Long-Term Improvement in a Chinese Cohort of Glucocorticoid-Resistant Childhood-Onset Myasthenia Gravis Patients Treated With Tacrolimus

Efficacy and Safety of Tacrolimus Therapy in Patients With Juvenile Myasthenia Gravis: A Single-Arm Meta-Analysis

BACKGROUND

Numerous guidelines recommend off-label use of tacrolimus (TAC) to treat myasthenia gravis (MG) in adults. This study aimed to evaluate whether TAC is beneficial in pediatric patients with juvenile MG (JMG).

METHODS

We conducted a systematic literature search using the keywords "Myasthenia Gravis," "TAC," "juveniles," and their synonyms. PubMed, Embase, Web of Science, Cochrane Library, and Chinese databases were searched for articles published until April 1, 2024. Two reviewers independently identified and extracted relevant retrospective/prospective comparison studies or randomized controlled trials and assessed the risk of bias for each study. Eligible studies were subsequently included in a meta-analysis that evaluated the clinical outcomes of TAC treatment for JMG using fixed- and random-effects models.

RESULTS

Of the 203 articles initially identified, nine were included in the meta-analysis. These studies included 313 children diagnosed with JMG, with ages ranging from 0 to 13.5 years. Among the included studies, two were comparison trials, whereas the remaining seven employed a single-group pretest-post-test design. Two studies were deemed to be of high quality, and seven were of moderate quality. The pooled overall response rate of the definite responder rate to TAC treatment in JMG was calculated as 3.92 (95% confidence interval: 2.06 to 7.45, I2 = 71%, P < 0.001).

CONCLUSIONS

This meta-analysis found that TAC improved symptoms and MG-related scores in patients with JMG with minimal adverse effects. These findings underscore the importance of TAC therapy for the treatment of JMG.

Long-term efficacy and safety of tacrolimus in anti-MuSK antibody-positive myasthenia gravis: a retrospective single-center cohort study

OBJECTIVE

To evaluate the long-term efficacy and safety of tacrolimus in patients with muscle-specific kinase antibody-positive myasthenia gravis (MuSK-MG).

METHODS

We performed a retrospective, single-center, and cross-sectional study analyzing medical records of 18 MuSK-MG patients treated with tacrolimus for more than 1 year. The efficacy and safety of tacrolimus were evaluated by modified Osserman scale, Myasthenia Gravis Foundation of America post-intervention status, prednisone dosage, quantitative MG (QMG) scores, MG-activity of daily living (MG-ADL) scores, anti-MuSK antibody titers, blood routine, and serum biochemicals.

RESULTS

After 4 weeks of tacrolimus treatment, there was a significant improvement in prednisone dose, QMG, and MG-ADL scores, which continued to improve over 1 year. In addition, clinical grade of modified Osserman scale was improved in all patients, 16 (88.9%) of whom were asymptomatic at the last visit. More importantly, the mean titers of anti-MuSK antibody were significantly decreased from 0.777 ± 0.381 to 0.283 ± 0.178 nmol/L after a median of 1.4 years of tacrolimus treatment in 9 patients with MuSK-MG (P = 0.015). All patients achieved minimal manifestations status (MMS) after tacrolimus treatment (range, 4-32 weeks). Subsequently, seven patients (38.9%) underwent a taper of tacrolimus dosage. However, four patients (57.1%) experienced an exacerbation. Adverse events occurred in 2 patients (11.1%), all of which were mild and resolved after the tacrolimus dose was adjusted or discontinued.

CONCLUSION

Our results suggest that tacrolimus may be an effective and safe steroid-sparing treatment for patients with MuSK-MG. However, tacrolimus should be carefully tapered to avoid disease exacerbation.

Treatment of juvenile myasthenia gravis with tacrolimus: A cohort study

BACKGROUND

We investigated the proper timing, efficacy and safety of tacrolimus for juvenile myasthenia gravis (JMG).

METHODS

We conducted a retrospective cohort study for JMG patients treated with tacrolimus at Xiangya Hospital, Central South University, Changsha, China from 2010 to 2023. The clinical information of patients with a follow-up of more than 1 year was collected. Comparisons of clinical features between groups of patients who achieved therapeutic goal and those who did not achieve therapeutic goal as well as between groups of patients treated with tacrolimus within or after 1 year from JMG onset was carried out.

RESULTS

Forty-three patients were enrolled, of whom 28 achieved therapeutic goal. Tacrolimus reduced glucocorticoids (GC) dosages for the 28 cases and 15 cases discontinued GC completely. Generalized myasthenia gravis (GMG) subtype had an association with a group of patients who achieved therapeutic goal (p = 0.001). Median duration from JMG onset to tacrolimus use was 10.50 months for those who achieved therapeutic goal and 36.00 months for those who did not achieve therapeutic goal (p = 0.010). The median Myasthenia Gravis Activities of Daily Living (MG-ADL) score improved significantly (p = 0.003). The initiation of tacrolimus within 1 year of JMG onset showed an association with achievement of therapeutic goal (p = 0.026). GMG subtype showed an association with a group of patients who received tacrolimus within 1 year (p = <0.001). Tacrolimus side effects were tolerable.

CONCLUSION

The provision of tacrolimus within 1 year of JMG onset is effective and safe.

Clinical Features, Treatment, and Prognostic Factors of Childhood-Onset Myasthenia Gravis in a Large Chinese Cohort

BACKGROUND

To describe the clinical features of patients with childhood-onset myasthenia gravis (MG) (CMG) and explore predictors affecting the treatment outcomes.

METHODS

A retrospective observational cohort analysis of 859 patients with CMG with disease onset before age 14 years was performed at Tongji Hospital.

RESULTS

Patients in the pubertal-onset group (n = 148) had a worse disease course than those in the prepubertal group (n = 711), including a higher incidence of generalized MG (GMG) at presentation, generalization of ocular MG (OMG), and more severe Myasthenia Gravis Foundation of America (MGFA) classification. All patients were initially treated with pyridostigmine, 657 with prednisone, and 196 with immunosuppressants (ISs). However, 226 patients were resistant to prednisone treatment. Multivariate analysis revealed that thymic hyperplasia, higher MGFA class, disease duration before prednisone administration, and thymectomy before prednisone administration were independent predictors of prednisone resistance. At the last visit, 121 of the 840 patients with OMG had developed GMG after a median of 10.0 years from symptom onset and 186 patients (21.7%) achieved complete stable remission (CSR). In multivariable analysis, age at onset, thymic hyperplasia, prednisone, and IS treatment were associated with generalization, whereas age at onset, disease duration, anti-acetylcholine receptor antibodies (AChR-ab), MGFA class II, short-term prednisone treatment, and IS treatment were associated with CSR.

CONCLUSIONS

The majority of patients with CMG have mild clinical symptoms and favorable outcomes, especially those with earlier onset age, shorter disease duration, and negative AChR-ab. In addition, early prednisone and ISs are shown to be effective and safe for most patients with CMG.

Remission and relapses of myasthenia gravis on long-term tacrolimus: a retrospective cross-sectional study of a Chinese cohort

Objective:

To identify the factors that predict the remission and relapses in myasthenia gravis (MG) patients improved by prednisone and tacrolimus treatment.

Methods:

A retrospective, observational cohort analysis of MG patients who achieved remission after receiving prednisone and tacrolimus were performed at Tongji Hospital. The main outcome measures were the time to remission, prednisone discontinuation, tacrolimus reduction–associated relapse, and treatment outcome.

Results:

After adding tacrolimus, 256 patients were able to achieve remission with a mean time to remission of 2.1 ± 1.4 months. After a median follow-up of 2.9 years, 167 patients (65.2%) discontinued prednisone, and 20 patients (7.8%) achieved complete stable remission. Moreover, 53 of the 109 patients who were tapering tacrolimus experienced relapses. In multivariable analysis, female sex, low tacrolimus concentrations, and quantitative myasthenia gravis (QMG) scores have a positive correlation with the time to remission; concomitant additional autoimmune disease (AID) and high anti-acetylcholine receptor antibody (AChR-ab) levels were significantly associated with low probabilities of prednisone discontinuation [odds ratio (OR) = 0.312–0.912, respectively]; rapid tacrolimus decrement speed (⩾0.76 mg/year) was an independent predictor for the development of relapse during tapering tacrolimus (OR = 5.662).

Conclusion:

Sex, tacrolimus concentrations, and QMG scores can be used as potential predictors of the time to remission in MG patients treated with tacrolimus and prednisone. Prednisone should be tapered slowly, especially in patients with additional AID or high serum titers of AChR-ab. To avoid symptoms recurrence, the dose of tacrolimus should reduce slowly, not exceeding 0.76 mg/year.

Tacrolimus Combined with Corticosteroids Improved the Outcome of CIDP Patients with Autoantibodies Against Paranodal Proteins

PURPOSE

To investigate the response of tacrolimus to chronic inflammatory demyelinating polyneuropathy (CIDP) with autoantibodies against paranodal proteins, including neurofascin-155 (NF155), contactin-1 (CNTN1) and contactin-associated protein 1 (Caspr1).

METHODS

We retrospectively reviewed all CIDP patients who carried anti-NF155, CNTN1 and Caspr1 antibodies and were treated with tacrolimus at Tongji hospital from Jan 2018 to Apr 2021.

RESULTS

There were 58 patients with CIDP and only 9 patients had autoantibodies against paranodal proteins (17.2%). Five of the 9 patients received tacrolimus treatment with an initial dose of 2-3 mg once daily. One patient with anti-CNTN1 antibody started tacrolimus and corticosteroid treatment, at the first episode and eventually achieved full clinical remission without relapse. Four patients with anti-NF155 or -Caspr1 antibodies experienced relapse during corticosteroids tapering. Then, they were given oral tacrolimus and presented with clinical improvement. During follow-up, only one patient developed worsening weakness due to unreasonable tacrolimus discontinuation. Moreover, 3 patients were successfully withdrawn from corticosteroids and 2 patients took corticosteroids at low maintenance dose (10mg/d) after tacrolimus treatment. No severe adverse events were observed in all the patients.

CONCLUSION

Patients with autoantibodies against paranodal proteins had a better long-term outcome after adding tacrolimus. Combination therapy with corticosteroids and tacrolimus may be an effective therapeutic regimen.