Anti-Purkinje Cell Cytoplasmic Antibody Type 2-Associated Autoimmune Cerebellar Degeneration in Children: A Different Phenotype From Adults

Background

Anti-Purkinje cell cytoplasmic antibody type 2 (PCA-2) is associated with various neurological conditions in adults. However, related studies have not been conducted in children. The present study aimed to characterize the clinical features and outcomes of PCA-2-related autoimmune cerebellar degeneration in pediatric patients.

Methods

A total of 357 pediatric patients with acute or subacute cerebellar ataxia were recruited for the study from June 2015 to September 2022. Of these, PCA-2 was identified in four patients. Information on the clinical manifestations, patient response to treatment, and outcomes was collected and analyzed.

Results

The patient cohort in the present study included two boys and two girls, with the age of onset from six to 12 years. Axial ataxia was the most remarkable symptom observed in the entire patient cohort (four of four), followed by dysmetria in 75% (three of four), dysarthria in 50% (two of four), and nystagmus in 25% (one of four) of patients. Cognitive impairment was present in one patient. Peripheral neuropathy, which is an extracerebellar symptom, was found in two patients. One patient was diagnosed with a pelvic neuroblastoma before the onset of ataxia. The presence of oligoclonal bands was confirmed in the cerebrospinal fluid, and cerebellar atrophy was observed. Immunotherapy, including glucocorticoids and/or intravenous immunoglobulin, was administered to all four patients immediately following diagnosis, and mycophenolate mofetil was administered to three patients. Three patients responded to immunotherapy.

Conclusions

In children, PCA2-associated autoimmune cerebellar degeneration is rare, and they show comparatively fewer symptoms than adults. Timely and appropriate immunotherapy is beneficial.