Background: HLA DR3 and DR4 have been recognized as independent risk factors for autoimmune hepatitis. We compared the clinical features and prognosis of patients with HLA DR4 to those with HLA DR3 and other phenotypes to determine if subclassification by HLA is a valid consideration.
Methods: Forty-four patients with HLA DR4; 41 patients with HLA DR3; and 16 patients with neither allele were studied. Ninety patients were treated with corticosteroids.
Results: Patients with HLA DR4 were older (51 +/- 2 years vs. 38 +/- 3 years, P = 0.0001) and more commonly women (89% vs. 68%, P = 0.04) than counterparts with HLA DR3. Additionally, these patients had higher serum immunoglobulin G levels (3300 +/- 216 mg/dL vs. 2732 +/- 192 mg/dL, P = 0.05) and a greater frequency of concurrent immunologic diseases (59% vs. 27%, P = 0.005). Similar differences in clinical presentation distinguished the patients with HLA DR4 from those with other phenotypes. Remission during corticosteroid therapy (85% vs. 63%, P = 0.05) occurred more commonly in the patients with HLA DR4 than in those with HLA DR3 and treatment failure (10% vs. 32%, P = 0.03) occurred less frequently.
Conclusions: Patients with HLA DR4 have a different clinical profile than counterparts with other phenotypes, and they have a better response to corticosteroid therapy than patients with HLA DR3. Subclassification of patients by HLA DR phenotype may have clinical and prognostic value.