[Immunology and oncology of paraproteins]

Since the first description by Apitz paraproteins were for a long time regarded as biologically abnormal proteins which normally do not appear in the human plasma. According to the modern biochemical knowledge this determination of the notion can no more be acknowledged, since analyses of amino acids did not reveal any differences in the composition of the complete paraproteins and the immune globulins. Apart from the complete paraproteins which consist either of gamma, my, delta, alpha or epsilon heavy chains on the one hand and of kappa or lambda easy chains on the other hand, also molecule fragments and isolated heavy or easy chains, respectively, appear. Like immune proteins paraproteins are formed by B-lymphocytes and their transformation forms, respectively, in which case the monoclonality represents their specific characteristic. Thus exist close relations to malignant changes of the B-lymphocyte system, in particular to the non-Hodgkin-lymphomas. Several functional peculiarities of the paraproteins, such as autoantibody effect, lymphocytotoxicity, aggregation ability and binding affinity to blood cells lead to multiform clinical phenomena. To this belong immune defects, nephropathies, haemocytopenias, amyloidoses and haemorrhagic diatheses. As evoking cause of the alteration of B-lymphocyte system with activation of one or several cell clones (e.g. in double paraproteinaemia) tumour viruses are taken into consideration. After an infection with oncogenic herpes viruses irreversible cell transformations in the lymphatic system have been proved. Thus it is doubtful, whether there are indeed true benign paraproteinaemias. One has rather to speak only of relatively benign forms of the course.