Comparative Analysis of Microendoscopic and Open Laminectomy for Single-Level Lumbar Spinal Stenosis at L1-L2 or L2-L3.

BACKGROUND: Several reports have highlighted comparable surgical outcomes between microendoscopic laminectomy (MEL) and open laminectomy (open) for lumbar spinal stenosis. However, the unilateral approach in MEL may present challenges for the upper lumbar levels, where facet joints are located deeper inside. Our objective was to compare surgical outcomes and radiographic evaluations for single-level decompression cases at L1-L2 or L2-L3 between MEL and open laminectomy. METHODS: We analyzed patients who underwent single-level decompression for upper lumbar spinal stenosis at 12 distinguished spine centers from April 2017 to September 2021. Baseline demographics, preoperative, and 1-year postoperative patient-reported outcomes, along with imaging parameters, were compared between the MEL and open groups. To account for potential confounding, patients' backgrounds were adjusted using the inverse probability weighting method based on propensity scores. RESULTS: Among the 2487 patients undergoing decompression surgery, 118 patients (4.7%) underwent single-level decompression at L1-L2 or L2-L3. Finally, 80 patients (51 in the MEL group, 29 in the open group) with postoperative data were deemed eligible for analysis. The MEL group exhibited significantly improved postoperative EuroQol 5-Dimension values compared to the open group. Additionally, the MEL group showed a lower facet preservation rate according to computed tomography examination, whereas the open group had a higher incidence of retrolisthesis. CONCLUSIONS: Although overall surgical outcomes were similar, the MEL group demonstrated potential advantages in enhancing EuroQol 5-Dimension scores. The MEL group's lower facet preservation rate did not translate into a higher postoperative instability rate.

Quality of Life and Postoperative Satisfaction in Patients with Benign Extramedullary Spinal Tumors: A Multicenter Study.

STUDY DESIGN: Retrospective cohort study using prospectively collected registry data. OBJECTIVE: The purpose of this study is to evaluate health-related quality of life (HRQOL) and postoperative satisfaction in patients with different histotypes of benign extramedullary spinal tumors (ESTs). BACKGROUND: Little is known about how different histotypes influence HRQOL and postoperative satisfaction in EST patients. MATERIALS AND METHODS: Patients undergoing primary benign EST surgery at 11 tertiary referral hospitals between 2017 and 2021 who completed preoperative and 1-year postoperative questionnaires were included. HRQOL assessment included the Physical Component Summary and Mental Component Summary (MCS) of Short Form-12, EuroQol 5-dimension, Oswestry/Neck Disability Index (ODI/NDI), and Numeric Rating Scales (NRS) for upper/lower extremities (UEP/LEP) and back pain (BP). Patients who answered "very satisfied," "satisfied," or "somewhat satisfied" on a seven-point Likert scale were considered to be satisfied with treatment. Student t -tests or Welch's t -test were used to compare continuous variables between two groups, and one-way analysis of variance was used to compare outcomes between the three groups of EST histotypes (schwannoma, meningioma, atypical). Categorical variables were compared using the χ 2 test or Fisher exact test. RESULTS: A total of 140 consecutive EST patients were evaluated; 100 (72%) had schwannomas, 30 (21%) had meningiomas, and 10 (7%) had other ESTs. Baseline Physical Component Summary was significantly worse in patients with meningiomas ( P =0.04), and baseline NRS-LEP was significantly worse in patients with schwannomas ( P =0.03). However, there were no significant differences in overall postoperative HRQOL or patient satisfaction between histology types. Overall, 121 (86%) patients were satisfied with surgery. In a subgroup analysis comparing intradural schwannomas and meningiomas adjusted for patient demographics and tumor location with inverse probability weighting, schwannoma patients had worse baseline MCS ( P =0.03), ODI ( P =0.03), NRS-BP ( P <.001), and NRS-LEP ( P =0.001). Schwannoma patients also had worse postoperative MCS ( P =0.03) and NRS-BP ( P =0.001), with no significant difference in the percentage of satisfied patients ( P =0.30). CONCLUSIONS: Patients who underwent primary benign EST resection had a significant improvement in HRQOL postoperatively, and ~90% of these patients reported being satisfied with their treatment outcomes one year after surgery. EST patients may exhibit a relatively lower threshold for postoperative satisfaction compared with patients undergoing surgery for degenerative spine conditions.

Impact of body mass index on outcomes after lumbar spine surgery.

The impact of body mass index (BMI) on outcomes after lumbar spine surgery is currently unknown. Previous studies have reported conflicting evidence for patients with high BMI, while little research has been conducted on outcomes for underweight patients. This study aims to examine the impact of BMI on outcomes after lumbar spine surgery. This prospective cohort study enrolled 5622 patients; of which, 194, 5027, and 401 were in the low (< 18.5 kg/m2), normal (18.5-30), and high (≥ 30) BMI groups, respectively. Pain was assessed via the numerical pain rating scale (NPRS) for the lower back, buttock, leg, and plantar area. Quality of life was assessed via the EuroQol 5 Dimension (EQ-5D) and Oswestry Disability Index (ODI). Inverse probability weighting with propensity scores was used to adjust patient demographics and clinical characteristics between the groups. After adjustment, the 1-year postoperative scores differed significantly between groups in terms of leg pain. The proportion of patients who achieved a 50% decrease in postoperative NPRS score for leg pain was also significantly different. Obese patients reported less improvement in leg pain after lumbar spine surgery. The outcomes of patients with low BMI were not inferior to those of patients with normal BMI.

Predictors for hemostatic thrombin-gelatin matrix usage in spine surgery: a multicenter observational study.

STUDY DESIGN: A prospective cohort study. OBJECTIVES: Thrombin-gelatin matrix (TGM) is a rapid and potent hemostatic agent, but it has some limitations, including the cost and its preparation time. The purpose of this study was to investigate the current trend in the use of TGM and to identify the predictors for TGM usage in order to ensure its proper use and optimized resource allocation. METHODS: A total of 5520 patients who underwent spine surgery in a multicenter study group within a year were included in the study. The demographic factors and the surgical factors including spinal levels operated, emergency surgery, reoperation, approach, durotomy, instrumented fixation, interbody fusion, osteotomy, and microendoscopy-assistance were investigated. TGM usage and whether it was routine or unplanned use for uncontrolled bleeding were also checked. A multivariate logistic regression analysis was used to identify predictors for unplanned use of TGM. RESULTS: Intraoperative TGM was used in 1934 cases (35.0%), among which 714 were unplanned (12.9%). Predictors of unplanned TGM use were female gender (adjusted odds ratio [OR]: 1.21, 95% confidence interval [CI]: 1.02-1.43, p = 0.03), ASA grade ≥ 2 (OR: 1.34, 95% CI: 1.04-1.72, p = 0.02), cervical spine (OR: 1.55, 95% CI: 1.24-1.94, p < 0.001), tumor (OR: 2.02, 95% CI: 1.34-3.03, p < 0.001), posterior approach (OR: 1.66, 95% CI: 1.26-2.18, p < 0.001), durotomy (OR: 1.65, 95% CI: 1.24-2.20, p < 0.001), instrumentation (OR: 1.30, 1.03-1.63, p = 0.02), osteotomy (OR: 5.00, 2.76-9.05, p < 0.001), and microendoscopy (OR: 2.24, 1.84-2.73, p < 0.001). CONCLUSIONS: Many of the predictors for unplanned TGM use have been previously reported as risk factors for intraoperative massive hemorrhaging and blood transfusion. However, other newly revealed factors can be predictors of bleeding that is technically challenging to control. While routine usage of TGM in these cases will require further justification, these novel findings are valuable for implementing preoperative precautions and optimizing resource allocation.

Single-cell RNA sequencing identifies Fgf23-expressing osteocytes in response to 1,25-dihydroxyvitamin D3 treatment.

Fibroblast growth factor 23 (FGF23), a hormone, mainly produced by osteocytes, regulates phosphate and vitamin D metabolism. By contrast, 1,25-dihydroxyvitamin D3, the active form of vitamin D, has been shown to enhance FGF23 production. While it is likely that osteocytes are heterogenous in terms of gene expression profiles, specific subpopulations of Fgf23-expressing osteocytes have not been identified. Single-cell RNA sequencing (scRNA-seq) technology can characterize the transcriptome of an individual cell. Recently, scRNA-seq has been used for bone tissue analysis. However, owing to technical difficulties associated with isolation of osteocytes, studies using scRNA-seq analysis to characterize FGF23-producing osteocytes are lacking. In this study, we characterized osteocytes secreting FGF23 from murine femurs in response to calcitriol (1,25-dihydroxyvitamin D3) using scRNA-seq. We first detected Dmp1, Mepe, and Phex expression in murine osteocytes by in situ hybridization and used these as marker genes of osteocytes. After decalcification, enzyme digestion, and removal of CD45+ cells, femoral bone cells were subjected to scRNA-seq. We identified cell clusters containing osteocytes using marker gene expression. While Fgf23 expression was observed in some osteocytes isolated from femurs of calcitriol-injected mice, no Fgf23 expression was detected in untreated mice. In addition, the expression of several genes which are known to be changed after 1,25-dihydroxyvitamin D3 treatment such as Ccnd2, Fn1, Igfbp7, Pdgfa, and Timp1 was also affected by calcitriol treatment in Fgf23-expressing osteocytes, but not in those lacking Fgf23 expression, even after calcitriol administration. Furthermore, box-and-whisker plots indicated that Fgf23 expression was observed in osteocytes with higher expression levels of the Fam20c, Dmp1, and Phex genes, whose inactivating mutations have been shown to cause FGF23-related hypophosphatemic diseases. These results indicate that osteocytes are heterogeneous with respect to their responsiveness to 1,25-dihydroxyvitamin D3, and sensitivity to 1,25-dihydroxyvitamin D3 is one of the characteristics of osteocytes with Fgf23 expression. It is likely that there is a subpopulation of osteocytes expressing several genes, including Fgf23, involved in phosphate metabolism.

A novel mouse model of cutaneous T-cell lymphoma revealed the combined effect of mogamulizumab with psoralen and ultraviolet a therapy.

Mycosis fungoides (MF) is a subtype of cutaneous T-cell lymphoma (CTCL). Topical or systemic treatment with psoralen, such as 8-methoxypsoralen (8-MOP), followed by ultraviolet A (UVA) irradiation (PUVA therapy) is an effective phototherapy for early-stage MF. However, the efficacy of PUVA therapy for advanced-stage MF is not satisfactory, and the ideal combination partner for PUVA therapy has not yet been found. In this study, we developed a new mouse model of CTCL in which efficacy of PUVA was detected and further evaluated the efficacy of combination treatment of PUVA and mogamulizumab, an anti-CCR4 monoclonal antibody. Cytotoxicity of PUVA therapy against HH cells, a CTCL cell line, was observed in vitro. The cytotoxicity was dependent on both 8-MOP and UVA. Using HH cells, we developed a mouse model in which HH cells were subcutaneously inoculated in the ear. In this model, PUVA therapy suppressed tumour growth with statistical significance, while 8-MOP or UVA alone did not. Combination therapy of PUVA and mogamulizumab showed greater antitumor activity than either monotherapy with statistical significance. In the histological analysis of the tumour tissue, PUVA accelerated tumour necrosis and then induced the infiltration inflammatory cells in the necrotic area, suggesting that these cells served as effector cells for mogamulizumab. This combination therapy is expected to be a beneficial option for CTCL therapy.

Postoperative outcomes after degenerative lumbar spine surgery in rheumatoid arthritis patients -a propensity score-matched analysis.

BACKGROUND: Although treatment options for rheumatoid arthritis (RA) have evolved significantly since the introduction of biologic agents, degenerative lumbar disease in RA patients remains a major challenge. Well-controlled comparisons between RA patients and their non-RA counterparts have not yet been reported. The objective of the present study was to compare postoperative outcomes of lumbar spine surgery between RA and non-RA patients by a retrospective propensity score-matched analysis. METHODS: Patients who underwent primary posterior spine surgery for degenerative lumbar disease in our prospective multicenter study group between 2017 and 2020 were enrolled. Demographic data including age, sex, body mass index (BMI), American Society of Anesthesiologists (ASA) physical status classification, diabetes mellitus, smoking, steroid usage, number of spinal levels involved, and preoperative patient-reported outcome (PRO) scores (numerical rating scale [NRS] for back pain and leg pain, Short Form-12 physical component summary [PCS], EuroQOL 5-dimension [EQ-5D], and Oswestry Disability Index [ODI]) were used to calculate a propensity score for RA diagnosis. One-to-one matching was performed and 1-year postoperative outcomes were compared between groups. RESULTS: Among the 4567 patients included, 90 had RA (2.0%). RA patients in our cohort were more likely to be female, with lower BMI, higher ASA grade and lower current smoking rate than non-RA patients. Preoperative NRS scores for leg pain, PCS, EQ-5D, and ODI were worse in RA patients. Propensity score matching generated 61 pairs of RA and non-RA patients who underwent posterior lumbar surgery. After background adjustment, RA patients reported worse postoperative PCS (28.4 vs. 37.2, p = 0.008) and EQ-5D (0.640 vs. 0.738, p = 0.03), although these differences were not significant between RA and non-RA patients not on steroids. CONCLUSIONS: RA patients showed worse postoperative quality of life outcomes after posterior surgery for degenerative lumbar disease, while steroid-independent RA cases showed equivalent outcomes to non-RA patients.

Effect of Early vs Delayed Surgical Treatment on Motor Recovery in Incomplete Cervical Spinal Cord Injury With Preexisting Cervical Stenosis: A Randomized Clinical Trial.

Importance: The optimal management for acute traumatic cervical spinal cord injury (SCI) is unknown. Objective: To determine whether early surgical decompression results in better motor recovery than delayed surgical treatment in patients with acute traumatic incomplete cervical SCI associated with preexisting canal stenosis but without bone injury. Design, Setting, and Participants: This multicenter randomized clinical trial was conducted in 43 tertiary referral centers in Japan from December 2011 through November 2019. Patients aged 20 to 79 years with motor-incomplete cervical SCI with preexisting canal stenosis (American Spinal Injury Association [ASIA] Impairment Scale C; without fracture or dislocation) were included. Data were analyzed from September to November 2020. Interventions: Patients were randomized to undergo surgical treatment within 24 hours after admission or delayed surgical treatment after at least 2 weeks of conservative treatment. Main Outcomes and Measures: The primary end points were improvement in the mean ASIA motor score, total score of the spinal cord independence measure, and the proportion of patients able to walk independently at 1 year after injury. Results: Among 72 randomized patients, 70 patients (mean [SD] age, 65.1 [9.4] years; age range, 41-79 years; 5 [7%] women and 65 [93%] men) were included in the full analysis population (37 patients assigned to early surgical treatment and 33 patients assigned to delayed surgical treatment). Of these, 56 patients (80%) had data available for at least 1 primary outcome at 1 year. There was no significant difference among primary end points for the early surgical treatment group compared with the delayed surgical treatment group (mean [SD] change in ASIA motor score, 53.7 [14.7] vs 48.5 [19.1]; difference, 5.2; 95% CI, -4.2 to 14.5; P = .27; mean [SD] SCIM total score, 77.9 [22.7] vs 71.3 [27.3]; P = .34; able to walk independently, 21 of 30 patients [70.0%] vs 16 of 26 patients [61.5%]; P = .51). A mixed-design analysis of variance revealed a significant difference in the mean change in ASIA motor scores between the groups (F1,49 = 4.80; P = .03). The early surgical treatment group, compared with the delayed surgical treatment group, had greater motor scores than the delayed surgical treatment group at 2 weeks (mean [SD] score, 34.2 [18.8] vs 18.9 [20.9]), 3 months (mean [SD] score, 49.1 [15.1] vs 37.2 [20.9]), and 6 months (mean [SD] score, 51.5 [13.9] vs 41.3 [23.4]) after injury. Adverse events were common in both groups (eg, worsening of paralysis, 6 patients vs 6 patients; death, 3 patients vs 3 patients). Conclusions and Relevance: These findings suggest that among patients with cervical SCI, early surgical treatment produced similar motor regain at 1 year after injury as delayed surgical treatment but showed accelerated recovery within the first 6 months. These exploratory results suggest that early surgical treatment leads to faster neurological recovery, which requires further validation. Trial Registration: ClinicalTrials.gov Identifier: NCT01485458; umin.ac.jp/ctr Identifier: UMIN000006780.

Outcomes of an Intraoperative Povidone-Iodine Irrigation Protocol in Spinal Surgery for Surgical Site Infection Prevention.

STUDY DESIGN: This was a retrospective observational study. OBJECTIVE: The aim of this study was to evaluate the efficacy of our new protocol for preventing postoperative surgical site infection (SSI) following spinal surgery. SUMMARY OF BACKGROUND DATA: SSI following spinal surgery is a serious postoperative complication. Several studies have recently assessed the effectiveness of wound irrigation with povidone-iodine (PVP-I) for SSI prevention, but no consensus has been reached as to how PVP-I should be used in clinical practice. We formed a PVP-I irrigation protocol focusing on the pharmacological properties of PVP-I. This study aimed to evaluate the efficacy and safety of our protocol for preventing SSI. MATERIALS AND METHODS: All cases of spinal surgery at our hospital between October 2011 and September 2016 were retrospectively reviewed. The exclusion criteria were PVP-I allergy, prior surgical debridement for infection, and implant removal surgery. The patients were subdivided into those who had received normal saline irrigation after 90 seconds of 1% PVP-I pooling every 1.5 hours (study group) or only routine saline irrigation every 1.5 hours (control group). The study and control groups comprised of 177 and 146 patients, respectively. This study compared the rate of SSI with and without the use of the PVP-I irrigation protocol. RESULTS: The SSI rates were 1.7% for the study group (3/177 patients) and 3.4% for the control group (5/146 patients), showing no significant statistical difference (P=0.32). There were no cases of deep SSI in the study group, whereas there were 4 cases in the control group. The deep SSI rate significantly decreased in the study group (P=0.027). No adverse events occurred in the study group. CONCLUSION: In this study, 90 seconds of 1% PVP-I pooling every 1.5 hours followed by saline irrigation demonstrated the effectiveness of our protocol for the prevention of postoperative deep SSI after spinal surgery.

Impact of Different Selectivity between Soluble and Membrane-bound Forms of Carcinoembryonic Antigen (CEA) on the Target-mediated Disposition of Anti-CEA Monoclonal Antibodies.

Carcinoembryonic antigen (CEA) is a tumor-specific antigen overexpressed in multiple cancers. CEA is expressed as a membrane protein, a part of which is cleaved from the cell membrane and secreted into blood. The soluble form of CEA (sCEA) has been shown to accelerate the clearance of anti-CEA antibody, which limits the antibody distribution in the tumor. To overcome this issue, we developed an anti-CEA monoclonal antibody, 15-1-32, which shows a strong affinity for membrane-bound CEA (mCEA) and relatively weak affinity for sCEA. In this study, we compared the effect of sCEA on the pharmacokinetics of 15-1-32 in mice with that of another anti-CEA monoclonal antibody, labetuzumab, showing less selectivity to mCEA than 15-1-32. As expected, the effect of sCEA on the serum concentration of 15-1-32 was much smaller than that of labetuzumab. The decrease in the area under the curve (AUC) of serum concentration was 22.5% for 15-1-32 when it was coadministered with sCEA, while that of labetuzumab was 79.9%. We also compared the pharmacokinetics of these two antibodies in CEA-positive tumor-bearing mice. The AUCs of 15-1-32 and labetuzumab were decreased in tumor-bearing mice compared with non-tumor-bearing mice to a similar extent (approximately 40% decrease). These results suggested that mCEA also contributes to the clearance of anti-CEA antibodies in CEA-positive tumor-bearing mice. Although the increased selectivity to mCEA minimized the effect of sCEA on the pharmacokinetics of 15-1-32, it may be insufficient to improve the pharmacokinetics in CEA-positive cancer patients. SIGNIFICANCE STATEMENT: Because previous studies reported the rapid clearance of anti-CEA antibodies mediated by soluble CEA, we obtained a monoclonal antibody, 15-1-32, selective to membrane-bound CEA and evaluated the effects of CEA on its pharmacokinetics. Although the effect of soluble CEA on the serum concentration of 15-1-32 was very small, the clearance of 15-1-32 in CEA-positive tumor-bearing mice was still rapid, suggesting membrane-bound CEA also contributes to the clearance of anti-CEA antibodies. These results indicated that increasing selectivity to membrane-bound CEA is not enough to improve the pharmacokinetics of anti-CEA antibody.

Development and evaluation of a novel antibody-photon absorber conjugate reveals the possibility of photoimmunotherapy-induced vascular occlusion during treatment in vivo.

Photodynamic therapy (PDT) utilize a photosensitizing agent and light for cancer therapy. It exerts anti-cancer effect mainly by inducing vascular occlusion at the irradiated site. By controlling the irradiation area, PDT can be used in a tumor-specific manner. However, the non-specific cellular damage in the surrounding normal tissue is still a serious concern. Photoimmunotherapy (PIT) is a new type of targeted cancer therapy that uses an antibody-photon absorber conjugate (APC). The superiority of PIT to PDT is the improved target specificity, thereby reducing the damage to normal tissues. Here, we developed a novel APC targeting epithelial cell adhesion molecule (EpCAM) as well as a negative control APC that does not bind to the EpCAM antigen. Our in vitro analysis of APC cytotoxicity demonstrated that the EpCAM APC, but not the negative control, was cytotoxic to EpCAM expressing COLO 205 cells after photoirradiation, suggesting that the cytotoxicity is antigen-dependent. However, in our in vivo analysis using a mouse xenograft tumor model, decreased volume of the tumors was observed in all the mice treated with irradiation, regardless of whether they were treated with the EpCAM APC or the negative control. Detailed investigation of the mechanism of these in vivo reveal that both APCs induce vascular occlusion at the irradiation site. Furthermore, the level of vascular occlusion was correlated with the blood concentration of APC, not the tumor concentration. These results imply that, similar to PDT, PIT can also induce non-targeted vascular occlusion and further optimization is required before widespread clinical use.

Novel anticarcinoembryonic antigen antibody-drug conjugate has antitumor activity in the existence of soluble antigen.

Carcinoembryonic antigen (CEA) is a classic tumor-specific antigen that is overexpressed in several cancers, including gastric cancer. Although some anti-CEA antibodies have been tested, to the best of our knowledge, there are currently no clinically approved anti-CEA antibody therapies. Because of this, we have created the novel anti-CEA antibody, 15-1-32, which exhibits stronger binding to membrane-bound CEA on cancer cells than existing anti-CEA antibodies. 15-1-32 also shows poor affinity for soluble CEA; thus, the binding activity of 15-1-32 to membrane-bound CEA is not influenced by soluble CEA. In addition, we constructed a 15-1-32-monomethyl auristatin E conjugate (15-1-32-vcMMAE) to improve the therapeutic efficacy of 15-1-32. 15-1-32-vcMMAE showed enhanced antitumor activity against gastric cancer cell lines. Unlike with existing anti-CEA antibody therapies, antitumor activity of 15-1-32-vcMMAE was retained in the presence of high concentrations of soluble CEA.

Psychometric Assessment of the Japanese Version of the Zurich Claudication Questionnaire (ZCQ): Reliability and Validity.

PURPOSE: The Zurich Claudication Questionnaire (ZCQ) is a self-administered measure to evaluate symptom severity, physical function, and surgery satisfaction in lumbar spinal stenosis (LSS). The purpose of this study is to assess the psychometric properties of the Japanese ZCQ in LSS patients. METHODS: LSS patients who are scheduled to undergo surgery were recruited from 12 facilities. Responses to several questionnaires, including the Japanese ZCQ; the visual analogue scale (VAS) to evaluate the degree of pain in the buttocks/legs, numbness in the buttocks/legs, and low back pain; the Oswestry Disability Index (ODI); and the SF-36v2, were collected before surgery and again 3 months after surgery (the post-surgery ZCQ was administered twice for test-retest reliability). For reliability, test-retest reliability was evaluated using the intra-class coefficient (ICC) and internal consistency was evaluated using Cronbach's alpha coefficient. Concurrent validity was assessed using Spearman's correlation coefficients between the Japanese ZCQ and other questionnaires. Effect size (ES) and standard response mean were calculated for responsiveness. All analyses were performed individually for the Japanese ZCQ symptom, function, and satisfaction domains. RESULTS: Data from 180 LSS patients were used in this analysis. The ICCs were 0.81, 0.89, and 0.88 and Cronbach's alpha coefficients were 0.78, 0.84, and 0.92 for the Japanese ZCQ symptom, function, and satisfaction domains, respectively. Regarding the concurrent validity, strong correlations (±0.5) were demonstrated between the Japanese ZCQ domains and the VAS leg pain, ODI, and SF-36v2 physical functioning or bodily pain, whereas correlations were approximately 0.3 in scales measuring other symptoms that are less related to symptom, function, or satisfaction domains. ESs showed high values for the ZCQ symptom and function domains (-1.73 for both). CONCLUSIONS: These psychometric assessments demonstrate that the Japanese ZCQ is a psychometrically reliable and valid measure in LSS. The Japanese ZCQ can evaluate both multi-dimensional aspects and the level of surgery satisfaction.

One-Step Conjugation Method for Site-Specific Antibody-Drug Conjugates through Reactive Cysteine-Engineered Antibodies.

Engineered cysteine residues are particularly convenient for site-specific conjugation of antibody-drug conjugates (ADC), because no cell engineering and additives are required. Usually, unpaired cysteine residues form mixed disulfides during fermentation in Chinese hamster ovarian (CHO) cells; therefore, additional reduction and oxidization steps are required prior to conjugation. In this study, we prepared light chain (Lc)-Q124C variants in IgG and examined the conjugation efficiency. Intriguingly, Lc-Q124C exhibited high thiol reactivity and directly generated site-specific ADC without any pretreatment (named active thiol antibody: Actibody). Most of the cysteine-maleimide conjugates including Lc-Q124C showed retro-Michael reaction with cysteine 34 in albumin and were decomposed over time. In order to acquire resistance to a maleimide exchange reaction, the facile procedure for succinimide hydrolysis on anion exchange resin was employed. Hydrolyzed Lc-Q124C conjugate prepared with anion exchange procedure retained high stability in plasma. Recently, various stable linkage schemes for cysteine conjugation have been reported. The combination with direct conjugation by the use of Actibody and stable linker technology could enable the generation of stable site-specific ADC through a simple method. Actibody technology with Lc-Q124C at a less exposed position opens a new path for cysteine-based conjugation, and contributes to reducing entry barriers to the preparation and evaluation of ADC.

Importance of the Side Chain at Position 296 of Antibody Fc in Interactions with FcγRIIIa and Other Fcγ Receptors.

Antibody-dependent cellular cytotoxicity (ADCC) is an important effector function determining the clinical efficacy of therapeutic antibodies. Core fucose removal from N-glycans on the Fc portion of immunoglobulin G (IgG) improves the binding affinity for Fcγ receptor IIIa (FcγRIIIa) and dramatically enhances ADCC. Our previous structural analyses revealed that Tyr-296 of IgG1-Fc plays a critical role in the interaction with FcγRIIIa, particularly in the enhanced FcγRIIIa binding of nonfucosylated IgG1. However, the importance of the Tyr-296 residue in the antibody in the interaction with various Fcγ receptors has not yet been elucidated. To further clarify the biological importance of this residue, we established comprehensive Tyr-296 mutants as fucosylated and nonfucosylated anti-CD20 IgG1s rituximab variants and examined their binding to recombinant soluble human Fcγ receptors: shFcγRI, shFcγRIIa, shFcγRIIIa, and shFcγRIIIb. Some of the mutations affected the binding of antibody to not only shFcγRIIIa but also shFcγRIIa and shFcγRIIIb, suggesting that the Tyr-296 residue in the antibody was also involved in interactions with FcγRIIa and FcγRIIIb. For FcγRIIIa binding, almost all Tyr-296 variants showed lower binding affinities than the wild-type antibody, irrespective of their core fucosylation, particularly in Y296K and Y296P. Notably, only the Y296W mutant showed improved binding to FcγRIIIa. The 3.00 Å-resolution crystal structure of the nonfucosylated Y296W mutant in complex with shFcγRIIIa harboring two N-glycans revealed that the Tyr-to-Trp substitution increased the number of potential contact atoms in the complex, thus improving the binding of the antibody to shFcγRIIIa. The nonfucosylated Y296W mutant retained high ADCC activity, relative to the nonfucosylated wild-type IgG1, and showed greater binding affinity for FcγRIIa. Our data may improve our understanding of the biological importance of human IgG1-Fc Tyr-296 in interactions with various Fcγ receptors, and have applications in the modulation of the IgG1-Fc function of therapeutic antibodies.

Identification of highly reactive cysteine residues at less exposed positions in the Fab constant region for site-specific conjugation.

Engineered cysteine residues are currently used for the site-specific conjugation of antibody-drug conjugates (ADC). In general, positions on the protein surface have been selected for substituting a cysteine as a conjugation site; however, less exposed positions (with less than 20% of accessible surface area [ASA]) have not yet been evaluated. In this study, we engineered original cysteine positional variants of a Fab fragment, with less than 20% of ASA, and evaluated their thiol reactivities through conjugation with various kinds of payloads. As a result, we have identified three original cysteine positional variants (heavy chain: Hc-A140C, light chain: Lc-Q124C and Lc-L201C), which exhibited similar monomer content, thermal stability, and antigen binding affinity in comparison to the wild-type Fab. In addition, the presence of cysteine in these positions made it possible for the Fab variants to react with variable-sized molecules with high efficiency. The favorable physical properties of the cysteine positional variants selected in our study suggest that less exposed positions, with less than 20% of ASA, provide an alternative for creating conjugation sites.

Comparison of the Japanese Orthopaedic Association (JOA) score and modified JOA (mJOA) score for the assessment of cervical myelopathy: a multicenter observational study.

OBJECTIVES: The Japanese Orthopaedic Association (JOA) score is widely used to assess the severity of clinical symptoms in patients with cervical compressive myelopathy, particularly in East Asian countries. In contrast, modified versions of the JOA score are currently accepted as the standard tool for assessment in Western countries. The objective of the present study is to compare these scales and clarify their differences and interchangeability and verify their validity by comparing them to other outcome measures. MATERIALS AND METHODS: Five institutions participated in this prospective multicenter observational study. The JOA and modified JOA (mJOA) proposed by Benzel were recorded preoperatively and at three months postoperatively in patients with cervical compressive myelopathy who underwent decompression surgery. Patient reported outcome (PRO) measures, including Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ), the Short Form-12 (SF-12) and the Neck Disability Index (NDI), were also recorded. The preoperative JOA score and mJOA score were compared to each other and the PRO values. A Bland-Altman analysis was performed to investigate their limits of agreement. RESULTS: A total of ninety-two patients were included. The correlation coefficient (Spearman's rho) between the JOA and mJOA was 0.87. In contrast, the correlations between JOA/mJOA and the other PRO values were moderate (|rho| = 0.03 - 0.51). The correlation coefficient of the recovery rate between the JOA and mJOA was 0.75. The Bland-Altman analyses showed that limits of agreement were 3.6 to -1.2 for the total score, and 55.1% to -68.8% for the recovery rates. CONCLUSIONS: In the present study, the JOA score and the mJOA score showed good correlation with each other in terms of their total scores and recovery rates. Previous studies using the JOA can be interpreted based on the mJOA; however it is not ideal to use them interchangeably. The validity of both scores was demonstrated by comparing these values to the PRO values.

The novel CA IX inhibition antibody chKM4927 shows anti-tumor efficacy in vivo.

Carbonic anhydrase IX (CA IX) is an attractive target for cancer therapy. Many anti-CA IX antibodies have been reported but few have been shown to possess inhibition activity. Furthermore, effective use of CA IX-inhibition antibodies for cancer immunotherapy has not been well-validated since data are mainly limited to in vitro assays. In this study, we established that chKM4927, an anti-CA IX chimeric antibody, recognizes CA IX and has CA IX-specific inhibition activity. ChKM4927 also retains antibody-dependent cellular cytotoxicity (ADCC) activity against CA IX-expressing cancer cells. Compared to controls, chKM4927 treatment (10 mg/kg) showed anti-tumor activity in the VMRC-RCW xenograft model in vivo. ChKM4927-attenuated ADCC activity showed equally effective anti-tumor activity. These results suggest that the CA IX-inhibition antibody chKM4927 has an anti-tumor effect in the VMRC-RCW xenograft model via an ADCC-independent mechanism.

Establishment of a signal peptide with cross-species compatibility for functional antibody expression in both Escherichia coli and Chinese hamster ovary cells.

Signal peptides are short peptides located at the N-terminus of secreted proteins. They characteristically have three domains; a basic region at the N-terminus (n-region), a central hydrophobic core (h-region) and a carboxy-terminal cleavage region (c-region). Although hundreds of different signal peptides have been identified, it has not been completely understood how their features enable signal peptides to influence protein expression. Antibody-derived signal peptides are often used to prepare recombinant antibodies expressed by eukaryotic cells, especially Chinese hamster ovary (CHO) cells. However, when prokaryotic Escherichia coli (E. coli) are utilized in drug discovery processes, such as for phage display selection or antibody humanization, signal peptides have been selected separately due to the differences in the expression systems between the species. In this study, we successfully established a signal peptide that enables a functional antibody to be expressed in both prokaryotic and eukaryotic cells by focusing on the importance of having an Ala residue in the c-region of the signal sequence. We found that changing Ser to Ala at only two positions significantly augmented the anti-HER2 antigen binding fragment (Fab) expression in E. coli. In addition, this altered signal peptide also retained the ability to express functional anti-HER2 antibody in CHO cells. Taken together, the present findings indicate that the signal peptide can promote functional antibody expression in both prokaryotic E. coli and eukaryotic CHO cells. This finding will contribute to the understanding of signal peptides and accelerate therapeutic antibody research.

Factors affecting the occurrence of pulmonary embolism after spinal surgery: data from the national administrative database in Japan.

BACKGROUND CONTEXT: Despite potentially devastating consequences, pulmonary embolism (PE) in patients undergoing spinal surgery remains poorly understood. To the best of our knowledge, few large studies have examined the prevalence and risk factors of PE after spinal surgery. PURPOSE: To investigate the prevalence of symptomatic PE in patients undergoing elective spinal surgery and to identify clinical variables associated with the occurrence of postoperative PE. STUDY DESIGN: A retrospective analysis of data abstracted from the diagnosis procedure combination (DPC) database, a nationally representative database in Japan. PATIENT SAMPLE: We included all patients with a diagnosis of spinal canal stenosis, disc herniation, spondylosis, spondylolisthesis, trauma, metastatic tumor, or infection who underwent spinal surgery between July 1 and December 31 of 2007 and 2008, respectively. OUTCOME MEASURES: The primary end point was defined as the occurrence of postoperative PE during hospitalization. The secondary end point was in-hospital death after postoperative PE. METHODS: We analyzed the association between the occurrence of postoperative PE and clinical variables recorded in the DPC database, including age, sex, comorbidities, location of surgery, primary diagnosis, anterior/posterior approach, use of instrumentation, and duration of anesthesia. RESULTS: A total of 47,743 patients were identified. Of these, 50 (0.10%) developed PE and four died as a result of PE. Logistic regression analyses revealed that occurrence of PE was associated with older age (70 years or older; odds ratio [OR], 3.15; 95% confidence interval [CI], 1.15-8.69; p=.026) and longer anesthesia time (more than 360 minutes; OR, 2.19; 95% CI, 0.88-5.44; p=.092). Patients with trauma were significantly more likely to have a PE than those with spinal canal stenosis (0.27% vs. 0.09%; OR, 2.86; 95% CI, 1.14-7.18; p=.026). CONCLUSIONS: This retrospective analysis of a nationally representative database identified older age, longer anesthesia time, and spinal trauma as risk factors for increased incidence of postoperative PE. Surgeons should be aware of the increased risk of postoperative PE in these subgroups of patients.