Diagnosis of lymphocytopenia

Lymphopenia is defined as a peripheral lymphocyte count lower than 1500/mm3 In adults and 4500/mm3 in children younger than eight months of age. We propose a classification of lymphopenia according to the mechanism involved. - lymphocyte production defects, including primary immune deficiencies and immune deficiencies secondary to malnutrition or zinc deprivation - excess catabolism, due to causes including radiotherapy chemotherapy immunosuppressive therapy HIV infection, and systemic lupus erythematosus - abnormal lymphocyte trapping, including mainly splenomegaly certain virol infections, septic shock, extended burns, systemic gronulomatosis, and corticosteroids - other causes of lymphocytopenia, with mechanisms that remain poorly understood: ethnicity (Ethiopians), lymphoma, renal insufficiency and idiopathic CD4 lymphocytopenia.