Kidney transplantation and pregnancy:

In vitro study of the toxic and teratogenic effects of prednisolone, azathioprine and mycophenolate mofetile on embryological development of rats

This study aimed to evaluate the effects of the glucocorticoid prednisolone, the mycophenolic acid prodrug, azathioprine, and the fungi fermentation end product, mycophenolate mofetile on the embryological development of rats. Nine day-old rat embryos were cultured in rat serum containing prednisolone at varying concentrations (5-30 µg/ml) for 48 h. The test groups were cultured separately in rat serum containing 0.3-10 µg/ml azathioprine and 1-10 µg/ml mycophenolate mofetile. Embryonic development parameter effects of both drugs in combination with prednisolone (20 µg/ml) were studied using morphological methods, with special attention given to the incidence of malformations. The genotoxic effects of agents evaluated with the TUNEL test revealed that prednisolone is not a cause of developmental toxicity. The maximum safe dose of prednisolone that could be used in combination with other immunosuppressive agents was determined to be 20 µg/ml. Azathioprine was found to be toxic and teratogenic for the rat embryos beginning at a dose of 1 µg/ml. Dose-dependent toxic and teratogenic effects of mycophenolate mofetile were detected at doses lower than normal clinical ones.

Thymoglobulin-Resistant T-Cell-Mediated Acute Rejection in a Pregnant Renal Transplant Recipient: Case Report and Review of the Literature

To avoid graft rejection during pregnancy, frequent monitoring of serum drug levels is recommended. Pregnancy induces hyperfiltration in transplanted kidneys, as in native kidneys; therefore, detection of rejection can be difficult when monitoring by serum creatinine. If rejection is suspected, ultrasonographguided graft biopsy can be done; once proven, it can be treated with pulse steroids, but data are scarce regarding other agents. Here, we present a 28-year-old pregnant female patient with resistant acute rejection but with successful pregnancy outcome. Our patient had end-stage kidney disease secondary to lupus nephropathy and underwent living-donor renal transplant in May 2013 after hemodialysis support for 1 year. She received thymoglobulin as induction therapy and was maintained on prednisolone, mycophenolate mofetil, and tacrolimus. She had normal renal graft function without proteinuria. After she received counseling, she became pregnant in February 2015. In June 2015, she presented with acute graft dysfunction with serum creatinine level of 365 μmol/L. Her abdominal ultrasonography showed mild hydronephrosis and viable fetus. She received empirical pulse steroids with partial response, and her graft biopsy showed acute T-cell-mediated rejection and negative C4d. Intravenous immunoglobulins and minipulse steroids were administered but without response. After gynecologic counseling and informed consent, she received 5 doses of thymoglobulin. She was dialysis dependent until premature vaginal labor, which resulted in birth of a viable 2-kg boy. We suggest that successful pregnancy outcomes could occur with close monitoring and daily dialysis in female kidney transplant patients with resistant rejection.

A best-practice position statement on pregnancy after kidney transplantation: focusing on the unsolved questions. The Kidney and Pregnancy Study Group of the Italian Society of Nephrology

Kidney transplantation (KT) is often considered to be the method best able to restore fertility in a woman with chronic kidney disease (CKD). However, pregnancies in KT are not devoid of risks (in particular prematurity, small for gestational age babies, and the hypertensive disorders of pregnancy). An ideal profile of the potential KT mother includes "normal" or "good" kidney function (usually defined as glomerular filtration rate, GFR ≥ 60 ml/min), scant or no proteinuria (usually defined as below 500 mg/dl), normal or well controlled blood pressure (one drug only and no sign of end-organ damage), no recent acute rejection, good compliance and low-dose immunosuppression, without the use of potentially teratogen drugs (mycophenolic acid and m-Tor inhibitors) and an interval of at least 1-2 years after transplantation. In this setting, there is little if any risk of worsening of the kidney function. Less is known about how to manage "non-ideal" situations, such as a pregnancy a short time after KT, or one in the context of hypertension or a failing kidney. The aim of this position statement by the Kidney and Pregnancy Group of the Italian Society of Nephrology is to review the literature and discuss what is known about the clinical management of CKD after KT, with particular attention to women who start a pregnancy in non-ideal conditions. While the experience in such cases is limited, the risks of worsening the renal function are probably higher in cases with markedly reduced kidney function, and in the presence of proteinuria. Well-controlled hypertension alone seems less relevant for outcomes, even if its effect is probably multiplicative if combined with low GFR and proteinuria. As in other settings of kidney disease, superimposed preeclampsia (PE) is differently defined and this impairs calculating its real incidence. No specific difference between non-teratogen immunosuppressive drugs has been shown, but calcineurin inhibitors have been associated with foetal growth restriction and low birth weight. The clinical choices in cases at high risk for malformations or kidney function impairment (pregnancies under mycophenolic acid or with severe kidney-function impairment) require merging clinical and ethical approaches in which, beside the mother and child dyad, the grafted kidney is a crucial "third element".

Congenital Esophageal Atresia and Microtia in a Newborn Secondary to Mycophenolate Mofetil Exposure During Pregnancy: A Case Report and Review of the Literature

Patient: Female, 20

Final Diagnosis: Esophageal atresia

Symptoms: Cough • gagging • poor feeding

Medication: Mycophenolate mofetil

Clinical Procedure: Esophageal repair

Specialty: Transplantology

Mycophenolic Acid-Induced Developmental Defects in Zebrafish Embryos

With the increasing use of mycophenolic acid (MPA) in solid organ transplantation, some clinical studies indicate that it is also a human teratogen. However, it is unknown by which mechanism MPA acts as a teratogen. Mycophenolic acid was a selective blocker of de novo purine synthesis, and its immunosuppressive effect is mediated by the inhibition of inosine monophosphate dehydrogenase, which could be a target for MPA-induced toxicity as well. The aim of our study was to examine the direct influence of MPA exposure on zebrafish ( Danio rerio) embryos. Morphological defects including tail curvature and severe pericardial edema in zebrafish embryos caused by MPA (3.7-11.1 µmol/L) were found in a dose-dependent manner. The teratogenic index (25% lethal concentration value (LC25)/no observed adverse effect level ratio) was 16, which indicated MPA as a teratogen. Quantitative polymerase chain reaction analysis revealed that the expression level of impdh1b and impdh2 was significantly reduced by MPA treatment at 8 µmol/L (equals to LC25 level). All the toxic effects could be partially reversed by the addition of 33.3 µmol/L guanosine. Our results indicated that MPA impairs the development of zebrafish embryos via inhibition of impdh activity, which subsequently caused a guanosine nucleotide depletion in vivo.

Obstetric and neonatal outcome of pregnancies fathered by males on immunosuppression after solid organ transplantation

Immunosuppressive drugs may influence spermatogenesis, but little is known about outcome of pregnancies fathered by transplanted males. We estimated risk of adverse outcomes in pregnancies (with data after the first trimester) fathered by males that had undergone organ transplantation and were treated with immunosuppression. A population-based study, linking data from the Norwegian transplant registry and the Medical Birth Registry of Norway during 1967-2009 was designed. All Norwegian men undergoing solid organ transplantation were included. Odds ratios for major malformations, preeclampsia, preterm delivery (<37 weeks) and small-for-gestational-age were obtained using logistic regression. A total of 2463 transplanted males, fathering babies of 4614 deliveries before and 474 deliveries after transplantation were identified. The risk of preeclampsia was increased (AOR: 7.4, 95% CI: 1.1-51.4,) after transplantation compared to prior to transplantation. No increased risk was found for congenital malformations or other outcomes when compared with pregnancies before transplantation or with the general population (2 511 506 births). Our results indicate an increased risk of preeclampsia mediated through the transplanted and immunosuppressed father. Importantly, no increased risk was found for other adverse obstetric outcomes or malformations, which may reassure male transplant recipients planning to father children.

Mycophenolate fetal toxicity and risk evaluation and mitigation strategies

The mycophenolic acid (MPA) preparations are one of the most commonly used immunosuppressants in the United States. However, these agents carry a black box warning regarding their use during pregnancy due to an association with increased risk of miscarriage and congenital defects. To ensure that the benefits of MPA outweigh the risks, the Food and Drug Administration (FDA) required all manufacturers of MPA products to propose risk evaluation and mitigation strategies (REMS). Four years after initially calling for proposals, the FDA approved a single shared REMS system in September 2012. The elements of the MPA REMS include a medication guide and elements to assure safe use (ETASU). The medication guide, which was previously FDA-approved in 2008, should continue to be distributed to patients, and the ETASU requires physicians to complete training and obtain patient signatures on the "Patient-Prescriber Acknowledgement Form." A single, national, voluntary pregnancy registry is available, and pregnant patients should be encouraged to participate. Although the impact of the MPA REMS on clinical practice is not clear, it is a step toward increasing the understanding of fetal risks with MPA products among patients and possibly practitioners.