Retrospective study comparing the accuracies of handheld infrared stereo camera and augmented reality-based navigation systems for total hip arthroplasty

BACKGROUND

The use of portable navigation systems (PNS) in total hip arthroplasty (THA) has become increasingly prevalent, with second-generation PNS (sPNS) demonstrating superior accuracy in the lateral decubitus position compared to first-generation PNS. However, few studies have compared different types of sPNS. This study retrospectively compares the accuracy and clinical outcomes of two different types of sPNS instruments in patients undergoing THA.

METHODS

A total of 158 eligible patients who underwent THA at a single institution between 2019 and 2022 were enrolled in the study, including 89 who used an accelerometer-based PNS with handheld infrared stereo cameras in the Naviswiss group (group N) and 69 who used an augmented reality (AR)-based PNS in the AR-Hip group (group A). Accuracy error, navigation error, clinical outcomes, and preparation time were compared between the two groups.

RESULTS

Accuracy errors for Inclination were comparable between group N (3.5° ± 3.0°) and group A (3.5° ± 3.1°) (p = 0.92). Accuracy errors for anteversion were comparable between group N (4.1° ± 3.1°) and group A (4.5° ± 4.0°) (p = 0.57). The navigation errors for inclination (group N: 2.9° ± 2.7°, group A: 3.0° ± 3.2°) and anteversion (group N: 4.3° ± 3.5°, group A: 4.3° ± 4.1°) were comparable between the groups (p = 0.86 and 0.94, respectively). The preparation time was shorter in group A than in group N (p = 0.036). There were no significant differences in operative time (p = 0.255), intraoperative blood loss (p = 0.387), or complications (p = 0.248) between the two groups.

CONCLUSION

An Accelerometer-based PNS using handheld infrared stereo cameras and AR-based PNS provide similar accuracy during THA in the lateral decubitus position, with a mean error of 3°-4° for both inclination and anteversion, though the AR-based PNS required a shorter preparation time.

A large preoperative pelvic oblique angle affects perception of leg length discrepancy after total hip arthroplasty

BACKGROUND

In some cases, patients feel a perceived leg length discrepancy (P-LLD) despite no radiographic leg length discrepancy (R-LLD) after total hip arthroplasty (THA). We aimed to investigate the rate of postoperative P-LLD and the factors that cause postoperative P-LLD.

METHODS

A retrospective study was conducted on 100 patients with R-LLD ≤5 mm after THA. Patients were classified into two groups based on P-LLD post-THA: group P (with P-LLD) and group E (without P-LLD). Relevant data on the general characteristics and radiological findings between the two groups were compared.

RESULTS

We observed that 25 & 75% of patients belonged to group P and group E, respectively, with no significant difference in patient background. Postoperative Japanese Orthopedic Association (JOA) classification of pain and activities of daily living scores were significantly lower in group P than in group E (37.2 ± 3.9 vs. 39.1 ± 2.2, respectively; P = 0.013, and 16.2 ± 4.2 vs. 18.2 ± 2.2, respectively; P = 0.011). The preoperative pelvic oblique angle (POA) was significantly larger in group P than in group E (3.3 ± 2.3° vs. -0.2 ± 2.1°; respectively; P < 0.01). The pelvis tilted toward the surgical side was significantly higher in group P than in group E(88% vs 57%; respectively; P = 0.013). The preoperative C7 coronal vertical axis (C7 CVA) was significantly larger in group P than in group E (6.7 ± 14.7 mm vs. -0.2 ± 10.3 mm; respectively; P = 0.028). Multivariate logistic analysis revealed that preoperative POA (OR, 3.71; 95% CI: 1.86-8.12; P < 0.01) and the pelvis tilted toward the surgical side (OR, 4.14; 95% CI: 2.07-9.71; P = 0.022) were independent risk factors for P-LLD after THA.

CONCLUSION

Even though there was no postoperative R-LLD, 25% of patients had P-LLD. A large preoperative POA and the pelvis tilted toward the surgical side were independent risk factors for P-LLD after THA.

Bone-Regeneration Therapy Using Biodegradable Scaffolds: Calcium Phosphate Bioceramics and Biodegradable Polymers

Calcium phosphate-based synthetic bone is broadly used for the clinical treatment of bone defects caused by trauma and bone tumors. Synthetic bone is easy to use; however, its effects depend on the size and location of the bone defect. Many alternative treatment options are available, such as joint arthroplasty, autologous bone grafting, and allogeneic bone grafting. Although various biodegradable polymers are also being developed as synthetic bone material in scaffolds for regenerative medicine, the clinical application of commercial synthetic bone products with comparable performance to that of calcium phosphate bioceramics have yet to be realized. This review discusses the status quo of bone-regeneration therapy using artificial bone composed of calcium phosphate bioceramics such as β-tricalcium phosphate (βTCP), carbonate apatite, and hydroxyapatite (HA), in addition to the recent use of calcium phosphate bioceramics, biodegradable polymers, and their composites. New research has introduced potential materials such as octacalcium phosphate (OCP), biologically derived polymers, and synthetic biodegradable polymers. The performance of artificial bone is intricately related to conditions such as the intrinsic material, degradability, composite materials, manufacturing method, structure, and signaling molecules such as growth factors and cells. The development of new scaffold materials may offer more efficient bone regeneration.

Cellular senescence is associated with osteonecrosis of the femoral head while mesenchymal stem cell conditioned medium inhibits bone collapse

Osteonecrosis of the femoral head (ONFH) is a type of ischemic osteonecrosis that causes pain, loss of function, and femoral head collapse. Here, we analyzed samples of femoral heads excised from patients with ONFH to clarify the relationship between ischemic osteonecrosis and cellular senescence. X-gal staining was strong and p16INK4a-positive cells were abundant in the transitional region of ONFH. The β-galactosidase-positive cells in the transitional region were also positive for nestin, periostin, or DMP-1. In contrast, no β-galactosidase-positive cells were detected in the healthy region. The senescence-associated p16INK4a, p21, and p53 were upregulated in ONFH tissue. We also examined and analyzed a mouse ischemic femoral osteonecrosis model in vivo to verify the association between ONFH and cellular senescence. Human mesenchymal stem cell-conditioned medium (MSC-CM) was administered to determine its therapeutic efficacy against cellular senescence and bone collapse. MSC-CM reduced the number of senescent cells and downregulated the aforementioned senescence-related genes. It also decreased the number of empty lacunae 4 weeks after ischemia induction and promoted bone formation. At 6 weeks post-surgery, MSC-CM increased the trabecular bone volume, thereby suppressing bone collapse. We conclude that cellular senescence is associated with ONFH and that MSC-CM suppresses bone collapse in this disorder.

Extension of the Antero-Posterior Necrotic Regions Associated With Collapse Cessation in Osteonecrosis of the Femoral Head

BACKGROUND

Collapse cessation is of utmost importance following a long period of collapse due to osteonecrosis of the femoral head (ONFH). This study investigated the relationship between collapse cessation and the extent of the necrotic regions of ONFH.

METHODS

Overall, 74 patients who had symptomatic ONFH (collapse < 3 mm) at the first visit with a minimum follow-up of 3 years were included in this study. Patients were categorized based on collapse progression or cessation into the progression and stable groups. The extent of the antero-posterior (AP) and medio-lateral necrotic regions between the groups was assessed using sagittal and coronal sections of T1-magnetic resonance imaging. Additionally, the most effective cutoff value was determined from the receiving operating characteristic curve where collapse cessation could be obtained, while the survival rates were determined with collapse progression as the endpoints were evaluated.

RESULTS

Overall, 45 and 29 patients were in the progression and stable groups, respectively. The AP and medio-lateral necrotic regions were significantly different (P < .01 and P < .01, respectively) between the progression and stable groups. A cutoff value of 62.1% of the AP necrotic regions was determined from the receiving operating characteristic curve analysis. The 5-year survival rates with collapse progression as the endpoints were 5.4 and 77.8% in the AP necrotic regions of ≥62.1 and <62.1%, respectively (P < .01).

CONCLUSIONS

Cases with AP necrotic regions of ≤62.1% can be expected to have collapse cessation, which could be a useful index for ONFH treatment strategies.

LEVEL OF EVIDENCE

Level IV.

Risk factors for intraoperative femoral fractures in cementless bipolar hip arthroplasty for femoral neck fracture in multicenter: The TRON group study

BACKGROUND

Intraoperative femoral fractures are more common in cementless bipolar hip arthroplasty (BHA) for displaced femoral neck fractures than they are in cemented BHA and remain one of the major concerns. This study aimed to investigate the risk factors for intraoperative femoral fractures in cementless BHA.

METHODS

The study included 1,392 patients who underwent cementless BHA for displaced femoral neck fractures from January 2015 to December 2019 in 14 hospitals of the Trauma Research Group. They were divided into two groups according to the presence or absence of intraoperative femoral fractures, and factors associated with intraoperative fractures were statistically examined.

RESULTS

Forty (2.9 %) intraoperative and 28 (2.0 %) postoperative, totally 68 (4.9 %) femoral fractures occurred. The mean age of the patients, presence of opposite-side proximal femoral fracture, approach, and cementless stem design were significantly different between the two groups (P < 0.05). The logistic regression analysis model showed that a fully HA-coated stem (odds ratio, 4.12; 95 % confidence interval, 1.43-11.9) was an independent factor associated with intraoperative femoral fractures.

CONCLUSION

This study investigated the risk factors associated with intraoperative fractures and showed that fully HA-coated stems were an independent factor associated with intraoperative femoral fractures. Surgeons should be cautious in the early stages of introducing fully HA-coated stems.

Fall risk in patient with dysplastic hip osteoarthritis

PURPOSE

Patients with dysplastic hip osteo arthritis (DHOA) often have a spinopelvic imbalance, and they are more likely to experience falls. This study aimed to evaluate the risk factors for falls in patients with DHOA, including spinopelvic parameters.

METHODS

In this cross-sectional study, a total of 103 patients with DHOA were included from 2019 to 2021. Fall risk was evaluated using the Fall Risk Index 5 items version (FRI-5). Demographics, functional outcomes, and spinopelvic parameters were compared between the high-risk group (FRI-5 ≥ 6) and the low-risk group (FRI-5 < 6). Multivariate analysis was performed using factors with significant differences in univariate analysis.

RESULTS

High-risk and low-risk groups comprised 54 and 49 patients, respectively. Females were significantly more common in the high-risk group than in the low-risk group. The Harris Hip Score was significantly lower in the high-risk group than in the low-risk group (p = 0.02). Pelvic incidence, tilt, and obliquity were significantly higher in the high-risk group than in the low-risk group (p < 0.01). In multivariate analysis, female sex (odds ratio [OR]: 3.76, 95% confidence interval [CI]: 1.11-12.64, p = 0.03), pelvic obliquity (OR: 1.36, 95% CI: 1.09-1.71, p < 0.01), and Harris hip score (OR: 0.96, 95% CI: 0.93-0.99, p = 0.02) were identified as risk factors.

CONCLUSION

Female sex, pelvic obliquity, and low Harris hip score were associated with an increased risk of falls among patients with DHOA.

The 33rd International Conference on Arabidopsis Research (ICAR2023)

The 33rd International Conference on Arabidopsis Research (ICAR2023) was held at Makuhari Messe International Conference Hall in Chiba prefecture from June 5 to 9, 2023. This annual conference, which rotates among hosts in North America, Asia-Oceania, and Europe, covers the full range of plant biology research involving Arabidopsis and other plant species. The conference hosted more than 1200 participants, including approximately 800 international attendees from 42 countries (or regions), and featured about 900 oral and poster presentations. Reflecting the conference theme, "Arabidopsis for Sustainable Development Goals (SDGs)," there were numerous exemplary presentations regarding basic plant science using Arabidopsis and translational research conducted to achieve SDGs by exploiting the knowledge gained from Arabidopsis to improve crop production. The conference concluded on a high note, with more than 99% of survey respondents expressing their general satisfaction with ICAR2023. This report aims to summarize the organization, objectives, and outcomes of the conference.

Does re-ossification after palliative radiotherapy for spinal bone metastases help maintain vertebral body height?

BACKGROUND CONTEXT

After palliative radiotherapy of spinal bone metastases, re-ossification is sometimes observed in bone with osteolytic changes. However, it remains unknown whether the re-ossification that is observed after radiotherapy is associated with preservation of vertebral body height.

PURPOSE

To investigate whether re-ossification observed after palliative radiotherapy can contribute to the preservation of vertebral body height.

STUDY DESIGN

This is a retrospective observational study.

PATIENTS SAMPLE

We investigated 111 vertebral bodies in 54 patients that underwent palliative radiotherapy at a single center for painful osteolytic/mixed metastatic spinal tumors in solid tumors between 2016 and 2020.

OUTCOME MEASURES

The outcome measures were the presence of re-ossification and vertebral body height reduction on the CT image.

METHODS

Re-ossification was evaluated according to the MD Anderson response classification criteria, and sagittal CT images were used to evaluate vertebral body height. A vertebral body ID was assigned to the irradiated vertebral body, and continuous CT images obtained for each vertebral body ID were evaluated. The median number of evaluation periods for each vertebral body was 4, and the total number of periods was 463. Logistic regression analysis was performed to investigate factors related to the occurrence of vertebral body height reduction before the subsequent CT. As a subanalysis, factors related to re-ossification were investigated.

RESULTS

The following primary cancer types were observed: lung cancer, 41 vertebral bodies; breast cancer, 19; renal cell cancer, 15; other, 36. A total of 62.2% showed re-ossification. The median time to confirmation of re-ossification by CT was 2 months. Factors significantly associated with vertebral body height reduction were presence of vertebral body height reduction before radiotherapy (odds ratio [OR] 6.8, 95% confidence interval [CI] 2.0-63, p=.01) and no re-ossification (OR 137, 95% CI 22-3469, p<.01). Factors associated with re-ossification were the type of cancer and total radiation dose. Those with lung cancer and those with a total radiation dose of 20 Gy or less were more prone to re-ossification.

CONCLUSIONS

Re-ossification was observed in 62.2% of vertebral bodies after palliative radiotherapy for painful osteolytic/mixed metastatic spinal tumors. The re-ossification group demonstrated significantly less vertebral body height reduction when compared with the non-re-ossification group. The presence of re-ossification may potentially serve an important role in maintaining vertebral body height.

Addressing osteoporosis treatment after hemiarthroplasty for a femoral neck fracture: impact on survival rates after a subsequent periprosthetic femoral fracture - a multicenter (TRON group) retrospective study

This study investigated the impact of osteoporosis treatment on the prognosis of patients with periprosthetic femoral fracture (PPF) following femoral neck fracture (FNF). Our results suggested an association between osteoporosis treatment and potentially improved survival prognosis in patients who underwent surgery for PPF. These results imply that osteoporosis treatment may have a beneficial effect on patient outcomes.

PURPOSE

This study aimed to investigate the effect of osteoporosis treatment on the prognosis of periprosthetic femoral fracture (PPF) patients after femoral neck fracture.

METHODS

A multicenter retrospective study named as TRON was conducted. The study population included 156 PPF patients who had undergone hemiarthroplasty for femoral neck fracture between January 2010 and December 2019. Patients were divided based on whether they had received osteoporosis treatment before PPF injury. A log-rank test was used to compare survival rates. We conducted a Cox proportional hazards analysis to identify factors associated with the survival rate after PFF injury.

RESULTS

Twenty-seven of the 156 patients had received osteoporosis treatment prior to PPF injury. The 1-year and 2-year overall survival rates after PPF were 80.9% and 75.3%, respectively. The log-rank test revealed that the 1-year survival rate with and without osteoporosis treatment was 89.5% and 78.1%, respectively (P=0.012). In the Cox proportional hazards analysis, age, BMI, presence or absence of surgery, and presence or absence of osteoporosis treatment showed independent associations with the survival rate after PFF injury. The hazard ratio for the presence of osteoporosis treatment was 0.22 (95% confidence interval 0.07-0.75, P=0.015).

CONCLUSION

The findings of this study suggest an association between osteoporosis treatment and potentially improved survival prognosis in patients who underwent surgery for PPF. These results imply that osteoporosis treatment may have a beneficial effect on patient outcomes. It is important to consider that osteoporosis treatment could be significant not only in preventing secondary fractures but also in potentially improving prognosis in the rare event of PPF.

Metabolic and transcriptomic profiling during wheat seed development under progressive drought conditions

Globally, bread wheat (Triticum aestivum) is one of the most important staple foods; when exposed to drought, wheat yields decline. Although much research has been performed to generate higher yield wheat cultivars, there have been few studies on improving end-product quality under drought stress, even though wheat is processed into flour to produce so many foods, such as bread, noodles, pancakes, cakes, and cookies. Recently, wheat cultivation has been affected by severe drought caused by global climate change. In previous studies, seed shrinkage was observed in wheat exposed to continuous drought stress during seed development. In this study, we investigated how progressive drought stress affected seed development by metabolomic and transcriptomic analyses. Metabolite profiling revealed the drought-sensitive line reduced accumulation of proline and sugar compared with the water-saving, drought-tolerant transgenic line overexpressing the abscisic acid receptor TaPYL4 under drought conditions in spikelets with developing seeds. Meanwhile, the expressions of genes involved in translation, starch biosynthesis, and proline and arginine biosynthesis was downregulated in the drought-sensitive line. These findings suggest that seed shrinkage, exemplifying a deficiency in endosperm, arose from the hindered biosynthesis of crucial components including seed storage proteins, starch, amino acids, and sugars, ultimately leading to their inadequate accumulation within spikelets. Water-saving drought tolerant traits of wheat would aid in supporting seed formation under drought conditions.

A fungal sesquiterpene biosynthesis gene cluster critical for mutualist-pathogen transition in Colletotrichum tofieldiae

Plant-associated fungi show diverse lifestyles from pathogenic to mutualistic to the host; however, the principles and mechanisms through which they shift the lifestyles require elucidation. The root fungus Colletotrichum tofieldiae (Ct) promotes Arabidopsis thaliana growth under phosphate limiting conditions. Here we describe a Ct strain, designated Ct3, that severely inhibits plant growth. Ct3 pathogenesis occurs through activation of host abscisic acid pathways via a fungal secondary metabolism gene cluster related to the biosynthesis of sesquiterpene metabolites, including botrydial. Cluster activation during root infection suppresses host nutrient uptake-related genes and changes mineral contents, suggesting a role in manipulating host nutrition state. Conversely, disruption or environmental suppression of the cluster renders Ct3 beneficial for plant growth, in a manner dependent on host phosphate starvation response regulators. Our findings indicate that a fungal metabolism cluster provides a means by which infectious fungi modulate lifestyles along the parasitic-mutualistic continuum in fluctuating environments.

DIENELACTONE HYDROLASE LIKE PROTEIN1 negatively regulates the KAI2-ligand pathway in Marchantia polymorpha

Karrikins are smoke-derived butenolides that induce seed germination and photomorphogenesis in a wide range of plants.1,2,3 KARRIKIN INSENSITIVE2 (KAI2), a paralog of a strigolactone receptor, perceives karrikins or their metabolized products in Arabidopsis thaliana.4,5,6,7 Furthermore, KAI2 is thought to perceive an unidentified plant hormone, called KAI2 ligand (KL).8,9 KL signal is transduced via the interaction between KAI2, MORE AXILLARY GROWTH2 (MAX2), and SUPPRESSOR of MORE AXILLARY GROWTH2 1 LIKE family proteins (SMXLs), followed by the degradation of SMXLs.4,7,10,11,12,13,14 This signaling pathway is conserved both in A. thaliana and the bryophyte Marchantia polymorpha.14 Although the KL signaling pathway is well characterized, the KL metabolism pathways remain poorly understood. Here, we show that DIENELACTONE HYDROLASE LIKE PROTEIN1 (DLP1) is a negative regulator of the KL pathway in M. polymorpha. The KL signal induces DLP1 expression. DLP1 overexpression lines phenocopied the Mpkai2a and Mpmax2 mutants, while dlp1 mutants phenocopied the Mpsmxl mutants. Mutations in the KL signaling genes largely suppressed these phenotypes, indicating that DLP1 acts upstream of the KL signaling pathway, although DLP1 also has KL pathway-independent functions. DLP1 exhibited enzymatic activity toward a potential substrate, suggesting the possibility that DLP1 works through KL inactivation. Investigation of DLP1 homologs in A. thaliana revealed that they do not play a major role in the KL pathway, suggesting different mechanisms for the KL signal regulation. Our findings provide new insights into the regulation of the KL signal in M. polymorpha and the evolution of the KL pathway in land plants.

Risk factors for lateralization or superiorization of the center of the femoral head in eccentric rotational acetabular osteotomy

PURPOSE

This study aimed to clarify the factors that cause the lateralization and superiorization of the femoral head after eccentric rotational acetabular osteotomy (ERAO) by examining the three-dimensional morphology of the osteotomy site using computed tomography (CT).

METHODS

This study included 52 patients who underwent ERAO for hip dysplasia. Postoperatively, the center of the femoral head was measured for lateralization and superiorization. We defined the iliac and sciatic osteotomy angles in the coronal and axial CT planes, respectively. The surgical factors for lateralization and superiorization were analysed using multiple logistic regression analysis. We also analysed the relationship between the femoral head relocation and clinical outcomes (as assessed using Japanese Orthopaedic Association (JOA) scores).

RESULTS

Thirty-five patients had hips with lateralized femoral heads, and 25 patients' femoral heads were superiorized. Logistic regression analysis revealed that a higher osteotomy angle of the ilium in the coronal plane served as a significant predictor of superiorization of the femoral head. Similarly, a larger osteotomy angle of the ischium in the axial plane and the amount of change in the lateral centre edge angle were identified as predictors of lateralization. A weak negative correlation was observed between the amount of lateralization and the JOA score.

CONCLUSION

Large osteotomy angles in the superior and posterior aspects of the acetabulum carry a risk of superiorization and lateralization of the center of the femoral head. Surgeons should be aware of the need to chisel through the internal plate to achieve the results described in the ERAO theory.

STUDY DESIGN

A single-center, retrospective study.

Muscle strength and functional recovery for soft-tissue sarcoma of the thigh: a prospective study

BACKGROUND

This study aimed to investigate changes in muscle strength and functional outcome before and after surgery for soft-tissue sarcoma of the thigh and to examine the timing of recovery.

METHODS

From 2014 to 2019, 15 patients who underwent multiple resections of the thigh muscle for soft-tissue sarcoma of the thigh were included in this study. The muscle strength was measured with an isokinetic dynamometer for the knee joint and with a hand-held dynamometer for the hip joint. The functional outcome assessment was based on the Musculoskeletal Tumor Society (MSTS) score, Toronto Extremity Salvage Score (TESS), European Quality of Life-5 Dimensions (EQ-5D), and maximum walking speed (MWS). All measurements were conducted preoperatively and at 3, 6, 12, 18, and 24 months postoperatively, and the ratio of postoperative to preoperative value was used. A repeated-measures analysis of variance was performed to compare changes over time and to investigate the recovery plateau. Correlations between changes in muscle strength and functional outcomes were also examined.

RESULTS

The muscle strength of the affected limb, MSTS score, TESS, EQ-5D, and MWS were significantly decreased at 3 months postoperatively. The recovery plateau was subsequently reached at 12 months postoperatively. The changes in muscle strength of the affected limb and functional outcome showed a significant correlation.

CONCLUSIONS

The estimated postoperative recovery for soft-tissue sarcoma of the thigh is 12 months after surgery.

Clinical Outcome of Low-Grade Myofibroblastic Sarcoma in Japan: A Multicenter Study from the Japanese Musculoskeletal Oncology Group

This retrospective multicenter study aimed to analyze the clinical features and prognosis of 24 patients diagnosed with LGMS between 2002 and 2019 in the Japanese sarcoma network. Twenty-two cases were surgically treated and two cases were treated with radical radiotherapy (RT). The pathological margin was R0 in 14 cases, R1 in 7 cases, and R2 in 1 case. The best overall response in the two patients who underwent radical RT was one complete response and one partial response. Local relapse occurred in 20.8% of patients. Local relapse-free survival (LRFS) was 91.3% at 2 years and 75.4% at 5 years. In univariate analysis, tumors of 5 cm or more were significantly more likely to cause local relapse (p < 0.01). In terms of the treatment of relapsed tumors, surgery was performed in two cases and radical RT was performed in three cases. None of the patients experienced a second local relapse. Disease-specific survival was 100% at 5 years. A wide excision aimed at the microscopically R0 margin is considered the standard treatment for LGMS. However, RT may be a viable option in unresectable cases or in cases where surgery is expected to cause significant functional impairment.

The usefulness of immunohistochemistry for phosphohistone H3 as a prognostic factor in myxoid liposarcoma

Myxoid liposarcoma (MLS) is a common subtype of liposarcoma. Although the prognosis is generally good, there are factors known to be associated with poor prognosis. Accurate indices are important to predict prognosis. We aimed to assess the usefulness of immunohistochemistry for phosphohistone H3 (PHH3) as a potential biomarker in comparison with Ki-67 antigen and other prognostic factors. Twenty-five patients with MLS were evaluated. Age, sex, depth of tumor, tumor size, surgical margin, oncological outcome, histological grade, presence of necrosis, proportion of round cell component (RC%), PHH3 index, and Ki-67 index were examined. Prognostic factors of the examination criteria were statistically analyzed, survival rate analyses were performed using the Kaplan-Meier method, and multivariate analysis was performed using Cox proportional-hazard regression analysis. The number of PHH3-positive tumor cells and the PHH3 and Ki-67 indices demonstrated a statistical correlation with the prognosis of MLS in univariate analysis (P < 0.001, P < 0.001, P = 0.01, respectively). PHH3 index and RC% were significant factors in multivariate analysis (P = 0.03, P = 0.02). The immunohistochemistry of PHH3 may be associated with prognosis and could serve as a valid criterion of histological grade in MLS.

Development of Rat Caries-Induced Pulpitis Model for Vital Pulp Therapy

Rodent animal models for vital pulp therapy are commonly used in dental research because their tooth anatomy and cellular processes are similar to the anatomy and processes in humans. However, most studies have been conducted using uninfected sound teeth, which makes it difficult to adequately assess the inflammatory shift after vital pulp therapy. In the present study, we aimed to establish a caries-induced pulpitis model based on the conventional rat caries model and then evaluate inflammatory changes during the wound-healing process after pulp capping in a model of reversible pulpitis induced by carious infection. To establish the caries-induced pulpitis model, the pulpal inflammatory status was investigated at different stages of caries progression by immunostaining targeted to specific inflammatory biomarkers. Immunohistochemical staining revealed that both Toll-like receptor 2 and proliferating cell nuclear antigen were expressed in moderate and severe caries-stimulated pulp, indicating that an immune reaction occurred at both stages of caries progression. M2 macrophages were predominant in moderate caries-stimulated pulp, whereas M1 macrophages were predominant in the severe caries-stimulated pulp. Pulp capping in teeth with moderate caries (i.e., teeth with reversible pulpitis) led to complete tertiary dentin formation within 28 d after treatment. Impaired wound healing was observed in teeth with severe caries (i.e., teeth with irreversible pulpitis). During the wound-healing process in reversible pulpitis after pulp capping, M2 macrophages were predominant at all time points; their proliferative capacity was upregulated in the early stage of wound healing compared with healthy pulp. In conclusion, we successfully established a caries-induced pulpitis model for studies of vital pulp therapy. M2 macrophages have an important role in the early stages of the wound-healing process in reversible pulpitis.

Novel Functional Peptide for Next-Generation Vital Pulp Therapy

Although vital pulp therapy should be performed by promoting the wound-healing capacity of dental pulp, existing pulp-capping materials were not developed with a focus on the pulpal repair process. In previous investigations of wound healing in dental pulp, we found that organic dentin matrix components (DMCs) were degraded by matrix metalloproteinase-20, and DMC degradation products containing protein S100A7 (S100A7) and protein S100A8 (S100A8) promoted the pulpal wound-healing process. However, the direct use of recombinant proteins as pulp-capping materials may cause clinical problems or lead to high medical costs. Thus, we hypothesized that functional peptides derived from recombinant proteins could solve the problems associated with direct use of such proteins. In this study, we identified functional peptides derived from the protein S100 family and investigated their effects on dental pulp tissue. We first performed amino acid sequence alignments of protein S100 family members from several mammalian sources, then identified candidate peptides. Next, we used a peptide array method that involved human dental pulp stem cells (hDPSCs) to evaluate the mineralization-inducing ability of each peptide. Our results supported the selection of 4 candidate functional peptides derived from proteins S100A8 and S100A9. Direct pulp-capping experiments in a rat model demonstrated that 1 S100A8-derived peptide induced greater tertiary dentin formation compared with the other peptides. To investigate the mechanism underlying this induction effect, we performed liquid chromatography-tandem mass spectrometry analysis using hDPSCs and the S100A8-derived peptide; the results suggested that this peptide promotes tertiary dentin formation by inhibiting inflammatory responses. In addition, this peptide was located in a hairpin region on the surface of S100A8 and could function by direct interaction with other molecules. In summary, this study demonstrated that a S100A8-derived functional peptide promoted wound healing in dental pulp; our findings provide insights for the development of next-generation biological vital pulp therapies.

Hip function in patients undergoing conservative treatment for osteonecrosis of the femoral head

PURPOSE

Once collapsed, osteonecrosis of the femoral head (ONFH) generally obtains collapse cessation naturally and surgical intervention can be avoided in the long term. This study aimed to investigate the process of hip function and secondary osteoarthritis changes in ONFH patients undergoing conservative treatment.

METHODS

We included 54 patients with symptomatic ONFH at the first visit with a minimum follow-up of three years with conservative treatment. Patients were divided into two groups based on collapse cessation < 3 mm (stable group) or progression to > 3 mm (progression group). Additionally, we investigated age, sex, body mass index (BMI), etiology, contralateral side hip joint, the Japanese Investigation Committee (JIC) type classification, Harris hip score (HHS), Japanese Orthopaedic Association Hip-Disease Evaluation Questionnaire (JHEQ), and survival rate with secondary osteoarthritis as the endpoint.

RESULTS

The stable and progression groups had 31 and 23 patients, respectively. No significant differences in age, sex, BMI, and aetiology were observed between the two groups, except for the contralateral side hip joint and JIC type classification. The HHS and JHEQ were significantly improved at the final follow-up than at the first visit in the stable group. However, there were no significant differences in HHS and JHEQ at the final follow-up than at the first visit in the progression group. The five year survival rates with secondary osteoarthritis as the endpoint were significantly higher in the stable group (100%) than in the progression group (32.5%).

CONCLUSION

Hip joint function improved by continuing conservative treatment in ONFH patients with collapse cessation < 3 mm.

Differences in peri-hip articular pain after total hip arthroplasty between taper wedge stem and fit-and-fill stem

Background

Total hip arthroplasty (THA) for hip disorders helps to alleviate pain and improve active daily life. When determining the effects of medical therapy and the subsequent clinical results, patient quality of life (QOL) also needs to be assessed. Recently, patient-reported outcomes (PRO) have become important as evaluation criteria. This study aimed to evaluate patient QOL and various PRO between different types of cementless stems and to clarify the relationship between PRO and stem-cortical bone contact.

Methods

The study comprised 138 consecutive patients undergoing cementless THA for hip osteoarthritis. We assessed three different types of PRO: the Japanese Orthopaedic Association Hip-Disease Evaluation Questionnaire (JHEQ), patient's joint perception, and peri-hip articular joint pain (PHAP). We measured the state of contact between femur and implant by density mapping.

Results

No significant difference was noted in PRO between stem types based on the JHEQ and patient's joint perception. PHAP occurred more frequently in the patients with a taper wedge stem versus a fit-and-fill stem. In both groups, distal contact was associated with PHAP but not with JHEQ results and patient's joint perception.

Conclusion

The difference in PHAP between the two stem types groups was significant, with postoperative PHAP being higher with the taper wedge stem because of the more distal contact between the taper wedge stem and femur cortical bone.

Effect of trochanter displacement on impingement and bone contact in total hip arthroplasty performed after curved intertrochanteric varus osteotomy for osteonecrosis of the femoral head: a simulation study

Background

Curved intertrochanteric varus osteotomy (CVO) is a useful treatment option for osteonecrosis of the femoral head (ONFH). However, the effect of proximal femoral deformity in cases of CVO converted to total hip arthroplasty (THA) remains unclear. The aim of this study was to evaluate the effect of trochanter displacement on impingement and the contact state of the implant and femur in THA.

Methods

Thirty-eight hips that had undergone CVO for ONFH were reviewed and compared with a control group of 30 contralateral hips that had not undergone surgery. The range of motion (ROM) and impingement patterns and the percentage of cortical bone in the stem placement within the femur were measured by simulation using CT-based three-dimensional template software. We also measured the ROM and the number of joints that achieved the ROM required for activities of daily living when the upward displaced apex of the greater trochanter with osteotomy was resected and compared the findings with those obtained when the apex was not resected.

Results

The CVO group showed a significantly greater bony impingement in external rotation (68.4% vs. 43.3%, p = 0.033) and abduction (78.9% vs. 33.3%, p < 0.001) than in the control group. The CVO group showed a significantly smaller range of external rotation (19.0° [interquartile range; 4.0–28.8] vs. 38.0° [interquartile range; 36.0–41.8], p < 0.001) and abduction (23.0° [interquartile range; 8.5–38.8] vs. 56.0° [interquartile range; 50.3–60.0], p < 0.001) than in the control group. Significantly more joints achieved the ROM necessary for activities of daily living when the apex was resected than when it was not (10.5% vs. 63.2%, p < 0.001). The percentage of cortical bone in the stem placement position was significantly higher in the CVO group than in the control group in the proximal portion of the stem (25.5% vs. 0.0%, p < 0.001).

Conclusion

In cases requiring conversion to THA, we recommend resecting the upward displaced apex to achieve a sufficient ROM and carefully resecting the bone to avoid malignment of the stem.

Viscoplastic Material Modeling for the Stretch Blow Molding Simulation

In this paper, the viscoplastic material model of PET (polyethylene terephthalate), which is intended to be used in the FEM (finite element method) simulation of stretch blow molding process, has been studied. Material tests of PET were performed with the constant strain rates varying from 0.01 to 1 (1/s), at temperatures ranging from 90 to 150 °C, based on the obtained data a two-stage model was proposed. The proposed model could precisely take into account the effects of strain hardening, strain rate sensitivity, variation of the hardening index, and temperature dependency. This model has been implemented into the nonlinear finite element code PBLOW3D, which is developed in the Riken, and its performance in the stretch blow molding simulation has been studied. It has been demonstrated that the proposed material model provides significant improvements, compared with two existing material models, in the simulation of the blow molding process of PET bottles.

Arrhythmogenic right ventricular cardiomyopathy patients with a markedly enlarged RV compressing LV to left side have an atypical distribution of epsilon waves and elevated plasma BNP

Funding Acknowledgements

Type of funding sources: None.

Background

Epsilon waves on V1-3 leads are specific ECG findings in patients with arrhythmogenic right ventricular (RV) cardiomyopathy (ARVC) suggesting RV conduction delay. Four dimensional (4D) cardiac CT visualizes ARVC characteristics, such as fibro-fatty invasion into RV and left ventricular (LV) myocardium (RVM, LVM), an enlarged RV, reduced RV motion, and bulging.

Purpose

We hypothesize that Epsilon waves in V4-6 leads suggest LV invasion in ARVC. Alternatively, extreme RV enlargement may compress the LV and cause clockwise rotation; an enlarged RV may itself cause epsilon waves in V4-6 leads.

Methods

Retrospective analysis of 17 patients (11 males, 57 ± 17 yrs) with suspected ARVC undergoing cardiac CT and ECG, 9 of whom met 2010 ARVC task force criteria.

Results

All 9 patients had epsilon waves on ECG; 5 had fibro-fatty invasion into the LVM. We divided the 9 into 5 groups by CT: 1) markedly enlarged RV compressing the LV to the left side with fibro-fatty changes exclusively in RVM (N = 1); 2) similar findings in both RVM and LVM (N = 2); 3) moderately enlarged RV without compression of the LV to the left side and fibro-fatty changes exclusively in RVM (N = 3); 4) the same in both RVM and LVM (N = 2); 5) severe mitral valve regurgitation, a markedly enlarged LV, and a fibro-fatty change in both RVM and LVM (N = 1). The patient in group (gp) 1 showed epsilon waves in V1-6 leads, patients in gp 2 had epsilon waves in V1-6 (N = 1), and V3-5 (N = 1) leads; patients in gp 3 had epsilon waves in V1-4 (N = 2), and V1-3 (N = 1) leads, patients in gp 4 had epsilon waves in V1-3 (N = 1), and V1, 2 (N = 1) leads; finally, the patient in gp 5 had epsilon waves in V4-6 leads. Plasma brain natriuretic peptide (BNP) levels were significantly greater in patients in gp 1 & 2 than gp 3 & 4 (1255 ± 838 vs 80 ± 52 pg/ml, P = 0.016).

Conclusions

ARVC patients with a markedly enlarged RV compressing the LV to the left side (gp 1,2) had a broad (V1-6) or different range (V3-5) distribution of epsilon waves and significantly elevated plasma BNP independent of fibro-fatty invasion of the LV, different from typical ARVC (gp 3,4). Additionally, structural change due to complicated heart disease, such as valvular disease (gp5), may also influence the distribution of epsilon waves in ARVC. Abstract Figure. CT and ECG in ARVC group 1

Influence of the adductor compartment resection on muscle strength and postoperative function in soft-tissue sarcoma of the thigh

OBJECTIVE

To predict the muscle strength and postoperative function for soft-tissue sarcoma arising from the adductor compartment of the thigh.

METHODS

Between 2003 and 2019, 17 cases that underwent resection of the adductor muscle group (adductor longus, adductor magnus, adductor brevis, gracilis and pectineus) for soft-tissue sarcoma in the adductor compartment of the thigh were included. The muscle strength was measured with an isokinetic dynamometer for the knee joint and with a hand-held dynamometer for the hip joint (ratio of affected to unaffected side). The Musculoskeletal Tumor Society score, Toronto Extremity Salvage Score, European Quality of Life-5 Dimensions and maximum walking speed were used to assess postoperative function and examine correlations with muscle strength.

RESULTS

In 13 cases that underwent an isolated resection of the adductor compartment, reduced adduction strength correlated with increased number of resected muscles in the adductor muscle group (P < 0.001). Postoperative function was maintained, showing no correlations with adduction strength. In four cases that underwent combined resections of other compartments, a decrease was observed in adduction strength as well as the muscle strength of other resected muscles, in addition to a decline in postoperative function. In the 4 or 5 adductor muscle resection group, the comparison between isolated and combined resection revealed comparable results for adduction strength but a significant decrease in postoperative function for the combined resection group.

CONCLUSIONS

Postoperative function can be preserved for isolated adductor compartment resection. Combined resections of multiple muscles in other compartments and most adductor muscles may result in decreased postoperative function.

Genomic prediction modeling of soybean biomass using UAV-based remote sensing and longitudinal model parameters

The application of remote sensing in plant breeding can provide rich information about the growth processes of plants, which leads to better understanding concerning crop yield. It has been shown that traits measured by remote sensing were also beneficial for genomic prediction (GP) because the inclusion of remote sensing data in multitrait models improved prediction accuracies of target traits. However, the present multitrait GP model cannot incorporate high-dimensional remote sensing data due to the difficulty in the estimation of a covariance matrix among the traits, which leads to failure in improving its prediction accuracy. In this study, we focused on growth models to express growth patterns using remote sensing data with a few parameters and investigated whether a multitrait GP model using these parameters could derive better prediction accuracy of soybean [Glycine max (L.) Merr.] biomass. A total of 198 genotypes of soybean germplasm were cultivated in experimental fields, and longitudinal changes of their canopy height and area were measured continuously via remote sensing with an unmanned aerial vehicle. Growth parameters were estimated by applying simple growth models and incorporated into the GP of biomass. By evaluating heritability and correlation, we showed that the estimated growth parameters appropriately represented the observed growth curves. Also, the use of these growth parameters in the multitrait GP model contributed to successful biomass prediction. We conclude that the growth models could describe the genetic variation of soybean growth curves based on several growth parameters. These dimension-reduction growth models will be indispensable for extracting useful information from remote sensing data and using this data in GP and plant breeding.

Ultrasound efficacy of targeted-synthetic disease-modifying anti-rheumatic drug treatment in rheumatoid arthritis: a multicenter prospective cohort study in Japan

OBJECTIVE

This study investigated the effectiveness of treatment with Janus kinase (JAK) inhibitors in rheumatoid arthritis (RA) assessed by ultrasonography (US) activity, and the influence of patient characteristics and previous treatments.

METHOD

This prospective study assessed 60 treatment initiations among 53 Japanese patients diagnosed with RA who underwent treatment with JAK inhibitors during June 2013 to February 2020. Of the 53 patients, seven patients were enrolled in duplicate because they were treated with two different JAK inhibitors at different periods. For each case, the improvement rate on the power Doppler (PD) score was assessed at 6 month follow-up. Median improvement rate of PD score was used to classify cases as either US responders or non-responders, and patient characteristics were compared between the two groups.

RESULTS

All indicators of clinical disease activity and US activity showed a significant improvement at 3 months compared with baseline. Although the JAK inhibitor-cycler group and the interleukin-6 (IL-6) inhibitor inadequate response (IR) group tended to show a later improvement for US activity, all indicators of clinical disease activity and US activity showed a significant improvement at 6 months compared with baseline for both groups. Multivariate analysis showed that concomitant methotrexate use and an IR to the previous biologic or targeted-synthetic disease-modifying anti-rheumatic drug (b/tsDMARD) treatment were independently and significantly associated with US responders.

CONCLUSION

Use of a JAK inhibitor in combination with methotrexate and an absence of IR to any previous b/tsDMARDs demonstrated superior effectiveness for patients with RA.

Comparison of accuracy of cup position using portable navigation versus alignment guide in total hip arthroplasty in supine position

BACKGROUND

Accelerometer-based portable navigation systems in supine total hip arthroplasty (THA) have been developed, but there are no reports on the accuracy of cup placement. We aimed to investigate and compare the accuracy of the accelerometer-based portable navigation system versus the acetabular alignment guide placed on the pelvis in THA using the direct anterior approach (DAA). Both devices tracked changes in the pelvic position.

METHODS

In this single-centre, retrospective study, we reviewed 115 hips in 113 patients who underwent primary THA via the DAA using an accelerometer-based portable navigation system in the supine position (portable navigation group) and 106 hips in 101 patients who underwent THA using an acetabular alignment guide (alignment guide group) as controls. Hips were evaluated postoperatively using computed tomography to measure cup orientation. The accuracy of cup orientation was compared between the 2 groups.

RESULTS

Absolute values of inclination error were 3.1° ± 2.2° and 2.9° ± 2.3° (p = 0.708) in the portable navigation and alignment guide groups and those of anteversion error were 2.8° ± 2.3° and 3.7° ± 2.7°, respectively (p = 0.005). The number of cups placed within 10° of error was 98.3% and 96.2% in the portable navigation and alignment guide groups, respectively (p = 0.304). The portable navigation group had significantly more hips (72.2%) placed within a 5° margin of error than did the alignment guide group (56.6%) (p = 0.016).

CONCLUSION

High accuracy in cup placement was achieved using accelerometer-based portable navigation in supine THA. Using a navigation system may contribute to improved long-term outcomes.

Impact of Smoking History on Pulmonary Metastasis-free Survival in Patients With Soft-tissue Sarcoma

Background/Aim

Although smoking history is predictive of poor pulmonary metastasis-free survival (PMFS) in patients with epithelial tumors, the impact of smoking history on PMFS in those with soft-tissue sarcoma (STS) is not known.

Patients and Methods

Patients undergoing treatment for STS at our institutes between 2008 and 2017 were enrolled. Patients were excluded if they had metastatic lesion, or had a histopathological classification demonstrating small round-cell sarcoma. The impact of smoking history on PMFS and overall survival was examined with multivariate analysis using a Cox proportional hazards model.

Results

A total of 250 patients were retrospectively reviewed. Patients with smoking history had worse PMFS on multivariate analysis (hazard ratio=2.00, 95% confidence interval=1.12-3.60). On the other hand, smoking history did not significantly affect overall survival (hazard ratio=1.26, 95% confidence interval=0.61-2.58).

Conclusion

Patients with STS need to be followed-up by frequent clinical assessments if they have a smoking history.

Discrepancy between clinical and ultrasound remissions in rheumatoid arthritis: a multicentre ultrasound cohort study in Japan

Objectives: Using multicentre ultrasound (US) cohort data among patients with rheumatoid arthritis (RA), we aimed to identify baseline factors that permit differentiation between two patient cohorts achieving US remission and clinical remission, and to determine the factors contributing to the discrepancy.Method: We reviewed 248 Japanese patients diagnosed with RA who underwent treatment with biological disease-modifying anti-rheumatic drugs at 13 centres. We performed US assessments of the synovia of 22 joints. We assessed the percentages of patients with clinical remission and US remission, defined as total power Doppler scores of 0 at 12 months.Results: The 87 patients who achieved US remission were divided into a group that achieved both clinical and US remission (n = 53) and a group that achieved US remission only (n = 34). Baseline factors that were significantly and independently associated with clinical remission at 12 months among patients who also achieved US remission included short disease duration, the presence of concomitant methotrexate use, and low patient global assessment score (p < 0.05, p < 0.05, and p < 0.005, respectively).Conclusions: RA patients with baseline high patient global assessment scores and long disease duration at baseline were unlikely to achieve clinical remission even after achieving US remission. Objective joint assessments using US provide additional information of potential importance for the management of RA.

Effects of body mass index and range of motion on intraoperative change in pelvic tilt during total hip arthroplasty using the direct anterior approach

BACKGROUND

Intraoperative pelvic tilt changes that occurs during total hip arthroplasty (THA) in the supine position affects cup placement and sometimes causes malalignment. The relationship between body mass index (BMI) and pelvic movement has been reported for some procedures, but not the direct anterior approach (DAA). The purpose of this study was to investigate intraoperative pelvic tilt changes that occurs during DAA.

METHODS

In this single-center, retrospective study, we reviewed 200 hips that underwent primary THA via DAA in the supine position using an accelerometer-based navigation system. Intraoperative changes in pelvic tilt and axial rotation from the start of surgery to cup placement were assessed using the navigation system. Preoperative clinical factors that increased pelvic tilt and axial rotation toward the surgical side by > 10° were analyzed via univariate and multiple logistic regression analyses.

RESULTS

The mean pelvic tilt value increased by 7.6° ± 3.8° (95% confidence interval [CI], 7.1-8.2; range, - 5.0-19.0) intraoperatively, and the axial rotation increased by 3.2° ± 2.7° (95% CI, 2.7-3.7; range, - 13.0-12.0). Univariate analysis revealed that the group with increased pelvic tilt showed significantly greater range of abduction and internal rotation, and significantly lower BMI than the group with no increased tilt. Pre-incisional pelvic tilt was significantly greater in the group with increased axial rotation than in the group with no increased rotation. On logistic regression analysis, BMI (odds ratio [OR], 0.889; 95% CI, 0.809-0.977; p = 0.014) and the range of internal rotation (OR, 1.310; 95% CI, 1.002-1.061; p = 0.038) were predictors of large increases in pelvic tilt. No predictors of large increases in axial rotation were identified.

CONCLUSION

Significant forward pelvic tilt was observed in patients with a low BMI values and high ranges of internal rotation via THA using the DAA. Findings indicated that surgeons should pay attention to intraoperative pelvic movements, which may help identify patients with significant pelvic tilt changes.

Distal femoral impaction bone grafting in revision for tumor endoprosthesis

BACKGROUND

Reconstruction using tumor endoprosthesis has been widely used in cases with large bone defects caused by bone and soft tissue tumor resection of the distal femur which extend into the knee joint. However, reconstruction failure can lead to major problems in the long term. We have been performing impaction bone grafting with allogeneic cancellous bone during revision surgery for tumor endoprosthesis of the distal femur to compensate for the thinness and fragility of the remaining femur. The aim of this study is to examine the surgical method, problems, and clinical outcomes of revision surgery with impaction bone grafting.

METHODS

Three patients who underwent revision surgery for tumor endoprosthesis using impaction bone grafting at our institution with more than 2 years of follow-up were included.

RESULTS

Union between the graft and host bone were achieved in all cases. The mean time to radiographic union was 1.0 year (0.6-1.5 years). Although intraoperative penetration to the anterior cortex of the distal femur occurred in 2 cases, there were no postoperative fractures. There were no failures of tumor endoprosthesis at final observation.

CONCLUSION

Good short-term results were observed in 3 patients who underwent revision tumor endoprosthesis with impaction bone grafting following a bone and soft tissue tumor resection of the distal femur. The method was considered to be a useful treatment option. Impaction bone grafting is an established surgical option that can be applied to revision surgery for tumor endoprosthesis.

IL-15 is a biomarker involved in the development of rapidly progressive interstitial lung disease complicated with polymyositis/dermatomyositis

BACKGROUND

Polymyositis/dermatomyositis (PM/DM) is an autoimmune disease that is sometimes complicated with rapidly progressive interstitial lung disease (RPILD). However, serum and lung biomarkers that can predict RPILD development remain unclear.

OBJECTIVES

To determine potential serum and lung biomarkers that can predict RPILD development in patients with PM/DM-ILD.

METHODS

In total, 49 patients with PM/DM-ILD were enrolled. We measured the serum levels of 41 cytokines/chemokines, ferritin and anti-MDA5 antibody, compared them between the RPILD (n = 23) and non-RPILD (n = 26) groups, and ranked them by their importance through random forest analysis. To distinguish the two groups, we determined biomarker combinations by logistic regression analysis. We also measured the bronchoalveolar lavage fluid (BALF) levels of 41 cytokines/chemokines. Using immunohistochemistry, we examined IL-15 expression in lung tissues. The IL-15 production was also investigated using A549 and BEAS-2B cells.

RESULTS

The RPILD group had significantly higher IL-15, IL-1RA, IL-6, CXCL10, VCAM-1, anti-MDA5 antibody and ferritin serum levels than the non-RPILD group, but it had a significantly low CCL22 level. Meanwhile, anti-MDA5 antibody, IL-15, CXCL8, CCL22, IL-1RA and ferritin were the best combination to distinguish the two groups. IL-15 and CCL22 were also predictive marker for RPILD development in anti-MDA5 antibody-positive patients. Additionally, the RPILD group had significantly high IL-15 levels in BALF. The lung tissues expressed IL-15, which increased after cytokine stimulation in the A549 cells.

CONCLUSION

This study identified a combination of biomarkers predicting PM/DM-RPILD progression, and IL-15 is an important cytokine for predicting RPILD development and reflecting ILD severity.

Ligand-receptor interactions in plant hormone signaling

Small-molecule plant hormones principally control plant growth, development, differentiation, and environmental responses. Nine types of plant hormones are ubiquitous in angiosperms, and the molecular mechanisms of their hormone actions have been elucidated during the last two decades by genomic decoding of model plants with genetic mutants. In particular, the discovery of hormone receptors has greatly contributed to the understanding of signal transduction systems. The three-dimensional structure of the ligand-receptor complex has been determined for eight of the nine hormones by X-ray crystal structure analysis, and ligand perception mechanisms have been revealed at the atomic level. Collective research has revealed the molecular function of plant hormones that act as either molecular glue or an allosteric regulator for activation of receptors. In this review, we present an overview of the respective hormone signal transduction and describe the structural bases of ligand-receptor interactions.

Carbon fibers for treatment of cancer metastasis in bone

When cancer metastasizes to bone, the resulting pain and functional disorders due to bone destruction adversely affect the patient's quality of life. We have developed a new cancer metastasis control system consisting of anticancer agents conjugated to carbon fibers (CFs), which are nonbiodegradable, carriers of a wide variety of molecules with extremely high affinity for bone. In the evaluation of cancer suppression effects on Walker 256 cancer cells, cisplatin (CDDP)-conjugated CFs (CF-CDDP) were found to be as effective in cancer suppression as CDDP. In the evaluation of the cancer suppression effects of local injection in the rat model of tibial cancer bone metastasis, similar cancer suppression was noted in the CF-CDDP group and CDDP group; however, blood Pt concentrations were significantly lower in the CF-CDDP group. Experiments with CDDP and CF-CDDP injected into bone actually destroyed by cancer metastases revealed the presence of significantly more newly formed bone tissue with the administration of CF-CDDP. Local administration of CF-CDDP is expected to become the first therapy to suppress cancer growth with low prevalence of adverse reactions, and to repair bone damaged by metastasis.

Local administration of cisplatin-conjugated carbon fibers is expected to become the first therapy to suppress cancer growth with low prevalence of adverse reactions, and to repair bone damaged by metastasis.

Significance of anti-Ro/SSA antibodies in the response and retention of abatacept in patients with rheumatoid arthritis: a multicentre cohort study

Objective: To determine whether the positivity of baseline anti-Ro/Sjögren's syndrome antigen A (SSA) antibodies influences the response to abatacept, we compared therapeutic responses between anti-Ro/SSA antibody-negative and -positive patients with rheumatoid arthritis (RA) using a multicentre RA ultrasonography prospective cohort. Method: We reviewed Japanese patients with RA who started abatacept as the first biological disease-modifying anti-rheumatic drug between June 2013 and April 2018. We assessed 28-joint Disease Activity Score-erythrocyte sedimentation rate (DAS28-ESR) change between baseline and 6 or 12 months after treatment in RA patients treated with abatacept, and European League Against Rheumatism (EULAR) response at 6 and 12 months. The Global OMERACT-EULAR Synovitis Score (GLOESS) was calculated at baseline and at 6 and 12 months. Results: Overall, 51 patients were enrolled and divided into anti-Ro/SSA antibody-negative and -positive groups of 35 and 16, respectively. Median age at baseline was significantly higher in the anti-Ro/SSA antibody-negative group (p = 0.04). The retention rate and percentage of EULAR good responders at 12 months were significantly higher in the anti-Ro/SSA antibody-negative group (both p = 0.02). Anti-Ro/SSA antibody-negative patients exhibited larger decreases in both DAS28-ESR and DAS28-C-reactive protein at 12 months than anti-Ro/SSA antibody-positive patients (p = 0.02 and 0.04, respectively). GLOESS decreased significantly at 6 months in anti-Ro/SSA antibody-negative patients (p = 0.03). Multivariate analyses showed that anti-Ro/SSA antibody positivity was an independent factor associated with change in the DAS28-ESR at 6 months (p < 0.05). Conclusion: Anti-Ro/SSA antibody positivity predicts a poor response to abatacept and low retention rate.

Metastases of soft tissue sarcoma to the liver: A Historical Cohort Study from a Hospital-based Cancer Registry

BACKGROUND

Hepatic metastasis of soft tissue sarcoma is rare compared to lung metastasis, and the literature is scarce. We examined the risk of hepatic metastasis according to the site of occurrence and histological type.

METHODS

From a Hospital-based Cancer Registry, 658 patients registered between 2007 and 2017 with soft tissue sarcomas were evaluated. The exclusion criteria were gastrointestinal stromal tumors, tumors of unknown origin, and follow-up periods of less than 1 month. SPSS 25 was used for statistical analysis.

RESULTS

The risk of hepatic metastasis was significantly higher in the retroperitoneum (HR, 5.981; 95% CI, 2.793-12.808) and leiomyosarcoma (HR, 4.303; 95% CI, 1.782-10.390). Multivariate analysis showed that the risk of hepatic metastasis as first distant metastasis was high in leiomyosarcoma (HR, 4.546; 95% CI, 2.275-9.086) and retroperitoneal onset (HR, 4.588; 95% CI, 2.280-9.231). The 2-year survival rate after hepatic metastasis was 21.7%.

CONCLUSIONS

The onset of hepatic metastasis indicates a poor prognosis. However, hepatic metastasis from retroperitoneal sarcoma and leiomyosarcoma may be the first distant metastasis in some cases. For retroperitoneal sarcoma and leiomyosarcoma, additional screening for hepatic metastasis such as contrast CT should be considered during staging and follow-up after treatment.

THU0315 THE CLINICAL RELEVANCE OF SERUM IMMUNE COMPLEXES IN ANCA-ASSOCIATED VASCULITIS

Background:

AAV is an autoimmune disease characterized by systemic vasculitis and pauci-immune-type crescentic glomerulonephritis (CGN) with ANCA production1). Several authors have reported cases of ANCA-associated CGN with definite IC deposits2)3), however, the clinical significance of IC in patients with ANCA-associated CGN remains unclear.

Objectives:

To investigate the clinical relevance of serum immune complexes (ICs) in ANCA-associated vasculitis (AAV) patients.

Methods:

We developed a novel proteomic strategy for identifying and profiling antigens in immune complexes in the serum of microscopic polyangiitis (MPA) and granulomatosis with polyangiitis (GPA) patients. The serum was collected from the cohort of Japan Research Committee of the Ministry of Health Labour, Welfare for Intractable Vasculitis (JPVAS) before treatment and 6 months after initiation of treatment. The serum from healthy individuals was used for control samples. The Baseline data of each patient was collected with demographic information, laboratory data, disease activity according to the Birmingham Vasculitis Activity Score (BVAS) 2003, disease severity, and imaging data.

Results:

We were able to examine 91 AAV patients (52 MPA patients and 39 GPA patients) with 82.4% for MPO-ANCA positive and 20.9% for PR3-ANCA positive. Almost half of the patients was female (56.0%). The median age was 70 years [interquartile range (IQR): 64-77]. The median BVAS was 17 (IQR: 12-23). We identified autoantigen of EGF-containing fibulin-like extracellular matrix protein 1 (EFEMP1) in 43 of MPA (82.6%) and 16 of GPA (41.0%) at baseline. After 6 months of treatment, no cases of EFEMP1 were identified in MPA and GPA. The clinical features of EFEMP1 positive in AAV patients were higher age at onset (p <0.01), less ear, nose and throat symptoms at initiation of treatment (p <0.05), higher serum Cr at initiation of treatment (p <0.01), higher vasculitis damage index (VDI) renal component at 12 months and 24 months after initiation of treatment (both p <0.05).

Conclusion:

Our findings indicate that an autoantigen as immune complexes of EFEMP1 were involved in the pathogenesis of AAV patients and may predict renal prognosis.

References:

[1]Wilde B et.al, Kidney Int. 2011 Mar;79(6):599-612.

[2]Falk RJ et.al, J Am Soc Nephrol. 1997 Feb;8(2):314-22.

[3]Haas M et.al, Kidney Int. 2004 Jun;65(6):2145-52.

Table.

Comparison with and without EFEMP1 (all cases)

groupEFEMP1 positive (n=59)EFEMP1 negative (n=32)**p-valueSex(%male)27/59 (45.8%)13/32 (40.6%)0.665Age, years74 (66-78)68 (60-71)0.003WBC(/ml)8270 (7325-12725)9150 (7325-11700)0.280Cr(mg/dl)1.4 (0.9-3.8)0.8 (0.6-1.5)0.005CRP(mg/dl)7.0 (2.3-12.5)7.6 (4.0-11.0)0.566MPA(%)43/59 (72.9%)9/32 (28.1%)<0.001GPA(%)16/59 (27.1%)23/32 (71.9%)<0.001MPO-ANCA positive54/59 (91.5%)24/32 (65.6%)0.003PR3-ANCA positive*7/56 (12.5%)12/32 (37.5%)0.012BVAS total15 (12-20)20 (12-25)0.087BVAS renal positive53/59 (89.8%)26/32 (81.3%)0.332BVAS chest positive16/59 (27.1%)14/32 (43.4%)0.161BVAS ENT positive17/59 (28.8%)18/32 (56.3%)0.014BVAS systemic positive40/59 (67.8%)24/32 (75.0%)0.631VDI renal 6 months1 (0-2)0 (0-1)0.053VDI renal 12 months1 (0-2)0 (0-1)0.007VDI renal 24 months1 (0-2)0 (0-1)0.012

IQR interquartile range. Values are median(IQR) or n(%), *missing data, **Wilcoxon signed-rank test/Fisher’s exact test

Disclosure of Interests:

Momoko Okamoto: None declared, Kunihiro Ichinose: None declared, Kaname Oyama: None declared, Ken-Ei Sada: None declared, Shin-ya Kaname: None declared, masayoshi harigai Grant/research support from: AbbVie Japan GK, Ayumi Pharmaceutical Co., Bristol Myers Squibb Co., Ltd., Eisai Co., Ltd., Mitsubishi Tanabe Pharma Co., Nippon Kayaku Co., Ltd., and Teijin Pharma Ltd. MH has received speaker’s fee from AbbVie Japan GK, Ayumi Pharmaceutical Co., Boehringer Ingelheim Japan, Inc., Bristol Myers Squibb Co., Ltd., Chugai Pharmaceutical Co., Ltd., Eisai Co., Ltd., Eli Lilly Japan K.K., GlaxoSmithKline K.K., Kissei Pharmaceutical Co., Ltd., Oxford Immuotec, Pfizer Japan Inc., and Teijin Pharma Ltd. MH is a consultant for AbbVie, Boehringer-ingelheim, Kissei Pharmaceutical Co., Ltd. and Teijin Pharma., Atsushi Kawakami: None declared

FRI0172 THE INFLUENCE OF CALCINEURIN INHIBITORS ON DEVELOPMENT OF CANCER IN PATIENTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS: A RETROSPECTIVE OBSERVATIONAL STUDY IN THE LUNA REGISTRY

Background:

It has been reported that the incidence of cancer in patients with systemic lupus erythematosus (SLE) is higher than that in healthy individuals, but the findings are inconsistent1. In the transplantation field, a few studies indicated an association between the use of immunosuppressants and an increased risk of cancer2. Calcineurin inhibitors (CNIs), which include cyclosporine and tacrolimus, have been used for >30 years to treat renal and extrarenal manifestations of SLE, but the effects of exposure to CNIs among SLE patients have not been established.

Objectives:

We investigated the incidence of various cancers (including cervical dysplasia) among SLE patients registered in the LUpus registry of NAtionwide institution (LUNA). We also investigate whether the registrants’ exposure to CNIs increased the risk of cancer.

Methods:

We calculated the standardized incidence ratio (SIR) of cancer among SLE patients based on the age-standardized incidence rate of cancer reported by Japan’s Ministry of Health, Labour and Welfare. A multivariate analysis of the risk of cancer was performed using the covariates of age, smoking history, CNI treatment history, maximum steroid dose in the past, and Systemic Lupus International Collaboration Clinics/American College of Rheumatology Damage Index [SDI]) value (excluding the occurrence of cancer) at the time of the patient’s registration.

Results:

We studied 714 patients (663 females; 88.9%).The median age at registry was 44 [interquartile range (IQR): 35–56] years. The median past max. steroid dose was 40 mg/day (IQR: 30–60 mg/day), and the SDI at registration was 1 (IQR 0–2). Smoking history was present in 248 patients (34.9%), and 53 patients (7.4%) experienced cancer complications. Gynecologic malignancies accounted for 71% of all cancers, including 12 cervical dysplasia cases. The standardized incidence rate of cancer in these SLE patients was 1.46 (95%CI: 1.07–1.85, p<0.01). The multivariate analysis showed that a CNI treatment history was not a risk factor for the development of cancer (OR 1.76, 95%CI: 0.63–4.88, p=0.30). After the covariance was adjusted for the propensity score, the risk of cancer in the CNIs group was not increased compared to the non-CNIs group (adjusted OR 2.46, 95%CI: 0.68–8.91, p=0.20).

Conclusion:

The incidence of cancer in SLE was higher in the LUNA cohort than in the general population. Our results suggest that CNI treatment for individuals with SLE is not a risk factor for the development of cancer.

References:

[1]Ladouceur A. et.al, Expert Rev Clin Immunol. 2018 Oct;14(10):793-802.

[2]Gutierrez-Dalmau A. et.al, Drugs 2007;67(8):1167-98.

Disclosure of Interests:

None declared

AB0413 INVESTIGATION OF THE ASSOCIATION OF CARDIOVASCULAR EVENTS AND ANTI- SS-A ANTIBODIES AS RISK OF DEVELOPMENT IN PATIENTS WITH LUPUS NEPHRITIS FROM THE LUNA REGISTRY: A CROSS-SECTIONAL STUDY

Background:

Cardiovascular disease(CVD) has been identified as a major cause of morbidity and mortality in patients with lupus nephritis(LN)1) 2). There is a clear causal relationship between the onset of neonatal lupus (cardiac complications) and SS-A antibodies3) 4), but no association has been reported in adults. In recent years, there have been reports from overseas that suggest the association between CVD and anti-SS-A antibody in adult systemic lupus erythematosus (SLE) patients5) 6). So far, no studies have not been reported to evaluate the relationship between anti-SS-A antibody and the risk of developing CVD in LN in a large cohort of patients with SLE in Japan.

Objectives:

The aim of this study was to evaluate the association between anti-SS-A antibody and the risk of developing CVD in LN patients using a multicenter registration study [Lupus registry of nationwide institution (LUNA)] in Japan.

Methods:

We identified 931 patients diagnosed with SLE in the Lupus registry of nationwide institution (LUNA), and further identified 275 LN patients with known the presence or absence of both development of CVD and presence of anti-SS-A antibody. We defined the exposure factor as anti-SS-A antibody, and the outcome as CVD. SELENA-SLEDAI score (at diagnosis), eGFR <60%, HbA1c, BMI, and steroid pulse treatment history were used as confounding factors and we analyzed using logistic regression analysis.

Results:

We found 68 patients (24.7%) complicated with CVD, including percarditis (7.3%), cerebrovascular disorder (6.2%), peripheral Arterial Disease (6.2%), Ischemic heart disease (2.9%),venous thromboembolism (2.9%),pulmonary hypertension (1.5%), vulvular heart disease (1.1%), and cardiomyopathy (0.4%). In univariate analysis, there was no significant difference in the occurrence of CVD depending on the presence or absence of anti-SS-A antibody (p = 0.32), and the results of multivariate analysis showed no significant difference in anti-SS-A antibody [p = 0.23, odds: 0.41, 95% confidence interval (0.09-1.89)].

Conclusion:

The association between anti-SS-A antibody and the development of CVD in LN patients in Japan has not been identified.

References:

[1]Lupus. 2000;9(3):166-9

[2]Arthritis Rheum.2019 Mar;71(3):403-410,

[3]J Intern Med 265:653-662, 2009

[4]Nat Clin Pract Rheumatol 5:139-148, 2009

[5]Ann Rheum Dis 1990;49:627-629

[6]Chest. 2018 Jan;153(1):143-151. Doi:

Disclosure of Interests:

None declared

Dynamic control of plant water use using designed ABA receptor agonists

Drought causes crop losses worldwide, and its impact is expected to increase as the world warms. This has motivated the development of small-molecule tools for mitigating the effects of drought on agriculture. We show here that current leads are limited by poor bioactivity in wheat, a widely grown staple crop, and in tomato. To address this limitation, we combined virtual screening, x-ray crystallography, and structure-guided design to develop opabactin (OP), an abscisic acid (ABA) mimic with up to an approximately sevenfold increase in receptor affinity relative to ABA and up to 10-fold greater activity in vivo. Studies in Arabidopsis thaliana reveal a role of the type III receptor PYRABACTIN RESISTANCE-LIKE 2 for the antitranspirant efficacy of OP. Thus, virtual screening and structure-guided optimization yielded newly discovered agonists for manipulating crop abiotic stress tolerance and water use.

Applications of Carbon Nanotubes in Bone Regenerative Medicine

Scaffolds are essential for bone regeneration due to their ability to maintain a sustained release of growth factors and to provide a place where cells that form new bone can enter and proliferate. In recent years, scaffolds made of various materials have been developed and evaluated. Functionally effective scaffolds require excellent cell affinity, chemical properties, mechanical properties, and safety. Carbon nanotubes (CNTs) are fibrous nanoparticles with a nano-size diameter and have excellent strength and chemical stability. In the industrial field, they are used as fillers to improve the performance of materials. Because of their excellent physicochemical properties, CNTs are studied for their promising clinical applications as biomaterials. In this review article, we focused on the results of our research on CNT scaffolds for bone regeneration, introduced the promising properties of scaffolds for bone regeneration, and described the potential of CNT scaffolds.

Nintedanib in patients with progressive fibrosing interstitial lung diseases-subgroup analyses by interstitial lung disease diagnosis in the INBUILD trial: a randomised, double-blind, placebo-controlled, parallel-group trial

BACKGROUND

The INBUILD trial investigated the efficacy and safety of nintedanib versus placebo in patients with progressive fibrosing interstitial lung diseases (ILDs) other than idiopathic pulmonary fibrosis (IPF). We aimed to establish the effects of nintedanib in subgroups based on ILD diagnosis.

METHODS

The INBUILD trial was a randomised, double-blind, placebo-controlled, parallel group trial done at 153 sites in 15 countries. Participants had an investigator-diagnosed fibrosing ILD other than IPF, with chest imaging features of fibrosis of more than 10% extent on high resolution CT (HRCT), forced vital capacity (FVC) of 45% or more predicted, and diffusing capacity of the lung for carbon monoxide (DLco) of at least 30% and less than 80% predicted. Participants fulfilled protocol-defined criteria for ILD progression in the 24 months before screening, despite management considered appropriate in clinical practice for the individual ILD. Participants were randomly assigned 1:1 by means of a pseudo-random number generator to receive nintedanib 150 mg twice daily or placebo for at least 52 weeks. Participants, investigators, and other personnel involved in the trial and analysis were masked to treatment assignment until after database lock. In this subgroup analysis, we assessed the rate of decline in FVC (mL/year) over 52 weeks in patients who received at least one dose of nintedanib or placebo in five prespecified subgroups based on the ILD diagnoses documented by the investigators: hypersensitivity pneumonitis, autoimmune ILDs, idiopathic non-specific interstitial pneumonia, unclassifiable idiopathic interstitial pneumonia, and other ILDs. The trial has been completed and is registered with ClinicalTrials.gov, number NCT02999178.

FINDINGS

Participants were recruited between Feb 23, 2017, and April 27, 2018. Of 663 participants who received at least one dose of nintedanib or placebo, 173 (26%) had chronic hypersensitivity pneumonitis, 170 (26%) an autoimmune ILD, 125 (19%) idiopathic non-specific interstitial pneumonia, 114 (17%) unclassifiable idiopathic interstitial pneumonia, and 81 (12%) other ILDs. The effect of nintedanib versus placebo on reducing the rate of FVC decline (mL/year) was consistent across the five subgroups by ILD diagnosis in the overall population (hypersensitivity pneumonitis 73·1 [95% CI -8·6 to 154·8]; autoimmune ILDs 104·0 [21·1 to 186·9]; idiopathic non-specific interstitial pneumonia 141·6 [46·0 to 237·2]; unclassifiable idiopathic interstitial pneumonia 68·3 [-31·4 to 168·1]; and other ILDs 197·1 [77·6 to 316·7]; p=0·41 for treatment by subgroup by time interaction). Adverse events reported in the subgroups were consistent with those reported in the overall population.

INTERPRETATION

The INBUILD trial was not designed or powered to provide evidence for a benefit of nintedanib in specific diagnostic subgroups. However, its results suggest that nintedanib reduces the rate of ILD progression, as measured by FVC decline, in patients who have a chronic fibrosing ILD and progressive phenotype, irrespective of the underlying ILD diagnosis.

FUNDING

Boehringer Ingelheim.

Continued growth of locally aggressive fibrous dysplasia of 22 years duration after reaching adulthood: a case report

Fibrous dysplasia generally stops growing when patients reach adulthood. Locally aggressive fibrous dysplasia is an extremely rare subtype of fibrous dysplasia that is characterized by progressive enlargement after bone maturation, cortical bone destruction and soft tissue invasion but without malignant transformation. At 50 years of age, a tumor was found in the rib of a patient. The tumor gradually enlarged over time and imaging findings suggested a malignant tumor. The case was further complicated by restrictive lung disorder. Biopsies from multiple sites showed no malignant findings, and marginal resection with partial curettage was performed. The final diagnosis was locally aggressive fibrous dysplasia, and the restrictive lung disorder improved postoperatively. The natural history of the disease is also unknown. This is the first report in the literature to describe a case in which a lesion exhibited long-term growth over a period of 22 years after reaching adulthood.

Comparison of Three Methods for Determination of Crude Protein in Meat: Collaborative Study

A study was designed to compare the Kjel-Foss automated macro-Kjeldahl method and a block digestion- steam distillation method. The official AOAC Kjeldahl method was used as a reference procedure. Six products with a crude protein range of 10-30% were analyzed by 23 laboratories. Five laboratories analyzed the samples by the official AOAC method, 8 laboratories used the automated Kjel-Foss method, and 11 laboratories used the block digestion with steam distillation method. Standard deviations for each product and each method for both repeatability and reproducibility are given. The block digestion- steam distillation method has been adopted official first action.

Anti-PD-1 antibody decreases tumour-infiltrating regulatory T cells

Background

There are many types of therapies for cancer. In these days, immunotherapies, especially immune checkpoint inhibitors, are focused on. Though many types of immune checkpoint inhibitors are there, the difference of effect and its mechanism are unclear. Some reports suggest the response rate of anti-PD-1 antibody is superior to that of anti-PD-L1 antibody and could potentially produce different mechanisms of action. On the other hand, Treg also express PD-1; however, their relationship remains unclear.

Methods

In this study, we used osteosarcoma cell lines in vitro and osteosarcoma mouse model in vivo. In vitro, we analyzed the effect of IFNγ for expression of PD-L1 on the surface of cell lines by flowcytometry. In vivo, murine osteosarcoma cell line LM8 was subcutaneously transplanted into the dorsum of mice. Mouse anti-PD-1 antibody was intraperitoneally administered. we analysed the effect for survival of anti-PD-1 antibody and proportion of T cells in the tumour by flowcytometry.

Results

We discovered that IFNγ increased PD-L1 expression on the surface of osteosarcoma cell lines. In assessing the relationship between anti-PD-1 antibody and Treg, we discovered the administration of anti-PD-1 antibody suppresses increases in tumour volume and prolongs overall survival time. In the tumour microenvironment, we found that the administration of anti-PD-1 antibody decreased Treg within the tumour and increased tumour-infiltrating lymphocytes.

Conclusions

Here we clarify for the first time an additional mechanism of anti-tumour effect—as exerted by anti-PD-1 antibody decreasing Treg— we anticipate that our findings will lead to the development of new methods for cancer treatment.