRP in delaying surgery. CONCLUSION: These data suggest that the application of PRP in KOA patients is a treatment that could delay TKA, although further studies are needed to understand and improve this therapy.

Platelet Lysate Nebulization Protocol for the Treatment of COVID-19 and Its Sequels: Proof of Concept and Scientific Rationale.

One of the most severe effects of coronavirus disease 2019 (COVID-19) is lung disorders such as acute respiratory distress syndrome. In the absence of effective treatments, it is necessary to search for new therapies and therapeutic targets. Platelets play a fundamental role in respiratory disorders resulting from viral infections, being the first line of defense against viruses and essential in maintaining lung function. The direct application of platelet lysate (PL) obtained from the platelet-rich plasma of healthy donors could help in the improvement of the patient due its anti-inflammatory, immunomodulatory, antifibrotic, and repairing effects. This work evaluates PL nebulization by analyzing its levels of growth factors and its biological activity on lung fibroblast cell cultures, besides describing a scientific basis for its use in this kind of pathology. The data of the work suggest that the molecular levels and biological activity of the PL are maintained after nebulization. Airway administration would allow acting directly on the lung tissue modulating inflammation and stimulating reparative processes on key structures such as the alveolocapillary barrier, improving the disease and sequels. The protocol developed in this work is a first step for the study of nebulized PL both in animal experimentation and in clinical trials.

Effects of Platelet-Rich Plasma on Cellular Populations of the Central Nervous System: The Influence of Donor Age.

Platelet-rich plasma (PRP) is a biologic therapy that promotes healing responses across multiple medical fields, including the central nervous system (CNS). The efficacy of this therapy depends on several factors such as the donor's health status and age. This work aims to prove the effect of PRP on cellular models of the CNS, considering the differences between PRP from young and elderly donors. Two different PRP pools were prepared from donors 65‒85 and 20‒25 years old. The cellular and molecular composition of both PRPs were analyzed. Subsequently, the cellular response was evaluated in CNS in vitro models, studying proliferation, neurogenesis, synaptogenesis, and inflammation. While no differences in the cellular composition of PRPs were found, the molecular composition of the Young PRP showed lower levels of inflammatory molecules such as CCL-11, as well as the presence of other factors not found in Aged PRP (GDF-11). Although both PRPs had effects in terms of reducing neural progenitor cell apoptosis, stabilizing neuronal synapses, and decreasing inflammation in the microglia, the effect of the Young PRP was more pronounced. In conclusion, the molecular composition of the PRP, conditioned by the age of the donors, affects the magnitude of the biological response.

Donor human leukocyte antigen-G single nucleotide polymorphisms are associated with post-lung transplant mortality.

Human leukocyte antigen (HLA)-G is a non-classical HLA that inhibits immune responses. Its expression is modified by single nucleotide polymorphisms (SNPs), which are associated with transplant outcomes. Our aim was to investigate the association of donor and recipient HLA-G SNPs with chronic lung allograft dysfunction (CLAD) and mortality after lung transplantation.In this single-centre study, we examined 11 HLA-G SNPs in 345 consecutive recipients and 297 donors of a first bilateral lung transplant. A multivariable Cox proportional hazards model assessed associations of SNPs with death and CLAD. Transbronchial biopsies (TBBx) and bronchoalveolar lavage (BAL) samples were examined using quantitative PCR, ELISA and immunofluorescence.Over a median of 4.75 years, 142 patients (41%) developed CLAD; 170 (49%) died. Multivariable analysis revealed donor SNP +3142 (GG+CG versus CC) was associated with increased mortality (hazard ratio 1.78, 95% CI 1.12-2.84; p=0.015). In contrast, five donor SNPs, -201(CC), -716(TT), -56(CC), G*01:03(AA) and 14 bp INDEL, conferred reduced mortality risk. Specific donor-recipient SNP pairings reduced CLAD risk. Predominantly epithelial HLA-G expression was observed on TBBx without rejection. Soluble HLA-G was present in higher concentrations in the BAL samples of patients who later developed CLAD.Specific donor SNPs were associated with mortality risk after lung transplantation, while certain donor-recipient SNP pairings modulated CLAD risk. TBBx demonstrated predominantly epithelial, and therefore presumably donor-derived, HLA-G expression in keeping with these observations. This study is the first to demonstrate an effect of donor HLA-G SNPs on lung transplantation outcome.

Effects of everolimus and HLA-G on cellular proliferation and neutrophil adhesion in an in vitro model of cardiac allograft vasculopathy.

Human leukocyte antigen-G (HLA-G) expression is modulated by immunosuppressant use and is associated with lower incidence of graft rejection and cardiac allograft vasculopathy (CAV). We examined whether everolimus induces HLA-G expression and inhibits human coronary artery smooth muscle cell (HCASMC) proliferation, a critical event in CAV. Also, we examined whether TNFα-stimulated neutrophil adhesion is inhibited by HLA-G on human coronary artery endothelial cells (HCAECs). HLA-G expression in HCASMCs following everolimus treatment was determined by western-blot densitometric analysis. HCASMCs proliferation following incubation with recombinant HLA-G was determined by automated cell counter detecting 2-10 µm particles. Assessment of recombinant HLA-G on neutrophil adhesion to HCAECs in response to TNF-α induced-injury was determined by nonstatic adhesion assays. HLA-G expression was upregulated in HCASMCs following everolimus exposure (1000 ng/ml; P < .05). HLA-G (500, 1000 ng/ml; both P < .05) reduced HCASMC proliferation and inhibited TNFα-stimulated neutrophil adhesion to endothelial cells at all concentrations (0.1-1 ng/ml; all P < .001). Our study reveals novel regulation of HLA-G by everolimus, by demonstrating HLA-G upregulation and subsequent inhibition of HCASMC proliferation. HLA-G is a potent inhibitor of neutrophil adhesion to HCAECs. Findings support HLA-G's importance and potential use in heart transplantation for preventative therapy or as a marker to identify patients at high risk for developing CAV.

Patterns of CMR measured longitudinal strain and its association with late gadolinium enhancement in patients with cardiac amyloidosis and its mimics.

BACKGROUND: Regional variability of longitudinal strain (LS) has been previously described with echocardiography in patients with cardiac amyloidosis (CA), however, the reason for this variability is not completely evident. We sought to describe regional patterns in LS using feature-tracking software applied to cardiovascular magnetic resonance (CMR) cine images in patients with CA, hypertrophic cardiomyopathy (HCM), and Anderson-Fabry's disease (AFD) and to relate these patterns to the distribution of late gadolinium enhancement (LGE). METHODS: Patients with CA (n = 45) were compared to LV mass indexed matched patients with HCM (n = 19) and AFD (n = 19). Peak systolic LS measurements were obtained using Velocity Vector Imaging (VVI) software on CMR cine images. A relative regional LS ratio (RRSR) was calculated as the ratio of the average of the apical segmental LS divided by the sum of the average basal and mid-ventricular segmental LS. LGE was quantified for the basal, mid, and apical segments using a threshold of 5SD above remote myocardium. A regional LGE ratio was calculated similar to RRSR. RESULTS: Patients with CA had significantly had worse global LS (-15.7 ± 4.6%) than those with HCM (-18.0 ± 4.6%, p = 0.046) and AFD (-21.9 ± 5.1%, p < 0.001). The RRSR was higher in patients with CA (1.00 ± 0.31) than in AFD (0.79 ± 0.24; p = 0.018) but not HCM (0.84 ± 0.32; p = 0.114). In CA, a regional difference in LGE burden was noted, with lower LGE in the apex (31.5 ± 19.1%) compared to the mid (38.2 ± 19.0%) and basal (53.7 ± 22.7%; p < 0.001 for both) segments. The regional LGE ratio was not significantly different between patients with CA (0.33 ± 0.15) and AFD (0.47 ± 0.58; p = 0.14) but lower compared to those with HCM (0.72 ± 0.43; p < 0.0001). LGE percentage showed a significant impact on LS (p < 0.0001), with a 0.9% decrease in absolute LS for every 10% increase in LGE percentage. CONCLUSION: The presence of marked "relative apical sparing" of LS along with a significant reduction in global LS seen in patients with CA on CMR cine analysis may provide an additional tool to differentiate CA from other cause of LVH. The concomitant presence of a base to apex gradient in quantitative LGE burden suggests that the regional strain gradient may be at least partially explained by the burden of amyloid deposition and fibrosis.

The Added Value of Exercise Variables in Heart Failure Prognosis.

INTRODUCTION: Diminished exercise capacity is a key symptom in heart failure (HF). Exercise predictors (peak VO2, VE/VCO2 slope, and oxygen uptake efficiency slope [OUES]) are prognostic markers but studied in isolation. We evaluated if these exercise variables offer additional prognostic value to clinical predictors in HF. METHODS AND RESULTS: This was a single-institution retrospective cohort study of 517 consecutive HF patients. We used Cox proportional hazards modeling to determine the additional prognostic value of exercise variables on mortality, HF hospital admissions, and a composite outcome of ventricular assistance device (VAD) implantation, heart transplantation (HT), and death. During a mean follow-up of 2.7 years, 52 deaths, 47 HTs, and 19 VAD implantations occurred. After adjusting for age, New York Heart Association functional class, ejection fraction, body mass index, creatinine, and B-type natriuretic peptide, peak VO2 (hazard ratio [HR] 0.91, 95% confidence interval [CI] 0.85-0.96), OUES (HR 0.92, 95% CI 0.87-0.97), and VE/VCO2 (HR 1.03, 95% CI 1.01-1.05) were independent predictors of the composite outcome. Similar discriminatory capacity existed between the exercise variables (c-statistics 0.77, 0.78, and 0.78, respectively). Only VE/VCO2 was an independent predictor of admissions (HR 1.04, 95% CI 1.01-1.07), and only peak VO2 was an independent predictor of mortality (HR 0.90, 95% CI 0.84-0.98). CONCLUSIONS: Peak VO2, OUES, and VE/VCO2 are independent predictors of HF prognosis over recognized clinical variables. However, no single exercise variable was superior.

Three-Dimensional Platelet-Rich Plasma Hydrogel Model to Study Early Tendon Healing.

Since the experimental conditions of cell cultures may bias results, it is critical to use suitable models. This is also true in the context of tendon cell biology and the study of platelet-rich plasma (PRP) therapies and PRP-augmented cell-based therapies. We compared the culture of human tendon cells in 2 dimensions (2D) with PRP-supplemented media to culture in matching 3-dimensional (3D) PRP hydrogels. Cell proliferation, cell shape, and the pattern of gene and protein expression were examined. Our data revealed modifications in cell shape and enhanced expression of tenomodulin and scleraxis in 3D hydrogels. Additionally, protein secretion analysis using glass-based arrays specific for angiogenesis revealed differences in interleukin (IL)-6 and IL-8 protein expression between 2D cultures and 3D hydrogels, while the secretion of other angiogenic or inflammatory cytokines was unaffected. Our study suggests that 3D hydrogels are physiologically more relevant than 2D cultures in the study of tendon cells, based on cell shape, support of tenocyte proliferation, phenotype, and the pattern of gene and protein expression.