Human autoantigens with which serum anti-B19 IgG cross reacts
| Human autoantigen | B19 protein and antigenic region (amino acid numbers) | Disease relevance | Reference |
|---|---|---|---|
| Collagen II* | VP2: 57–80 | Rheumatoid arthritis (RA) | 225 |
| Keratin* | VP2: 57–80 | Systemic lupus erythematosus (SLE) | 225 |
| ssDNA* | VP2: 57–80 | RA, SLE, myositis, hepatitis | 225 |
| Cardiolipin* | VP2: 57–80 | Antiphospholipid syndrome, SLE | 225 |
| Angiotensin II type 1 receptor† | VP2: 419–425 | Pre-eclampsia, kidney transplant rejection | 226 |
| Myelin basic protein‡ | Not studied | Multiple sclerosis | 227 |
| Platelet membrane glycoprotein IIb/IIIa§ | NS1: 70–79 | Autoimmune thrombocytopenic purpura | 228 |
*Anti-B19 IgG purified on a column to a single specificity using B19 peptide, FSPAASSCHNASGKEAKVCTISPI, cross-reacted with collagen II, keratin, ssDNA and cardiolipin.
†Human IgG monoclonal antibody reacted with AT1 receptor, which could be blocked by AT1 receptor blocker and by the epitope amino acid sequence.
‡Myelin basic protein decreased binding of anti-B19 IgG to B19 antigen in a dose-dependent manner, suggesting a role for anti-B19 IgG in a subset of clinical patients with multiple sclerosis.
§This B19 NS1 peptide was shown to exhibit ∼5% inhibition of the platelet membrane glycoprotein autoantibodies of adults with chronic autoimmune thrombocytopenic purpura.