Long-term effects of combined immunosuppressive treatment on myasthenic crisis

Plasma Exchange versus Intravenous Immunoglobulin in Worsening Myasthenia Gravis: A Systematic Review and Meta-Analysis with Special Attention to Faster Relapse Control

Currently used rescue interventions to prevent rapid myasthenic deterioration are plasma exchange (PLEX) and intravenous immunoglobulin (IVIG). We investigated the evidence to determine whether the two methods were interchangeable or whether one was superior to the other. This review was registered on PROSPERO (CRD42021285985). Only randomized controlled trials (RCTs) comparing the efficacy and safety of PLEX and IVIG in patients with moderate-to-severe myasthenia gravis (MG) were included. Five major databases were systematically searched (PubMed, CENTRAL, Embase, Scopus, and Web of Science). Odds ratios (OR) with 95% confidence intervals (CI) were calculated for adverse events and mean differences (MD) for changes in quantitative myasthenia gravis scores (QMG). Three RCTs met the inclusion criteria. Two investigating 114 patients in total were eligible for meta-analysis to analyze efficacy and safety. For the change in QMG score, the MD was -2.8 (95% CI: -5.614-0.113), with PLEX performing better. For adverse events, an OR of 1.04 was found (95% CI: 0.25-4.27). This study demonstrated a low risk of bias in evaluating treatment efficacy but indicated a high risk of bias in assessing procedural safety outcomes. Although the results did not show any significant difference, there was a tendency indicating faster efficacy of PLEX in the first two weeks of treatment. In such a critical clinical condition, this tendency may be clinically meaningful, but further studies should clarify this benefit.

Greater Number of Plasma Exchanges Does Not Improve Outcome in Myasthenic Crisis

OBJECTIVES

To determine the relationship between the number of plasma exchanges and clinical outcome in patients experiencing myasthenic crisis.

METHODS

We retrospectively reviewed all episodes of myasthenia gravis exacerbation/crisis who received plasmapheresis in patients admitted to a single-center tertiary care referral center from July 2008 to July 2017. We performed statistical analyses to determine whether the increased number of plasma exchanges improves the primary outcome (hospital length of stay) and the secondary outcome (disposition to home, skilled nursing facility, long-term acute care hospital, or death).

RESULTS

There is neither clinically observable nor statistically significant improvement in length of stay or disposition on discharge in patients who received 6 or greater sessions of plasmapheresis.

CONCLUSIONS

This study provides class IV evidence that extending the number of plasma exchanges beyond 5 does not correlate with decreased hospital length of stay or improved discharge disposition in patients experiencing myasthenic crisis.

Relapses of Anti-NMDAR, Anti-GABABR and Anti-LGI1 Encephalitis: A Retrospective Cohort Study

Objective

To investigate the relapse rate and study the factors that may predict the subsequent relapse in anti-NMDAR, anti-GABABR and anti-LGI1 encephalitis in Northeast China.

Methods

In the retrospective cohort study, we consecutively enrolled patients with anti-N1MDAR, anti-GABABR and anti-LGI1 encephalitis between March 2015 and November 2021. The patients were followed up for at least 6 months. The outcome variable was a binary variable of relapse or not. Predictors of relapse were identified.

Results

A total of 100 patients were enrolled. Relapse occurred in 26 (26%) patients after a median follow-up of 18 months since the first event. The relapse rates of anti - NMDAR, anti - GABABR and anti - LGI1 encephalitis were 25%, 33.3%, and 28.6%, respectively. The multivariable analysis results suggested that immunotherapy delay at the acute phase was independently associated with an increased risk of relapse in total patients (HR = 2.447, 95% CI = 1.027 - 5.832; P = 0.043). Subgroup analysis results showed that antibody titer was associated with the likelihood of relapse in anti-LGI1 encephalitis. The higher the concentration, the more likely it was for patients to have relapse (p=0.019).

Conclusion

The general relapse rate of anti-NMDAR, anti-GABABR and anti-LGI1 encephalitis was 26%. The risk of subsequent relapse was elevated in those with delayed immunotherapy in the first episode. In subgroup of anti-LGI1 encephalitis, higher antibody titer was the risk factors of relapse. Thus, timely and aggressive immunotherapy may be beneficial for patients to prevent subsequent relapse.

Myasthenic crisis treated in a Chinese neurological intensive care unit: clinical features, mortality, outcomes, and predictors of survival

BACKGROUND

Myasthenic crisis (MC) often requires admission to an intensive care unit (ICU).

METHODS

We retrospectively investigated 113 consecutive patients with first MC admitted to the neurological ICU. Patients' demographic, clinical and other characteristics were examined, as well as therapeutic interventions, mortality and functional outcome.

RESULTS

MC patients at first onset admitted to neurological ICU had a mortality rate of 18.6%. PCO₂ level before intubation and score on Myasthenia Gravis-Activities of Daily Living (MG-ADL) scale at MC onset correlated with duration of ventilation and length of ICU stay. Compared with patients with good functional outcome, patients with intermediate or poor functional outcome were older at first MC onset, had lower pH and PO₂, and had higher PCO₂ before intubation. Multivariate logistic analysis identified pre-intubation PCO₂ level as an independent predictor of survival. Cox regression showed that age at first MC onset requiring ICU management was the factor which significantly influenced the mortality.

CONCLUSIONS

Our results suggest that PCO₂ before intubation and MG-ADL score at MC onset may be useful indicators of more severe disease likely to require extensive respiratory support and ICU management. Higher pre-intubation PCO₂ indicates chronic respiratory acidosis that can increase risk of severe disability and death, especially in patients with older age at first MC onset.

A systematic analysis of the complement pathways in patients with neuromyelitis optica indicates alteration but no activation during remission

Neuromyelitis optica (NMO) is an autoimmune demyelinating inflammatory disorder, mediated by pathogenic autoantibodies against aquaporin 4 (AQP4), the main water channel of the central nervous system (CNS). NMO is characterized by local IgG deposition and complement activation within the CNS, but the three complement pathways have not been systematically investigated. We evaluated the overall activation of the classical, alternative, and MBL-lectin pathways in the peripheral blood of 25 patients with AQP4-seropositive NMO spectrum during remission and 113 healthy controls by three ways: (1) we measured the concentrations of native complement proteins of the three pathways [C1-inhibitor (C1-inh), C1q, C4, C3, C5, factor I, factor B, properdin]; (2) the concentrations of complement products suggesting in vivo activation (C1rC1sC1-inh, C3a, C3bBbP, and SC5b-9); and (3) the total activity of the three complement pathways. Additionally we measured levels of C1rC1sC1-inh, C3a, C3bBbP in cerebrospinal fluid (CSF) of 6 patients with relapsing NMO and of 18 patients with relapsing multiple sclerosis (MS). The serological studies indicated that total complement activity of the classical [median (interquartile range) 72 (61-82) vs. 65 (56-73) CH50/mL; p=0.0122] and of the lectin pathways [73 (59-111) vs. 49 (3-92)%; p=0.0078)] were elevated compared with the controls, whereas that of the alternative pathway was not significantly different. The levels of C3 [1.1 (0.9-1.3) vs. 1.4 (1.2-1.5)g/L; p<0.0001], factor B [89 (77-115) vs. 103 (93-113)%; p=0.0397] and factor I [85 (69-95) vs. 101 (93-107)%; p=0.0007], as well as of properdin [92 (74-104) vs. 108 (97-122)%; p=0.0028] were significantly lower in the patients than in the controls. The only increase in the patients was ascertained in the relative concentration of C1rC1sC1-inh vs. the C1-inhibitor (42.3 [31.9-65.0] vs. 30.8 [13.5-43.5] AU/mg; p=0.0007). The absolute and relative levels of the other complement activation products were not elevated in the patients. On the contrary, the serum concentrations of C3a, C3bBbP, and SC5b-9 of the patients were lower than those of the controls. The absolute concentration of the complement activation products (C1rC1sC1-inh, C3bBbP, C3a) and the ratio of C3bBbP/C1rC1sC1-inh did not differ in NMO and MS CSF samples. The ratio of C3bBbP/C1rC1sC1-inh was similar in NMO plasma and CSF samples. We found a higher ratio of C3bBbP/C1rC1sC1-inh in the plasma of control subjects compared to those in any pathological samples. Our results do not indicate substantial systemic complement activation if NMO activity is adequately controlled; nevertheless, the complement system is abnormally affected even during remission. The relative ancillarity of the alternative compared to the classical pathway may also suggest that suppression of the alternative pathway by treatment may be important to achieve remission.

Safety of prednisone for ocular myasthenia gravis

BACKGROUND

Treatment with chronic corticosteroids has been associated with frequent significant adverse effects. We hypothesized that a long-term low-dose prednisone regimen for ocular myasthenia gravis (OMG) would have a low rate of major side effects.

METHODS

Consecutive OMG patients from a single institution over a 16-year period and treated with ≥1 month of daily prednisone were included. Steroid-related complications were defined as the development/worsening of conditions requiring alteration to medical therapy. Serious complications included conditions requiring emergency care, hospitalization, or surgery.

RESULTS

Eighty-three patients with follow-up period ranging from 1 to 271 months (median, 58 months) were included. Fifty-eight (70%) patients had follow-up period of ≥24 months. The maximum prednisone dose ranged from 10 to 60 mg. Tapering to ≤10 mg/d required ≤4 months for all but 2 patients. Median average daily dose following the initial course was 5 mg daily (interquartile range, 4-7.5 mg). During the first 2 years, there were 24.5 complications per 100 person-years. Only one patient had a serious complication within the first 2 years (2-year cumulative risk, 1%), but this individual was not following the recommended regimen.

CONCLUSIONS

Low-dose prednisone for OMG has an acceptable side-effect profile and causes few serious complications (2-year risk, ∼1%). However, patients need monitoring to detect the relatively common, but less serious, complications (2-year risk, ∼39%) to adjust medical therapy in a timely fashion.

Anti-NMDA receptor encephalitis. The disorder, the diagnosis and the immunobiology

Anti-NMDAR encephalitis is a newly characterized syndrome with a progressive, predictable clinical course and the possibility of effective treatment. Accurate and timely diagnosis is critical to selection and implementation of treatments, and optimal patient outcomes. Outcomes are improved with early diagnosis via indirect immunofluorescence or cell-based assays, and the rapid and appropriate administration of immunosuppressant and anti-psychotic therapies. Three possible scenarios accounting for the immunopathogenesis of anti-NMDAR encephalitis are presented, with the most probable one being that of paraneoplastic autoimmunity. Future efforts in this disorder should focus on elucidating the mechanisms that contribute to initiation of this antibody response, as well as exploring the role of tumors, infectious triggers and immune-reactivation. Finally, accessible tools need to be developed that allow for reliable identification of specific antibody markers against synaptic proteins.