Long-term ovarian reserve and fertility outcomes in female survivors of childhood acute lymphoblastic leukemia.

Acute lymphoblastic leukemia (ALL) is the most common childhood malignancy, yet data regarding long-term ovarian reserve of female survivors are limited. The aim of this study was to investigate whether there is a differential pattern of anti-Mullerian hormone (AMH) levels in female childhood ALL survivors compared with the normal age-matched population. In a cohort of 56 female childhood ALL survivors (median age 29 years; median follow-up 20.6 years), a negative correlation was found between age at leukemia diagnosis and age-adjusted anti-Mullerian hormone (AMH) levels (r = -0.334, p = .031). Despite alkylating agent therapy, AMH levels did not differ significantly from age-related nomograms (age < 30, p = .17; age ≥ 30, p = .94). The mean number of children per fertile woman adjusted for maternal age was similar to the national average (2.76 versus 3.11, p = .19). Our results imply that reproductive outcomes are not significantly hampered in female pediatric ALL survivors. Long-term surveillance of ovarian reserve may enable personalized survivorship counseling.

Bone pain at leukemia diagnosis and other risk factors for symptomatic osteonecrosis in children with acute lymphoblastic leukemia.

BACKGROUND: Osteonecrosis is a major cause of acute and long-lasting complications of acute lymphoblastic leukemia (ALL) therapy in children. Our study aimed to evaluate the prevalence, characteristics, risk factors, and outcome of osteonecrosis in children with ALL. PROCEDURE: The cohort included 559 children aged 1-20 years diagnosed with ALL between 2003 and 2018 at two tertiary medical centers in Israel and enrolled in two consecutive protocols: ALL-IC BFM 2002 and AIEOP-BFM ALL 2009. Symptomatic osteonecrosis was prospectively captured as an adverse event. RESULTS: Osteonecrosis occurred in 51 patients (9.1%). Ninety-four percent of the events were graded as moderate or severe (grades 3-4, Ponte di Legno Toxicity Working Group classification) and multiple bone involvement was common. Full resolution of osteonecrosis was documented in only 16% of the children (median follow-up 4.2 years). Stepwise logistic regression identified five risk factors for osteonecrosis, with a high predictive value (AUC = 0.88): older ageat ALL diagnosis, high-risk ALL group, T-cell immunophenotype, female gender, and a novel risk factor: bone pain at the time of leukemia diagnosis. In addition, osteonecrosis was less common among children of Arab ethnicity. Thrombophilia and an elevated age-adjusted body mass index were not confirmed as risk factors for osteonecrosis. CONCLUSION: Due to the low rates of osteonecrosis resolution and its debilitating long-term impact, the identification of patients at high risk for osteonecrosis is important for their inclusion in further studies evaluating potential therapeutic adjustments.

Mucormycosis in children with haematological malignancies is a salvageable disease: a report from the Israeli Study Group of Childhood Leukemia.

Mucormycosis has emerged as an increasingly important cause of morbidity and mortality in immunocompromised patients, but contemporary data in children are lacking. We conducted a nationwide multicentre study to investigate the characteristics of mucormycosis in children with haematological malignancies. The cohort included 39 children with mucormycosis: 25 of 1136 children (incidence 2·2%) with acute leukaemias prospectively enrolled in a centralized clinical registry in 2004-2017, and an additional 14 children with haematological malignancies identified by retrospective search of the databases of seven paediatric haematology centres. Ninety-two percent of mucormycosis cases occurred in patients with acute leukaemias. Mucormycosis was significantly associated with high-risk acute lymphoblastic leukaemia (OR 3·75; 95% CI 1·51-9·37; P = 0·004) and with increasing age (OR 3·58; 95% CI 1·24-9·77; P = 0·01). Fifteen patients (38%) died of mucormycosis. Rhinocerebral pattern was independently associated with improved 12-week survival (OR 9·43; 95% CI 1·47-60·66; P = 0·02) and relapsed underlying malignancy was associated with increased 12-week mortality (OR 6·42; 95% CI, 1·01-40·94; P = 0·05). In patients receiving frontline therapy for their malignancy (n = 24), one-year cumulative mucormycosis-related mortality was 21 ± 8% and five-year overall survival was 70 ± 8%. This largest paediatric population-based study of mucormycosis demonstrates that children receiving frontline therapy for their haematological malignancy are often salvageable.

Blinatumomab as a bridge to further therapy in cases of overwhelming toxicity in pediatric B-cell precursor acute lymphoblastic leukemia: Report from the Israeli Study Group of Childhood Leukemia.

Tremendous progress in the therapy of pediatric acute lymphoblastic leukemia (ALL) has been achieved through combination cytotoxic chemotherapy, leading to high cure rates, at the cost of significant life-threatening toxicity. The bispecific T-cell engager blinatumomab, recently approved for relapsed/refractory ALL, has a unique nonmyelotoxic toxicity profile. As blinatumomab causes B-cell depletion, the safety of its use during severe chemotherapy-induced toxicity is unclear. We report 11 pediatric patients with ALL, treated with blinatumomab following overwhelming chemotherapy-associated toxicity, with recovery of all patients and successful bridging to further antileukemia therapy. Blinatumomab can be considered for rare patients who cannot tolerate cytotoxic therapy.

Thrombophilia screening and thromboprophylaxis may benefit specific ethnic subgroups with paediatric acute lymphoblastic leukaemia.

This study investigated the prevalence of inherited thrombophilia, risk of venous thromboembolism (VTE) and benefit of low molecular weight heparin prophylaxis in 476 Israeli children with acute lymphoblastic leukaemia (ALL) treated between 2004 and 2016. Thrombophilia was found in 15·5%. Arab children had a higher prevalence of F5 R506Q (factor V Leiden) than Jewish children (19·4% vs. 2·9%, P < 0·01). Patients with thrombophilia had higher VTE rates VTE (26·5% vs. 5·6%, P < 0·001). None of the thrombophilic children given prophylaxis had severe VTE. Routine evaluation for inherited thrombophilia followed by thromboprophylaxis when findings are positive may benefit at-risk patients with ALL.

Ectopic PDX-1 expression directly reprograms human keratinocytes along pancreatic insulin-producing cells fate.

BACKGROUND: Cellular differentiation and lineage commitment have previously been considered irreversible processes. However, recent studies have indicated that differentiated adult cells can be reprogrammed to pluripotency and, in some cases, directly into alternate committed lineages. However, although pluripotent cells can be induced in numerous somatic cell sources, it was thought that inducing alternate committed lineages is primarily only possible in cells of developmentally related tissues. Here, we challenge this view and analyze whether direct adult cell reprogramming to alternate committed lineages can cross the boundaries of distinct developmental germ layers. METHODOLOGY/PRINCIPAL FINDINGS: We ectopically expressed non-integrating pancreatic differentiation factors in ectoderm-derived human keratinocytes to determine whether these factors could directly induce endoderm-derived pancreatic lineage and ß-cell-like function. We found that PDX-1 and to a lesser extent other pancreatic transcription factors, could rapidly and specifically activate pancreatic lineage and ß-cell-like functional characteristics in ectoderm-derived human keratinocytes. Human keratinocytes transdifferentiated along the ß cell lineage produced processed and secreted insulin in response to elevated glucose concentrations. Using irreversible lineage tracing for KRT-5 promoter activity, we present supporting evidence that insulin-positive cells induced by ectopic PDX-1 expression are generated in ectoderm derived keratinocytes. CONCLUSIONS/SIGNIFICANCE: These findings constitute the first demonstration of human ectoderm cells to endoderm derived pancreatic cells transdifferentiation. The study represents a proof of concept which suggests that transcription factors induced reprogramming is wider and more general developmental process than initially considered. These results expanded the arsenal of adult cells that can be used as a cell source for generating functional endocrine pancreatic cells. Directly reprogramming somatic cells into alternate desired tissues has important implications in developing patient-specific, regenerative medicine approaches.

Hormonal regulation of GnRH and LHbeta mRNA expression in cultured rat granulosa cells.

We have recently demonstrated that the rat ovary expresses LHbeta, FSHbeta, and the common alpha subunit mRNA. In the present report, we studied the regulation of LHbeta and of gonadotropin-releasing hormone (GnRH) mRNA expression in granulosa cells that were isolated from immature rats treated with either estrogen or pregnant mare serum gonadotropin (PMSG). In both cell types, GnRH agonist treatment resulted in a decrease in LHbeta mRNA expression. However, only in cells derived from PMSG-treated rats, GnRH treatment produced an increase in GnRH mRNA expression. A markedly increased GnRH mRNA expression was also obtained in granulosa cells derived from PMSG-primed rats in response to LH. In addition, FSH reduced the expression of LHbeta mRNA in granulosa cells from estrogen-primed rats. These results suggest that the expression of LHbeta in the ovary is regulated by locally produced GnRH and by FSH from either the ovary or the pituitary.

Local production of the gonadotropic hormones in the rat ovary.

The gonadotropic hormones, luteinizing hormone (LH) and follicle-stimulating hormone (FSH) are synthesized by and released from the anterior pituitary in response to the hypothalamic gonadotropin-releasing hormone (GnRH) signaling. In the female, LH and FSH affect folliculogenesis, ovarian steroid production, oocyte maturation, ovulation and corpus luteum formation. We have recently studied the expression of GnRH and its receptor in the rat ovary and found organ-specific, estrous cycle-dependant, fluctuations. Subsequently, we wished to determine whether rat ovaries also express gonadotropic hormones. Using RT-PCR, we detected LHbeta, FSHbeta and the common alpha-subunit mRNA's in intact follicles, theca cells, corpora lutea and in meiotically competent and incompetent oocytes. Granulosa cells, however, express mRNA's for LHbeta and the common alpha-subunit, but not for FSHbeta. We cloned and sequenced the ovarian LHbeta transcript and found it to be longer (2.3kb) than the one produced by pituitary gonadotropes (0.8kb), due to a longer 5'-UTR. We studied the regulation of ovarian LHbeta mRNA in sexually immature female rats administered with pregnant mare serum gonadotropin (PMSG) and in adult cyclic rats. PMSG administration caused a significant decrease in LHbeta mRNA expression, detected by real-time PCR. Similarly, LHbeta mRNA levels were lower on estrous morning versus proestrous evening. Interestingly, ovarian content of LH remained unchanged following hypophysectomy, although ovarian weight was immensely reduced. Taken together, it seems probable that ovarian LH is heterologously/homologously regulated by pituitary, and possibly also by local gonadotropins. Thus, these findings may imply the existence of a local GnRH-gonadotropin axis in the mammalian ovary that may be involved in the management of processes that lead to ovulation.