Table 1.
Clinical and laboratory findings in patients with anti-Zo autoantibodies
| Case 1 | Case 2 | Case 3 | Case 4 | Case 5 | Case 6 | Case 7 | Case 8 | Case 9 | |
|---|---|---|---|---|---|---|---|---|---|
| Demographics | |||||||||
| Gender | Female | Female | Female | Female | Male | Female | Male | Male | Female |
| Ethnicity | Caucasian | Caucasian | Afro-Caribbean | African | Caucasian | Caucasian | Caucasian | Caucasian | Caucasian |
| Age at onset | 49 | 35 | 62 | 40 | 35 | 52 | 40 | 51 | 79 |
| Muscle disease | |||||||||
| Clinical | Proximal myopathy | Proximal myopathy | Myalgia | Proximal myopathy | Myalgia. Mild proximal myopathy | Proximal myopathy | Not present | Myalgia | Not present |
| Muscle enzymes | CK >9000 | CK >1000 | CK elevated | CK elevated | CK >2000 | CK elevated | Mild CK rise. 255 maximum | CK >1500. | Normal |
| EMG | Not done | Normal | Abnormal | Myopathic | Myopathic | Normal | Not done | Not done | Not done |
| Muscle biopsy | Necrotizing myopathy | HLA class 1 upregulation | Not done | Inflammatory myopathy | Not done | Inflammatory myopathy | Not done | Not done | Not done |
| Other | Not applicable | MRI showed fasciitis | Not applicable | Not applicable | Not applicable | Not applicable | Not applicable | Oesophageal dysmotility on barium swallow | Not applicable |
| Interstitial lung disease | |||||||||
| Yes (NSIP) | Yes (NSIP) | Yes (UIP) | Not present | Yes (OP with mild NSIP ) | Not present | Yes (NSIP) | Yes (OP) | Yes (NSIP) | |
| Other anti-synthetase syndrome features | |||||||||
| RP | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Not present | Yes |
| Arthritis/arthralgia | Yes | Yes | Yes | Not present | Yes | Yes | Not present | Not present | Yes |
| Mechanics’ hands | Not present | Yes | Not present | Not present | Yes | Not available | Yes | Yes | Not present |
| Rash | Not present | Not present | Not present | Heliotrope rash and V-sign | Gottron’s papules | Not present | Heliotrope rash | Not present | Not present |
| Laboratory findings | |||||||||
| Hep2 Indirect Immunofluorescence | ANA negative | ANA negative | ANA negative | ANA negative | Homogeneous ANA, Fine Cytoplasmic Speckle 1: 640 | ANA negative | ANA negative | ANA negative | ANA negative |
| Fine Cytoplasmic Speckle 1: 1280 | Fine Cytoplasmic Speckle 1: 1280 | Fine Cytoplasmic Speckle 1: 640 | Fine Cytoplasmic Speckle 1: 160 | Fine Cytoplasmic Speckle 1: 160 | Fine Cytoplasmic Speckle 1: 1280 | Fine Cytoplasmic Speckle 1: 320 | Fine Cytoplasmic Speckle 1: 1280 | ||
| ENA | Ro52 | Ro52 | Ro52, SSB | Ro52, SSA | Ro52, SSA, SSB, anti-nucleosome | Ro52, SSA | Negative | Negative | Negative |
| Genotype | HLA-DRB1*03: 01 homozygous | HLA-DRB1*03: 01 heterozygous | Not available | Not available | Not available | HLA-DRB1*03: 01 heterozygous | Not available | Not available | Not available |
| The effect of autoantibody status on ACR/EULAR Classification Criteria for Idiopathic Inflammatory Myopathies [16] | |||||||||
| Probability of IIM | 39–96% | 23–91% | 13–83% | 97–100% Definite IIM | 70–99% Probable IIM | 39–96% | 47–97% | 23–83% | 4–57% |
| Probability of IIM including anti-Zo a | 97–100% | 94–100% | 88–100% | 100% | 99–100% | 97–100% Definite IIM | 98-100% | 94–100% | 66–98% |
| Definite IIM | Definite IIM | Probable IIM | Definite IIM | Definite IIM | Definite IIM | Definite IIM | Definite IIM | ||
The demographics and clinical features of patients identified as having anti-Zo autoantibodies are summarized below along with additional laboratory findings. aAnti-Jo1 selected in place of anti-Zo. CK: creatine kinase; IIM: idiopathic inflammatory myophathy; NSIP: non-specific interstitial pneumonia; UIP: usual interstitial pneumonia; OP: organizing pneumonia. Interstitial lung disease patterns as reported on high-resolution CT.