Infections and the relationship to treatment in neuromuscular autoimmunity

Palatal prolapse during nasal expiration in patients with myasthenia gravis

INTRODUCTION/AIMS

We have encountered patients with myasthenia gravis (MG) who exhibited palatal prolapse (PP) during nasal expiration in the supine position while awake. This may be an overlooked cause of dyspnea in MG patients. This study aimed to examine and describe the characteristics of MG patients with PP.

METHODS

We reviewed the medical records of 183 consecutive patients who were diagnosed with MG in our hospital from 2012 to 2021. Thirty-two patients underwent laryngoscopy because of bulbar symptoms. Eight of these patients (25%) exhibited PP on laryngoscopy. Clinical features of these eight patients were retrospectively characterized.

RESULTS

Median age of the eight patients with PP was 70 years. Six were men. Median body mass index was 21.6 kg/m2 . All patients exhibited PP in the supine position but not the sitting position. Although no patient had abnormal findings on spirometry nor chest computed tomography, six reported dyspnea or difficulty with nasal expiration only in the supine position. PP improved in all four patients who underwent edrophonium testing. All eight patients eventually improved after immunotherapy.

DISCUSSION

PP during nasal expiration may be a cause of dyspnea in MG patients, along with respiratory muscle impairment, lung disease, and vocal cord paralysis. Laryngoscopy in the supine position is required to confirm.

Epidemiology of Chronic Inflammatory Demyelinating Polyneuropathy in South Korea: A Population-Based Study

BACKGROUND AND PURPOSE

We performed a population-based study to determine the prevalence and incidence of chronic inflammatory demyelinating polyneuropathy (CIDP) in South Korea using data from the Korean Health Insurance Review and Assessment Service (HIRA) database.

METHODS

Data recorded in the HIRA database between January 2016 and December 2020 were analyzed. The inclusion criteria in this study for patients with CIDP were a diagnostic code of G61.8 in the seventh and eighth revision of the Korean Standard Classification of Disease and a >3-month history of oral immunosuppressant use. The age-adjusted incidence rate and prevalence of CIDP in South Korea were also analyzed.

RESULTS

CIDP was newly diagnosed in 953 patients during the study period. The mean age at diagnosis was 58.36 years, and the male-to-female ratio was 1.74. The age-adjusted incidence rates were 0.22, 0.21, 0.23, 0.30, and 0.25 per 100,000 person-years in 2016, 2017, 2018, 2019, and 2020, respectively. The age-adjusted prevalence was estimated at 1.16 per 100,000 persons in 2020. Age and the Elixhauser Comorbidity Index were associated with the in-hospital mortality of patients with CIDP. Infection and cardiovascular disease (CVD) were also significantly associated with the in-hospital mortality of those patients. Acute-onset CIDP was initially diagnosed in an estimated 101 out of 953 patients with CIDP.

CONCLUSIONS

The prevalence and incidence rates of CIDP in South Korea were comparable between this nationwide cohort study and previous studies. Common comorbidities such as CVD and diabetes should be appropriately monitored in patients with CIDP to prevent a poor prognosis and socioeconomic burden.

Pneumonia in myasthenia gravis: Microbial etiology and clinical management

Introduction

Patients with myasthenia gravis (MG) are prone to the development of pneumonia due to the long-term immunotherapies they receive and a tendency for aspiration. Pneumonia remains a risk factor for MG worsening and is the most prevalent cause of mortality in MG patients. Classification of the pathogens involved and exploration of the risk factors for mechanical ventilation (MV) could aid in improving clinical outcomes.

Methods

Between January 2013 and October 2022, we performed an inpatient database review for MG patients with pneumonia concurrence in a tertiary research center specializing in neuromuscular disorders. The clinical and microbiological characteristics of 116 MG patients with pneumonia were retrospectively analyzed.

Results

In our cohort, 90.32% (112/124) of organisms were bacteria and 42.86% (48/112) of pathogenic bacteria were carbapenem-resistant. A high abundance of Epstein-Barr virus (EBV) was detected using next-generation sequencing (NGS) in 12 patients, while cytomegalovirus (CMV) was detected in 8 patients. Non-fermentative Gram-negative bacilli were the most prevalent microorganisms, in which ampicillin, sulfamethoxazole-trimethoprim (SMZ-TMP), piperacillin, cefoperazone, ceftazidime, and cefepime may have an anti-infectious effect. Moreover, peripheral lymphocyte percentage [odds ratio (OR) 0.88, 95% CI 0.75-0.96, p = 0.02] and serum globulin (OR 1.16, 95% CI 1.02-1.35, p = 0.03) were significantly associated with the risk of MV demand.

Discussion

Our identification of the microbial etiology of pneumonia in MG patients may provide future perspectives on accurate antibiotic options and enable early interventions when risk factors are present.

Application of lymphoplasmapheresis in the treatment of severe myasthenia gravis

Background

Lymphoplasmapheresis (LPE) is a treatment that combines traditional plasma exchange and lymphocyte removal technique. It has been applied to treat a variety of autoimmune diseases, but its application value in the treatment of severe myasthenia gravis (MG) is not yet clear. Therefore, the aim of this study was to investigate the efficacy and safety of LPE in severe MG.

Methods

Clinical data of 123 severe patients with MG (Myasthenia Gravis Foundation of America Clinical Classification, Class IV) who received LPE treatment were included in a retrospective analysis. Efficacy was evaluated by the change of Quantitative Myasthenia Gravis score (QMGS) before and after treatment. Univariate and multivariate logistic regression analysis was used to explore clinical factors affecting efficacy.

Results

A total of 220 replacements were performed in 123 patients, with an average of 1.79 replacements per patient. The overall safety of LPE was good, and no serious adverse reactions occurred. After treatment, the mean QMGS of patients decreased significantly, from 23.40 ± 4.25 points before treatment to 17.93 ± 5.61 points after treatment, a decrease of 5.47 ± 4.16 points. 75.6% of patients experienced remission of clinical symptoms. During a 2-month follow-up of 64 patients, a progressive improvement in QMGS was found. Each muscle group involved in MG responded well to LPE treatment. In addition, LPE significantly reduced the levels of AChR-Ab and inflammatory cytokines in patients. Age ≥ 50 years and co-infection were unfavorable factors affecting the efficacy.

Conclusions

In this study cohort, LPE is safe for the treatment of severe MG and achieves good treatment outcome with fewer replacements. In patients with MG, the avoidance and timely control of infection are necessary. Our study provides a potential new treatment option for severe MG.

Opinions on pneumocystis jirovecci prophylaxis in autoimmune neuromuscular disorders

Pneumocystis jirovecci (PJ) is ubiquitously present in the environment and capable of causing an interstitial pneumonia in immunocompromised subjects. It has been advocated that routine prophylaxis against PJ be given to patients with autoimmune neuromuscular conditions which require prolonged usage of corticosteroid therapy and/or other immunosuppressive agents. Available data, however, suggest that the risk of PJ infection in patients with autoimmune neuromuscular diseases is extremely low and a widespread usage of prophylactic therapy is likely unnecessary. Comorbidities including intestinal lung disease, prolonged lymphopenia, low CD4 count, parenchymal organ failure, and active cancer status appear to increase risk for PJ infection, and it is our opinion that these risk factors should be considered to determine the risk of PJ infection and the requirement for prophylaxis.

Adverse Side Effects Associated with Corticosteroid Therapy: A Study in 39 Patients with Generalized Myasthenia Gravis

Background

The tolerability of high-dose oral corticosteroids in patients with generalized myasthenia gravis (gMG) has not been systematically assessed. We evaluated adverse side effects (ASEs) of corticosteroid treatment in patients with gMG.

Material/Methods

Retrospective analysis was conducted of ASEs reported as being related to corticosteroid treatment in 39 patients with gMG who were treated with oral corticosteroids for ≥1 year.

Results

Median (interquartile range [IQR]) age was 60 (21) years, 53.8% of patients were women, and 66.7% were aged ≤65 years. Median (IQR) prednisone treatment duration was 14 (2) months; median (IQR) daily dose was 40 (15) mg. The median number of ASEs reported as corticosteroid-related was 2/patient (IQR, 1). Pre-diabetes and weight gain were most common (each 43.6% of patients). Bruising, insomnia, and osteoporosis were more prevalent in patients aged >65 years, while irritability, osteopenia, and pre-diabetes were more common in patients aged ≤65 years, although differences were not statistically significant. Irritability and weight gain were more prevalent in women (P=0.010 for irritability); osteoporosis and pre-diabetes more common in men (P=0.015 for osteoporosis). ASEs were generally more common in the high-dose prednisone group (>30 mg/day), but were only statistically significant for irritability (P=0.001).

Conclusions

Corticosteroid-related ASEs were common in patients with gMG. Some of these ASEs can have serious medical consequences, and certain ASEs appeared to be associated with specific patient characteristics. Demographics and comorbidities of patients with gMG must be carefully considered before corticosteroid initiation. Potential ASEs, such as unanticipated osteoporosis in men, require extra vigilance.

Pneumocystis jirovecii Pneumonia in Neurologic Disorders: Is Prophylaxis Necessary?

BACKGROUND

The incidence of Pneumocystis jirovecii pneumonia (PJP) in patients with underlying neurologic conditions is not well established, and the necessity of PJP prophylaxis for immunocompromised patients with neurologic disorders is uncertain.

METHODS

Single-center retrospective analysis of non-HIV PJP patients at a tertiary referral center from 2007 to 2016 to determine the incidence of PJP in patients with primary neurologic disorders.

RESULTS

The study included 142 patients with PJP without HIV. Twenty patients had primary neurologic diagnoses, and 122 had non-neurologic conditions. Associated neurologic diagnoses included brain malignancies (N = 14), myasthenia gravis (MG) (N = 2), myopathy (N = 2), neuromyelitis optica (NMO) (N = 1), and CNS vasculitis (N = 1). Estimated incidences of PJP were 0.7% for patients with NMO and 0.3% for patients with MG for the 10-year study period, whereas 4.6% of patients with NMO and 3.8% of patients with MG were placed on PJP prophylaxis. A survey of 24 neurologists who prescribe immunotherapy or chemotherapy confirmed an infrequent occurrence of PJP in their practice. Malignancy or parenchymal organ failure was present in 90% of neurologic patients with PJP, and coexisting infections occurred in 45%.

CONCLUSIONS

The overall incidence of PJP in patients with non-neoplastic neurologic disorders is exceedingly low, raising doubt about the value of routine PJP prophylaxis in neurologic patients outside neuro-oncology. PJP infection occurs frequently in patients with malignancy or parenchymal organ failure, indicating that overall health status may serve as a predisposing factor for PJP.

Doctor-Should I get the COVID-19 vaccine? Infection and immunization in individuals with neuromuscular disorders

The clinical course of neuromuscular disorders (NMDs) can be affected by infections, both in immunocompetent individuals, and in those with reduced immunocompetence due to immunosuppressive/immunomodulating therapies. Infections and immunizations may also trigger NMDs. There is a potential for reduced efficacy of immunizations in patients with reduced immunocompetence. The recent vaccination program for coronavirus disease-2019 (COVID-19) raises several questions regarding the safety and efficacy of this vaccine in individuals with NMDs. In this Practice Topic article, we address the role of vaccine-preventable infections in NMDs and the safety and efficacy of immunization in individuals with NMDs, with emphasis on vaccination against COVID-19.

Sepsis Mortality Is high in Patients With Connective Tissue Diseases Admitted to the Intensive Care Unit (ICU)

Objectives:

Patients with connective tissue diseases (CTD) such as systemic lupus erythematosus (SLE) have an increased risk for infections. This study investigated the outcome and characteristics of CTD patients under intensive care unit (ICU) treatment for sepsis.

Methods:

A single-center retrospective analysis was conducted and reviewed all patients with a CTD diagnosis admitted to the ICU of a university hospital for sepsis between 2006 and 2019. Mortality was computed and multivariate logistic regression was used to detect independent risk factors for sepsis mortality. Furthermore, the positive predictive value of ICU scores such as Sequential Organ Failure Assessment (SOFA) score was evaluated.

Results:

This study included 44 patients with CTD (mean age 59.8 ± 16.1 years, 68.2% females), most of them with a diagnosed SLE (61.4%) followed by systemic sclerosis (15.9%). 56.8% (n = 25) were treated with immunosuppressives and 81.8% (n = 36) received glucocorticoids. Rituximab was used in 3 patients (6.8%). The hospital mortality of septic CTD patients was high with 40.9%. It was highest among systemic sclerosis (SSc) patients (85.7%). SOFA score and diagnosis of SSc were independently associated with mortality in multivariate logistic regression (P = 0.004 and 0.03, respectively). The Simplified Acute Physiology Score II (SAPS II), SOFA and Acute Physiology and Chronic Health Evaluation II (APACHE II) scores were good predictors of sepsis mortality in the investigated cohort (SAPS II AUC 0.772, P = 0.002; SOFA AUC 0.756, P = 0.004; APACHE II AUC 0.741, P = 0.007).

Conclusions:

In-hospital sepsis mortality is high in CTD patients. SSc diagnoses and SOFA were independently associated with mortality. Additionally, common ICU scores were good predictors for mortality.

Diagnosis and treatment of myasthenia gravis

PURPOSE OF REVIEW

This article provides an update on the most recent advances in diagnostic procedures and therapeutic approaches for myasthenia gravis, spanning from autoantibody and neuroelectrophysiological tests as diagnostic tools, to innovative and promising treatments based on biological drugs.

RECENT FINDINGS

Novel studies performed by cell-based assays (CBAs) indicate an improvement in the chance of identifying serum autoantibodies in myasthenic patients. Clinical trials on the use of biological drugs were recently concluded, providing important data on safety and efficacy of eculizumab, efgartigimod and amifampridine phosphate: the first, a complement blocker, showed long-term safety and efficacy in acetylcholine receptor (AChR)-positive myasthenic patients with refractory generalized disease; the second, the neonatal Fc receptor blocker, was well tolerated and clinically effective in both AChR-specific and muscle-specific kinase receptor (MuSK)-positive patients; the third, a blocker of presynaptic potassium channels, was found to be well tolerated and effective in MuSK-positive patients.

SUMMARY

CBAs can lead to a significant reduction of seronegative patients, improving myasthenia gravis diagnostic process. New biological drugs offer innovative approaches to treat myasthenic patients with generalized disease, promising to change the paradigm of treatment and to significantly enhance therapeutic success within a precision medicine framework.

Pneumocystis jirovecii Pneumonia and Other Infections in Idiopathic Inflammatory Myositis

Purpose of Review

The management of patients with idiopathic inflammatory myositis (IIM) can be complex and challenging due to the myriad of complications they can experience. The continued use of corticosteroids, in addition to the rise of combination immunosuppressive therapy, has contributed to the ongoing concern for infection. Perhaps the most feared infection in IIM patients is Pneumocystis jirovecii pneumonia (PJP) given its infrequent occurrence yet high mortality. The field has been, and continues to be, without evidence-based guidelines to help clinicians determine which patients with IIM to prescribe prophylaxis. Herein, we review this literature to provide the clinician with an up-to-date view of infections in IIM.

Recent Findings

In the past 5 years, a number of studies have been reported highlighting various infectious complications, which help us better understand their frequency and associated risk factors. In addition, data has been published on the potential harms of PJP prophylaxis, to better inform the risk/benefit of our decision-making.

Summary

Infection remains a major contributor to morbidity and mortality in IIM. A better understanding of which patient subgroups are at risk for particular infections will inform optimal management strategies.

Are we aiming to miss in translational autoimmunity treatments?

Autoimmunity treatments, fruitfully pioneered in mouse models, can be disappointing or result in immunosuppression and opportunistic infections in translational trials. Many possible reasons exist, but one major, overlooked reason may be the treatment timing in relation to circadian oscillations of the immune system. Mice and humans both have immunological circadian clocks and experience the same circulatory oscillations of immune cells with regards to their sleep/wake phases, but have opposite sleep/wake phases with regard to the daylight cycle. Therefore, researchers mainly study mice and potential autoimmunity treatments during the murine sleep/rest phase, which is when pro-inflammatory mediators and more adaptive immune cells are prevalent in the circulation. In translational trials, however, treatment administration happens primarily during a patient's wake/activity phase, during the daytime, which is when more local and acute immune responses are active in the circulation. Therefore, we believe that the most opportune window for autoimmunity treatment may be missed in translational trials. Shifting the timing, and adjusting dosing to target only immune cells that are active at that time, may result in higher success with minimized immunosuppression or toxicities.

Neonatal Stress Has a Long-Lasting Sex-Dependent Effect on Anxiety-Like Behavior and Neuronal Morphology in the Prefrontal Cortex and Hippocampus

The long-lasting effects of early stress on brain development have been well studied. Recent evidence indicates that males and females respond differently to the same stressor. We examined the chronic effects of daily maternal separation (MS) on behavior and cerebral morphology in both male and female rats. Cognitive and anxiety-like behaviors were evaluated, and neuroplastic changes in 2 subregions of the prefrontal cortex (dorsal agranular insular cortex [AID] and cingulate cortex [Cg3]) and hippocampus (CA1 and dentate gyrus) were measured in adult male and female rats. The animals were subjected to MS on postnatal day (P) 3-14 for 3 h per day. Cognitive and emotional behaviors were assessed in the object/context mismatch task, elevated plus maze, and locomotor activity test in early adulthood (P87-P95). Anatomical assessments were performed in the prefrontal cortex (i.e., cortical thickness and spine density) and hippocampus (i.e., spine density). Sex-dependent effects were observed. MS increased anxiety-related behavior only in males, whereas locomotor activity was higher in females, with no effects on cognition. MS decreased spine density in the AID and increased spine density in the CA1 area in males. Females exhibited an increase in spine density in the Cg3. Our findings confirm previous work that found that MS causes long-term behavioral and anatomical effects, and these effects were dependent on sex and the duration of MS stress.