Investigation of monoclonal gammopathy of undetermined significance: a single-centre study

Abstract

Summary The main characteristic of monoclonal gammopathies (MG) is the presence of an increased amount of both electrophoretically and immunologically homogeneous immunoglobulins (M component). According to the WHO classification, monoclonal gammopathies are classified among the non-Hodgkin's lymphomas as 'plasma cell dyscrasias'. The unknown behaviour state, so-called MGUS (monoclonal gammopathy of undetermined significance), is distinguished from the malignant diseases. We investigated the frequency and features of MG and MGUS by reviewing the serum immunochemistry protein analyses between 1998 and 2004. Among 18,642 analyses, MG was found in 1,983 cases (10.39%) derived from one or more samples of 416 patients. Case histories of 340 patients were analysed. A malignant lymphoproliferative disease was proved in 171 cases, while in 169 cases the behaviour of the gammopathy was unknown. In 65 cases, the disease was possibly not related to MG. Mean follow-up time of the 65 patients with MGUS was 42 (9-81) months. During the follow-up period seven patients progressed into a malignant lymphoproliferative disorder-- mean probability of the malignant transformation was 3.07%/year and it occurred more frequently in the presence of immunoglobulin A isotype. There was no correlation between the progression of the disease and other laboratory findings. Besides the analyses of MG-related diseases, we focus on the malignant transformation of MGUS and on the importance of regular clinical and laboratory control examinations.

Evaluation of Monoclonal and Oligoclonal Gammopathies in a Pediatric Population in a Major Urban Center

“…Similar patterns of disease groups were also noted in a large hospital population study, which revealed a monoclonal protein in 10% of all patients older than 40 years. 28 That study found an overall distribution analogous to that seen in our younger pediatric population, with 67% with IgG, 18% with IgM, and 15% with an IgA gammopathy. In their review of patient history, they also noted many similar underlying conditions associated with the monoclonal protein including autoimmune diseases (rheumatoid arthritis, systemic lupus erythematosus, Sjögren syndrome, systemic sclerosis, Crohn disease, etc), solid tumors, hematologic diseases (Castleman disease, mycosis fungoides, hairy cell leukemia, Hodgkin disease, marginal zone lymphoma, follicular lymphoma, diffuse large B-cell lymphoma, and chronic lymphoid leukemia), renal diseases, liver cirrhosis, bacterial sepsis, immunemediated polyneuropathy, and myelodysplasia.…”

“…A main difference between our study and studies conducted in the adult population was that 50% of the adult population have been found to have a malignant monoclonal gammopathy, including multiple myeloma, plasmacytoma, primary amyloidosis, and Waldenström macroglobulinemia. 28 Nevertheless, our patients are distinct from the adult cases reported by Simon et al 28 in that none of the aforementioned malignant monoclonal gammopathies (multiple myeloma, plasmacytoma, primary amyloidosis, and Waldenström macroglobulinemia) were identified in our young cohort.…”