Factors related to masticatory performance in junior and senior high school students and young adults: A cross-sectional study

PURPOSE

Maintaining good masticatory function from a young age promotes lifelong health, yet limited studies have explored masticatory performance in young individuals. We investigated the relationship of sex, age, and individual oral functions with masticatory performance among junior and senior high school students and young adults.

METHODS

This cross-sectional study included students aged 12-13, 14-15, and 16-17 years (groups S1, S2, and S3, respectively) and young adults aged 20-40 years (group YA). We assessed oral functions, the number of functional teeth, and anthropometric measurements. Masticatory performance was evaluated using color-changeable chewing gum. We analyzed sex-related differences in each group and age-related differences in each sex. Multiple linear regression analysis was performed using masticatory performance as the dependent variable to investigate related factors.

RESULTS

Among the 522 children and 100 young adults, males exhibited significantly higher masticatory performance than females in groups S1, S3, and YA. Among males, groups S2, S3, and YA exhibited significantly higher masticatory performance than group S1. Among females, group S2 exhibited higher masticatory performance than groups S1 and S3. Male sex, the maximum occlusal force and tongue pressure, and the number of functional teeth were significantly correlated with masticatory performance.

CONCLUSIONS

Masticatory function development differed by sex, with males exhibiting higher masticatory performance than females. We identified that male sex, the maximum occlusal force and tongue pressure, and the number of functional teeth were significantly associated with masticatory performance. Our findings provide a basis for masticatory performance assessment in different age groups.

Phase Ib/II Study of a Liposomal Formulation of Eribulin (E7389-LF) plus Nivolumab in Patients with Advanced Solid Tumors: Results from Phase Ib

Purpose

To determine a recommended dose of liposomal eribulin (E7389-LF) in combination with nivolumab in patients with advanced solid tumors, and to evaluate the safety, efficacy, pharmacokinetics, and biomarker impact of this regimen.

Experimental Design

Japanese patients with advanced, nonresectable, or recurrent solid tumors and no existing alternative standard/effective therapy (except nivolumab monotherapy) were assigned to either E7389-LF 1.7 mg/m² plus nivolumab 360 mg every 3 weeks, E7389-LF 2.1 mg/m² plus nivolumab 360 mg every 3 weeks, E7389-LF 1.1 mg/m² plus nivolumab 240 mg every 2 weeks, or E7389-LF 1.4 mg/m² plus nivolumab 240 mg every 2 weeks. Primary objectives were to evaluate the safety/tolerability of each dose cohort and to determine the recommended phase II dose (RP2D). Secondary/exploratory objectives, including safety [dose-limiting toxicities (DLT) and adverse events (AE)], pharmacokinetics, efficacy [including objective response rate (ORR)], and biomarker results were used in determining the RP2D.

Results

Twenty-five patients were enrolled to treatment [E7389-LF 1.7 mg/mg² every 3 weeks (n = 6), E7389-LF 2.1 mg/m² every 3 weeks (n = 6), E7389-LF 1.1 mg/m² every 2 weeks (n = 7), E7389-LF 1.4 mg/m² every 2 weeks (n = 6)]. Twenty-four patients were evaluated for DLTs, of whom 3 had DLTs (1 at E7389-LF 1.7 mg/m² every 3 weeks, 1 at 1.1 mg/m² every 2 weeks, and 1 at 1.4 mg/m² every 2 weeks). All patients had ≥1 treatment-related treatment-emergent AE (TEAE); 68.0% had ≥1 grade 3-4 treatment-related TEAE. Changes in vasculature and IFN-related biomarkers were seen in each cohort. The overall ORR was 16%.

Conclusions

E7389-LF plus nivolumab was tolerable overall; the recommended dose for future study was 2.1 mg/m² plus nivolumab 360 mg every 3 weeks.

Significance

This phase Ib part of a phase Ib/II study assessed the tolerability and activity of a liposomal formulation of eribulin (E7389-LF) plus nivolumab in 25 patients with advanced solid tumors. The combination was tolerable overall; 4 patients had a partial response. Vasculature and immune-related biomarker levels increased, suggesting vascular remodeling.

Factors Related to Oral Problems in Patients with Prolonged Disorders of Consciousness in Long-Term Care: A Cross-Sectional Study

Factors influencing oral problems, such as malocclusion and oral motor dysfunction, in patients with prolonged disorders of consciousness (DOC) remain unclear. This study aimed to clarify the relationship between oral problems and physical function, communication, respiration, and oral intake status, as well as related factors in patients with DOC receiving long-term care at home. A cross-sectional study was conducted in October 2018; 127 patients who developed DOC > 5 years ago were analyzed. The differences between patients with and without oral problems were examined, and a binomial logistic regression analysis was performed to examine factors associated with oral problems, with the presence of oral problems as the dependent variable, and age, the number of years since onset, drooling, oral intake status, and the presence of a family dentist as explanatory variables. A post hoc power analysis of the binomial logistic regression analysis for oral problems (odds ratio: 2.05, alpha value: 0.05, incidence of oral problems: 0.80, and total sample size: 127) demonstrated an observed power of 93.09%. Oral intake status (p = 0.010) and the number of years since onset (p = 0.046) were significantly related to oral problems. Preventive oral management and rehabilitation from the early stage after onset may be effective for oral problems in patients with DOC.

Association between characteristics of swallowing-related muscles and trunk muscle mass

Swallowing function is associated with systemic factors. Whether trunk or appendicular skeletal muscle mass is a better indicator of swallowing-related muscle characteristics in community-dwelling older adults is not clear. Hence, we investigated the association between the characteristics of swallowing-related muscles (e.g., mass and quality) and trunk muscle mass. Community-dwelling older adults aged ≥ 65 years (n = 141; men: n = 45, women: n = 96) were recruited for this cross-sectional observational study via a health survey conducted in 2018. Trunk muscle mass index (TMI) and appendicular skeletal muscle mass index (SMI) were measured using bioelectrical impedance analysis. Cross-sectional areas (CSAs) and echo intensity (EI) of the geniohyoid muscle (GHM) and tongue were evaluated using an ultrasonic diagnostic apparatus. Multiple regression analysis was used to examine the relationship of the characteristics of swallowing-related muscle with TMI and SMI. Multiple regression analysis showed that CSA of the GHM was positively associated with both TMI (B = 24.9, p < 0.001) and SMI (B = 13.7, p = 0.002). EIs of swallowing-related muscles were not associated with TMI and SMI. Trunk muscle mass was associated with swallowing-related muscle mass and not muscle quality. The results of this study shed light on the elucidation of association of dysphagia with TMI and SMI.

Analysis of swallowing function after anterior/posterior surgery for cervical degenerative disorders and factors related to the occurrence of postoperative dysphagia

BACKGROUND CONTEXT

Dysphagia is one of the postoperative complications of cervical degenerative disorders. However, few studies have evaluated the pre- and postoperative swallowing function in detail.

PURPOSE

To analyze pre- and postoperative swallowing dynamics kinetically and investigate factors associated with postoperative dysphagia in patients with cervical degenerative disorders.

STUDY DESIGN

Retrospective review of prospectively collected data.

PATIENT SAMPLE

A total of 41 consecutive patients who underwent an anterior approach (anterior cervical discectomy/corpectomy and fusion (ACDF, ACCF), hybrid surgery (ACDF+ACCF) and total disc replacement) and 44 consecutive patients who underwent a posterior approach (laminoplasty and laminoplasty/laminectomy with fusion).

OUTCOME MEASURES

We compared the pre- and postoperative functional oral intake scale (FOIS), dysphagia severity scale (DSS), esophageal dysphagia, anterior/superior hyoid movement, upper esophageal sphincter (UES) opening, pharyngeal transit time, bolus residue scale (BRS), and the number of swallows.

METHODS

Videofluoroscopy was performed on the day before surgery and within two weeks after surgery. Data related to age, gender, disease, surgical procedure, surgical site, operative time, and blood loss were collected from the medical records. Pre- and postoperative data were compared for each item in the anterior and posterior approaches. The odds ratio of dysphagia after an anterior approach was also calculated.

RESULTS

In the anterior approach, DSS, FOIS, the anterior and superior hyoid movements, maximum UES opening, BRS, and number of swallows worsened postoperatively (p<.05, respectively). In the posterior approach, DSS, FOIS, the anterior hyoid movement, and BRS worsened postoperatively (p<.05, respectively). The factors associated with dysphagia were a proximal surgical site above C3 (OR: 14.40, CI: 2.84-73.02), blood loss >100 mL (OR: 9.60, CI: 2.06-44.74), an operative time >200 minutes (OR: 8.18, CI: 1.51-44.49), and an extensive surgical field of more than three intervertebral levels (OR: 6.72, CI: 1.50-30.07). The decline in swallowing function after the posterior approach was related to aging (p=.045).

CONCLUSIONS

Each approach may decrease swallowing function, especially because of the limitation on the anterior hyoid movement. Dysphagia after anterior approaches was associated with the operative site, operative time, and blood loss.

Effects of tongue right positioner use on tongue pressure: a pilot study

The effectiveness of the tongue right positioner (TRP) use on oral and swallowing functions remains unclear. To investigate the effects of TRP use on tongue function in patients with dysphagia. This interventional study included eight participants with dysphagia who visited a university dental hospital. The measurement variables included tongue pressure (TP) as the primary outcome and lip and tongue movements, peak nasal inspiratory flow, and changes in the tongue and suprahyoid muscle regions on ultrasonography as the secondary outcomes. Each participant was asked to use a TRP for at least 8 h every night for 2 months. The measurement variables before and after the intervention were compared using the paired t test and Wilcoxon signed-rank test. TP after intervention (31.5 ± 13.1 kPa) was significantly higher than that before intervention (23.0 ± 13.4 kPa), while other measurement variables did not significantly improve. Numerous exercises have been suggested to improve TP; however, most require patients' adherence to instructions. In contrast, although participants did not perform active exercises, most participants in this study observed an improved TP. Our findings show that TRP can greatly improve TP after 2 months of usage.Trial registration number: University Hospital Medical Information Network Clinical Trials Registry (UMIN000040253, date of first registration: 27/04/2020).

Application of organoid culture from HPV18-positive small cell carcinoma of the uterine cervix for precision medicine

BACKGROUND

Small cell carcinoma of the uterine cervix (SCCC) is a rare and highly malignant human papillomavirus (HPV)-associated cancer in which human genes related to the integration site can serve as a target for precision medicine. The aim of our study was to establish a workflow for precision medicine of HPV-associated cancer using patient-derived organoid.

METHODS

Organoid was established from the biopsy of a patient diagnosed with HPV18-positive SCCC. Therapeutic targets were identified by whole exome sequencing (WES) and RNA-seq analysis. Drug sensitivity testing was performed using organoids and organoid-derived mouse xenograft model.

RESULTS

WES revealed that both the original tumor and organoid had 19 somatic variants in common, including the KRAS p.G12D pathogenic variant. Meanwhile, RNA-seq revealed that HPV18 was integrated into chromosome 8 at 8q24.21 with increased expression of the proto-oncogene MYC. Drug sensitivity testing revealed that a KRAS pathway inhibitor exerted strong anti-cancer effects on the SCCC organoid compared to a MYC inhibitor, which were also confirmed in the xenograft model.

CONCLUSION

In this study, we confirmed two strategies for identifying therapeutic targets of HPV-derived SCCC, WES for identifying pathogenic variants and RNA sequencing for identifying HPV integration sites. Organoid culture is an effective tool for unveiling the oncogenic process of rare tumors and can be a breakthrough for the development of precision medicine for patients with HPV-positive SCCC.

Time Spent Away from Bed to Maintain Swallowing Function in Older Adults

INTRODUCTION

The aim of this study was to determine the associations of time spent away from bed with whole-body muscle mass and swallowing function in older adults with low activities of daily living (ADL).

METHODS

This cross-sectional study was conducted at Tokyo Medical and Dental University and included adults over 65 years of age who underwent a medical intervention at their residence. Data regarding age, sex, body height and weight, activity status, medical history, time spent away from bed, and Functional Oral Intake Scale (FOIS) were collected. We calculated the body mass index, Charlson Comorbidity Index, whole-body muscle mass, the appendicular skeletal muscle mass index (ASMI), and the trunk muscle mass index (TMI). According to the time spent away from bed, the subjects were grouped as follows: <4 but ≥0 h (S), <6 but ≥4 h (M), and ≥6 h (L). These variables were analyzed using the one-way analysis of variance, the Kruskal-Wallis test, and the χ2 test, then differences among the three groups were examined. To adjust for confounding factors, we performed multiple regression analysis with ASMI and TMI as the dependent variables and ordinal logistic regression analysis with FOIS as the objective variable.

RESULTS

Ninety subjects (male: n = 42; female: n = 48; mean age = 82.9 ± 8.8 years, and groups S: n = 23; M: n = 30; L: n = 37) were analyzed. Group L had a significantly higher ASMI, TMI, and FOIS score than groups S and M, while group M had a significantly higher ASMI and FOIS score than group S. After adjusting for confounding factors, the significant explanatory factors for ASMI were sex, activity status, time spent away from bed, and TMI. The factors for TMI were activity status, time spent away from bed, ASMI, and FOIS. The factors for FOIS were time spent away from bed and TMI.

CONCLUSION

Spending 4 or more hours away from the bed is related to appendicular skeletal muscle mass and FOIS, while spending 6 or more hours is related to appendicular skeletal muscle mass, trunk muscle mass, and FOIS in this population. These findings highlight factors that can prevent a decline in swallowing function in the daily life of older adults with low ADL who have difficulty performing exercises to preserve swallowing function.

The Safety of Oral Rehydration Solution Jelly for Water and Electrolyte Intake in Patients with Dysphagia

Purpose

Oral rehydration solutions (ORSs) are effective in replacing fluids and electrolytes and are widely used. OS-1 Jelly (Otsuka Pharmaceutical Factory, Tokushima, Japan) is a jelly drink corresponding to code 2-1 of the 2021 Japanese Dysphagia Diet. Although jelly drinks are less likely to be aspirated than liquids, their physical properties vary depending on the product. Therefore, the severity of dysphagia may affect intake status. This study aimed to investigate the association between the intake status of ORS jelly and swallowing function.

Patients and Methods

Thirty-six patients with dysphagia who required videoendoscopic swallowing evaluation at our university hospital were enrolled. Videoendoscopic swallowing evaluation was performed, and each participant swallowed 5 mL of OS-1 Jelly or thickened water modified to International Dysphagia Diet Standardization Initiative (IDDSI) level 2 three times. Statistical analysis was performed to determine the difference in the number of swallows, time until the swallowing reflex, position for inducing the swallowing reflex, presence of pharyngeal residue, penetration, or aspiration between ORS jelly and thickened water.

Results

The time until the swallowing reflex was induced and the position of the swallowing reflex triggered were significantly earlier for ORS jelly (p=0.012, p=0.001). The incidence of pharyngeal residue was significantly lower with ORS jelly (p=0.002). The Penetration-Aspiration Scale score was similar for both samples (p=0.062), and no aspiration was observed in either sample.

Conclusion

Patients with dysphagia who can swallow thickened water modified to IDDSI level 2 can consume ORS jelly. ORS jelly, which requires no thickening and can be easily and safely consumed, is effective for water and electrolyte intake in patients with dysphagia.

The Cross-Sectional Area of the Middle and Base of the Tongue is Associated with Swallowing-Related Muscle Strength

Muscle strength and function are generally positively correlated with muscle quantity and negatively correlated with muscle quality; however, the tongue shows a unique tendency, different from limb muscles. The relationship between the characteristics of each part of the tongue, muscle strength and function, and systemic factors has been unclear. The aim of the study was to investigate the relationship between cross-sectional area (CSA) and echo intensity (EI) of the middle and base of the tongue and swallowing, articulation function, and body composition. Eighty-nine healthy individuals were included in this cross-sectional study. Swallowing was assessed using tongue pressure (TP) and jaw opening force (JOF) as they indicate swallowing-related muscle strength. Articulation function was evaluated through oral diadochokinesis (ODK). Bioelectrical impedance analysis was performed for body composition. CSAs and EIs of the middle and base of the tongue were measured using ultrasound. Multiple regression analysis was used to examine the relationship between the characteristics of the tongue, swallowing-related muscle strength, and ODK. In multiple regression analysis with TP as the dependent variable, age (β = - 0.22, P < 0.01) and CSA of the middle part (β = 0.02, P < 0.01) were significant explanatory variables. In multiple regression analysis with JOF as the dependent variable, sex (β = - 2.76, P < 0.01) and CSA of the base (β = - 0.004, P < 0.05) were significant explanatory variables. Multiple regression analysis with articulation function as the dependent variable did not yield significant results. The CSA of the tongue is a better indicator of swallowing-related muscle strength than EI. Ultrasonography may be used for assessing swallowing-related muscle strength.

Single-cell transcriptomics reveals an angiogenic cell population for therapeutic angiogenesis in adipose tissue

Background

Therapeutic angiogenesis mediated by stem/progenitor cells is an attractive therapeutic option against cardiovascular disease (CVD). Adipose tissue (AT) can be safely obtained even in CVD patients with anti-platelet medications, and it is a readily available source of culture-expanded adipose-derived stem cells (ADSCs) for transplantation. Single-cell transcriptome enables us to screen all the surface markers at once, while conventional strategies have been limited for the number of target markers. Furthermore, gene profiling at single-cell resolution can be used for the quantification of each marker by how many favorable cells can be purified without mixing of detrimental cells.

Purpose

We aimed to identify and characterize a cell population with in vivo angiogenic potential by single-cell RNA sequencing (scRNA-seq) analysis and xenograft experiments.

Methods

We revisited scRNA-seq datasets of single cell fraction from AT, bone-marrow (BM), and umbilical-cord blood (UCB, n=6/organ) to find cell populations with pro-angiogenic potential. Next, we collected AT from CVD patients (n=23) and used multicolor flow cytometry to quantify and sort the specific populations. PBS, the specific marker-negative and unsorted ADSCs were used as controls. Xenograft models of PKH26 pre-labeled human ADSC transplantation in limb ischemia were used to evaluate the lectin capillary density, PKH+ engrafted ADSCs, and blood flow recovery.

Results

Clustering divided CD45–CD31–CD34+ progenitor fraction into 3 clusters. We identified pro-/anti-angiogenic clusters based on the expressions of well-known pro-/anti-angiogenic factors. All genes encoding cell-surface proteins were compared in this functional clustering, resulted in 17 markers screened (Fig. 1A, B). Taken together with enrichment analysis, CD271+ cells showed predominant and pro-angiogenic gene profile from the other top candidates including CD36 and CD54 (Fig. 1C, D). Next, we evaluated the number and gene profile of CD271+ cells in well-known stem cell sources including BM and UCB. Surprisingly, the number of CD271 expressing cells were significantly lower and did not show angiogenic gene profile in BM and UCB (Fig. 2A). In analysis of AT from 23 CVD patients, CD271+ cells were significantly decreased by donor insulin resistance (Fig. 2B). Cell therapy using CD271+ ADSCs demonstrated in vivo angiogenic capacity compared to those of CD271– ADSCs and PBS in limb ischemia model. Furthermore, CD271+ ADSC transplantation showed enhanced efficacy compared to unsorted ADSCs from the same donors (Fig. 2C–E).

Conclusion

In this study, we identified CD271+ cell population in AT as an angiogenic cell population through scRNA-seq analysis and cell therapy experiments. AT obtained from donors without insulin resistance would be the most suitable for CD271+ ADSC isolation. CD271+ ADSC transplantation with a promising angiogenic capacity could contribute better cell-based therapy tackling CVD.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Japan Society for the Promotion of Science (JSPS) KAKENHI (Tokyo, Japan)

Impact of Chocolate percutaneous transluminal angioplasty balloon on vessel preparation in drug-coated balloon angioplasty for femoropopliteal lesion

Purpose

To compare the impact of Chocolate and conventional balloons on vessel preparation in percutaneous transluminal angioplasty.

Materials and methods

This single-center retrospective study included 111 endovascular therapy consecutive cases of femoropopliteal lesions using drug-coated balloon strategy with a 1:1 pre-dilation balloon diameter between February 2020 and August 2021, divided into the Chocolate percutaneous transluminal angioplasty (n = 48) and conventional (n = 63) groups. Before the availability of Chocolate balloons in Japan (December 2020), a standard semi-compliant or non-compliant balloon was used for vessel preparation. The primary endpoint was rate of severe dissection after pre-dilatation. Secondary endpoints were angiographic percent diameter stenosis, bailout stent rate, primary patency rate, and freedom from target-lesion-revascularization rate at six months.

Results

There was no significant difference in patient and lesion characteristics. The procedural characteristics comprised balloon length 90 ± 37 and 149 ± 95 mm (P = 0.004) and inflation pressure 11 ± 3 and 16 ± 7 atm (P < 0.001) in the Chocolate and conventional groups, respectively. Regarding primary endpoint, rates of severe dissection were 4.2% and 25% (P = 0.003); regarding secondary endpoints, percent diameter stenosis was 18 ± 15% and 20 ± 17% (P = 0.409), and the rate of bailout stenting was 2.1% and 15.9% (P = 0.016) in the Chocolate and conventional groups, respectively. The primary patency rates at six months were 89.1% and 85.2% (P = 0.670), and freedom from target-lesion-revascularization rate at six months was 100% and 92.8% (P = 0.691) in the Chocolate and conventional groups, respectively.

Conclusion

Chocolate percutaneous transluminal angioplasty balloons reduce the rate of severe dissection while maintaining a sufficient dilatation effect during drug-coated balloon vessel preparation.

Cough Test Results during Screening for Silent Aspiration Are Affected by Risk Factors for Silent Cerebral Infarct in Older Adults with Chronic Disease

The cough reflex does not change with age. However, older adults with chronic diseases often have a reduced cough reflex. The effects of several risk factors on reduced cough sensitivity in older adults remain unclear. This study aims to clarify the risk factors for reduced cough sensitivity in older adults with chronic diseases. This cross-sectional study included participants aged <65 years (young group; n = 21), those aged ≥65 years (older adults with chronic disease group; n = 18), and those with dysphagia (dysphagia group; n = 16). A cough test was performed on all participants using an ultrasonic nebulizer with a mist of 1% w/v citric acid physiologic saline. Cough response was observed in the young (21/21), older adult (9/18), and dysphagia (13/16) groups. The difference between the young and older adult groups was significant (p < 0.01). The older adult and dysphagia groups had decreased cough sensitivity compared to the younger group. Cough sensitivity was affected by risk factors for silent cerebral infarct and age. Our findings show that cough test results might be affected by risk factors for silent cerebral infarction in older adults with chronic diseases.

Association between Tongue Pressure and Jaw-Opening Force in Older Adults

Tongue pressure (TP) is used to assess tongue muscle strength and is related to function and frailty. While performing TP, it is necessary to elevate the tongue and oral floor by contracting the suprahyoid muscles. However, the association between TP and suprahyoid muscle strength remains unclear. Accordingly, this study investigated the relationship between TP and jaw-opening force (JOF), an indicator of suprahyoid muscle strength. This cross-sectional study included 88 independent community-dwelling participants aged ≥65 years. Age, sex, and the number of remaining teeth were recorded. Ultrasonography was used to evaluate the cross-sectional area of the tongue and geniohyoid muscle, as representatives of the suprahyoid muscles. Sarcopenia was diagnosed based on appendicular skeletal muscle mass index, handgrip strength, and gait speed. Multiple regression analysis was performed with TP as the dependent variable. TP was significantly associated with JOF (β = 0.371, p = 0.003). This study revealed that decreased TP was associated with a decline in JOF and suprahyoid muscle mass in older adults. Thus, low TP may be associated with decreased JOF. Prevention of the weakness of the suprahyoid muscles and maintaining TP may also contribute to the prevention of frailty associated with TP.

Photoinduced Intramolecular Cyclization of Acylsilanes Bearing a Boronate Moiety: Construction of a Highly Strained trans-Fused Bicyclo[3.3.0]octane Skeleton

A reliable strategy for the construction of trans-fused bicyclo[n.3.0] skeletons was explored by utilizing photoinduced cyclization of acylsilanes bearing a boronate. The substrates having an acylsilane and a boronate in a 1,2-trans relationship were prepared via hydroboration of cycloalkene derivatives. The desired cyclization was efficiently promoted by photoirradiation to give the trans-fused bicyclo[n.3.0] derivatives as a single diastereomer. It is noteworthy that this methodology enables the efficient construction of a highly strained trans-5-5 ring system.

O-207 Incidence of Y chromosome microdeletions and microdissection testicular sperm extraction (micro TESE) in patients with Japanese azoospermic patients

Study question

What is the frequency of azoospermia factor (AZF) microdeletions and sperm retrieval rate (SRR) by micro TESE in patients with these deletions?

Summary answer

AZFc is most frequent of Y chromosome microdeletions and a predictor of micro TESE outcome in Japanese azoospermic men.

What is known already

After Klinefelter syndrome, Y chromosome microdeletions are the second most frequent genetic cause of male infertility, with a prevalence of 2%-10% in non-obstructive azoospermia (NOA) and three spermatogenesis loci in the Y chromosome long arm (Yq11) have been classified as AZFa, AZFb, and AZFc. The classical correlation of histopathology phenotypes with these three microdeletions comprises of complete absence of germ cells (Sertoli cell-only syndrome) in patients with AZFa microdeletions, maturation arrest of meiosis in patients with AZFb microdeletions, and hypospermatogenesis in patients with AZFc microdeletions, however, individual variation in the extent of deletions has led to various spermatogenic phenotypes.

Study design, size, duration

We performed a retrospective study based on two reproduction centers in Japan and evaluated 1373 azoospermic patients in our clinics between September 2013 and December 2021. We investigated the frequency of AZF microdeletions and SRR by micro TESE in patients with these microdeletions and therefore aimed to evaluate the correlation between AZF microdeletions and micro TESE results.

Participants/materials, setting, methods

A total of 1373 azoospermic were enrolled. After the diagnosis of azoospermia, karyotype analysis and detection of Y chromosome microdeletions were performed on peripheral blood lymphocytes of these patients. Y chromosome microdeletions in AZFa, AZFb, and AZFc regions were detected using Promega Y Chromosome AZF Analysis System version 2.0 (Promega Co.). Twenty sequence-tagged sites within the AZF region of Yq11 and the sex-determining region Y gene were targeted for polymerase chain reaction (PCR) amplification.

Main results and the role of chance

One hundred and fifty-two AZF microdeletions (11.1%) were detected in the azoospermic patients. The most common deleted region was AZFc (60 cases, 4.4%). Among the patients, 17 (1.2%), 1 (0.1%), 42 (3.1%), 13 (1.0%), and 6 (0.5%) had AZFa, AZFa+b, AZFb+c, AZFb, and AZFa+b+c microdeletions, respectively. When the cases were grouped according to causes of infertility that could be detected, no Y chromosome microdeletions were detected in some groups (cases with Klinefelter Syndrome, hypogonadotropic hypogonadism, congenital absence of vas deferens, and 47, XYY karyotype). Fifty-three azoospermic men with AZFc microdeletions underwent micro TESE, and spermatozoa were detected in 88.7% (47/53) of these men. In contrast, we detected spermatozoa in only 20.4% (109/534) of the azoospermic men without AZF microdeletions. The SRR was much higher in patients with AZFc microdeletions than that of patients without AZF deletions. Although three azoospermic men with AZFb+c microdeletions had also undergone micro TESE following patient request, we did not retrieve spermatozoa.

Limitations, reasons for caution

We excluded post chemotherapy NOA showing 46, XX and AZFa+b+c deletions post bone marrow transplantation from female donor. Additionally, we did not detect AZFc partial deletion including gr/gr deletion. The cohort size of this study is not small, however, our screened population of infertile men may be biased.

Wider implications of the findings

NOA patients with AZFc microdeletions had a high percentage of successful sperm retrieval by micro TESE. Our study emphasizes that diagnosis of Y chromosome microdeletions is critical for preconception genetic counseling and provides clinically valuable prognostic information to couples considering surgical sperm retrieval.

Trial registration number

None