Anti-GQ1b antibodies: usefulness of its detection for the diagnosis of Miller-Fisher syndrome

Background: TO study the presence of anti-GQ1b antibodies as a tool for the diagnosis of Miller-Fisher syndrome (MFS). Patients and Method: We studied 54 patients with probable diagnosis of MFS and 10 patients diagnosed as Guillain-Barre syndrome plus ophthalmoplegia ( 1 case), Bickerstaff's encephalitis (1 case), relapsing ophthalmoplegia (7 cases) and relapsing diplopia (1 case). Results were compared with 130 pati ents with other disimmune neuropathies. Antibodies were detected by ELISA a nd checked by thin layer chromatography. Campylobacter jejuni serology was studied using a complement fixation test. Results: Diagnosis of MFS was confirmed in 38 patients. A 97.3% were positi ve for GQ1b, being all negative for Campylobacter jejuni serology. A second test after 4-5 weeks of nadir was negative in 84.2% (16/19), concomitant w ith clinical recovery. Conclusions: Anti-GQ1b antibodies are useful markers for the differential d iagnosis of MFS, specially with some acute brainstem disorders. Testing mus t be performed during the first four weeks of clinical course. This correla tion between the triad ataxia, arreflexia and ophthalmoplegia and anti-GQ1b antibodies confirms that they are highly specific of MFS.