Current concepts on monoclonal gammopathies

This is a review of the monoclonal gammopathies, including a discussion of cause. The role of T lymphocytes and B lymphocytes is presented. The recognition of a monoclonal protein in the serum and urine is presented in detail.
The frequency of benign and malignant monoclonal gammopathies is provided. A long-term follow-up of 241 patients with apparently benign monoclonal gammopathy is examined closely. In this series, multiple myeloma, macroglobulinaemia, amyloidosis, or related disorders developed in 22% of the 241 patients with long-term disease. The median duration from the recognition of the monoclonal protein until the development of serious disease was approximately eight to ten years.
The differentiation of benign from malignant monoclonal gammopathics is examinad in detail. The point is made that paticnu must be folld indefinitely because malignancy may develop more than 20 years later. The association of monoclonal gammopathies with other apparently unrelated diseases discussed. (Aust NZ J Med 1992; 22: 291–302.)     

Monoclonal immunoglobulins in patients with renal transplants: characterization,evolution and risk factors

Gammopathies were found to be present in 25 (13%) of 192 HIV-negative renal transplant recipients with more than 30 months follow-up prospectively investigated for monoclonal or oligoclonal immunoglobulins (mIg) by agarose gel electrophoresis and immunofixation. Eleven patients had only one monoclonal band, whereas 14 had two or more bands. Of these bands, 60 % were IgG kappa, 29 % IgG lambda and 11 % IgM lambda or kappa, and 90 % did not exceed 2 g/l. Most gammopathies occurred early post-transplant (median 5 months) and they were always transient. Some predisposing factors for mIg emergence could be identified: 1. age, but only in women, 2. duration of dialysis, 3. occurrence of prior cytomegalovirus infection, and 4. immunosuppressive regimen including cyclosporine. Serological evidence for active EBV infection was obtained in ten patients, but in six cases infection occurred subsequent to the finding of mIg. In eight patients, the clinical course was characterised by severe infection or tumours (one Kaposi's sarcoma, one B-cell brain lymphoma). The present findings and experimental studies support the view that the development of mIg in renal transplant patients is associated with a failure of regulatory T-cell function. This T-B-cell imbalance requires a careful follow-up in these patients.     

Binding of swine IgM immunoglobulins to peripheral nerve myelin sheaths in electron microscopic immunocytochemistry

Summary The IgM fraction of normal swine serum (NSS) was found to adhere to human peripheral nerve myelin sheaths from randomly selected neuropathies and control nerves in electron microscopic immunocytochemical assays. The reaction could be blocked by preincubation with undiluted fetal calf serum (FCS), whereas endoneurial background staining was already abolished by preincubation with 10% FCS. Only the IgM, but not the IgG or the IgA fraction of NSS adhered to peripheral nerve tissue. Such strong adherence of one of the components in an immunocytochemical assay may be a source of misinterpretation. Binding of swine IgM to human peripheral nerve myelin has not been described before and is of interest in the discussion about IgM binding to myelin-associated glycoprotein in IgM gammopathies.Supported in part by a grant from the Deutsche Forschungsgemeinschaft (CS)     

Solitary extramedullary plasmacytoma of the liver without systemic monoclonal gammopathy

Extramedullary plasmacytoma of the liver is a very rare tumor. Although a few cases of extramedullary plasmacytoma of the liver have been reported, we could not find any report on truly localized extramedullary plasmacytoma of the liver in the literature. The patient was a 63-yr-old man who exhibited a solitary liver mass on dynamic computed tomography and magnetic resonance imaging. Histologically, the tumor was composed of mature plasma cells with mild atypia. Immunohistochemistry demonstrated monoclonal IgG and Kappa light chain expression. Bone marrow examination revealed no abnormalities. There was no evidence of a monoclonal protein in the serum and urine, lytic bone lesions, anemia, renal insufficiency, and hypercalcemia. The patient was treated with 5,000 cGy of radiotherapy, and the tumor disappeared 6 months after treatment.