Primary specific immunodeficiency results from failure to manifest an efficient humoral or cellular immune response. Excluded from the definition are pure hypercatabolic states, such as protein-losing enteropathy, immunodeficiency associated with lymphopenia secondary to intestinal lymphangiectasia and immunodeficiency from exogenous causes such as x-rays and cytotoxic drugs.Immunodeficiency, often associated with malignant proliferation of the lymphoid system (myeloma, chronic lymphatic leukemia, Hodgkin's disease), is considered to be a secondary phenomenon, but the inter-relation between them is complex. Primary complement and phagocytic cell defects are not included in this editorial, which deals only with specific response deficits. The relation between immunodeficiency and . . .