CNS aquaporin-4 autoimmunity in children.

 

 

 

BACKGROUND:

 

In adult patients, autoantibodies targeting the water channel aquaporin-4 (AQP4) are a biomarker for a spectrum of CNS inflammatory demyelinating disorders with predilection for optic nerves and spinal cord (neuromyelitis optica [NMO]). Here we describe the neurologic, serologic, and radiographic findings associated with CNS AQP4 autoimmunity in childhood.

 

 

METHODS:

 

A total of 88 consecutive sero-positive children were identified through service evaluation for NMO-IgG. Sera of 75 were tested for coexisting autoantibodies. Clinical information was available for 58.

 

 

RESULTS:

 

42 patients (73%) were non-Caucasian, and

20 (34%) had African ethnicity.

 

Median age at symptom onset was

12 years (range 4-18).

 

57 (98%) had attacks of either optic neuritis (n = 48; 83%) or transverse myelitis (n = 45; 78%), or both.

26 (45%) had episodic cerebral symptoms (encephalopathy, ophthalmoparesis, ataxia, seizures, intractable vomiting, or hiccups). 38 (68%) had brain MRI abnormalities, predominantly involving periventricular areas (in descending order of frequency): the medulla, supratentorial and infratentorial white matter, midbrain, cerebellum, thalamus, and hypothalamus.

 

Additional autoantibodies were detected in

57 of 75 patients (76%), and

16 of 38 (42%) had a coexisting autoimmune disorder recorded (systemic lupus erythematosus, Sjögren syndrome, juvenile rheumatoid arthritis, Graves disease).

 

Attacks were recurrent in

54 patients (93%; median follow-up, 12 months).

43 of 48 patients (90%) had residual disability:

26 (54%) visual impairment and

21 (44%) motor deficits

(median Expanded Disability Status Scale 4.0 at 12 months).

 

 

CONCLUSIONS:

 

Aquaporin-4 autoimmunity is a distinctive recurrent and widespread inflammatory CNS disease in children.

 

Departments of Neurology and Laboratory Medicine and Pathology, Mayo Clinic College of Medicine,

Rochester, MN 55905,

USA.