Abstract
Objectives: It has been over ten 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 characterise 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 organising pneumonia all described. Other features of the anti-synthetase syndrome such as Raynaud’s phenomenon 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 present 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.
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 organising pneumonia all described. Other features of the anti-synthetase syndrome such as Raynaud’s phenomenon 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 present 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.
Original language | English |
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Journal | Rheumatology (Oxford) |
Early online date | 26 Oct 2019 |
DOIs | |
Publication status | E-pub ahead of print - 26 Oct 2019 |
Keywords
- myositis and muscle disease
- autoantigens and autoantibodies
- respiratory
- biomarkers