Hypogammaglobulinemia

An immunodeficiency characterized by abnormally low serum immunoglobulin or antibody levels (IgG <7 g/L or <700 mg/dL), resulting in impaired humoral immune responses and increased susceptibility to recurrent or severe infections.

Causes

• Primary immunodeficiency disorders

  • Agammaglobulinemia

  • Severe combined immunodeficiency (SCID)

  • DiGeorge syndrome

  • Other congenital disorders affecting B-cell development or antibody production

  • Transient hypogammaglobulinemia of infancy

• Hematological and malignant causes

  • B-cell malignancies

  • Chronic lymphocytic leukemia

  • Lymphoma

  • Plasma cell disorders affecting normal immunoglobulin production

• Medications suppressing antibody production

  • Chemotherapy

  • Anticonvulsants

  • Immunosuppressive therapies

  • B-cell-depleting therapies

• Infectious causes

  • Human immunodeficiency virus (HIV) infection

  • Epstein–Barr virus (EBV) infection

• Gastrointestinal protein-loss causes

  • Protein-losing enteropathy

  • Intestinal lymphangiectasia

• Nephrotic syndrome

• Severe burns causing loss of plasma proteins

• Severe malnutrition

• Post-transplant immunosuppression