Final answer:
The main difference between primary and secondary/acquired immunodeficiencies is that primary immunodeficiencies are caused by genetic defects and are typically present from birth, whereas secondary immunodeficiencies are acquired due to external factors and can often be reversible.
Step-by-step explanation:
Difference Between Primary and Secondary/Acquired Immunodeficiencies:
Primary immunodeficiencies are disorders caused by genetic abnormalities. These defects can affect various components of the immune system, such as phagocyte function, B cells, or T cells. Common examples include chronic granulomatous disease X-linked agammaglobulinemia, selective IgA deficiency and severe combined immunodeficiency disease. Because they are genetic, these conditions typically present early in life and are often not reversible. Secondary immunodeficiencies, on the other hand, are acquired through external factors such as disease, dietary deficiencies or environmental exposures.
They may result from environmentally induced defects in B cells, T cells or both and are often reversible if the underlying cause is resolved. The most common worldwide cause of secondary immunodeficiency is severe malnutrition, which impairs both innate and adaptive immunity. Opportunistic infections like Candida spp. and P. jirovecii are more common in individuals with secondary immunodeficiencies. While primary immunodeficiencies are inherent secondary ones can develop at any time due to external factors, and they can sometimes be reversed with appropriate treatment of the underlying cause.