Gonadal function and immunosuppressive therapy after renal transplantation

Immunosuppressive Therapy, Puberty and Growth Outcomes in Pediatric Kidney Transplant Recipients: A Pragmatic Review

Kidney transplantation in children with end-stage kidney disease significantly enhances survival and quality of life but poses unique challenges related to chronic immunosuppressive therapy. In fact, despite being essential for preventing organ rejection, immunosuppressive therapy can have significant side effects specific to pediatric patients, such as adverse impacts on physiological growth, puberty, and fertility. The resulting short stature and delayed or incomplete pubertal development can profoundly affect young patients' psychological and social well-being, impacting self-esteem and overall quality of life, and may significantly hamper compliance and therapeutic adherence. Most studies on immunosuppression in pediatric kidney transplant recipients focus on general side effects and outcomes like long-term graft survival or acute complications. On the other side, there is limited evidence in the current literature on the specific issues of growth, puberty, and fertility in this patient population. In this pragmatic review, we aimed to summarize the most relevant information available on these critical aspects of post-transplant management in pediatric patients, also providing some practical indications on management strategies for minimizing these often neglected but still important complications.

Kidney transplantation restores sex hormone profile and improves sexual function in ESRD patients with erectile dysfunction

BACKGROUND

Erectile dysfunction (ED) and sex hormone profile disturbances are common in ESRD patients.

OBJECTIVE

To assess the effect of kidney transplant (KT) and Hemodialysis/peritoneal dialysis (HD/PD) on the serum sex hormone profile and sexual functions in ESRD patients with ED.

PATIENTS AND METHODS

A single-center, nonconcurrent cohort study included a hundred ESRD patients with ED, on regular HD/PD (group A, n = 50) and after KT (group B, n = 50) at Armed Forces Hospitals Southern Region, KSA.

RESULTS

the mean age of patients was 47.3 ± 7.01 and 56.8 ± 9.6 years in groups A and B, respectively. The cohorts were comparable regarding patient demographics, apart from a higher incidence of comorbidities in group B. After KT the mean testosterone level was higher in Group B (13.64 ± 3.21 nmol/L vs 10.26 ± 3.26 nmol/L, p < 0.001). Similarly, LH and prolactin levels were lower in group B than in group A (p < 0.05). As regards sexual function, ED was reported in 92% of patients in group A compared to 42% in group B (p < 0.001). In groups A and B, mild ED was found in 48% and 14% of patients, while moderate ED was found in 16% and 8%, respectively. The mean total IIEF-15 score was 36.42 ± 9.33 and 43.87 ± 9.146 in groups A and B, respectively (p = 0.0001). Sexual desire and orgasm were significantly better in Group B.

CONCLUSIONS

Our study showed that kidney transplantation could improve erectile function and restore normal sex hormone levels in ESRD male patients with ED, with better outcomes compared to HD/PD.

Thyroid, Gonadal and Adrenal Dysfunction in Kidney Transplant Recipients: A Review for the Clinician

While chronic kidney disease-associated mineral and bone disorders (CKD-MBD) prevail in the endocrinological assessment of CKD patients, other endocrine abnormalities are usually overlooked. CKD is associated with significant thyroid, adrenal and gonadal dysfunction, while persistent and de novo endocrinological abnormalities are frequent among kidney transplant recipients (KTR). Low T3 levels prior to transplantation may help identify those at risk for delayed graft function and are often found in KTR. Thyroid surveillance after kidney transplantation should be considered due to structural anomalies that may occur. Despite the rapid recovery of gonadal hormonal secretion after renal transplantation, fertility is not completely restored. Testosterone may improve anemia and general symptoms in KTR with persistent hypogonadism. Female KTR may still experience abnormal uterine bleeding, for which estroprogestative administration may be beneficial. Glucocorticoid administration suppresses the hypothalamic-pituitary-adrenal axis in KTR, leading to metabolic syndrome. Patients should be informed about signs and symptoms of hypoadrenalism that may occur after glucocorticoid withdrawal, prompting adrenal function assessment. Clinicians should be more aware of the endocrine abnormalities experienced by their KTR patients, as these may significantly impact the quality of life. In clinical practice, awareness of the specific endocrine dysfunctions experienced by KTR patients ensures the correct management of these complications in a multidisciplinary team, while avoiding unnecessary treatment.

Sexual Dysfunction Among Patients With Chronic Kidney Disease

Sexual dysfunction (SD) in patients with chronic kidney disease is common and negatively impacts quality of life. SD is often under-appreciated because of overall low awareness. Diagnosis of SD is subjective, and manifestations can be different among men and women. Causes of SD are multifactorial, including psychological disorders, hormonal imbalances, vascular disorders, neurological disorders, and medication side effects. Non-specific approaches to improving sexual function include addressing underlying psychological disorders, promoting lifestyle modifications, optimizing dialysis care, and facilitating successful kidney transplantation, whereas treatment with phosphodiesterase type 5 inhibitor, hormone replacement, and mechanical devices can be offered to patients with specific indications.

Usage of Tacrolimus and Mycophenolic Acid During Conception, Pregnancy, and Lactation, and Its Implications for Therapeutic Drug Monitoring: A Systematic Critical Review

BACKGROUND

Conception, pregnancy, and lactation following solid organ transplantation require appropriate management. The most frequently used immunosuppressive drug combination after solid organ transplantation consists of tacrolimus (Tac) plus mycophenolic acid (MPA). Here, the effects of Tac and MPA on fertility, pregnancy, and lactation are systematically reviewed, and their implications for therapeutic drug monitoring (TDM) are discussed.

METHODS

A systematic literature search was performed (August 19, 2019) using Ovid MEDLINE, EMBASE, the Cochrane Central Register of controlled trials, Google Scholar, and Web of Science, and 102 studies were included. Another 60 were included from the reference list of the published articles.

RESULTS

As MPA is teratogenic, women who are trying to conceive are strongly recommended to switch from MPA to azathioprine. MPA treatment in men during conception seems to have no adverse effect on pregnancy outcomes. Nevertheless, in 2015, the drug label was updated with additional risk minimization measures in a pregnancy prevention program. Data on MPA pharmacokinetics during pregnancy and lactation are limited. Tac treatment during conception, pregnancy, and lactation seems to be safe in terms of the health of the mother, (unborn) child, and allograft. However, Tac may increase the risk of hypertension, preeclampsia, preterm birth, and low birth weight. Infants will ingest very small amounts of Tac via breast milk from mothers treated with Tac. However, no adverse outcomes have been reported in children exposed to Tac during lactation. During pregnancy, changes in Tac pharmacokinetics result in increased unbound to whole-blood Tac concentration ratio. To maintain Tac concentrations within the target range, increased Tac dose and intensified TDM may be required. However, it is unclear if dose adjustments during pregnancy are necessary, considering the higher concentration of (active) unbound Tac.

CONCLUSIONS

Tac treatment during conception, pregnancy and lactation seems to be relatively safe. Due to pharmacokinetic changes during pregnancy, a higher Tac dose might be indicated to maintain target concentrations. However, more evidence is needed to make recommendations on both Tac dose adjustments and alternative matrices than whole-blood for TDM of Tac during pregnancy. MPA treatment in men during conception seems to have no adverse effect on pregnancy outcomes, whereas MPA use in women during conception and pregnancy is strongly discouraged.

The effect of paternal exposure to immunosuppressive drugs on sexual function, reproductive hormones, fertility, pregnancy and offspring outcomes: a systematic review

BACKGROUND

Information regarding the possible influence of immunosuppressive drugs on male sexual function and reproductive outcomes is scarce. Men diagnosed with immune-mediated diseases and a wish to become a father represent an important neglected population since they lack vital information to make balanced decisions about their treatment.

OBJECTIVE AND RATIONALE

The aim of this research was to systematically review the literature for the influence of paternal immunosuppressive drug use on many aspects of male sexual health, such as sexual function, fertility, pregnancy outcomes and offspring health outcomes.

SEARCH METHODS

A systematic literature search was performed in the bibliographic databases: Embase (via Elsevier embase.com), MEDLINE ALL via Ovid, Cochrane Central Register of Trials (via Wiley) and Web of Science Core Collection. Additionally, Google Scholar and the Clinical trial registries of Europe and the USA were searched. The databases were searched from inception until 31 August 2019. The searches combined keywords regarding male sexual function and fertility, pregnancy outcomes and offspring health with a list of immunosuppressive drugs. Studies were included if they were published in English and if they included original data on male human exposure to immunosuppressive drugs. A meta-analysis was not possible to perform due to the heterogeneity of the data.

OUTCOMES

A total of 5867 references were identified, amongst which we identified 161 articles fulfilling the eligibility criteria. Amongst these articles, 50 included pregnancy and offspring outcomes and 130 included sexual health outcomes. Except for large Scandinavian cohorts, most of the identified articles included a small number of participants. While a clear negative effect on sperm quality was evident for sulfasalazine and cyclophosphamide, a dubious effect was identified for colchicine, methotrexate and sirolimus. In three articles, exposure to tumour necrosis factor-α inhibitors in patients diagnosed with ankylosing spondylitis resulted in improved sperm quality. The information regarding pregnancy and offspring outcomes was scant but no large negative effect associated with paternal immunosuppressive drug exposure was reported.

WIDER IMPLICATIONS

Evidence regarding the safety of immunosuppressive drugs in men with a wish to become a father is inconclusive. The lack of standardisation on how to evaluate and report male sexual function, fertility and reproduction as study outcomes in men exposed to immunosuppressive drugs is an important contributor to this result. Future research on this topic is needed and should be preferably done using standardised methods.

Infertility in Female and Male Solid Organ Recipients - From Diagnosis to Treatment: An Up-To-Date Review of the Literature

Around 20% to 30% of patients after solid organ transplantation are of reproductive age. The estimated rate of infertility in this group is slightly higher than in the general population. Choosing the optimal moment for pregnancy in transplanted patients plays a pivotal role, regardless of the method of conception. The first part of this article presents an up-to-date review of the problem of infertility in female and male solid organ recipients, with special attention to the influence of specific immunosuppressive drugs on semen parameters. The second part discusses the current knowledge regarding infertility treatment and the results of assisted reproductive techniques in this specific group of patients.

Despite restoring gonadal functions after transplantation, the patients should be informed about possible negative effects of medications on fertility, course of pregnancy, and the fetus. Interdisciplinary care should always be provided for infertile graft recipients, especially women, as it ensures safety both for the graft and for the potential gestation. The process of infertility diagnosis and tools used for that purpose are the same in transplanted patients as in the general population. The treatment with assisted reproductive techniques is acceptable and gives favorable results as long as patients are managed rationally, with special attention paid to prevention of iatrogenic complications.

Paternity in male kidney transplant recipients: a French national survey, the PATeRNAL study

Background

There is concern about the impact of immunosuppressive agents taken by male kidney transplant (KT) recipients on the risk of foetal malformations. The aim of our survey was to estimate the paternity rate and the outcomes of pregnancies fathered by kidney transplanted males.

Methods

This survey analysed 1332 male KT recipients older than 18 years, followed in 13 centres in France. A self-reported questionnaire was used to collect data on the patients, treatments at the time of conception and the pregnancy outcomes.

Results

The study included data on 349 children from 404 pregnancies fathered by 232 male KT recipients. The paternity rate was 17% (95% CI [15–20]). There were 37 (9%, 95% CI [7–12]) spontaneous abortions, 12 (3%, 95% CI [2–5]) therapeutic abortions, 2 (0.5%, 95% CI [0.1–1]) still births, and 13 (4%, 95% CI [2–6]) malformations reported. Compared to the general population, there was no difference in the proportion of congenital malformations nor unwanted outcomes whether the father was exposed or not to immunosuppressive agents.

Conclusions

This survey does not provide any warning signal that pregnancies fathered by male patients exposed to immunosuppressive agents, notably the debated MMF/MPA, have more complications than pregnancies in the general population.

Supplementary Information

Supplementary information accompanies this paper at 10.1186/s12882-020-02115-x.

Prospective Study on Sexual Dysfunction in Male Chinese Liver Transplant Recipients

In patients with end-stage liver disease, hypogonadism and erectile dysfunction are often seen. This study was to determine the incidence of erectile dysfunction before and after liver transplantation (LT) with correlation to change in sex hormone levels from a Chinese cohort. This prospective longitudinal study was registered with The University of Hong Kong Clinical Trials Centre (HKUCTR-1563). The Institutional Review Board approval number is UW-12-273. The study period was from January 2012 to December 2016. Adult male patients with end-stage liver disease enlisted for LT were recruited on informed written consent. All recruited patients were to complete a cross-sectional cohort questionnaire-International Index of Erectile Function, version 5 (IIEF5)-and to receive serum sex hormone checks before and after LT. Twenty-eight patients who underwent LT were included in the analysis. The included patients had significantly reduced prolactin ( p < .001) and 17-beta-estradiol ( p = .024) after LT. There was also a significant drop of IIEF5 score at 1 month after LT, but the score returned to pre-LT level at 6 months. This study demonstrated that there was improvement in sex hormone levels after LT, namely, normalization of estradiol level and lowering of prolactin and progesterone levels. However, improvement in sex hormone levels did not translate into improvement of erectile dysfunction.

Rapid recovery of hypogonadism in male patients with end stage renal disease after renal transplantation

PURPOSE

End stage renal disease (ESRD) in male patients is associated with a high prevalence of hypogonadism. After renal transplantation (RTx) an improvement in gonadal function is often observed. However, the time course of changes in pituitary-gonadal axis after RTx and the influence of renal function, age and anthropometric parameters are not well characterized. We prospectively evaluated pituitary-gonadal axis in male patients with ESRD before and after RTx for up to 1 year.

METHODS

Ninety-seven male patients with ESRD were consecutively investigated on day of surgery and 1, 3, 6, and 12 months after RTx. Time course of changes in sex hormones (total testosterone ((TT)), calculated free testosterone ((cfT)), estradiol (E₂), LH, FSH and prolactin), and interdependence with renal function, age, anthropometric factors, cause of ERDS, time on dialysis, and transplant associated factors were analyzed.

RESULTS

Hypogonadism (TT < 8 nmol/l) was present in 40% of pts prior to RTX and in only 18% at 1 year after RTX. Recovery from hypogonadism was significantly higher in pts < 50 years and occurred within 3 months. RTx resulted in a decrease in E₂/T ratio starting at 1 month and suggesting a shift from estrogen to testosterone production. BMI and waist circumference had the similar impact on T levels after successful RTx compared to patients without renal disease. No specific impact on recovery of hypogonadism was found for time on dialysis prior to RTx and living or cadaver transplantation.

CONCLUSIONS

Successful RTx is associated with a rapid recovery from hypogonadism within 3 months preceeded by improvement in renal function particularly in patients younger than 50 years.

Hand-Grip Strength Is Associated With Serum Testosterone and Albumin Levels in Male Kidney Transplant Recipients

OBJECTIVES

In kidney transplant recipients, reduced muscle mass and hand-grip strength are associated with impaired nutritional status. Serum testosterone is highly associated with muscle strength in the general population. Here, we aimed to determine the associations among serum testosterone, hand-grip strength, and nutritional and inflammatory parameters, as well as graft function.

MATERIALS AND METHODS

Our study included 144 stable male kidney transplant recipients from our renal transplant outpatient clinic. All patients were evaluated for clinical parameters (age, duration of hemodialysis, and posttransplant time), biochemical parameters (calcium, phosphorus, parathyroid hormone, C-reactive protein, albumin, creatinine), and serum testosterone levels. Body composition was analyzed with the bioimpedance spectroscopy analysis technique using a body composition monitor that estimates body mass index and percent fat. Hand-grip strength was analyzed by using a dynamometer (ProHealthcareProducts.com, Park City, UT, USA). We calculated estimated glomerular filtration rate using the Modification of Diet in Renal Disease-4 equation.

RESULTS

Demographic characteristics, duration of dialysis before transplant, biochemical parameters, and estimated glomerular filtration rates were similar among study patients. Mean (standard deviation) serum testosterone was 588.0 (55.5) ng/dL, mean body mass index was 26.8 (0.6) kg/m2, and mean hand-grip strength was 42.2 (1.7) mm2. Serum testosterone levels were positively correlated with hand-grip strength (r = 0.445; P = .033) and serum albumin (r = 0.399; P = .05) and negatively correlated with serum C-reactive protein (r = -0.454; P = .05) and age. In linear multiple regression analysis, serum albumin (P = .033) and testosterone levels (P = .038) were shown to be predictors of hand-grip strength. However, we could not show a significant correlation between graft function and testosterone.

CONCLUSIONS

Serum testosterone level is correlated with hand-grip strength and C-reactive protein and albumin levels, which may indicate that testosterone affects nutritional status and inflammation in male renal transplant recipients.

Inhibition of mTOR pathway decreases the expression of pre-meiotic and meiotic markers throughout postnatal development and in adult testes in mice

Rapamycin (mTOR inhibitor) has been reported to have negative effect on human male gonadal function. Previously, we showed that mTOR signalling molecules are expressed during early spermatogenesis in mice. The objective of this study was to investigate the role of mTOR signalling in meiosis both during the first wave of spermatogenesis and also during adult spermatogenesis. Day 5 post-partum mice were administered rapamycin and retinoic acid (RA; a Stra8 activator), and expression of p-p70S6K and Stra8 proteins was evaluated. p-p70S6K and Stra8 protein expressions decreased in post-natal testes after rapamycin treatment. Stra8 protein expression increased after RA and rapamycin+RA administrations in post-natal testes. In adult mice, rapamycin was administrated for 1 or 4 weeks. Morphological analysis for testicular damage and TUNEL assay was performed. After rapamycin administration, germ cell loss increased in adult testes. Ultrastructural analysis revealed disorganised testicular morphology and vacuolisation. The number of apoptotic germ cells increased after 4 weeks rapamycin administration. Stra8 and Dmc1 expressions decreased in 4 weeks rapamycin group, whereas Sycp3 and VASA expression did not change. Our findings suggest that mTOR pathway has an important role in meiotic progress of male germ cells both during first wave of spermatogenesis and in adult mice.

Mammalian target of rapamycin (mTOR): a central regulator of male fertility?

Mammalian target of rapamycin (mTOR) is a central regulator of cellular metabolic phenotype and is involved in virtually all aspects of cellular function. It integrates not only nutrient and energy-sensing pathways but also actin cytoskeleton organization, in response to environmental cues including growth factors and cellular energy levels. These events are pivotal for spermatogenesis and determine the reproductive potential of males. Yet, the molecular mechanisms by which mTOR signaling acts in male reproductive system remain a matter of debate. Here, we review the current knowledge on physiological and molecular events mediated by mTOR in testis and testicular cells. In recent years, mTOR inhibition has been explored as a prime strategy to develop novel therapeutic approaches to treat cancer, cardiovascular disease, autoimmunity, and metabolic disorders. However, the physiological consequences of mTOR dysregulation and inhibition to male reproductive potential are still not fully understood. Compelling evidence suggests that mTOR is an arising regulator of male fertility and better understanding of this atypical protein kinase coordinated action in testis will provide insightful information concerning its biological significance in other tissues/organs. We also discuss why a new generation of mTOR inhibitors aiming to be used in clinical practice may also need to include an integrative view on the effects in male reproductive system.

Immunosuppressants and Male Reproduction

Prolonged use of immunosuppressant medications is occasionally seen in infertile men with chronic inflammatory conditions; autoimmune disorders; or an organ or hematopoietic stem cell transplant. Chronic inflammation impacts negatively on male reproductive endpoints, so immunosuppressant therapy can produce improvements. Corticosteroids have been used to treat antisperm antibodies and even as an empirical treatment for male infertility in general. Trials of these methods have provided mixed results on semen quality and fertility, with improvement, no change and negative effects reported by different investigators. In a substantial number of observational studies, patients on long-term therapy with prednisone for chronic inflammatory disease, testosterone levels were lower compared to untreated controls, though randomized controlled trials have not been conducted. Similarly decreases in testosterone have been reported in men receiving corticosteroids to minimize transplant rejection; however, most were treated with multiple immunosuppressive medications that may have contributed to this effect. A large number of trials of healthy men treated with corticosteroids have shown some disruption in reproductive hormone levels, but other studies reported no effect. Studies in monkeys, rats (at human equivalent dose), cattle, sheep, and horses have shown endocrine disruption, including low testosterone with dexamethasone treatment. Of the cytostatic immunosuppressives, which have high potential for cellular damage, cyclophosphamide has received the most attention, sometimes lowering sperm counts significantly. Methotrexate may decrease sperm numbers in humans and has significant negative impacts in rodents. Other chemotherapeutic drugs used as immunosuppressants are likely to impact negatively on male fertility endpoints, but few data have been collected. The TNF-α Inhibitors have also received little experimental attention. There is some evidence that the immunophilin modulators: cyclosporine, sirolimus, and everolimus cause endocrine disruption and semen quality impairment. As we review in this chapter, results in experimental species are concerning, and well-designed studies are lacking for the effects of these medications on reproductive endpoints in men.

[Management of side effects of targeted therapies in renal cancer: sexual disorders]

Since sexual disorders were not specifically studied in the principal series, epidemiological data is scarce. Nevertheless, in practice, when sexuality is dealt with during the monitoring of patients undergoing targeted therapies, more than half of the patients questioned say that they attach importance to their quality of sex life, despite the severity of their metastatic renal cancer. At the start of treatment, it is therefore important to inform patients of the possible occurrence of problems and to encourage them to report them. During treatment, screening for sexual disorders by questioning is desirable: desire, lubrication, dyspareunia, erectile dysfunction. In the event of the onset of a sexual disorder during treatment, it is not usually necessary to stop or modify the treatment. Therapeutic measures depend on the discomfort felt and are under the control of the specialist: erectile dysfunction, male libido disorders, vaginal dryness and vulvovaginitis. A consultation with an oncology psychologist and/or sex therapist is useful, if possible with the partner, based on the impact of the sexual problems.

Inhibition of mammalian target of rapamycin signaling pathway decreases retinoic acid stimulated gene 8 expression in adult mouse testis

OBJECTIVE

To evaluate the expression of mammalian target of rapamycin (mTOR) pathway molecules in mouse spermatogenesis and as well as its role during proliferation and meiotic initiation of spermatogenic cells.

DESIGN

Experimental animal study.

SETTING

University.

ANIMAL(S)

C57Balb-C adult male mice.

INTERVENTION(S)

Expressions of mTOR signaling pathway proteins in adult testis were evaluated. Then the effect of inhibition of this pathway on proliferation and differentiation of spermatogonial stem cells was investigated using seminiferous tubule culture.

MAIN OUTCOME MEASURE(S)

Immunohistochemistry was performed to evaluate the expressions of mTOR signaling pathway proteins. To inhibit mTOR signaling pathway by rapamycin, seminiferous tubule culture was done. Viability assay and terminal deoxynucleotidyl transferase dUTP nick end labeling was performed to evaluate the culture conditions and to examine cell death, respectively. Western blot was used to determine the expressions of the PCNA, STRA8, and VASA proteins.

RESULT(S)

Our results showed that spermatogonial stem cells and preleptotene spermatocytes express total mTOR, p-mTOR, total p70S6K, p-p70S6K, and p-4EBP1. Expressions of p-p70S6K, p-4EBP1, PCNA, and STRA8 decreased significantly in the rapamycin-treated group, where no difference was observed in VASA expression. Cell viability and the number of apoptotic cells were similar for all groups.

CONCLUSION(S)

Our findings suggest that the mTOR signaling pathway may have role in the proliferation and stimulation of meiotic initiation of spermatogonial stem cells. To the best of our knowledge, this is the first ex vivo study that reports the function of the mTOR pathway in adult mouse spermatogenesis.

Management of pregnancy in the post-cardiac transplant patient

Over the past 10 years, heart transplantation survival has increased among transplant recipients. Because of improved outcomes in both congenital and adult transplant recipients, the number of male and female patients of childbearing age who desire pregnancy has also increased within this population. While there have been many successful pregnancies in post-cardiac transplant patients reported in the literature, long-term outcome data is limited. Decisions regarding the optimal timing and management of pregnancy in male and female post-cardiac transplant patients are challenging and should be coordinated by a multidisciplinary team of healthcare providers. Pregnant patients will need to be counseled and monitored carefully for complications including rejection, graft dysfunction, and infection. This review focuses on preconception counseling for both male and female cardiac transplant recipients. The maternal and fetal risks during pregnancy and the postpartum period, including risks to the fetus fathered by a male cardiac transplant recipient will be reviewed. It also provides a brief summary of our own transplant experience and recommendations for overall management of pregnancy in the post-cardiac transplant recipient.

mTOR inhibitors in pediatric kidney transplantation

The mammalian target of the rapamycin (mTOR) inhibitors sirolimus and everolimus are increasingly being used in pediatric kidney transplantation in different combinations and doses. Several studies have shown beneficial effects of using mTOR inhibitors in children after pediatric renal transplantation. A switch to a low-dose calcineurin inhibitor (CNI) and mTOR inhibitor has been proven to stabilize the glomerular filtration rate. Additionally, de novo studies using a low-dose CNI and an mTOR inhibitor have shown good graft survival and a low number of rejections. Side effects of mTOR inhibitors, such as hyperlipidemia, wound healing problems, and proteinuria, mainly occur if high doses are given and if treatment is not combined with a CNI. Lower doses of mTOR inhibitors do not result in growth impairment or reduced testosterone levels. Treatment with mTOR inhibitors is also associated with a lower number of viral infections, especially cytomegalovirus. Due to their antiproliferative effect, mTOR inhibitors could theoretically reduce the risk of post-transplant lymphoproliferative disease. mTOR inhibitors, especially in combination with low-dose CNIs, can safely be used in children after kidney transplantation as de novo therapy or for conversion from CNI- and mycophenolate mofetil-based regimens.

A prospective study in male recipients of kidney transplantation reveals divergent patterns for inhibin B and testosterone secretions

Background

Male patients with chronic kidney disease often exhibit the biological and clinical hallmarks of an abnormal hypothalamo–pituitary–gonadal axis. It is known that dialysis does not reverse this impaired endocrine status; however, the impact of kidney transplantation (KT) is still controversial. The aim of our study was to investigate the levels of serum gonadotropins, testosterone, and inhibin B during dialysis and after KT.

Methods

A longitudinal and prospective single center study was led in an academic setting. Blood hormones levels were assayed by immunoassays in 53 men (mean age: 37 years) receiving dialysis (T₀) and at 6 months post-KT (T₁₈₀). These data were compared with those from 46 fertile semen donors (mean age: 37 years). The main outcome measure was the between-groups differences in hormones levels. A second criterion was the comparison of T₀ and T₁₈₀ hormones levels according to the immunosuppressive regimen.

Results

For patients ongoing dialysis, luteinizing hormone (LH) and follicle-stimulating hormone (FSH) mean levels were high, whereas testosterone and inhibin B mean levels remained normal. After KT, LH levels returned to normal whereas FSH was significantly increased. Testosterone levels remained normal whereas inhibin B levels significantly decreased. We found that the combination tacrolimus plus mycophenolic acid significantly decreased post-KT inhibin B levels. Moreover, we found that pre-graft inhibin-B level was independent of testosterone and could predict low post-operative inhibin B level with a sensitivity of 77% and a specificity of 92%.

Conclusions

Our study suggests that endocrine secretions of Leydig and Sertoli cells are differently impacted by dialysis, KT and immunosuppressive regimen raising new issues to explore.

Growing experience with mTOR inhibitors in pediatric solid organ transplantation

Controlled trials of mTOR inhibitors in children following solid organ transplantation are scarce, although evidence from prospective single-arm studies is growing. Everolimus with reduced CNI therapy has been shown to be efficacious and safe in de novo pediatric kidney transplant patients in prospective trials. Prospective and retrospective data in children converted from CNI therapy to mTOR inhibition following kidney, liver, or heart transplantation suggest preservation of immunosuppressive efficacy. Good renal function has been maintained when mTOR inhibitors are used de novo in children following kidney transplantation or after conversion to mTOR inhibition with CNI minimization. mTOR inhibition with reduced CNI exposure is associated with a low risk for developing infection in children. Growth and development do not appear to be impaired during low-dose mTOR inhibition, but more studies are required. No firm conclusions can be drawn as to whether mTOR inhibitors should be discontinued in children requiring surgical intervention or whether mTOR inhibition delays progression of hepatic fibrosis after pediatric liver transplantation. In conclusion, current evidence suggests that use of mTOR inhibitors in children undergoing solid organ transplantation is efficacious and safe, but a number of issues remain unresolved and further studies are required.

Outcomes of Pregnancies Fathered by Solid-Organ Transplant Recipients Exposed to Mycophenolic Acid Products

Context

In women, exposure to mycophenolic acid products during pregnancy results in an increase in both miscarriages and birth defects in the live born.

Objective

To describe the outcomes of pregnancies fathered by transplant recipients who were being maintained on mycophenolic acid products at the estimated time of conception and compare these pregnancies with pregnancies in the general population.

Methods

Data were collected by the National Transplantation Pregnancy Registry via questionnaires, telephone interviews, and medical records.

Results

One hundred fifty-two male transplant recipients with exposure to mycophenolic acid products fathered 205 pregnancies (208 outcomes, including 3 pairs of twins). Pregnancy outcomes included 194 live births with a prematurity rate of 10.8%, 14 spontaneous abortions, and no therapeutic abortions or stillbirths. Among the live births, 6 malformations were reported, for an incidence of 3.1%. No pattern of malformations was identified.

Conclusion

The outcomes of pregnancies fathered by transplant recipients treated with mycophenolic acid products appear similar to outcomes in the general population.

Linear growth in pediatric renal transplant recipients receiving sirolimus

SRL is a potent macrolide immunosuppressive agent that can be used as maintenance therapy for prevention of rejection and avoidance of CNI nephrotoxicity. However, animal studies indicate that SRL may inhibit skeletal and muscle growth. We analyzed linear growth in 25 children, age 1-15 yr old, maintained on SRL to determine whether SRL is detrimental to linear growth. Height z-scores at baseline were compared with those at 24 months. We also compared linear growth in children receiving SRL to patients maintained on TAC. Height z-scores over 24 months did not significantly change in the SRL group as a whole. Z-scores improved in 13 of 25 patients (52%). Children with improved z-scores were significantly younger than patents who did not display improved growth: 6 ± 5 yr vs. 11 ± 4 yr (p < 0.05). Height z-scores in SRL and TAC-based patients were no different initially and at 24 months, and a similar number of patients in each group displayed improved height scores. Height z-scores improved in 52% of patients on SRL and occurred predominantly in younger patients for the initial 24 months of treatment. Linear growth in SRL patients was also similar to the results in TAC-based patients. Therefore, our data did not identify a significant adverse effect of SRL on growth.

Tacrolimus and sirolimus induce reproductive abnormalities in female rats

BACKGROUND

Immunosuppression medications contribute to posttransplant diabetes mellitus in patients and can cause insulin resistance in male rats. Tacrolimus (TAC)-sirolimus (SIR) immunosuppression is also associated with appearance of ovarian cysts in transplant patients. Because insulin resistance is observed in patients with polycystic ovary syndrome, we hypothesized that TAC or SIR may induce reproductive abnormalities.

METHODS

We monitored estrus cycles of adult female rats treated daily with TAC, SIR, and combination of TAC-SIR, or diluent (control) for 4 weeks. Animals were then challenged with oral glucose to determine their glucose and insulin responses, killed, and their blood and tissues, including ovaries and uteri harvested.

RESULTS

TAC and TAC-SIR treatments increased mean random glucose concentrations (P<0.05). TAC, SIR, and TAC-SIR treatments also increased the glucose response to oral glucose challenge (P<0.05). The insulin response to glucose was significantly higher in rats treated with SIR compared with TAC (P<0.05). TAC, SIR and TAC-SIR treatments reduced number of estrus cycles (P<0.05). The ovaries were smaller after SIR and TAC-SIR treatment compared with controls. The TAC and TAC-SIR treatment groups had fewer preovulatory follicles. Corpora lutea were present in all groups. Ovarian aromatase expression was reduced in the SIR and TAC-SIR treatment groups. A significant (P<0.05) reduction in uterine size was observed in all treatment groups when compared with controls.

CONCLUSION

In a model of immunosuppressant-induced hyperglycemia, both TAC and SIR induced reproductive abnormalities in adult female rats, likely through different mechanisms.

Five-year experience using sirolimus-based, calcineurin inhibitor-free immunosuppression in pediatric renal transplantation

From December 2003 to December 2008, we employed a protocol for withdrawing TAC and converting to SRL in a cohort of low-risk renal pediatric transplant recipients. We report our experience in these children with respect to graft survival, AR episodes, renal function, and adverse events. All patients received basiliximab induction and TAC, MMF, and prednisone. Criteria for conversion to SRL included first transplants without histologic evidence for AR on three-month surveillance biopsies. Patient exclusion criteria included AR prior to or before surveillance biopsies, polyoma (BK) virus nephropathy, a history of nephrotic syndrome, or multiple organ transplants. Fifty-one of 137 patients who received transplants from December 2003 to December 2008 met criteria for withdrawal of TAC and were converted to SRL. SRL was discontinued in 11 children because of adverse events within 12 months after conversion. Among the remaining 40 patients, actuarial graft survival was 91% at five yr. AR occurred in 13% of patients within one yr after conversion. Complications from SRL included aphthous ulcers (30%); viremia with BK virus (20%), EBV (13%), and CMV (3%); proteinuria (7%); elevated cholesterol (7%); diabetes mellitus (2%); thrombocytopenia (2%); erectile dysfunction (2%); and lymph edema (2%). SRL was discontinued in 20%, predominantly for aphthous ulcers. Our experience with SRL-based immunosuppression demonstrates that a CNI-free regimen can be successful in lower-risk patients meeting our selection criteria. Aphthous ulcers and BK virus viremia were the most prevalent adverse events.

Measurements of serum pituitary-gonadal hormones and investigation of sexual and reproductive functions in kidney transplant recipients

Objective. To investigate changes in serum pituitary-gonadal hormones and restoration of sexual and reproductive functions after successful kidney transplantation. Patients and Methods. Serum pituitary-gonadal hormones before and after kidney transplantation were measured in 78 patients with end-stage renal disease (ESRD) and in 30 healthy adults. Pre- and postoperative semen specimens of 46 male recipients and 15 male controls were collected and compared. Additional 100 married kidney transplant recipients without children were followed up for 3 years to observe their sexual function and fertility. Results. Serum PRL, LH, and T or E₂ levels gradually restored to the normal ranges in all kidney transplant recipients, and sperm density, motility, viability, and morphology significantly improved in the male recipients 4 months after successful kidney transplantation (P < .05). Thirty-three male recipients (55.93%) reobtained normal erectile function, and 49 kidney transplant recipients (61.25%) had children within the 3-year follow-up period. Conclusion. Successful kidney transplantation could effectively improve pituitary-gonadal hormone disturbance and sexual and reproductive dysfunctions of ESRD patients.

Sexual dysfunction in chronic liver disease: is liver transplantation an effective cure?

The goal of liver transplantation is not only to ensure patient long-term survival but also to offer the opportunity to achieve psychologic and physical integrity. Quality of life after liver transplantation may be affected by unsatisfactory sexual function. Before liver transplantation, sexual dysfunction and sex hormone disturbances are reported in men and women mainly due to abnormality of physiology of the hypothalamic-pituitary-gonadal axis and, in some cases, origin of liver disease. Successful liver transplantation should theoretically restore hormonal balance and improve sexual function both in men and women, thus improving the reproductive performance. However, after transplantation, up to 25% of patients report persistent sexual dysfunction, and approximately one third of patients describe the appearance of de novo sexual dysfunction. Despite the described high prevalence of this condition, epidemiologic data are relatively scant. Further studies on pathophysiology and risk factors in the field of sexual function after liver transplantation along with new strategies to support and inform patients on the waiting list and after surgery are needed.

Effect of everolimus on cell viability in nonfunctioning pituitary adenomas

CONTEXT

Pituitary adenomas can cause specific syndromes due to hormone excess and/or determine sellar mass symptoms. Pituitary cell growth can sometimes be influenced by medical therapy, such as for somatotroph adenomas treated with somatostatin analogs or prolactinomas treated with dopaminergic drugs. However, nonfunctioning pituitary adenomas (NFAs) are still orphans of medical therapy. Everolimus (RAD001), a derivative of rapamycin, is a well-known immunosuppressant drug, which has been recently shown to have antineoplastic activity in several human cancers.

OBJECTIVE

The objective of the study was to investigate the possible antiproliferative effects of RAD001 in human NFAs.

DESIGN

We collected 40 NFAs that were dispersed in primary cultures, treated without or with 1 nm to 1 microm RAD001, 10 nm cabergoline, 10 nm SOM230 (a somatostatin receptor multiligand), and/or 50 nm IGF-I. Cell viability and apoptosis were evaluated after 48 h, and vascular endothelial growth factor (VEGF) secretion was assessed after an 8-h incubation. Somatostatin and dopamine subtype 2 receptor expression was investigated by quantitative PCR.

RESULTS

In 28 cultures (70%), Everolimus significantly reduced cell viability (by approximately 40%; P < 0.05 vs. control), promoted apoptosis (+30%; P < 0.05 vs. control), inhibited p70S6K activity (-20%), and blocked IGF-I proliferative and antiapoptotic effects. In selected tissues cotreatment with SOM230, but not cabergoline, exerted an additive effect. Everolimus did not affect VEGF secretion but blocked the stimulatory effects of IGF-I on this parameter.

CONCLUSIONS

Everolimus reduced NFA cell viability by inducing apoptosis, with a mechanism likely involving IGF-I signaling but not VEGF secretion, suggesting that it might represent a possible medical treatment of invasive/recurrent NFAs.

Sexual dysfunction after liver transplantation

1. The goal of liver transplantation is not only to ensure the survival of patients but also to offer patients the opportunity to achieve a good balance between the functional efficacy of the graft and their psychological and physical integrity. The quality of life after transplantation may be affected by unsatisfactory sexual activity and reproductive performance. 2. Sexual dysfunction and sex hormone disturbances are widely reported in men and women with chronic liver disease before liver transplantation. 3. Successful liver transplantation should lead to improvements in sexual function and sex hormone disturbances in both men and women, therefore improving reproductive performance, but immunosuppressive drugs may interfere with hormone metabolism. 4. Pregnancy is often successful after liver transplantation, despite the potentially toxic effects of immunosuppressive drug therapy, but fetal and maternal outcomes should be regularly assessed. 5. More detailed and comprehensive data are needed in the field of sexual function after transplantation, and new strategies are needed to support and inform patients on the waiting list and after liver transplantation.

The effect of sirolimus on prostate-specific antigen (PSA) levels in male renal transplant recipients without prostate cancer

In kidney recipients, the immunosuppressant sirolimus has been associated with a decreased incidence of de novo posttransplant malignancies (including prostate cancer). But the effect of sirolimus on the prostate-specific antigen (PSA) blood level, an important prostate cancer screening tool, remains unknown. We studied male kidney recipients >50 years old (transplanted from January 1994 to December 2006) without clinical evidence for prostate cancer. Pre- and posttransplant PSA levels were analyzed for 97 recipients (n = 19 on sirolimus, n = 78 on tacrolimus [control group]). Pretransplant PSA was similar for sirolimus versus tacrolimus recipients (mean, 1.8 versus 1.7 ng/mL, p = 0.89), but posttransplant PSA was significantly lower for recipients on sirolimus (mean, 0.9 versus 1.9 ng/mL, respectively, p < 0.001). The mean difference between pretransplant and posttransplant PSA was -0.9 ng/mL (50.0%, p = 0.006) for the sirolimus group versus +0.2 ng/mL (+11.8%, p = 0.24) for the tacrolimus group. By multivariate analysis, only pretransplant PSA and immunosuppression with sirolimus independently impacted posttransplant PSA. Our data strongly suggest that sirolimus is associated with a significant PSA decrease in kidney recipients. Future studies must investigate the clinical implications of our findings for the use of PSA for prostate cancer screening in male kidney recipients on sirolimus.

Pregnancy after kidney transplantation

Reproductive success is a common, expected outcome for male and female recipients of solid-organ transplants. Men can father children, and women can become pregnant and carry the fetus to delivery. There are, however, important maternal and fetal complications that need to be considered to provide optimal care to the mother and her infant. Although pregnancy is common after the transplantation of all solid organs, guidelines for optimal counseling and clinical management are limited. This review discusses information to help the physician counsel the kidney transplant recipient about risks of pregnancy for the mother and the fetus and provides information to help guide treatment of the pregnant transplant recipient.

Transplant recipient renal function is donor renal mass- and recipient gender-dependent

The effect of both donor renal mass and gender on renal function, in both gender recipients, was examined. Qualifying consecutive living-donor renal transplants (n = 730) were stratified into 4 donor-recipient groups: female-female (n = 177), male-female (n = 151), female-male (n = 240), male-male (n = 162). Groups were equivalent in age, race, body mass index (BMI), match, ischemia time, operative time, and estimated glomerular filtration rate (eGFR). Female recipients had lower serum creatinine (Cr(s)). Male recipients had higher Cr(s) wherever they received a female allograft. Male recipients of male kidneys had a higher eGFR than all other groups for 3 years. Renal function of the recipient correlated with the renal mass of the donor within each group. Male and female kidneys functioned equivalently in the female-recipient environment. Large nephron-mass male donor kidneys function more poorly in female recipients. The male kidney loses 15-20 ml/min eGFR in the female host. The diminished graft function may be related to androgen deprivation. Female and male donor kidneys function equivalently in the male recipient if adjusted for renal mass transplanted. Female kidneys improve eGFR by 7-10 ml/min by being transplanted into a male environment. Donor renal mass and gender affect recipient graft function Expectations of ultimate recipient renal function should take into account both the gender and mass disparity of the donor-recipient pair.

Use of sirolimus in solid organ transplantation

Sirolimus is a mammalian target of rapamycin (mTOR) inhibitor that inhibits cell cycle progression and has proven to be a potent immunosuppressive agent for use in solid organ transplant recipients. The drug was initially studied as an adjunct to ciclosporin (cyclosporine) to prevent acute rejection in kidney transplant recipients. Subsequent studies have shown efficacy when combined with a variety of other immunosuppressive agents. The most common adverse effects of sirolimus are hyperlipidaemia and myelosuppression. The drug has unique antiatherogenic and antineoplastic properties, and may promote immunological tolerance and reduce the incidence of chronic allograft nephropathy. Although sirolimus is relatively non-nephrotoxic when administered as monotherapy, it pharmacodynamically enhances the toxicity of calcineurin inhibitors. Ironically, the drug has been used to facilitate calcineurin inhibitor-free protocols designed to preserve renal function after solid organ transplantation. Whether sirolimus can be used safely over the long term with low doses of calcineurin inhibitors requires further study. The use of sirolimus as a corticosteroid-sparing agent also remains to be proven in controlled trials. Postmarketing studies have revealed a number of unforeseen adverse effects including impaired wound healing and possibly proteinuria, oedema, pneumonitis and thrombotic microangiopathy. Overall, sirolimus is a powerful agent when used judiciously with other available immunosuppressants. As is true for all immunosuppressive drugs available for treatment of solid organ transplant recipients, the efficacy of the drug must be balanced against its considerable adverse effects.

Gonadal impact of target of rapamycin inhibitors (sirolimus and everolimus) in male patients: an overview

The immunosuppressive agents target of rapamycin inhibitors (TOR-I) (sirolimus, and everolimus) have been widely used in kidney transplantation for >10 years. Up to 40% of men receiving a kidney transplant are younger than 50, and fertility as well as erectile function are major concerns. In this review, we provide a synopsis of past studies focusing on gonadal function in men treated with TOR-I, mainly sirolimus, to establish what impact they have on male gonads, and which pathophysiological pathways are involved. A PubMed search for the years 1990-2006 selected articles that focused on the gonadal impact of TOR-I. Primary outcome measures were testosterone, follicle-stimulating hormone (FSH), and luteinizing hormone (LH) levels. Secondary outcome measures were sexual function, fertility status and sperm parameters. Treatment with TOR-I results in a decrease in testosterone level, and an opposite increase in LH. Moreover, spermatogenesis seems to be disrupted by TOR-I and FSH levels are increased. Sirolimus and everolimus inhibit the activity of mammalian targets of rapamycin, a serine/threonine kinase involved in numerous cell-growth processes. Molecular mechanisms of action of TOR-I on the testis involve inhibition of a stem cell factor/c-kit-dependant process in spermatogonia. Preliminary results appear to show that TOR-I treatment has deleterious actions on the testis and impairs gonadal function after renal transplantation, but the impact of these effects are unknown.