Pneumonien bei Immunsuppression

Abstract

Due to the large surface area, heat, high humidity and high oxygen supply in the lung makes an ideal environment for the propagation of germs. The purpose of the immune system is to establish and maintain the balance between saprophytes and immune defense so as to depress and ultimately kill germs as they infiltrate the body. This usually is achieved by the use of a highly complex immune system. It is a perfect combination of non-specific, cellular and humoral immune mechanisms with very specific immune cells and antibodies, which are specialized on particular pathogens. The specific defenses potentiate the effect of the nonspecific defense in a large extent so as to prevent re-infection and ultimately eliminate recognized pathogens. The causes of immune deficiency can be related to either the cellular or humoral level and affect both the specific and nonspecific defenses. There is a different excitation spectrum depending on the type of immune deficiency. Immune deficiency can prevalently cause complications in the course of infections, decelerate the healing and allow the occurrence of rare pathogens. In particular, the radiological characteristics of typical and atypical pneumonia in immunocompromised patients will be discussed. Particular emphasis is placed on the appearance of bacterial infections, mycobacterioses, PCP, CMV, and laid fungual pneumonia. Even it is not possible to identify certain pathogens radiologically, it is often possible to narrow the spectrum of germs causing pulmonary infections significantly by comparing with other pulmonary complications such as lymphoma or kaposisarcomas.