hematology and oncology
Lymphocytopenia
Etiology of Lymphocytopenia
Lymphocytopenia can be Acquired Inherited Acquired lymphocytopenia can occur with a number of other disorders (see table Causes of Lymphocytopenia ). Themost common causesinclude Protein-energy undernutrition HIV infection COVID-19 Certain other viral infections Protein-Energy Undernutrition (PEU) is the most common cause worldwide. Lymphocytopenia is often transient when caused by many viral and bacterial infections, sepsis, corticosteroid treatment, and stress responses. Patients with Human Immunodeficiency Virus (HIV) Infection routinely have lymphocytopenia, which arises from destruction of CD4+ T cells infected with the HIV virus ( Patients with COVID-19 also frequently have lymphocytopenia (35 to 83% of patients) ( Lymphocytopenia may occur with Overview of Lymphoma , ). Long-term treatment for psoriasis using psoralen and ultraviolet A irradiation may destroy T cells. Long-term glucocorticoid therapy can induce lymphocyte destruction, as can Cushing Syndrome . Inherited lymphocytopenia (see table Causes of Lymphocytopenia ) most commonly occurs in Severe Combined Immunodeficiency (SCID) None Wiskott-Aldrich Syndrome None It may occur with inherited Overview of Immunodeficiency Disorders and disorders that involve impaired lymphocyte production ( 1.Moir S, Chun TW, Fauci AS: Pathogenic mechanisms of HIV disease.Annu Rev Pathol6:223-6248, 2011. doi: 10.1146/annurev-pathol-011110-130254 2.Agbuduwe C, Basu S: Haematological manifestations of COVID-19: From cytopenia to coagulopathy.Eur J Haematol105(5):540-546, 2020. doi: 10.1111/ejh.13491 3.Puck JM: Newborn screening for severe combined immunodeficiency and T-cell lymphopeniaImmunol Rev287(1):241-252, 2019. doi: 10.1111/imr.12729. 