Four successful pregnancies in a patient with mucopolysaccharidosis type I treated by allogeneic bone marrow transplantation

Reproduction in Animal Models of Lysosomal Storage Diseases: A Scoping Review

Background: Lysosomal storage diseases (LSDs) are caused by a mutation in a specific gene. Enzymatic dysfunction results in a progressive storage of substrates that gradually affects lysosomal, cellular and tissue physiology. Their pathophysiological consequences vary according to the nature of the stored substrate, making LSDs complex and multisystemic diseases. Some LSDs result in near normal life expectancies, and advances in treatments mean that more people reach the age to have children, so considering the effects of LSDs on fertility and the risks associated with having children is of growing importance. Objectives: As there is a lack of clinical studies describing the effect of LSDs on the physiology of reproductivity, we undertook a scoping review of studies using animal models of LSDs focusing on reproductive parameters. Methods: We searched six databases: MEDLINE, LILACS, Scopus, Web of Science, Embase and SciELO, and identified 49 articles that met our inclusion criteria. Results: The majority of the studies used male animal models, and a number reported severe morphological and physiological damage in gametes and gonads in models of sphingolipidoses. Models of other LSDs, such as mucopolysaccharidoses, presented important morphological damage. Conclusion: Many of the models found alterations in reproductive systems. Any signs of subfertility or morphological damage in animal models are important, particularly in rodents which are extremely fertile, and may have implications for individuals with LSDs. We suggest the use of more female animal models to better understand the physiopathology of the diseases, and the use of clinical case studies to further explore the risks of individuals with LSDs having children.

Evidence that glycosaminoglycan storage and collagen deposition in the cauda epididymidis does not impair sperm viability in the Mucopolysaccharidosis type I mouse model

Mucopolysaccharidosis type I (MPS I) is a lysosomal storage disease caused by a deficiency of the lysosomal hydrolase, α-L-iduronidase (IDUA). IDUA degrades heparan and dermatan sulfates, two types of glycosaminoglycan (GAG), important signalling and structural molecules of the extracellular matrix. Because many cell types store GAGs, MPS I has been investigated in human and animal models. Enzyme replacement therapy is available for MPS I patients and has improved their life expectancy, allowing them to achieve reproductive age. The aim of this study was to evaluate epididymal and sperm morphology and function in a murine model of MPS I. We used C57BL Idua+/+ and Idua-/- adult male mice (6 months old) to investigate epididymal morphology, sperm ultrastructure, GAG characterisation and mating competence. Epithelial GAG storage, especially in the cauda epididymidis, was seen in Idua-/- mice. Regardless of the morphologic change and GAG storage found in the cauda epididymis, sperm morphology and motility were normal, similar to wild types. In the interstitium, vacuolated cells were found in addition to deposits of GAGs. Mating was not impaired in Idua-/- males and litter sizes were similar between groups. At the time point of the disease evaluated, the deficiency in IDUA affected the morphology of the epididymis in male Idua-/- mice, whereas sperm appearance and motility and the male's capacity to mate and impregnate females were preserved.

Morphologic description of male reproductive accessory glands in a mouse model of mucopolysaccharidosis type I (MPS I)

Mucopolysaccharidosis type I (MPS I) is a genetic disease caused by a deficiency of the lysosomal hydrolase α-L-iduronidase (IDUA). IDUA degrades two types of glycosaminoglycans (GAGs): heparan and dermatan sulfates, important components of extracellular matrix, with signaling and structural functions. The accumulation of GAGs results in progressive physiological impairments in a variety of tissues, making MPS I a complex and multisystemic disease. Due the advent of therapeutic strategies which have increased patients' life expectancy, our group have been investigating the effect of IDUA deficiency on the reproductive system. In the present study, we aimed to characterize some of the accessory glands of the male reproductive tract in an MPS I mouse model. We used 6-month-old Idua+/+ and Idua-/- male mice to evaluate the histology of the seminal vesicles and prostate. Interstitial deposits of GAGs and collagen fibers were also observed. Seminal vesicles were smaller in the Idua-/- group, regardless of the normal staining pattern of the epithelial cells, marked with antiandrogen receptor. The prostate of Idua-/- mice presented necrotic acini and increased deposition of collagen fibers in the interstitium. All glands presented evident deposits of GAGs in the extracellular matrix, especially inside vacuolated interstitial cells. We concluded that, at this stage of the disease, the prostate is the most damaged accessory gland and may therefore, be the first to manifest functional impairments during disease progression.

Sexual behaviour in a murine model of mucopolysaccharidosis type I (MPS I)

Mucopolysaccharidosis Type I (MPS I) is a rare genetic lysosomal storage disease caused by a mutation of IDUA gene. IDUA codes for α-L-iduronidase (IDUA), a lysosomal hydrolase that degrades glycosaminoglycans (GAGs): heparan sulphate and dermatan sulphate. GAGs are structural and signalling molecules that have a crucial role in controlling a variety of cell functions and their interaction with the extracellular matrix. Because of GAG's widespread action in cellular metabolism, MPS I is a progressive and disabling multisystemic disorder. Nowadays, the therapies available allowed patients to reach the adult life and the consequences of the disease in their reproductive system are mostly unknown. We aimed to investigate whether IDUA disruption influences sexual behaviour and sexual steroid production in male and female MPS I mice. We used 3 and 6-month-old male and 3-month-old female Idua+/_ and Idua-/- mice to evaluate typical rodent copulatory behaviours. In males we observed the frequency and latency of mounts, intromissions and ejaculations. In females, we evaluated the lordosis quotient. We also analysed the locomotor capacity of mice in the open field test, since mobility is essential for copulatory behaviour. We also quantified steroidal hormonal levels in plasmatic samples. We detected an increase in the latencies of intromissions in Idua-/- males when compared to Idua+/_. However, the number of intromissions was not statistically different between groups. No parameter of female sexual behaviour was statistically different between control and knockout females. In both sexes, we detected diminished mobility in Idua-/- mice. Plasma hormone levels did not differ between Idua+/_ and Idua-/- mice, both in males and females. Although the motor disability predicted to MPS I animals, we concluded that in the considered time point of MPS I progression studied, mice are able to perform sexual behaviour.

Fertility Preservation Using GnRH Agonists: Rationale, Possible Mechanisms, and Explanation of Controversy

The only clinically accepted method of fertility preservation in young women facing gonadotoxic chemo- and/or radiotherapy for malignant or autoimmune diseases is cryopreservation of embryos or unfertilized ova, whereas cryopreservation of ovarian tissue for future reimplantation, or in vitro maturation of follicles, and the use of gonadotropin-releasing hormone agonists (GnRHa) are still considered investigational, by several authorities. Whereas previous publications have raised the fear of GnRHa's possible detrimental effects in patients with hormone receptor-positive breast cancers, recent randomized controlled trials (RCTs) have shown that it either improves or does not affect disease-free survival (DFS) in such patients. This review summarizes the pros and cons of GnRHa co-treatment for fertility preservation, suggesting 5 theoretical mechanisms for GnRHa action: (1) simulating the prepubertal hypogonadotropic milieu, (2) direct effect on GnRH receptors, (3) decreased ovarian perfusion, (4) upregulation of an ovarian-protecting molecule such as sphingosine-1-phosphate, and (5) protecting a possible germinative stem cell. We try to explain the reasons for the discrepancy between most publications that support the use of GnRHa for fertility preservation and the minority of publications that did not support its efficiency.

Endocrine prevention of chemotherapy-induced ovarian failure

PURPOSE OF REVIEW

Fertility preservation has recently gained a worldwide interest among fertility specialists, oncologists, and all healthcare providers. Thus, the protection against iatrogenic infertility caused by chemotherapy assumes a high priority. Specifically, the issue of endocrine prevention of gonadotoxicity is still a controversial subject.

RECENT FINDINGS

During the last year, many publications on this subject appeared, swinging the pendulum toward the beneficial role of gonadotropin-releasing hormone agonist (GnRHa) cotreatment for fertility preservation despite gonadotoxic chemotherapy. Here, we summarize the recent publications on fertility preservation and minimizing chemotherapy-induced gonadotoxicity.

SUMMARY

More than 10 recent meta-analyses have concluded that GnRHa is beneficial and may decrease the risk of premature ovarian failure and increase the pregnancy rate in survivors. Furthermore, two recent international meetings of experts have concluded that GnRHa is effective and should be offered to every young woman facing gonadotoxic chemotherapy.

Pregnancy in patients with mucopolysaccharidosis: a case series

The mucopolysaccharidoses (MPS disorders) are rare inherited diseases associated with multi-organ accumulation of glycosaminoglycans, leading to musculoskeletal, respiratory, cardiac, neurological, ophthalmological, otolaryngological, and gastrointestinal abnormalities. As a result of improvements in diagnosis, multi-disciplinary care, and therapies such as enzyme replacement therapy and hematopoietic stem cell transplantation, an increasing number of patients with MPS are reaching adulthood and are involved in family planning. Data on fertility and pregnancy outcome in MPS is sparse and comprises primarily isolated case reports. To address this evidence gap, we present a case series on fertility and pregnancy in eight mothers and five fathers with MPS. This case series demonstrates that women with MPS have high-risk pregnancies and deliveries secondary to their underlying disease. However, with appropriate pre-conceptual multi-disciplinary evaluation, optimization and discussion regarding potential risks, combined with regular multi-disciplinary maternal and fetal surveillance in a tertiary center, the outcome of most pregnancies in this case series seems to be favorable with all babies developing normally. Partners of fathers with MPS had uncomplicated pregnancies and deliveries. All children were healthy, with normal growth and development.

Gonadotropin-Releasing Hormone Agonist Cotreatment During Chemotherapy May Increase Pregnancy Rate in Survivors

BACKGROUND

The use of gonadotropin-releasing hormone analogs (GnRHas) for fertility preservation is not unequivocally accepted. It is controversial whether GnRHa can increase the pregnancy rate in survivors.

PATIENTS AND METHODS

This is a retrospective cohort study. Every patient referred for fertility preservation was offered cryopreservation of embryos, ova, and ovarian tissue and GnRHa. The patients were consecutively included. The primary outcome was spontaneous pregnancies. The secondary outcome was cyclic ovarian function (COF) versus premature ovarian failure (POF). These outcomes were assessed 2 years or more after chemotherapy.

RESULTS

We compared 286 patients who received gonadotropin-releasing hormone agonist (GnRHa) with chemotherapy with 188 patients who were treated with chemotherapy alone. Ovarian function could be determined in 217 patients. Overall, 87% (127 of 146) of the patients in the GnRHa group retained COF and 13% (19 of 146) suffered POF, whereas in the control group, 49% (35 of 71) experienced COF and 51% (36 of 71) suffered POF (p = .0001). The odds ratio (OR) for preserving COF was 6.87 for the patients who received GnRHa (95% confidence interval [CI] 3.4-13.4). Overall 60% (112 of 188) of the survivors conceived: 69.3% (84 of 122) of the patients in the GnRHa group compared with 42.4% (28 of 66) in the control group (p = .006). In the GnRHa group, 123 healthy newborns were delivered, versus 40 in the controls. Spontaneous pregnancies occurred in 65.6% (80 of 122) of the survivors in the GnRHa group versus 37.9% (25 of 66) in the control group (p = .0004, OR 3.12, 95% CI 1.7-5.8).

CONCLUSION

Adding GnRHa to chemotherapy significantly increases the OR for spontaneous conception, in addition to COF. It is suggested that GnRHa cotreatment should be added before and during gonadotoxic chemotherapy.

IMPLICATIONS FOR PRACTICE

The use of gonadotropin-releasing hormone analogs (GnRHa) for fertility preservation is not unequivocally accepted and is even controversial. This study compared 286 patients who received GnRHa with chemotherapy with 188 patients who were treated with chemotherapy alone. Ovarian function could be determined in 217 patients. The odds ratio for preserving cyclic ovarian function was 6.87 for the patients who received GnRHa. Furthermore, the total and spontaneous pregnancy rate was significantly higher for those who received the agonist (p = .006). Adding GnRHa to chemotherapy significantly increased the odds ratio for spontaneous conception, in addition to preserving regular ovarian function. It is suggested that GnRHa cotreatment should be administered to young women in conjunction with gonadotoxic chemotherapy.

Preserving fertility when choosing chemotherapy regimens - the role of gonadotropin-releasing hormone agonists

INTRODUCTION

The late effects of cancer treatment have recently gained a worldwide ubiquitous interest among reproductive endocrinologists, oncologists, and all health care providers. Despite many publications on this subject, there are many equivocal issues necessitating summary. The case for and against using GnRH-agonist for fertility preservation is summarized with the rationale that preventing ovarian failure may be better than treating it.

AREAS COVERED

We searched Medline in the last 10 years using terms: 'fertility preservation', 'female chemotherapy', 'Gonadotropin-releasing hormone (GnRH) analogues', 'GnRH agonists' 'gonadotoxicity', and 'cancer treatment'. We included mainly publications from the past 7 years, but did not exclude previous, commonly referenced publications. Here, we summarize the various methods available for fertility preservation and minimizing chemotherapy induced gonadotoxicity.

EXPERT OPINION

Until now, 20 studies (15 retrospective and 5 randomized controlled trial) have reported on 2038 patients treated with GnRH-a in parallel to chemotherapy, showing a significant decrease in premature ovarian failure (POF) rate in survivors versus 8 studies reporting on 509 patients, with negative results. Patients treated with GnRH-a in parallel to chemotherapy preserved their cyclic ovarian function in 91% of cases as compared to 41% of controls, with a pregnancy rate of 19 - 71% in the treated patients. Furthermore, over 10 recent meta-analyses have concluded that GnRH-a are beneficial and may decrease the risk of POF in survivors. Because most of the methods involving ovarian or egg cryopreservation are not yet clinically established and unequivocally successful, these young patients deserve to be informed with all the various modalities to minimize gonadal damage and preserve ovarian function and future fertility. Combining the various modalities for a specific patient may increase the odds of preservation of future fertility.

'An ounce of prevention is worth a pound of cure': the case for and against GnRH-agonist for fertility preservation

The late effects of cancer treatment have recently gained a worldwide interest among reproductive endocrinologists, oncologists, and all health-care providers, and the protection against iatrogenic infertility caused by chemotherapy assumes a high priority. Here, we summarize the case for and against using GnRH-agonist for fertility preservation and minimizing chemotherapy-induced gonadotoxicity. The rationale and philosophy supporting its use is that preventing premature ovarian failure (POF) is preferable to treating it, following the dictum: 'an ounce of prevention is worth a pound of cure'. Despite many publications on this subject, there are many equivocal issues necessitating summary. Until now, 20 studies (15 retrospective and 5 randomized, controlled trials) have reported on 1837 patients treated with GnRH-a in parallel to chemotherapy, showing a significant decrease in POF rate in survivors versus 9 studies reporting on 593 patients, with results not supporting GnRH-a use. Patients treated with GnRH-a in parallel to chemotherapy preserved their cyclic ovarian function in 91% of cases when compared with 41% of controls, with a pregnancy rate of 19-71% in the treated patients. Furthermore, seven meta-analyses have concluded that GnRH-a are beneficial and may decrease the risk of POF in survivors. However, controversy still remains regarding the efficiency of GnRH-a in preserving fertility. Since not all the methods involving fertility preservation are unequivocally successful and safe, these young patients deserve to be informed of all the various modalities to minimize gonadal damage and preserve ovarian function and future fertility. Combining several methods for a specific patient may increase the odds for minimally invasive fertility preservation.

Chemotherapy and fertility

The overall increase in cancer prevalence and the significant increase in long-term survival have generated worldwide interest in preserving fertility in young women exposed to gonadotoxic chemo- and radiotherapy. Infertility represents one of the main long-term consequences of combination chemotherapy given for lymphoma, leukaemia and other malignancies in young women. The gonadotoxic effect of various chemotherapeutic agents is diverse, may involve a variety of pathophysiologic mechanisms, and is not unequivocally understood. Proliferating cells, such as in tissues with high turnover (i.e. bone marrow, gastrointestinal tract and growing ovarian follicles) are more vulnerable to the toxic effect of alkylating agents. These agents may also be cytotoxic to cells at rest, as they are not cell-cycle specific. Alkylating agents, the most gonadotoxic chemotherapeutic medications, cause dose-dependent, direct destruction of oocytes and follicular depletion, and may bring about cortical fibrosis and ovarian blood-vessel damage. The reported rate of premature ovarian failure after various diseases and chemotherapeutic protocols differ enormously, and depend mainly on the chemotherapeutic protocol used and age range of the woman. Several options have been proposed for preserving female fertility, despite gonadotoxic chemotherapy: ovarian transposition, cryopreservation of embryos, unfertilised metaphase-II oocytes and ovarian tissue, and administration of gonadotropin-releasing hormone agonistic analogs in an attempt to decrease the gonadotoxic effects of chemotherapy by simulating a prepubertal hormonal milieu. None of these methods is ideal and none guarantees future fertility in all survivors; therefore, a combination of methods is recommended for maximising women's chances of future fertility.