[Membranoproliferative glomerulonephritis in non-Hodgkin's lymphoma nad myeloproliferative syndrome--a causal relationship?].

A pathogenetic relationship is postulated for the development of membranoproliferative glomerulonephritis type I in non-Hodgkin's lymphoma (B-cell lymphoma of low-grade malignancy) and myeloproliferative syndrome, which we have observed in eight patients. This hypothesis is supported by the fact that chronic lymphatic leukaemia and immunocytoma are often associated with immunodysregulative phenomena, and by the immunohistological and ultrastructural findings in the kidney, especially the frequent electron-microscopic finding of cryoglobulins, which results in the membranoproliferative type of immune-complex glomerulonephritis, an expression of a disturbance in immune balance. The pathogenetic mechanism may involve cryoglobulins themselves as immune complexes; it is also possible that monoclonal cryoglobulins combine with an antigen to form immune complexes or lead to in situ formation of immune complexes. In addition, other immune complexes, for example with endogenous tumour-associated antigens and exogenous antigens (e.g. hepatitis antigens), may be involved in the pathogenesis.