Microanatomical Compartments of the Human Spleen

Abstract

In contrast to rats the different compartments of the splenic white pulp in man are much more difficult to recognise in conventional HE-stained sections. In addition, the quantity of red and white pulp tends to be individually variable in humans. In general, the white pulp appears less prominent in human than in rat spleens. However, not only the relationship between red and white pulp, but also the predominance of PALS or follicles in the white pulp differs among individuals. In general, the follicles form the most prominent part of the white pulp in man. The PALS is only sparsely distributed (Fig. 6A). Most spleens investigated in our study did not show full-blown secondary follicles, but only primary follicles or follicles with degenerating germinal centres. This phenomenon is most likely influenced by the age and the immunological state of the individual. In adult humans “remnants” of germinal centres may normally prevail, because fully developed germinal centre reactions do not last long if there is no continuous supply of antigen.