ABSTRACT
Many factors influencing the function of the immune system can lead to variable degrees of immunoincompetence. Infections, exposure to toxic environmental factors, physical trauma, and therapeutic interventions can all be associated with immune dysfunction (Table 1). In some cases, the primary disease that causes the immunodeficiency is very obvious, while in others a high degree of suspicion is necessary for its detection. The pathogenic mechanisms are very clear in some cases, and totally obscure in others. The following is a brief summary of some of the most common secondary immunodeficiencies, followed by a more detailed discussion of acquired immunodeficiency syndrome (AIDS).
