MuSK myasthenia gravis and pregnancy

Pregnancy planning may impact maternal and neonatal outcomes in people with myasthenia gravis

INTRODUCTION

Myasthenia Gravis (MG) is an acquired autoimmune condition commonly diagnosed in young people of reproductive age resulting in neuromuscular junction dysfunction. The course of MG during pregnancy and its impact on maternal and neonatal outcomes is vary in the literature. Pregnancy planning is a known strategy and modifiable risk factor in obstetric practice to decrease maternal and neonatal morbidity. We aim to assess if planning a pregnancy impacts maternal and neonatal outcomes, MG exacerbation, and pregnancy-related complications.

METHODS

This study utilized data from an online, North American survey entitled "A Patient Centered study on Pregnancy in People with Myasthenia Gravis", distributed with the assistance of MG advocacy groups in the United States and Canada. It included individuals with MG who had at least one pregnancy in the last 10-years. Key maternal and neonatal outcomes were compared between planned and unplanned pregnancies.

RESULTS

Out of 156 survey participants, 58 had a pregnancy following MG diagnosis, totaling 90 reported pregnancies. Of these, 56 (62.2%) were planned and 34 (37.8%) were unplanned pregnancies. The unplanned pregnancies were associated with more MG exacerbations, hospitalizations, and intensive care unit admission (37.7% vs. 13.7%, 26.5% vs. 11%, and 17.6% vs. 8.9%, respectively, p ≤ .05). The neonatal outcomes did not significantly differ between the groups.

DISCUSSION

Planned pregnancies in people with MG may be associated with a reduced gestational and post-partum risk of MG exacerbation, hospitalizations, and ICU admissions. Larger studies are required to confirm this association and account for potential contributing variables.

The burden of myasthenia gravis - highlighting the impact on family planning and the role of social support

Background

Myasthenia gravis (MG) is a rare autoimmune disease and chronic condition that necessitates specialized care. Patients experience a significant burden of disease affecting various aspects of their lives. The aim of this study was to investigate the impact of MG on family planning, challenges associated with pregnancy, childcare responsibilities and the extent to which MG patients perceive and utilize social support.

Methods

This analysis used data from our main data of a large cross-sectional study built on a questionnaire-based survey encompassing 1,660 MG patients and members of the German Myasthenia Association (Deutsche Myasthenie Gesellschaft), and focused on sociodemographic, clinical and family planning relevant data points.

Results

Decisions regarding family planning were significantly impacted for individuals with MG when MG symptoms started either before or during their family planning (men: n = 19 and 29.7%; women: n = 156 and 58.4%). In this subgroup a substantial proportion opted against parenthood due to MG (men: n = 8 and 50.0%; women: n = 54 and 38.0% and/or another n = 12 and 8.4% of female participants encountered partner-related refusals). In the subgroup of female SP with MG starting before or during family planning who have reported ever been pregnant the self-reported miscarriage rate was 29.0% (n = 51). MG patients with medium incomes or moderate disease severity reported lower levels of perceived social support. 42.7% (n = 606) of participants needed assistance in negotiations with health insurers and 28.0% (n = 459) needed support for transportation to medical appointments.

Conclusion

This study shows a significant impact of MG on family planning decisions, affecting both women and men, and often resulting in life-altering decisions such as voluntary childlessness due to MG. The significance of social support becomes evident as a vital factor, especially when navigating through the healthcare system. Tailored healthcare approaches, organized guidance and comprehensive support is needed to enable informed decision-making and offer assistance for MG patients.

Clinical trial registration

https://clinicaltrials.gov/study/NCT03979521, Registered 7 June 2019 (retrospectively registered).

Immunotherapies in MuSK-positive Myasthenia Gravis; an IgG4 antibody-mediated disease

Muscle-specific kinase (MuSK) Myasthenia Gravis (MG) represents a prototypical antibody-mediated disease characterized by predominantly focal muscle weakness (neck, facial, and bulbar muscles) and fatigability. The pathogenic antibodies mostly belong to the immunoglobulin subclass (Ig)G4, a feature which attributes them their specific properties and pathogenic profile. On the other hand, acetylcholine receptor (AChR) MG, the most prevalent form of MG, is characterized by immunoglobulin (Ig)G1 and IgG3 antibodies to the AChR. IgG4 class autoantibodies are impotent to fix complement and only weakly bind Fc-receptors expressed on immune cells and exert their pathogenicity via interfering with the interaction between their targets and binding partners (e.g. between MuSK and LRP4). Cardinal differences between AChR and MuSK-MG are the thymus involvement (not prominent in MuSK-MG), the distinct HLA alleles, and core immunopathological patterns of pathology in neuromuscular junction, structure, and function. In MuSK-MG, classical treatment options are usually less effective (e.g. IVIG) with the need for prolonged and high doses of steroids difficult to be tapered to control symptoms. Exceptional clinical response to plasmapheresis and rituximab has been particularly observed in these patients. Reduction of antibody titers follows the clinical efficacy of anti-CD20 therapies, a feature implying the role of short-lived plasma cells (SLPB) in autoantibody production. Novel therapeutic monoclonal against B cells at different stages of their maturation (like plasmablasts), or against molecules involved in B cell activation, represent promising therapeutic targets. A revolution in autoantibody-mediated diseases is pharmacological interference with the neonatal Fc receptor, leading to a rapid reduction of circulating IgGs (including autoantibodies), an approach already suitable for AChR-MG and promising for MuSK-MG. New precision medicine approaches involve Chimeric autoantibody receptor T (CAAR-T) cells that are engineered to target antigen-specific B cells in MuSK-MG and represent a milestone in the development of targeted immunotherapies. This review aims to provide a detailed update on the pathomechanisms involved in MuSK-MG (cellular and humoral aberrations), fostering the understanding of the latest indications regarding the efficacy of different treatment strategies.

Choices and Challenges With Treatment of Myasthenia Gravis in Pregnancy: A Systematic Review

Myasthenia gravis (MG) is an autoimmune disease affecting young women in their second and third decades, coinciding with their reproductive years. We aim to explore the choices and challenges in the treatment of MG in pregnancy. Cochrane, PubMed, Google Scholar, and Embase were the four databases systematically searched for studies with patients reporting pregnancy outcomes for women with MG during pregnancy using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) technique. Quality assessment was done using the Joanna Briggs Institute critical tool (JBI, Adelaide, Australia) for methodological quality. From 2000 to 2023, 40 studies from database search results were considered. There is a substantial risk of complications with MG, especially if it appears during pregnancy. In particular, widespread weakness is a cause of severe, life-threatening disorders, but several treatment options are available.

Pregnancy in MuSK-positive myasthenia gravis: A single-center case series

INTRODUCTION/AIMS

Myasthenia gravis (MG) with muscle-specific tyrosine kinase (MuSK) antibodies (MMG) is predominantly seen in women of childbearing age. Our objective in this study was to describe the course of MMG during pregnancy and within 6 months postpartum, and to document any effect on fetal health.

METHODS

A retrospective review was performed of medical records of patients with MMG seen in the Duke Myasthenia Gravis Clinic from 2003 to 2022. MMG patients with onset of MMG symptoms before or during pregnancy as well as within 6 months postpartum were reviewed.

RESULTS

A total of 14 pregnancies in 10 patients were included in our study cohort. Initial MG symptoms developed during pregnancy or within 6 months postpartum in six patients. Four patients had two pregnancies, three of whom developed MG during their first pregnancy. In the patients diagnosed before pregnancy, MG symptoms increased in five of eight patients during pregnancy or postpartum. Four patients required rescue therapy with plasma exchange or intravenous immunoglobulin during pregnancy or postpartum. One patient had a cesarean section after prolonged labor due to failure of progression. There were no other complications of pregnancy or delivery, and all infants were healthy at delivery.

DISCUSSION

As in non-MuSK MG, women with MMG may also have worsening or may develop initial MG symptoms during pregnancy or within 6 months postpartum. More aggressive medical therapy may be required for pregnant patients with MMG. Further study is needed to identify the mechanism and risk of worsening of MMG during pregnancy or postpartum.

Treatment considerations in myasthenia gravis for the pregnant patient

INTRODUCTION

Myasthenia gravis (MG) is an autoimmune disease where muscle antibodies form against the acetylcholine receptor (AChR), MuSK, or LRP4 at the neuromuscular junction leading to weakness. Patients worry about consequences for pregnancy, giving birth, nursing, and child outcome.

AREAS COVERED

This review lists the pharmacological treatments for MG in the reproductive age and gives recommendations. Consequences for pregnancy, giving birth, breastfeeding, and child outcome are discussed.

EXPERT OPINION

Pyridostigmine, corticosteroids in low doses, and azathioprine are regarded as safe during pregnancy and should be continued. Mycophenolate mofetil, methotrexate, and cyclophosphamide should not be used in reproductive age. Rituximab should not be given during pregnancy. Other monoclonal IgG antibodies such as eculizumab and efgartigimod should be given only when regarded strictly necessary to avoid long-term and severe incapacity. Intravenous and subcutaneous immunoglobulin and plasma exchange are safe treatments during pregnancy and are recommended for exacerbations with moderate or severe generalized weakness. Most MG women have spontaneous vaginal deliveries. Indications for Cesarean section are obstetrical and similar to non-MG women. Neonatal myasthenia manifests as a transient weakness caused by the mother's IgG muscle antibodies and affects 10% of the babies. MG women should be supported in their wish to have children.

An update on the use of immunoglobulins as treatment for myasthenia gravis

INTRODUCTION

Myasthenia gravis (MG) is an antibody mediated disease where pathogenic antibodies interact with the acetylcholine receptor or other proteins at the post-synaptic neuromuscular junction. There is growing evidence that immunoglobulin infusions are beneficial for clinical exacerbations and chronic refractory disease and may be an option for patients unresponsive to conventional immunosuppressive therapies.

AREAS COVERED

We performed an extensive literature review, looking for evidence on the use of immunoglobulins for the treatment of MG, by conducting a search in MEDLINE (1946 to present), EMBASE (1947 to present) and Clinicaltrials.gov. We have included studies on the use of intravenous immunoglobulins (IVIG) and subcutaneous immunoglobulins (SCIG) for acute deterioration and chronic disease.

EXPERT OPINION

The use of IVIG in MG provides an option for rapid improvement in critical deterioration, being preferred over more invasive and less available therapies such as plasmapheresis. For refractory MG, the addition of IVIG can improve a patient's status and reduce the dosage of immunosuppressive medications. The alternative of SCIG is also effective and has advantages of infusion time flexibility, fewer side-effects, and patient independence. The safety and efficacy of both interventions, patient preferences and quality of life may direct therapeutic choices in the future.

Risk factors for pregnancy-related clinical outcome in myasthenia gravis: a systemic review and meta-analysis

OBJECTIVE

Myasthenia gravis (MG) is an autoimmune disorder that frequently affects females at reproductive age. Herein, we aimed to assess the associations of clinical factors with pregnancy-related outcome in MG.

METHODS

We searched PubMed and EMBASE for case-control and cohort studies that reported the MG status during or after pregnancy and relevant clinical variables. The data was extracted in proportions and odds ratios (ORs) with 95% confidence intervals (CIs) in subsequent meta-analysis.

RESULTS

Fifteen eligible articles reporting on 734 pregnancies with 193 worsening and 51 improved episodes were included out of 1765 records. The estimated worsening proportions in total, antepartum and postpartum periods were 0.36 (95% CI 0.25-0.40), 0.23 (95% CI 0.14-0.34) and 0.11 (95% CI 0.04-0.22) respectively. The proportion of pregnancy-related improvement in enrolled patients was 0.28 (95% CI 0.17-0.40), with 0.07 (95% CI 0.00-0.28) during pregnancy and 0.14 (95% CI 0.02-0.34) after pregnancy. No significant associations were disclosed between the clinical factors and MG worsening. Thymectomy before delivery is a strong predictor for MG improvement in postpartum period (OR 4.85, 95% CI 1.88-12.50, p = 0.001).

CONCLUSION

The total proportion of pregnancy-related MG worsening and improvement in MG was 0.36 (95% CI 0.25-0.40) and 0.28 (95% CI 0.17-0.40), respectively. Thymectomy before the delivery may aid in clinical improvements associated with pregnancy. Future prospective cohort studies are required to determine more relevant factors.

Clinical and pathophysiologic relevance of autoantibodies in neonatal myasthenia gravis

Between 10% and 20% of neonates born to mothers with myasthenia gravis (MG) develop neonatal MG due to the transfer of maternal autoantibodies across the placenta. Neonatal MG can occur in infants born not only from mothers with acetylcholine receptor (AChR) or muscle-specific tyrosine kinase (MuSK) antibodies but also from mothers without detectable muscle antibodies. The low incidence rate may be due to specific autoantibody characteristics that differ among individuals, but a genetic predisposition in some infants is possible. The majority of reported neonatal MG cases are anti-AChR antibody-positive (AChR-MG), and a high anti-fetal/anti-adult AChR titer ratio in the mother is predictive of its occurrence. However, patients with anti-MuSK antibody-positive MG (MuSK-MG) are more likely to experience exacerbations during pregnancy and have a higher probability of developing neonatal MG than AChR-MG patients. Moreover, maternal MuSK-MG may be associated with early-onset and more severe manifestations of neonatal MG. Although cholinesterase inhibitors have been effectively used for treating neonatal AChR-MG, neonatal MuSK-MG may be more difficult to treat with this type of medication. Maternal MuSK-MG usually greatly benefits from intravenous immunoglobulin (IVIG) and plasma exchange. In neonatal MG, IVIG is considered for severely affected infants with MuSK-MG, but the efficacy of IVIG remains unclear. Although exchange transfusion may be a management adjunct, its clinical benefits are controversial. As the therapy-induced reduction of autoantibodies may be advantageous for fetal outcomes, maternal MG should be effectively treated during pregnancy. However, caution of drug contraindication during pregnancy and lactation must be exercised to avoid unwanted effects for the fetus and neonate. In the future, MG caused by anti-lipoprotein receptor-related protein 4 or other antibodies might be also identified in pregnant women and neonates. Therefore, the determination of autoantibody specificity is essential for successful management.

Myasthenia gravis during pregnancy: what care should be taken?

Myasthenia gravis (MG) is an autoimmune disease in which the peak incidence is among women of childbearing age. For this reason, there is an overlap between the occurrence of this disease and pregnancy. It is known that MG symptoms can worsen during pregnancy and postpartum, and that pregnancy has special characteristics in MG patients. Children born to myasthenic mothers are at risk of having transient neonatal myasthenia. We briefly review the main relationships between MG and pregnancy, and we make recommendations for MG therapy, pregnancy, delivery, breastfeeding and newborns.

Myasthenia gravis and pregnancy

Myasthenia gravis (MG) is an autoimmune disorder of neuromuscular junction that has higher incidence in younger women than men, which could be related to differences in sex hormones physiology and immune system functioning between males and females. MG can first present during pregnancy and variably affect pregnancy, labor, and postpartum period. In this paper, we had an updated overview on our understanding about MG presentation and its effect on pregnancy and vice versa, therapeutic options for MG pregnant women, management of pregnancy or labor complications in MG patients, and finally fetal and neonatal considerations in MG pregnant women. A multidisciplinary approach, involving obstetricians/gynecologists, neurologists, and anes-thesiologists, plays a pivotal role in improving the clinical outcomes in both MG mothers and their infants during pregnancy, delivery and postpartum.

A challenging case of hypercapnic respiratory failure during pregnancy

We describe a 40-year-old female who presented with progressive breathlessness and hypercapnic respiratory failure during pregnancy secondary to undiagnosed muscle-specific kinase myasthenia gravis. Her presentation was progressive and protracted, having over five contacts with healthcare professionals over nine months, many of these predating her pregnancy. Her atypical presentation for myasthenia with minimal limb weakness led to consideration of other causes of hypercapnic respiratory failure. Once diagnosed, she was treated with intravenous immunoglobulin and non-invasive ventilation. She gave birth to a pre-term infant by planned caesarean section. Her insidious presentation and the progressive nature of her breathlessness were unusual and our report highlights the predominant involvement of respiratory muscles in muscle-specific kinase myasthenia. Her pregnancy may have further delayed her diagnosis due the attribution of some symptoms to normal pregnancy. Early recognition and treatment of myasthenia gravis are important to prevent life-threatening complications.

Evidence-Based Practice in Rehabilitation of Myasthenia Gravis. A Systematic Review of the Literature

Myasthenia gravis is a rare neuromuscular disorder characterized by muscle weakness and fatigue. This review analyzes the most recent evidence regarding the effectiveness and safety of different rehabilitative approaches to the disease. The review was carried out in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A total of 365 articles were found in the main scientific databases. Applying the inclusion/exclusion criteria, 11 studies were admitted to the final phase of the review. Three different rehabilitative approaches were identified: physical training, respiratory training, and balance training. All rehabilitative modalities contributed to enhancing functional outcomes, reducing fatigue, and improving quality of life, but currently none can be recommended over another for the lack of cross-comparative studies. The included studies showed methodological quality from low to fair. Despite the range of rehabilitative interventions available, there is a lack of high-quality evidence. However, this review suggests that a multidisciplinary rehabilitation approach should be recommended to people with myasthenia gravis, and above all, for those with mild to moderate symptomatology.

Gender issues of antibody-mediated diseases in neurology: (NMOSD/autoimmune encephalitis/MG)

Neuromyelitis optica spectrum disorder (NMOSD), autoimmune encephalitis (AE), myasthenia gravis (MG) and Lambert-Eaton myasthenic syndrome (LEMS) are antibody-mediated neurological diseases. They have mostly female predominance, affecting many women during childbearing age. Interactions between the underlying disease (or necessary treatment) and pregnancy can occur in every of these illnesses. Herein, we present the characteristics of NMOSD, AE, MG and LEMS in general, and review published data regarding the influence of the different diseases on fertility, pregnancy, puerperium, treatment strategy during pregnancy and post-partum period, and menopause but also male factors. We summarise key elements that should be borne in mind when confronted with such cases.

Myasthenia Gravis Can Have Consequences for Pregnancy and the Developing Child

Myasthenia gravis (MG) with onset below 50 years, thymic hyperplasia and acetylcholine receptor (AChR) antibodies is more common in females than in males. For a relatively large group of MG patients, pregnancy represents therefore an important question. The muscle weakness, the circulating autoantibodies, the hyperplastic thymus, the MG drug treatment, and any autoimmune comorbidity may all influence both mother and child health during pregnancy and also during breastfeeding in the postpartum period. Mother's MG remains stable in most patients during pregnancy. Pyridostigmine, prednisolone, and azathioprine are regarded as safe during pregnancy. Mycophenolate, methotrexate and cyclophosphamide are teratogenic and should not be used by women with the potential to become pregnant. Rituximab should not be given during the last few months before conception and not during pregnancy. Intravenous immunoglobulin and plasma exchange can be used for exacerbations or when need for intensified therapy. Pregnancies in MG women are usually without complications. Their fertility is near normal. Vaginal delivery is recommended. MG patients have an increased rate of Cesarean section, partly due to their muscle weakness and to avoid exhaustion, partly as a precaution that is often unnecessary. Around 10% of the newborn develop neonatal myasthenia during the first few days after birth. This is transient and usually mild with some sucking and swallowing difficulties. In rare cases, transplacental transfer of AChR antibodies leads to permanent muscle weakness in the child, and arthrogryposis with joint contractures. Repeated spontaneous abortions have been described due to AChR antibodies. MG women should always give birth at hospitals with experience in newborn intensive care. MG does not represent a reason for not having children, and the patients should be supported in their wish of becoming pregnant.

Neuromuscular disorders in pregnancy

Many neuromuscular disorders preexist or occur during pregnancy. In some cases, pregnancy unmasks a latent hereditary disorder. Most available information is based on case reports or series or retrospective clinical experience or patient surveys. Of special interest are pregnancy-induced changes in disease course or severity and likelihood for baseline recovery of function postpartum. Labor and delivery present special challenges in many conditions that affect skeletal but not smooth (uterine) muscle; so labor complications must be anticipated. Anesthesia for cesarean section surgery requires special precautions in many disorders. The types of conditions reviewed are broad and include examples of autoimmune, hereditary, and compressive/mechanical processes. Disorders include carpal tunnel syndrome and other focal neuropathies, Bell palsy, myasthenia gravis, and other neuromuscular junction disorders, acute and chronic inflammatory neuropathy, hereditary and acquired muscle diseases, spinal muscular atrophy, amyotrophic lateral sclerosis, channelopathies, autonomic neuropathy, and dysautonomia. Many commonly used therapies have fetal animal but no proven human toxicity concerns, complicating treatment and risk decisions. Weaning off effective therapeutic agents or preemptive aggressive treatment or surgery prior to planned pregnancy is an option in some conditions.

Myasthenia gravis and pregnancy: retrospective evaluation of 27 pregnancies in a tertiary center and comparison with previous studies

BACKGROUND AND AIM

To share our experience with the management of pregnancies in women with myasthenia gravis (MG) in a tertiary center.

METHODS

The study retrospectively evaluated 27 pregnancies in 12 patients. The pregnancies were divided into 3 groups on the basis of the clinical course of MG during pregnancy: improvement (n = 7), disease-stable (n = 9), and deterioration (n = 11). The groups were compared with respect to patient characteristics, clinical features, and obstetric outcomes.

RESULTS

There were 4 miscarriages (14.8%), 3 preterm births (11.1%), and 4 cases of preterm premature rupture of the membranes (PPROM) (14.8%). Exacerbation was observed in 25.9% of the cases; the remission rate during the postpartum period and after miscarriage was 37%. The cesarean section (CS) rate was 78.3%. Pregnancies with deterioration of MG were statistically more likely to have higher miscarriage, preterm birth, PPROM, CS, and transient neonatal MG rates, in addition to a lower gestational age at birth, birth weight, and 5-min Apgar score than pregnancies with improved or stable disease (p values < 0.001, 0.04, 0.03, 0.009, 0.02, < 0.001, 0.002, and 0.043, respectively).

CONCLUSION

Physicians who manage pregnant women with MG must be familiar with the clinical features of the condition; a multidisciplinary approach is necessary for a better prognosis.