Anti-Ma and anti-Ma2-associated paraneoplastic neurological syndromes

Management of Paraneoplastic Syndromes in the Era of Immune Checkpoint Inhibitors

OPINION STATEMENT

Our understanding of paraneoplastic neurologic syndromes (PNS) has blossomed over the past few decades. Clinicians have access to more robust diagnostic criteria and have a heightened index of suspicion for these disorders. Nonetheless, treatment, which typically includes immunosuppression, and response to treatment, varies. Due to persistent difficulty in making a definitive diagnosis, we favor empiric treatment when a possible diagnosis of PNS is suspected, and other alternative causes have substantially been excluded (e.g., infections, toxic-metabolic derangements, metastasis, or leptomeningeal disease). Treatment of the underlying cancer, if identified, is the first therapeutic step and can prevent disease worsening and in rare cases, can reverse neurologic symptoms. In addition to anti-cancer treatment, first line immunotherapies, which include corticosteroids, intravenous immunoglobulins (IVIG), or plasma exchange (PLEX) are typically used. If partial or no benefit is seen, second line immunotherapeutic agents such as rituximab are considered. Additionally, the severity of the initial presentation and possible risk for relapse influences the use of the latter agents. Symptomatic management is also an important component in our practice and will depend on the syndrome being treated. One of the more novel entities we are facing currently is the management of immune checkpoint (ICI)-induced PNS. In those cases, current American Society of Clinical Oncology (ASCO) guidelines are followed.

[Autoimmune encephalitis: psychiatric aspects]

Autoimmune encephalitis is a group of diseases researched by both neurologists and psychiatrists. Despite a large number of studies and practical recommendations, the differential diagnosis and early diagnostics still remains an important issue. The most difficult to diagnose are cases that debut as mental disorders and/or occur without neurological symptoms. The literature review presents the current state of the problem with an emphasis on the practice of a psychiatrist.

Paraneoplastic Neurologic Disorders

PURPOSE OF REVIEW

To provide an overview and highlight recent updates in the field of paraneoplastic neurologic disorders.

RECENT FINDINGS

The prevalence of paraneoplastic neurologic disorders is greater than previously reported and the incidence has been rising over time, due to improved recognition in the era of antibody biomarkers. Updated diagnostic criteria that are broadly inclusive and also contain diagnostic risk for clinical presentations (high and intermediate) and diagnostic antibodies (high, intermediate, and low) have replaced the original 2004 criteria. Antibody biomarkers continue to be characterized (e.g., KLHL-11 associated with seminoma in men with brainstem encephalitis). Some paraneoplastic antibodies also provide insight into likely immunotherapy response and prognosis. The rise of immune checkpoint inhibitors as cancer therapeutics has been associated with newly observed immune-mediated adverse effects including paraneoplastic neurological disorders. The therapeutic approach to paraneoplastic neurologic disorders is centered around cancer care and trials of immune therapy. The field of paraneoplastic neurologic disorders continues to be advanced by the identification of novel antibody biomarkers which have diagnostic utility, and give insight into likely treatment responses and outcomes.

Anti-Ma2 Antibody-Associated Paraneoplastic Neurological Syndromes: A Pilot Study

Paraneoplastic neurologic syndromes (PNSs) are a heterogeneous group of disorders caused by the remote effects of cancer with immune-mediated pathogenesis. Anti-Ma2 antibody was defined as one of the well-characterized onconeural antibodies that could help establish a definite PNS diagnosis. We aimed to report and explore patients with anti-Ma2 antibody-associated paraneoplastic neurologic syndrome (Ma2-PNS) who frequently exhibit sensorimotor neuropathy (SMN) using a new method of factor analysis of mixed data (FAMD). Clinical data from a case series of eight patients with definite diagnoses were retrospectively reviewed. FAMD conducted further analyses with a comprehensive visualization in R software. Our cohort, with a predominance of females (5/8), presented more frequently with SMN (4/8), followed by limbic encephalitis (LE) (3/8). Two patients with LE were found to have a testicular germ-cell tumor and a thymoma, respectively. In addition, a patient who developed chronic SMN was diagnosed with multiple myeloma (MM) involving multiple organs. FAMD exhibited the overall features into a two-dimensional coordinate and located each individual into their corresponding position with high relevance. It provided a clue for determining their potential relationships and predictors. Our findings indicated that Ma2-PNS could frequently involve the peripheral nervous system, MM might be one of its associated cancers with a presentation of chronic SMN, and FAMD might be a clinically valuable tool.

Low-dose interleukin-2 as a novel therapeutic option for refractory paraneoplastic neurologic syndrome: a case of chronic relapsing anti-Ma2/Ta paraneoplastic myeloradiculopathy

Paraneoplastic neurologic syndromes (PNS) caused by anti-Ma2/Ta antibodies have diverse presentations. Myeloradiculopathy is one anti-Ma2/Ta-associated PNS manifestation. We report the case of a patient with chronic relapsing anti-Ma2/Ta paraneoplastic myeloradiculopathy. The patient was successfully treated with low-dose human recombinant interleukin-2, despite having chronic relapsing symptoms and a refractory response to conventional immunotherapy.