Post-streptococcal opsoclonus-myoclonus syndrome associated with anti-neuroleukin antibodies
- P M Candler1,
- R C Dale1,
- S Griffin3,
- A J Church1,
- R Wait2,
- M D Chapman1,
- G Keir1,
- G Giovannoni1,
- J H Rees1
- 1Department of Neuroinflammation, Institute of Neurology, Queen Square, London, WC1N 3BG, UK
- 2The Kennedy Institute of Rheumatology, Imperial College, London, UK
- 3Department of Neurochemistry, Institute of Neurology, Queen Square, London, WC1N 3BG, UK
- Correspondence to: Paul M Candler Department of Neuroinflammation, Institute of Neurology, Queen Square, London, WC1N 3BG, UK;
- Received 9 August 2005
- Accepted 11 October 2005
- Revised 6 October 2005
Background: Adult opsoclonus-myoclonus (OM), a disorder of eye movements accompanied by myoclonus affecting the trunk, limbs, or head, is commonly associated with an underlying malignancy or precipitated by viral infection.
Methods: We present the first two reports of post-streptococcal OM associated with antibodies against a 56 kDa protein. Two young girls presented with opsoclonus and myoclonus following a febrile illness and pharyngitis. Protein purification techniques were employed. Amino acid sequences of human neuroleukin (NLK) and streptococcal proteins were compared using the protein-protein BLAST application.
Results: The antigen was identified as NLK (glucose-6-phosphate isomerase, GPI). GPI is present on the cell surface of streptococcus making the protein a candidate target for molecular mimicry.
Conclusions: We have identified NLK as an antigenic target in two patients with post-streptococcal OM. The pathogenicity of the antibodies is uncertain. The potential role of anti-neuroleukin antibodies in the pathogenesis of OM is discussed. We propose that OM may represent a further syndrome in the growing spectrum of post-streptococcal neurological disorders. The role of streptococcus in OM and the frequency with which anti-NLK responses occur in both post-infectious and paraneoplastic OM should be investigated further.
- ASOT, anti-streptolysin-O titre
- GPI, glucose-6-phosphate isomerase
- HVA, homovanillic acid
- IEX, ion exchange chromatography
- NLK, neuroleukin
- OM, opsoclonus-myoclonus
- PAGE, polyacrylamide gel electrophoresis
- rNLK, recombinant neuroleukin
- TBS, Tris-buffered saline
- VMA, vanillylmandelic acid
Competing interests: none declared
Patient details are published with consent