Persistent Herpes Gestationis Treated with High-dose Intravenous Immunoglobulin

Abstract

Sir, Pemphigoid gestationis (PG) is a rare autoimmune blistering disease specific to pregnancy that usually presents in the second or third trimester or during the immediate postpartum period (1, 2). PG may develop in association with other autoimmune diseases, as well as with trophoblastic tumours, hydatiform mole and choriocarcinoma (3). The pathogenesis of PG is not fully established. However, most patients develop antibodies against 2 hemidesmosomal proteins, BP180 (BPAG2, collagen XVII) and, less frequently, BP230. Historically known as the herpes gestationis factors, these circulating antibodies belong to the heat-stable immunoglobulin G1 subclass. Sera from PG can recognize 5 distinct epitopes within BP180 NC16A, 4 of which have been reported as major antigenic sites targeted by bullous pemphigoid antibodies (4). The PG has a strong association with human leukocyte antigens HLA-DR3 and HLA-DR4 or both, and virtually all patients with a history of PG have demonstrable anti-HLA antibodies (5). During pregnancy PG is often treated with topical corticosteroids and systemic antihistamines. However, in some patients with severe disease, systemic steroid therapy is needed. If the disease continues, treatment options are limited. Although plasmapheresis, cyclophosphamide, azathioprine, cyclosporine and dapsone, as monotherapy or in combined regimens all have been reported to be beneficial, they have potential side-effects that can be harmful to both the mother and the foetus (6, 7). There are only 2 case reports in the literature describing the use of intravenous immunoglobulin (IVIg) therapy in PG (6, 8). We report here a persistent case of PG, refractory to the conventional treatment with steroid plus azathioprine or dapsone, which responded positively to IVIg.