Variable expression of IgG2 deficiency.

Sustained and significant reversal of antibody deficiencies is uncommon, although it has been noted in some cases during childhood and after viral infections. We report a case of reversal of IgG2 deficiency after splenectomy. A 46-year-old man who suffered recurrent sinusitis despite antibiotic therapy was noted to have IgG2 deficiency and cutaneous anergy. Replacement therapy with intravenous immunoglobulin ameliorated his symptoms. After 13 months of therapy, the patient had a diagnostic laparotomy and splenectomy because of portal hypertension, hypersplenism, and consideration of underlying malignancy. No evidence of malignancy or infection, including human immunodeficiency virus, active cytomegalovirus, or Epstein-Barr virus infection, was found. After splenectomy, the patient's serum IgG2 level normalized without replacement therapy. Subsequently, it fell, then normalized once more, and remains normal. The patient also demonstrated positive reactions to delayed hypersensitivity testing after splenectomy, but, subsequently, became anergic and remains anergic at the present time. Since the splenectomy he has remained clinically well without antibiotics or immunoglobulin replacement. In vitro analysis of his lymphocyte function demonstrated impaired T cell proliferation as well as an intrinsic B cell differentiation defect. This case demonstrates the potentially dynamic nature of IgG subclass deficiencies.