Prepubertal Patients Research Articles

An advantageous practical modification in mini-laparoscopic pyeloplasty for prepubertal children: Extracorporeal ureteral spatulation, suturing and stenting - EUSSS technique.

Ureteral spatulation, the first ureteral suture, and double-J stenting may be challenging and time-consuming in laparoscopic pyeloplasty, especially in small children. We aimed to present our comparative results of the extracorporeal ureteral spatulation, suturing, and stenting (EUSSS) technique in mini-laparoscopic pyeloplasty (MLP) and the conventional intracorporeal technique in prepubertal children. The data of 46 prepubertal pediatric patients (< 12 years) who underwent laparoscopic pyeloplasty by a single surgeon between January 2021 and October 2023 were retrospectively reviewed. The patients were divided into two groups: who underwent EUSSS-MLP (Group-1, n = 26) and who underwent conventional intracorporeal pyeloplasty (Group-2, n = 20). The mean age of all patients was 5.3 years (4.8 ± 2.8 years in Group-1 and 6.0 ± 2.1 years in Group-2 p = 0.126). The mean duration of ureteral preparation plus double-J stenting was 5.7 ± 1.6min in Group-1 and 19.2 ± 4.1min in Group-2 (p < 0.0001). The mean duration of surgery was statistically significantly higher in Group-2 (p = 0.034). There was no significant difference in terms of postoperative complications (p = 0.482). Laparoscopic pyeloplasty was successful in 42 (91.3%) patients, with no statistically significant difference between the two groups (Group-1: 24 (92.3%), Group-2:18 (90%), p = 0.783). Extracorporeal ureteral preparation and double-J stenting can be safely and effectively preferred in MLP for prepubertal children.

Epidemiological, Clinical, Laboratory, and Radiological Characteristics of Children and Adolescents Diagnosed with Hashimoto's Thyroiditis: A Single-Center Experience.

This study aimed to investigate the epidemiological, clinical, laboratory, and radiological characteristics of children diagnosed with Hashimoto's thyroiditis and to present the experiences of a referral center. This study included 200 pediatric patients diagnosed with Hashimoto's thyroiditis between January 2020 and May 2024 at a single center. The data were extracted and compiled from the participants' medical records, including clinical information, physical examination findings, laboratory test results, and radiological imaging. Mean age of the study population was 11.3 ± 3.2 years at diagnosis, with a female predominance. At the time of clinical presentation, 8.5% of the study participants were 6 years of age or younger. The majority of patients, comprising 39.5% of the cohort, exhibited euthyroid thyroid function. Additionally, 33.5% of the patients were classified as having subclinical hypothyroidism, 22% demonstrated overt hypothyroidism, and 5% presented with hyperthyroidism. Approximately one-third of the study participants were referred for further evaluation due to the identification of abnormal thyroid function test results during routine screening examinations. 48% of the patients had a documented family history of thyroid disease. At diagnosis, 39.5% were prepubertal. The rate of overt hypothyroidism was higher in prepubertal patients compared to pubertal patients (41.8% vs. 9.1%, P < .005). Mean gland volume SDS was 2.61 ± 3.69, and 45.5% had goiter. Thyroid nodular lesions were identified in 5.5% of the study participants. Fine-needle aspiration biopsy was performed on five patients, revealing benign findings in three cases and atypia of undetermined significance in the remaining two cases. Patints with subclinical hypothyroidism who have a baseline TSH level exceeding 8.5 mIU/L at initial presentation and do not receive treatment are likely to progress to overt hypothyroidism during subsequent follow-up. Prepubertal cases were more frequently observed compared to previous reports, and the course of hypothyroidism was more severe in prepubertal patients. These findings suggest a potential shift towards earlier onset of autoimmunity in children. Further studies are warranted to substantiate this observation.

6432 Enriching Testicular Organoid Aggregates to Promote Germ Cell Homing

Abstract Disclosure: A. Patel: None. O.O. Printy: None. C. Joswiak: None. M.M. Laronda: None. The long-term effects of life-saving chemotherapy treatments, such as an increased risk of infertility, are of concern to the growing number of childhood cancer survivors. De novo testicular morphogenesis seeks to generate testicular organoids that are structurally and functionally similar to the native testis. These organoids serve as a tool for investigating patient-specific models for restoring spermatogenesis for prepubertal cancer patients. Our lab has previously developed testicular organoids containing tubule-like structures (TLS) resembling the native seminiferous tubules as assessed by immunohistochemistry of testicular cell-type markers for Leydig cells (HSD3B2), peritubular myoid cells (ACTA1), Sertoli cells (SOX9), germ cells (DDX4), and spermatogonial stem cells (SSCs) (SALL4). Internal architecture demonstrated semi-continuous ring-like structures composed of ACTA1-positive cells encapsulating a population of SOX9-positive cells with HSD3B2-positive cells clustering near the periphery of the organoids. However, organoids lacked native germ cell populations. We hypothesized that murine testicular organoids would merge to form elongated TLS, within which exogenous SSCs would home to existing Sertoli cell niches, when cultured within structures designed from the appropriate dimensions and materials. Organoids were generated from testicular tissue isolated from 5 days-post-partum (dpp) CD1 mice using cell-seeding densities and microenvironmental conditions previously established by our lab. To promote aggregate formation, 48-hour-old organoids were transferred to trough-shaped structures formed from 2% agarose using 3D printed silicone molds. Separately, SSCs were isolated from 5 dpp tdTomato+ mice via magnetic-activated cell sorting of THY1+ cells. Organoids and aggregates were enriched with SSCs by three methods: (1) enrichment of cell suspension during organoid formation, (2) enrichment of culture during aggregate formation, and (3) injection of SSCs into aggregate using 20 µm glass pipette. Organoids transferred to agarose troughs on day 2 of culture merged to form aggregates by day 5 and continued to display dynamic architecture, shortening in length and increasing in width over time. Aggregates were more elongated in shape when cultured in narrow troughs less than 700µm in width. Observations thus far indicate that attempts to inject aggregates resulted in penetrance and inclusion of the SSC suspension; additionally, tdTomato+ cells were visualized within injected aggregates on day 17 of culture. Research is ongoing to define where exogenous SSCs take up residence, how long they survive, and if they proliferate over time within the testicular aggregates. This research expands upon foundational work establishing testicular organoids as an approach to in vitro spermatogenesis with clinical applications in fertility restoration. Presentation: 6/2/2024

6432 Enriching Testicular Organoid Aggregates to Promote Germ Cell Homing

Abstract Disclosure: A. Patel: None. O.O. Printy: None. C. Joswiak: None. M.M. Laronda: None. The long-term effects of life-saving chemotherapy treatments, such as an increased risk of infertility, are of concern to the growing number of childhood cancer survivors. De novo testicular morphogenesis seeks to generate testicular organoids that are structurally and functionally similar to the native testis. These organoids serve as a tool for investigating patient-specific models for restoring spermatogenesis for prepubertal cancer patients. Our lab has previously developed testicular organoids containing tubule-like structures (TLS) resembling the native seminiferous tubules as assessed by immunohistochemistry of testicular cell-type markers for Leydig cells (HSD3B2), peritubular myoid cells (ACTA1), Sertoli cells (SOX9), germ cells (DDX4), and spermatogonial stem cells (SSCs) (SALL4). Internal architecture demonstrated semi-continuous ring-like structures composed of ACTA1-positive cells encapsulating a population of SOX9-positive cells with HSD3B2-positive cells clustering near the periphery of the organoids. However, organoids lacked native germ cell populations. We hypothesized that murine testicular organoids would merge to form elongated TLS, within which exogenous SSCs would home to existing Sertoli cell niches, when cultured within structures designed from the appropriate dimensions and materials. Organoids were generated from testicular tissue isolated from 5 days-post-partum (dpp) CD1 mice using cell-seeding densities and microenvironmental conditions previously established by our lab. To promote aggregate formation, 48-hour-old organoids were transferred to trough-shaped structures formed from 2% agarose using 3D printed silicone molds. Separately, SSCs were isolated from 5 dpp tdTomato+ mice via magnetic-activated cell sorting of THY1+ cells. Organoids and aggregates were enriched with SSCs by three methods: (1) enrichment of cell suspension during organoid formation, (2) enrichment of culture during aggregate formation, and (3) injection of SSCs into aggregate using 20 µm glass pipette. Organoids transferred to agarose troughs on day 2 of culture merged to form aggregates by day 5 and continued to display dynamic architecture, shortening in length and increasing in width over time. Aggregates were more elongated in shape when cultured in narrow troughs less than 700µm in width. Observations thus far indicate that attempts to inject aggregates resulted in penetrance and inclusion of the SSC suspension; additionally, tdTomato+ cells were visualized within injected aggregates on day 17 of culture. Research is ongoing to define where exogenous SSCs take up residence, how long they survive, and if they proliferate over time within the testicular aggregates. This research expands upon foundational work establishing testicular organoids as an approach to in vitro spermatogenesis with clinical applications in fertility restoration. Presentation: 6/2/2024

Safety and effectiveness of controlled ovarian stimulation and oocyte retrieval during prepubertal and peripubertal period.

Is itsafe and effective to perform controlled ovarian stimulation (COS) and oocyte retrieval (OR) in prepubertal and peripubertal patients? In this retrospective cohort study, data of 20 pre-/peripubertal patients who underwent COS and OR for the purpose of oocyte cryopreservation (OC) between 2008 and 2023 were reviewed.Following COS, all OR procedures were performed transabdominally using a vaginal ultrasound probe. Ovarian reserve was assessed by serum FSH, LH, estradiol, AMH, and antral follicle counts (AFC) in all subjects. All mature oocytes were vitrified. Mean age of the patients was 15.05 ± 1.87, mean AMH was 0.84 ± 0.8ng/ml, mean FSH was 6.39 ± 3.95IU/L, mean estradiol was 61.6 ± 51.9pg/ml, mean LH was 4.69 ± 3.46IU/L, and mean AFC was 5.5 ± 5.82. Among the patients, 12 had regular menstrual cycle, 5 had irregular menstrual cycle, whereas 3 patients still did not have their menarche yet. The indications for OC were as follows: primary ovarian insufficiency (n = 7), ovarian surgery for ovarian tumors (n = 5) or ovarian torsion (n = 1), mosaic Turner syndrome (n = 2), acute lymphoblastic leukemia (n = 1) anaplastic B-cell lymphoma (n = 1), Ewing's sarcoma (n = 1), Noonan syndrome (n = 1), and Thalassemia (n = 1). The mean number of oocytes retrieved, MII oocytes frozen, and maturation rate were 5.11 ± 5.0, 3.92 ± 4.48, and 75.1 ± 25.6%, respectively.Stepwise linear regression analysis demonstrated a positive correlation between AFC and number of total oocytes retrieved and number of MII oocytes. In the case diagnosed with Noonan syndrome, all 7 retrieved oocytes were MI and all frozen at MI phase. No patient had any complication related to COS or OR. Even though number of the enrolled subjects is limited and mean AMH is lower in our cohort, we demonstrated that performing COS and OR is safe in pre-/peripubertal patients. If required, transabdominal route can be performed in this age group for OR. AFC appears as a prognostic factor for stimulation outcome in this age group. Pediatric patients or young adolescents at risk for primary ovarian insufficiency should not bediscouragedfrom utilizing OC.

Have orthodontists changed their retention and follow-up protocols due to contemporary orthodontics? An online survey.

With advancements in orthodontic technology, treatment durations have shortened, often concluding at earlier ages. This shift prompts scrutiny of contemporary retention and post-treatment protocols. The study aimed to assess current professional preferences, compare them against patient age and treatment duration, and investigate the potential impacts of reduced treatment times on professional protocols, particularly when treatment concludes before pubertal growth. A questionnaire comprising 12 multiple-choice questions focused on active treatment and retention phases was developed using an online survey platform. It was distributed to licensed orthodontists engaged in patient treatment. Bivariate analysis was conducted using ANOVA and the Kruskal-Wallis test, with pairwise comparisons facilitated by the Dwass-Steel-Critchlow-Fligner method. Of 743 respondents, representing a 32% response rate, approximately 70% reported initiating treatment with fixed appliances in pre-pubertal patients. The most prevalent treatment combination involved commencing treatment during early permanent dentition and lasting between 12 to 24 months, resulting in treatment completion before full growth maturation. No discernible individualization was observed in retention protocols or post-retention follow-ups. Traditional retainer prescription post-orthodontic therapy was unanimous among respondents. Notably, experienced orthodontists tended to prefer regular patient visits for follow-up, while less experienced counterparts discharged patients after 12 months. Contemporary orthodontic treatments are characterized by shorter durations, yet orthodontists have not adopted retention and post-treatment follow-up practices accordingly. There is a pressing need for evidence-based guidelines to develop protocols tailored to the shorter treatment durations and the increasing prevalence of younger patients completing treatment.

Testicular mosaicism in non-mosaic postpubertal Klinefelter patients with focal spermatogenesis and in non-mosaic prepubertal Klinefelter boys.

Do testis-specific cells have a normal karyotype in non-mosaic postpubertal Klinefelter syndrome (KS) patients with focal spermatogenesis and in non-mosaic prepubertal KS boys? Spermatogonia have a 46, XY karyotype, and Sertoli cells surrounding these spermatogonia in postpubertal patients also have a 46, XY karyotype, whereas, in prepubertal KS boys, Sertoli cells surrounding the spermatogonia still have a 47, XXY karyotype. A significant proportion of patients with non-mosaic KS can have children by using assisted reproductive techniques thanks to focal spermatogenesis. However, the karyotype of the cells that are able to support focal spermatogenesis has not been revealed. Testicular biopsy samples from non-mosaic KS patients were included in the study. Karyotyping for sex chromosomes in testis-specific cells was performed by immunohistochemical analysis of inactive X (Xi) chromosome and/or fluorescent in situ hybridization (FISH) analysis of chromosomes 18, X, and Y. A total of 22 KS patients (17 postpubertal and 5 prepubertal) who were non-mosaic according to lymphocyte karyotype analysis, were included in the study. After tissue processing, paraffin embedding, and sectioning, the following primary antibodies were used for cell-specific analysis and Xi detection; one section was stained with MAGE A4 for spermatogonia, SOX9 for Sertoli cells, and H3K27me3 for Xi; the other one was stained with CYP17A1 for Leydig cells, ACTA2 for peritubular myoid cells, and H3K27me3 for Xi. Xi negative (Xi-) somatic cells (i.e. Sertoli cells, Leydig cells, and peritubular myoid cells) were evaluated as having the 46, XY karyotype; Xi positive (Xi+) somatic cells were evaluated as having the 47, XXY. FISH stain for chromosomes 18, X, and Y was performed on the same sections to investigate the karyotype of spermatogonia and to validate the immunohistochemistry results for somatic cells. According to our data, all spermatogonia in both postpubertal and prepubertal non-mosaic KS patients seem to have 46, XY karyotype. However, while the Sertoli cells surrounding spermatogonia in postpubertal samples also had a 46, XY karyotype, the Sertoli cells surrounding spermatogonia in prepubertal samples had a 47, XXY karyotype. In addition, while the Sertoli cells in some of the Sertoli cell-only tubules had 46, XY karyotype, the Sertoli cells in some of the other Sertoli cell-only tubules had 47, XXY karyotype in postpubertal samples. In contrast to the postpubertal samples, Sertoli cells in all tubules in the prepubertal samples had the 47, XXY karyotype. Our data also suggest that germ cells lose the extra X chromosome during embryonic, fetal, or neonatal life, while Sertoli cells lose it around puberty. Peritubular myoid cells and Leydig cells may also be mosaic in both postpubertal patients and prepubertal boys, but it requires further investigation. The number of prepubertal testicle samples containing spermatogonia is limited, so more samples are needed for a definitive conclusion. The fact that not all the cell nuclei coincide with the section plane limits the accurate detection of X chromosomes by immunohistochemistry and FISH in some cells. To overcome this limitation, X chromosome analysis could be performed by different techniques on intact cells isolated from fresh tissue. Additionally, there is no evidence that X chromosome inactivation reoccurs after activation of the Xi during germ cell migration during embryogenesis, limiting the prediction of X chromosome content in germ cells by H3K27me3. Our findings will lay the groundwork for new clinically important studies on exactly when and by which mechanism an extra X chromosome is lost in spermatogonia and Sertoli cells. This study was funded by The Scientific and Technological Research Council of Türkiye (TUBITAK) (2219 - International Postdoctoral Research Fellowship Program for Turkish Citizens) and the Strategic Research Program (SRP89) from the Vrije Universiteit Brussel. The authors declare no competing interests. N/A.

Generation of mouse testicular organoids with highly compartmentalized tubular lumen structure and their cryopreservation

Testicular organoids have great potential for maintaining male fertility and even restoring male infertility. However, existing studies on generating organoids with testis-specific structure and function are scarce and come with many limitations. Research on cryopreservation of testicular organoids is even more limited, and inappropriate cryopreservation methods may result in the loss of properties in resuscitated or regenerated organoids, rendering them unsuitable for clinical or research needs. In this paper, we investigated the effects of mouse age and cell number on the self-aggregation of testicular cells into spheres in low-adsorption plates. Various media compositions, culture systems, and cell numbers were used to culture cell spheres for 14 days to form testicular organoids, and the self-organization of the organoids was assessed by histological and immunofluorescence staining. We determined the appropriate cryopreservation conditions for testicular cells, cell spheres, and tissues. Subsequently, organoids derived from cryopreserved testicular tissues, testicular cells, and testicular cell spheres were compared and evaluated by histological and immunofluorescence staining. The results indicate that testicular cell spheres consisting of 30 × 104 testicular cells from 2-week-old mice were able to form organoids highly similar to the luminal structure and cell distribution of natural mouse testicular tissues. This transformation occurred over 14 days of incubation in α-MEM medium containing 10 % knockout serum replacer (KSR) using an agarose hydrogel culture system. Additionally, the Sertoli cells were tightly connected to form a blood-testis barrier. The relative rates of tubular area, germ cells, Sertoli cells, and peritubular myoid cells were 36.985 % ± 0.695, 13.347 % ± 3.102, 47.570 % ± 0.379, and 27.406 % ± 1.832, respectively. The optimal cryopreservation protocol for primary testicular cells involved slow freezing with a cryoprotectant consisting of α-MEM with 10 % dimethyl sulfoxide (DMSO). Slow freezing with cryoprotectants containing 5 % DMSO and 5 % ethylene glycol (EG) was optimal for all different volumes of testicular cell spheres. Compared to testicular organoids generated from frozen testicular tissue and cell spheres, freezing testicular cells proved most effective in maintaining organoid differentiation characteristics and cell-cell interactions. The findings of this study contribute to a “universal” testicular organoid in vitro culture protocol with promising applications for fertility preservation and restoration in prepubertal cancer patients and adult infertile patients.

Half-life of serum alpha-fetoprotein in prepubertal testicular yolk sac tumors: an index significantly associated with prognosis.

To evaluate the association between serum alpha-fetoprotein (AFP) half-life (HL) and prognosis in prepubertal children with elevated AFP values 3 to 4 weeks after surgery for testicular yolk sac tumors (YST). Prepubertal patients with testicular YST treated with radical orchiectomy between January 2016 and December 2022 were retrospectively reviewed. Negative outcomes were defined as relapse, metastasis or death. Univariate and multivariate logistic regression analyses were conducted to select risk factors for negative outcomes. A total of 42 patients were eventually enrolled into the study. Patients were divided into non-negative and negative outcomes groups, consisting of 35 and 7 patients, respectively. Thirty-five patients were stage I, two cases were stage II, and five cases were stage IV, according to the Children's Oncology Group staging system. The overall survival (OS) rate was 100%. Average AFP values significantly decreased after resection (P < 0.001). A significant positive correlation was shown between pre- and postoperative AFP values (r = 0.60, P < 0.001). Long AFP HL was considered as an independent risk factor for negative outcomes in YST patients underwent radical orchiectomy (P = 0.04). The cut-off value for AFP HL was 5.78 days, regardless of age division. Testicular YST is a relatively rare disease in children with an OS of 100%, and salvage chemotherapy is effective even in grade IV patients. The postoperative AFP HL was significantly associated with prognosis in prepubertal patients with testicular YST. The cut-off value for AFP HL is 5.78 days regardless of the effect of physiological AFP elevation.

Safety and efficacy of selumetinib in pediatric and adult patients with neurofibromatosis type 1 and plexiform neurofibroma.

The MEK inhibitor, selumetinib, reduces plexiform neurofibroma (PN) in pediatric patients with neurofibromatosis type 1 (NF1). Its safety and efficacy in adults with PN and effectiveness in other NF1manifestations (e.g., neurocognitive function, growth reduction, and café-au-lait spots) are unknown. This open-label, phase 2 trial enrolled 90 pediatric or adult NF1 patients with inoperable, symptomatic, or potentially morbid, measurable PN (≥ 3cm). Selumetinib was administered at doses of 20 or 25mg/m2 or 50mg q 12 hrs for 2 years. Pharmacokinetics, PN volume, growth parameters, neurocognitive function, café-au-lait spots, and quality of life (QoL) were evaluated. Fifty-nine children and 30 adults (median age, 16 years; range, 3-47) received an average of 22±5 (4-26) cycles of selumetinib. Eighty-eight (98.9%) out of 89 per-protocol patients showed volume reduction in the target PN (median, 40.8%; 4.2%-92.2%), and 81 (91%) patients showed partial response (≥ 20% volume reduction). The response lasted until cycle 26. Scores of neurocognitive functions (verbal comprehension, perceptual reasoning, processing speed, and full-scale IQ) significantly improved in both pediatric and adult patients (P <0.05). Prepubertal patients showed increases in height score and growth velocity (P <0.05). Café-au-lait spot intensity decreased significantly (P <0.05). Improvements in QoL and pain scores were observed in both children and adults. All adverse events were CTCAE grade 1 or 2 and were successfully managed without drug discontinuation. Selumetinib decrease PN volume in the majority of pediatric and adult NF1 patients while also showing efficacy in non-malignant diverse NF1 manifestations.

In Vitro Generation of Haploid Germ Cells from Human XY and XXY Immature Testes in a 3D Organoid System.

Increasing survival rates of children following cancer treatment have resulted in a significant population of adult survivors with the common side effect of infertility. Additionally, the availability of genetic testing has identified Klinefelter syndrome (classic 47,XXY) as the cause of future male infertility for a significant number of prepubertal patients. This study explores new spermatogonia stem cell (SSC)-based fertility therapies to meet the needs of these patients. Testicular cells were isolated from cryopreserved human testes tissue stored from XY and XXY prepubertal patients and propagated in a two-dimensional culture. Cells were then incorporated into a 3D human testicular organoid (HTO) system. During a 3-week culture period, HTOs maintained their structure, viability, and metabolic activity. Cell-specific PCR and flow cytometry markers identified undifferentiated spermatogonia, Sertoli, Leydig, and peritubular cells within the HTOs. Testosterone was produced by the HTOs both with and without hCG stimulation. Upregulation of postmeiotic germ cell markers was detected after 23 days in culture. Fluorescence in situ hybridization (FISH) of chromosomes X, Y, and 18 identified haploid cells in the in vitro differentiated HTOs. Thus, 3D HTOs were successfully generated from isolated immature human testicular cells from both euploid (XY) and Klinefelter (XXY) patients, supporting androgen production and germ cell differentiation in vitro.

O-282 Detection and elimination of malignant cells from cryopreserved testis and ovarian tissue?

Abstract For young patients receiving treatments that might impair their reproductive functions, gonadal tissue cryopreservation emerges as a technique to preserve their future fertility. The reimplantation of cryopreserved prepubertal gonadal tissue is currently the most promising strategy for restoring fertility in these individuals. There have been reports of successful births after autotransplanting ovarian tissue harvested at peri-puberty. In males, although autotransplantation of testicular tissue has not yet led to the production of viable sperm, successful reproduction has been documented in primate studies following such procedures. The preservation of gonadal tissue in the setting of cancer introduces concerns regarding the potential for malignant cell contamination, leading to worries about the future reimplantation of contaminated tissue. Recent analysis shows significant contamination rates with cancer cells in cryopreserved gonadal tissues from children with leukemia and lymphoma — 37% in testicular tissues and 12% in ovarian tissues. The risk of contamination extends beyond hematological cancers with documented cases of cancer cell contamination in ovarian tissue from patients with apparently localized sarcoma, and detection of neuroblastoma cells in cryopreserved testicular tissue. Such significant contamination rates prompt discussions about harvesting tissue post-chemotherapy, although gonadotoxic treatments may adversely affect the quality of the cryopreserved germ cells. Emerging diagnostic techniques, especially molecular methods, are being investigated for their ability to more accurately detect residual maliganat disease. While traditional histology and immunohistochemistry have been the norm, their sensitivity is relatively low. More precise molecular-genetic techniques, such as Polymerase Chain Reaction (PCR) and Reverse Transcriptase-quantitative PCR, demonstrate greater sensitivity. Moreover, advanced methods like next-generation sequencing offer even higher precision in detecting minimal residual disease. Xenotransplantation of gonadal tissue into immunodeficient animals may also provide some insights as a preclinical method for relapse prediction. Future research is essential to refine these diagnostic techniques to achieve the necessary sensitivity for clinical application. This presentation aims to explore the current knowledge on gonadal tissue contamination rates for both hematological cancers and solid tumors in prepubertal patients and to review strategies for decontaminating gonadal tissues. A critical examination of existing knowledge gaps will be conducted with the objective of identifying secure methods for fertility restoration in cancer survivors.

Pediatric sex estimation using AI-enabled ECG analysis: influence of pubertal development

AI-enabled ECGs have previously been shown to accurately predict patient sex in adults and correlate with sex hormone levels. We aimed to test the ability of AI-enabled ECGs to predict sex in the pediatric population and study the influence of pubertal development. AI-enabled ECG models were created using a convolutional neural network trained on pediatric 10-second, 12-lead ECGs. The first model was trained de novo using pediatric data. The second model used transfer learning from a previously validated adult data-derived algorithm. We analyzed the first ECG from 90,133 unique pediatric patients (aged ≤18 years) recorded between 1987–2022, and divided the cohort into training, validation, and testing datasets. Subgroup analysis was performed on prepubertal (0–7 years), peripubertal (8–14 years), and postpubertal (15–18 years) patients. The cohort was 46.7% male, with 21,678 prepubertal, 26,740 peripubertal, and 41,715 postpubertal children. The de novo pediatric model demonstrated 81% accuracy and an area under the curve (AUC) of 0.91. Model sensitivity was 0.79, specificity was 0.83, positive predicted value was 0.84, and the negative predicted value was 0.78, for the entire test cohort. The model’s discriminatory ability was highest in postpubertal (AUC = 0.98), lower in the peripubertal age group (AUC = 0.91), and poor in the prepubertal age group (AUC = 0.67). There was no significant performance difference observed between the transfer learning and de novo models. AI-enabled interpretation of ECG can estimate sex in peripubertal and postpubertal children with high accuracy.

NFS-06. MANAGEMENT TRENDS OF MEK INHIBITOR DERMATOLOGIC ADVERSE EVENTS FOR NEUROFIBROMATOSIS PATIENTS

Abstract BACKGROUND Selumetinib, a MEK inhibitor (MEKi), is approved for the treatment of plexiform neurofibromas (PN) in pediatric neurofibromatosis (NF) patients. In pivotal trials, nearly 70% of participants had PN shrinkage; however, 93% experienced a rash. This is the first study to characterize management trends of MEKi induced dermatologic adverse events (DAEs). METHODS Physicians treating NF patients were surveyed to assess MEKi DAE frequency, treatment, and effect on MEKi therapy. The survey was distributed using the Children’s Tumor Foundation listserv. RESULTS The survey was completed by MD/DOs (n=15) who were pediatric hematologists/oncologists (n=13) and pediatric neurologists (n=2). Physicians treated pediatric patients (n=8), adult patients (n=2), or both (n=5). Common DAEs included folliculitis (range:10-50% of treated patients; n=11), xerosis (range:1-80%;n=8), acneiform eruptions (range: 20-80%;n=10), eczematous dermatitis (range: 10-80%;n=12), paronychia (range: 10-80%;n=12), and seborrheic dermatitis (range:1-60%;n=8). Approximately half of physicians (n=8) used prophylactic DAE treatment. Prophylaxis for pre-pubertal patients included emollients (n=4), bleach baths (n=2), topical clindamycin (n=1), and doxycycline (n=1). Post-pubertal prophylaxis included emollients (n=5), doxycycline (n=5), topical clindamycin (n=4), bleach baths (n=1), and topical hydrocortisone (n=1). Almost all physicians modified MEKi treatment at least once because of a DAE (n=14), including dose hold (range: 1-25%;n=10), dose reduction (range:1-25%;n=10), and MEKi discontinuation (range:1-25%;n=8). Of the 10 physicians who reported dose holds, 6 were from physicians utilizing prophylactic therapy. Of the 8 physicians who reported MEKi discontinuations, only 3 were reported by physicians utilizing prophylactic therapy. CONCLUSIONS Most physicians modified MEKi treatment for DAEs, and many started prophylactic DAE therapy. The benefit of prophylactic treatment cannot yet be determined. Given the low response rate, future research will be aimed at collecting more data. There is a need for more studies to establish standardized treatment guidelines to reduce the frequency of MEKi modifications secondary to DAEs.

Phase IB study of tovorafenib for children with relapsed/recurrent low-grade gliomas and other MAPK pathway activated tumors.

10001 Background: LGGs present a therapeutic challenge often occurring in areas of brain and spine not amenable to resection and carrying high morbidity with currently available therapies. The majority harbor alterations in the MAPK pathway. Our study (NCT03429803) aimed to establish the recommended phase 2 dose (RP2D) and assess the safety, tolerability and preliminary efficacy of type II RAF-inhibitor tovorafenib in such tumors. Methods: Eligible patients were &gt; 1 year and &lt; 25 years old with radiographically recurrent/progressive MAPK pathway-altered tumors. We applied a novel 2S-Sub-TITE design to determine a RP2D with posterior probability of toxicity closest to the 20% target for patients with BSA ≤1.5 and &gt; 1.5 m2 based on preliminary exposure-efficacy data. Toxicities were graded according to CTCAE version 5. Patients with complete response (CR), partial response (PR) or stable disease (SD) were designated responders. Results: We treated 35 eligible patients, including 20 KIAA1549:BRAF-, 9 BRAF V600E- and 1 FGFR1-altered tumors; 5 possessed novel RAF fusions. Histologically, there were 27 grade 1 gliomas, 3 anaplastic pleomorphic xanthoastrocytomas, 3 pilomyxoid astrocytomas, 1 high-grade glioma and 1 soft tissue sarcoma. There were 6 grade 3 DLTs (2 fatigue, 3 rash, 1 menorrhagia) in 30 evaluable patients: 3 in each BSA subgroup, all at 530 mg/m2/dose. Using AAP guidelines for minimum pubertal peak growth velocities (GV) in males (7 cm/year) and females (6 cm/year), decreased GV (median 0.09 cm/year; range 0.02-0.3) was an unexpected, related AE observed in all 13 of 13 pre-pubertal females &lt; 14 or males &lt; 16 years of age receiving &gt;6 months of protocol 1B therapy. Three of 13 patients with decreased GV were treated at 420 mg/m2. Three of the remaining 10 patients with decreased GV originally treated at 530 mg/m2 were dose reduced for other toxicities and hence, 6 of 13 patients with decreased GV were treated at the RP2D. For patients with follow-up data available, GV appears to show recovery off drug. The 2S-Sub-TITE model recommended 530 mg/m2 for BSA ≤1.5m2 and 420 mg/m2 for BSA &gt; 1.5m2. Dose modifications were required in 8/22 versus 1/13 patients treated at 530 and 420 mg/m2, respectively. Twenty-seven of 35 patients were evaluable for objective response performed by an independent single reader. Overall, 25 patients had SD, PR or CR with median duration of response of 11.3 months (range 0.03-35.4) at data cutoff. Conclusions: Oral weekly tovorafenib is well tolerated and shows preliminary efficacy. Decreased GV was observed in pre-pubertal patients on drug and warrants further investigation to understand the mechanism of action. Based on the number of dose modifications required for toxicity, the chosen RP2D for weekly oral dosing of tovorafenib was 420 mg/m2. Clinical trial information: NCT03429803 .

Decreased spermatogonial numbers in boys with severe haematological diseases.

This study examines spermatogonial numbers in testicular samples from 43 prepubertal patients undergoing haematopoietic stem cell transplantation (HSCT). High-dose chemotherapy and/or radiation during HSCT can impact spermatogenesis requiring fertility preservation. Results show that 49% of patients have decreased and 19% severely depleted spermatogonial pool prior to HSCT. Patients with Fanconi anaemia exhibit significantly reduced spermatogonial numbers. Patients with immunodeficiency or aplastic anaemia generally present within the normal range, while results in patients with myelodysplastic syndrome or myeloproliferative neoplasm vary. The study emphasizes the importance of assessing spermatogonial numbers in patients with severe haematological diseases for informed fertility preservation decisions.

Total osteocalcin levels are independently associated with worse testicular function and a higher degree of hypothalamic–pituitary–gonadal axis activation in Klinefelter syndrome

PurposeThe role of osteocalcin (OCN) in pubertal development, male hypogonadism, and the effect of testosterone (Te) replacement therapy (TRT) remains unclear. We aimed to investigate the total OCN (tOCN) concentrations in male patients with Klinefelter syndrome (KS), a model of adult hypergonadotropic hypogonadism.MethodsThis retrospective longitudinal study investigated 254 male patients with KS (47,XXY) between 2007 and 2021 at an academic referral center, categorized as (1) prepubertal, (2) pubertal, and (3) adults. All prepubertal patients were Te-naïve. Adult patients were subcategorized as (1) eugonadal, (2) hypogonadal, and (3) receiving TRT. We also analyzed 18 adult patients with available tOCN levels before and 3 months after TRT commencement.ResultsThe tOCN levels varied throughout the lifespan according to pubertal status, were highest in eugonadal and significantly lower in TRT subjects, correlated with both LH (p = 0.017) and FSH levels (p = 0.004) in adults, and significantly declined after 3 months of TRT (p = 0.006) in the adult KS cohort. HPG-axis hormones levels demonstrated no correlation in prepubertal boys. Adjustment for age and body mass index confirmed previous results and revealed significant inverse correlations with total Te (p = 0.004), calculated free Te (p = 0.016), the Te/LH (p = 0.010), and calculated free Te/LH ratios (p = 0.031).ConclusionIn KS, a model of male hypergonadotropic hypogonadism, tOCN levels were not associated with gonadal function during normal prepuberty and pubertal development but were associated with worse testicular function and a higher degree of HPG stimulation in adults. TRT acutely reduced tOCN levels in adults.

Vitrification alters growth differentiation factor 9 and follicle-stimulating hormone receptor expression in human cumulus-mural granulosa cells.

Ovarian tissue vitrification is widely utilized for fertility preservation in prepubertal and adolescent female patients with cancer. The current literature includes reports of successful pregnancy and live birth following autografting. However, the effects of the vitrification process on cumulus-mural granulosa cells (C-mGCs)-somatic cells in ovarian tissue crucial for oocyte maturation and early embryonic development-remain unclear. This study was conducted to explore the impact of vitrification on the cellular function of C-mGCs by quantifying the expression of growth differentiation factor 9 (GDF-9), bone morphogenetic protein 15 (BMP-15), follicle-stimulating hormone receptor (FSHR), luteinizing hormone receptor (LHR), connexin 37, survivin, and caspase 3. Mature and immature C-mGCs were obtained from 38 women with polycystic ovary syndrome who participated in an in vitro fertilization program. The C-mGCs were then divided into two groups: fresh and vitrified. The expression levels of target genes were assessed using real-time quantitative polymerase chain reaction. After vitrification, GDF-9 expression was significantly decreased among both mature and immature C-mGCs, with 0.2- and 0.1-fold changes, respectively (p<0.01). Similarly, FSHR expression in the mature and immature groups was reduced by 0.1- and 0.02-fold, respectively, following vitrification (p<0.01). The expression levels of the other genes, including BMP-15, LHR, connexin 37, survivin, and caspase 3, remained similar across the examined groups (p>0.05). Vitrification may compromise oocyte maturation through reduced GDF-9 and FSHR expression in C-mGCs after warming.

Enhancement of Vascularization and Ovarian Follicle Survival Using Stem Cells in Cryopreserved Ovarian Tissue Transplantation-A Systematic Review.

The increase in cancer survival rates has put a focus on ensuring fertility preservation procedures for cancer patients. Ovarian tissue cryopreservation presents the only option for prepubertal girls and patients who require immediate start of treatment and, therefore, cannot undergo controlled ovarian stimulation. We aimed to provide an assessment of stem cells' impact on cryopreserved ovarian tissue grafts in regard to the expression of growth factors, angiogenesis promotion, tissue oxygenation, ovarian follicle survival and restoration of endocrine function. For this systematic review, we searched the Scopus and PubMed databases and included reports of trials using murine and/or human cryopreserved ovarian tissue for transplantation or in vitro culture in combination with mesenchymal stem cell administration to the grafting site. Of the 1201 articles identified, 10 met the criteria. The application of stem cells to the grafting site has been proven to support vascular promotion and thereby shorten the period of tissue hypoxia, which is reflected in the increased number of remaining viable follicles and faster recovery of ovarian endocrine function. Further research is needed before implementing the use of stem cells in OT cryopreservation and transplantation procedures in clinical practice. Complex ethical dilemmas make this process more difficult.

Time to therapy and safety of testicular tissue cryopreservation in children undergoing gonadotoxic treatment or hematopoietic stem cell transplant

BackgroundWith the use of multimodal treatments and hematopoietic stem cell transplant, the majority of children diagnosed with malignancies and hematologic diseases are now surviving into adulthood. Due to the gonadotoxic effects and potential for future infertility associated with many of these treatments, fertility counseling with sperm cryopreservation prior to starting therapy is the standard of care for post-pubertal males. Unfortunately, the options are limited for pre-pubertal patients or those unable to provide a specimen. Testicular tissue cryopreservation (TTC) is an investigational method to surgically obtain germ cells from testicular tissue and potentially restore future spermatogenesis. While TTC has been shown to be safe, little is reported on the time to treatment following the procedure to ensure adequate wound healing and avoid delays in definitive therapy. ObjectivesThe primary outcome was the time to initiation of treatment following TTC. Secondary outcomes were complication rates, delays in treatment due to TTC, and presence of germ cells. MethodsWe conducted a single-institution retrospective cohort study of patients undergoing TTC between 2017-2023. Patients at significant risk for treatment related infertility based on established criteria were eligible for TTC. Patients were excluded if they received their oncology or hematology care elsewhere. All patients were enrolled in an IRB approved research protocol with 75% of the tissue submitted for cryopreservation and 25% for research purposes. Time to therapy was defined as the first receipt of gonadotoxic treatment following TTC. ResultsA total of 122 patients (53=malignant, 69=non-malignant) underwent TTC with a median age of 5.9 years (IQR 2.3-9.35). Germ cells were identified in 115 (94%) specimens. A total of 109 (89%) patients underwent concomitant procedures. The median time to initiation of therapy was 5 (IQR 1.0-7.0) and 7 days (IQR 6.0-13.0) for malignant and non-malignant disease, respectively. The 30-day surgical complication rate was 2.5% and was similar between malignant vs non-malignant diagnoses (p=0.58). All surgical complications were managed non-operatively. No patients had a delay in definitive treatment due to concern for wound healing or complications. DiscussionOur surgical complication rates are similar to previous studies and are not affected by the time to treatment following TTC. Limitations of the study are its retrospective design, single institution, and short-term follow up. ConclusionTTC can be performed safely, efficiently, and in conjunction with other necessary procedures without resulting in delays of definitive treatment . TTC affords the opportunity for fertility preservation in children who have no other options.