The myositis clinical phenotype associated with anti-Zo autoantibodies: a case series of nine UK patients.
OBJECTIVES
It has been over 10 years since the first report of autoantibodies directed against phenylalanyl tRNA synthetase (anti-Zo) in a patient with features of the anti-synthetase syndrome. In that time no further cases have been published. Here we aim to characterize more fully the clinical phenotype of anti-Zo-associated myositis by describing the clinical features of nine patients.


METHODS
Anti-Zo was identified by protein-immunoprecipitation in patients referred for extended spectrum myositis autoantibody testing at our laboratory. Results were confirmed by immunodepletion using a reference serum. Medical records were retrospectively reviewed to provide detailed information of the associated clinical phenotype for all identified patients. Where possible, HLA genotype was imputed using Illumina protocols.


RESULTS
Nine patients with anti-Zo were identified. The median age at disease onset was 51 years, and six patients were female. Seven patients had evidence of inflammatory muscle disease, seven of interstitial lung disease and six of arthritis. The reported pattern of interstitial lung disease varied with usual interstitial pneumonia, non-specific interstitial pneumonia and organizing pneumonia all described. Other features of the anti-synthetase syndrome such as RP and mechanics hands were common. HLA data was available for three patients, all of whom had at least one copy of the HLA 8.1 ancestral haplotype.


CONCLUSION
Patients with anti-Zo presenting with features of the anti-synthetase syndrome and interstitial lung disease is a common finding. Like other myositis autoantibodies, there is likely to be a genetic association with the HLA 8.1 ancestral haplotype.
['Tansley|Sarah L|SL|', 'Betteridge|Zoe|Z|', 'Lu|Hui|H|', 'Davies|Emma|E|', 'Rothwell|Simon|S|', 'New|Paul P|PP|', 'Chinoy|Hector|H|', 'Gordon|Patrick|P|', 'Gunawardena|Harsha|H|', 'Lloyd|Mark|M|', 'Stratton|Richard|R|', 'Cooper|Robert|R|', 'McHugh|Neil J|NJ|']
D000328:Adult D017668:Age of Onset D000368:Aged D001323:Autoantibodies D005260:Female D006801:Humans D008297:Male D008875:Middle Aged D009220:Myositis D010641:Phenotype D010652:Phenylalanine-tRNA Ligase D012189:Retrospective Studies D006113:United Kingdom
autoantigens and autoantibodies biomarkers myositis and muscle disease respiratory