Table 1.
Characteristics of lupus twins.
| Ethnicity† | Zygosity‡ | Subject | Age at Dx | Age at blood draw | SLE Dx§ | Immunoglobulin M (IgM) autoantibody profiles¶ | IgG autoantibody profiles | Medications | |
|---|---|---|---|---|---|---|---|---|---|
| F001†† | c | MZ | AA | 26 | 28 | + | − | − | Prednisone 40 mg/day, hydroxychloroquin |
| BB | − | None | |||||||
| F122 | as | MZ | 744 | 28 | 30 | + | Co-distribute | − | Prednisone 20 mg/day, hydroxychloroquin |
| 745 | − | None | |||||||
| F124 | c | MZ | 751 | 20 | 24 | + | Cluster | Cluster | Prednisone <10 mg/day, hydroxychloroquin, NSAID |
| 765 | ND | + | Unknown | ||||||
| F167 | c | MZ | 927 | 44 | 52 | + | − | − | Unknown |
| 933 | 46 | + | Unknown | ||||||
| F191 | c | MZ | 498 | 48 | 57 | + | Co-distribute | Cluster | Unknown |
| 499 | ND | + | Unknown | ||||||
| F225 | as | MZ | 1218 | 23 | 44 | + | − | Cluster | Unknown |
| 1219 | 30 | + | Unknown | ||||||
| F323 | aa | MZ | 1730 | ND | ND | + | − | Cluster | NSAID |
| 1760 | ND | + | NSAID | ||||||
| F794 | c | MZ | 4213 | 12 | 25 | + | NR | Cluster | Unknown |
| 4214 | ND | + | Prednisone 1 mg/day, hydroxychloroquin, MMF | ||||||
| F986 | c | MZ | 4827 | ND | 34 | + | − | Co-distribute | Unknown |
| 4828 | ND | + | Prednisone 20 mg/day, hydroxychloroquin | ||||||
| F1008 | aa | MZ | 4884 | 15 | 16 | + | Cluster | Cluster | Prednisone, hydroxychloroquin, MMF |
| 4885 | 15 | + | Prednisone, hydroxychloroquin, MMF and i.v. cyclophosphamide | ||||||
| F7 | c | DZ | 31 | 15 | 24 | + | − | − | Prednisone, hydroxychloroquin, methotrexate NSAID, IVIG |
| 34 | 13 | + | Unknown | ||||||
| F285 | c | DZ | 1402 | 38 | 40 | + | − | Co-distribute | Unknown |
| 1403 | ND | + | Unknown | ||||||
| F988 | as | DZ | 4832 | 43 | 46 | + | Cluster | Cluster | Prednisone <10 mg/day, hydroxychloroquin, NSAID |
| 4849 | − | None | |||||||
| F1001 | c | DZ | 4862 | 78 | −(GCA)‡‡ | Co-distribute | Co-distribute | Unknown | |
| 4863 | + | Prednisone, hydroxychloroquin, azathioprine |
Ethnicity was self-determined: aa: African American; as: Asian; c: Caucasian.
Zygosity: MZ, monozygotic; DZ, dizygotic.
Systemic lupus erythematosus (SLE) diagnosis was determined based on American College of Rheumatology criteria [1].
Based on comparisons of autoantibody profiles determined by microarray, twin sets that distributed into paired terminal dendrogram were termed a ‘cluster’, twins that distributed adjacent to one another but not in the same dendrogram were termed ‘co-distribute’. If the profiles of twins neither clustered nor co-distributed, comparisons for a twin set were designated negative (–). Only the F794 were found to be non-reactive (NR) for all IgM autoantibodies, even though found to be positive in control assays for detectable total IgM and control antigens on slides.
Detailed Ig repertoire analyses of the F001 twins, AA and BB, have been reported previously [14].
At time of blood draw this dizygotic twin fulfilled criteria for giant cell arteritis (GCA) but not SLE. NSAID, non-steroidal anti-inflammatory drug; MMF, mycophenolate mofetil. ND, not determined.