Immunodeficiency-Associated Lymphoproliferative Disorders

摘要

Immunodeficiencies maybe congenital or acquired. There are over 80 recognized congenital immunodeficiency syndromes that are generally classified by an absent or defective component of the immune system, namely humoral, cellular, or combined immunity, the phagocytic cells, and the complement proteins. Most primary immunodeficiencies are hereditary, autosomal recessive, or X-linked, such as the common variable immunodeficiency (humoral immunodeficiency), the DiGeorge syndrome, the ZAP-70 deficiency, the X-linked lymphoproliferative syndrome (T-cell immunodeficiency), the Ataxia-telangiectasia, the Wiskott-Aldrich syndrome (combined humoral and cellular immunodeficiency), the Chediak-Higashi syndrome (phagocytic cell defects), and the C1 or C2 deficiencies (complement deficiencies). Acquired immunodeficiencies may be caused by different agents and conditions, such as prolonged serious illness, diabetes, cytotoxic chemotherapy, HIV infection, bone marrow ablation before transplantation, radiation therapy, and malnutrition. Most acquired immunodeficiencies are only of clinical interest and histopathologists or cytopathologists are rarely involved in their diagnosis and clinical management. This is the case when immunodeficiencies cause lymph node enlargements (LNe) and carry a high risk of lymphoproliferative processes or other neoplasms. In this perspective, HIV-related and post-transplant lymphoproliferative diseases (PTLD) are those of main interest to cytopathologists.