Background Finding of monoclonal immunoglobulins and light chains in serum and urine of SS pts suggests the possibility of SS transformation into malignant lympho-proliferative diseases.

Objectives To characterise the spectrum of monoclonal secretion in SS, to evaluate the role of monoclonal immunoglobulinopathy in the development of I-secreting lymphomas in SS.

Methods 24 females aged 25–75 years (49.2(3.4) with SS duration of 2–28 years admitted into Institute of Rheumatology during 2000 had typing of monoclonal immunoglobulins or their fragments with the help of: I – serum agarosa gel and concentrated urine electrophoresis with subsequent densitometry of electrophoregraphs, 2 – immunofixation and immunoelectrophoresis with monospesific anti-serums ã, á, ì, å, ä, ê, ë.

Results IgMk-3, IgAk-2 monoclonal immunoglobulins were found in 5 pts (25%) in blood serum, Bens-Johns protein (BJk) was found in urine of 3 pts and IgMk in one patient. Thorough examination of pts with monoclonal secretion with carrying out of immunophenotyping of bioptates on lymphatic nodes and small salivary glands on lower lip enabled us to diagnose big cell lymphoma (2-ptorein BJk in the urine, IgMk in serum in 4 pts and plasmacytoma (IgGk) in one patient. It was not possible to confirm the presence of malignant lymphatic proliferation in this study in pts with IgAk (2), IgMk (1) monoclonal secretion in serum and vestige protein secretion BJk in the urine.

Conclusion Revealing of monoclonal immunoglobulins and light chains of immunoglobulins enables us to suggest the appearing of malignant lymphatic proliferation in SS pts and during further immunophenotyping of lymphatic nodes to diagnose the development of immunosecreting lymphomas in the half (55%) of pts.