[Lymphadenopathies and diseases with manifestations of autoimmunity]

The diseases responsible for lymphadenopathies with autoimmune features were examined. Such features play a major role in a vast number of clinical conditions whose aetiology is for the most part unknown but which present several clinical, histological and laboratory aspects in common. The most significant of these conditions are serum sickness and similar pictures induced by drugs, iodised contrast media and hymenoptera venom, angioimmunoblastic lymphadenopathies, giant multicentric lymph node hyperplasia, diffuse connectivitis, Wegener's granulomatosis lymphoid granulomatosis, necrotic lymphadenitis without granulocyte infiltration, mucocutaneous lymph node syndrome, angiofollicular hyperplasia with eosinophilia and histiocytosis of the sinuses. In some of these conditions, the lymphadenopathy is a constant and characteristic feature of the disease; in others it is common, in others rare and at time purely local. The autoimmune changes encountered in these conditions may, at times, be responsible for the morbidity, as in serum sickness. In others they merely constitute major or minor symptoms. In some they are no more than marginal aspects. The onset is usually acute with widespread symptoms and a clinical control featuring manifestations of hypersensitivity and immune deficiency. The most common and characteristic laboratory findings are polyclonal hypergammaglobulinaemia, circulating immune complexes, cryoglobulinemia and hypocomplementaemia and finally medullary plasmocytosis. Lymph node biopsy also tends to reveal a standard picture characterised by polymorphic infiltration of immunologically normal cells and the proliferation of newly formed small calibre blood vessels, mostly venules: In other words an aspecific reactive picture. For this reason diagnosis will sometimes be provided by blood tests, sometimes by repeated biopsy at a later date, sometimes by the evolution of the clinical picture. One other feature of these conditions and common, incidentally, to almost all diseases involving immunological alterations, is that they may be complicated by the appearance of lymphomas. Among the diseases quoted particular attention was paid to angioimmunoblastic lymphadenopathy and Castleman's disease given their greater frequency and the importance of their aetiopathogenic and clinical aspects.