Susac's syndrome as an immune-related adverse event after pembrolizumab: a case report

The Impact of Monoclonal Antibody Usage on Hearing Outcomes: A Systematic Review

OBJECTIVE

To ascertain trends in ototoxicity observed with monoclonal antibodies (mABs) and understand the impact they may have on hearing function.

DATA SOURCES

PubMed, Embase, Scopus.

REVIEW METHODS

A systematic review was performed following PRISMA guidelines. Data were reviewed for demographics, utilized mABs with respective indication and dosing, audiometric outcomes, and treatment for otologic effects.

RESULTS

Of 757 studies reviewed, a total of 44 were included, encompassing 18,046 patients treated with mABs. Mean age of the sample was 57.8 years old. The search yielded 18 agents of ototoxicity, with reported symptoms of ototoxicity such as hearing loss, tinnitus, and/or aural fullness occurring in 1079 of total patients. Main agents causing ototoxicity were teprotumumab (n = 17/44 studies), nivolumab (n = 10/44), ipilimumab (n = 9/44), pembrolizumab (n = 5/44), and rituximab (n = 4/44). Thirty-one of 44 studies encompassing eight agents reported audiometric data for ototoxic agents, showing sensorineural hearing loss primarily in the high-frequency range. Only two articles performed ultrahigh-frequency audiograms.

CONCLUSION

Monoclonal antibody usage is expanding, but the vast majority of studies lack substantial audiometric data. Where reported, study design and inclusion criteria vary greatly. Future studies would benefit from rigid inclusion of audiometric data, prospective study design, and consideration of formal ototoxicity screening. Otolaryngologists should be aware of the cochlear immune response and potential impact of this expanding medication class on hearing function. Laryngoscope, 2024.

Clinical characteristics and treatment approaches in patients with Susac syndrome: a scoping review of cases

BACKGROUND

Susac syndrome (SuS) is a rare disease characterized by encephalopathy, hearing impairment and visual disturbances. Immunosuppressive treatments are used based on the hypothesis that an autoimmune endotheliopathy drives the disease. However, a solid evidence-based treatment approach is lacking. The aim of this review is to provide an overview of patient characteristics, disease course and treatment patterns related to successful outcome that have been reported in literature since 2013.

METHODS

Three reviewers conducted a systematic literature search in February 2022. The primary outcome was treatment used, derived from cases classified as probable or definite SuS, describing successful treatment outcome (i.e. no signs of disease activity for ≥ 1 month). Secondary outcomes were time-to-relapse and follow-up time. Published case reports and case series were included. Various clinical characteristics and treatment(s) were extracted and categorized into different phases of treatment.

RESULTS

A total of 810 records was identified. 120 articles met inclusion criteria and 161 cases were extracted. Of these, 151 cases were classified as probable or definite SuS and included in the final analysis. Number of combinations of treatments used per treatment phase were: 6 empirically, 35 after confirmed diagnosis, 43 for maintenance treatment, 22 after relapse, 18 during maintenance post-relapse. Median follow-up time was 12.3 months (0.5; 120) and median time to relapse was 4 months (1; 120).

CONCLUSION

This scoping review summarizes treatment approaches in patients with SuS, highlighting variability. International efforts to collect clinical, imaging and treatment data from patients with SuS in registries are needed, in order to provide less biased and long-term follow-up information on treatment response, predictors of relapse and patient outcomes. This may lead to more evidence-based therapeutic approaches.

Immune checkpoint inhibitor-related hearing loss: a systematic review and analysis of individual patient data

PURPOSE

Immune checkpoint inhibitors (ICIs) are related to various immune-related adverse events (irAEs). However, the knowledge is limited with rare irAEs like hearing loss. Therefore, we evaluated the characteristics, presentation, and treatment of ICI-related hearing loss by reviewing the individual patient data from the previous studies.

METHODS

We conducted a systematic search of the Web of Science, PubMed, and Embase databases for studies published until 17 November 2022. The selected MeSH search terms were "hearing loss" OR "hearing impairment" OR "ototoxicity" OR "vestibular toxicity" OR "audiovestibular toxicity" AND "immune checkpoint inhibitor" OR "immunotherapy."

RESULTS

A total of 38 patients were included. Melanoma was the most frequent diagnosis (73.7%). The median time from ICI initiation to hearing loss development was 3 months. The hearing impairment was secondary to bilateral sensorineural hearing loss (SNHL) in 24 (68.6%) patients, and at least one other irAE accompanied the hearing loss in 24 patients. Hearing loss significantly improved in 45.7% of the patients. The overall response rate and disease control rate were 67.6% and 85.3%, respectively.

CONCLUSION

We observed that most cases of ICI-related hearing loss were reversible, observed in patients with melanoma, accompanied by other irAEs, and associated with a high response rate to ICIs. With the expanded use of ICIs in the earlier treatment lines and adjuvant settings, the number of survivors with ICI-related hearing loss is expected to increase. Further research is needed to define the true prevalence of ICI-related hearing loss, optimal diagnosis, and management.

Sudden onset hearing loss as initial presentation of Susac syndrome: a rare case report and brief review

Susac syndrome is a rare disease presenting with a classic triad of symptoms. These are sensorineural hearing loss, encephalopathy, and branch retinal artery occlusions. Initial presentation is usually headache and symptoms of encephalopathy. Hearing loss is unusual in the early stages but, when it does present, can often lead to a misdiagnosis of sudden sensorineural hearing loss. Hence, neurological and retinal examinations are essential to an accurate diagnosis. In this study, we aimed to raise awareness of Susac syndrome among physicians and facilitate recognition of its manifestation, especially in those patients presenting with hearing loss alone. Identifying Susac syndrome that presents as sudden sensorineural hearing loss can be challenging but a number of case reviews have been reported in recent years and treatment guidelines are available.