Measurement of serum heavy/light chain in monoclonal plasma cell proliferative disor-ders / 中国肿瘤临床

Monoclonal protein (M protein) is a serum surrogate used to conduct diagnostic, prognostic, and therapeutic evaluations of monoclonal plasma cell proliferative disorders. Two basic methods, namely, serum protein electrophoresis and immunofixation elec-trophoresis, are employed to detect and characterize M protein. Although these techniques have considerably improved, M protein quantification exhibits several drawbacks. In serum protein electrophoresis, M protein can migrate to various locations, and low M pro-tein levels cannot form a typical peak;as a consequence, additional problems in measurements arise. In 2009, a novel immunoassay in-volving a heavy/light chain (HLC) was developed. HLC recognizes immunoglobulins with specific heavy and light chain isotypes. The ra-tio between an involved monoclonal immunoglobulin and an uninvolved background polyclonal immunoglobulin can be calculated through immunoglobulin quantitation by using isotype-specific light chains. This review summarizes relevant parameters that provide diagnostic, prognostic, and therapeutic data regarding monoclonal plasma cell proliferative disorders.

Evaluation of the Screening Tests for the Diagnosis of Plasma Cell Neoplasm

BACKGROUND: Plasma cell neoplasm is diagnosed by performing bone marrow examination, serum- and urine-protein electrophoresis, and quantification of free light chains of immunoglobulins. We characterized and quantified monoclonal proteins typical of different diagnosed conditions to determine the best screening test(s). METHODS: We retrospectively reviewed diagnosis of and the characteristics of monoclonal proteins from 113 patients with monoclonal gammopathy. Monoclonal proteins were detected by agarose-gel electrophoresis and capillary electrophoresis, and if the results were ambiguous, they were confirmed by immunofixation electrophoresis. Free light chains were measured using nephelometry. RESULTS: The concentrations of monoclonal proteins in 113 patients with different conditions were as follows: multiple myeloma (MM) (67%), 2.66 (0.87-9.48) g/dL; monoclonal gammopathy of undetermined significance (MGUS) (26%), 0.62 (0.08-2.95) g/dL; lymphoma (3%), 3.65 (1.59-6.54) g/dL; Waldenstrom's macroglobulinemia (2%), 1.99 (1.08-2.90) g/dL; amyloidosis (2%), 0.61 g/dL; and POEMS syndrome (1%), 0.99 g/dL. There was a significant difference in the concentration and kappa/lambda ratio (which was based on the immunetype of the monoclonal proteins) of the monoclonal proteins in patients with MM and MGUS (P<0.001 and P=0.004, respectively). The diagnostic sensitivity of serum-protein electrophoresis, free-light-chain assay, and bone marrow analysis was 87.6%, 84.1%, and 84.5%, respectively. The sensitivity of a combination of 2 or 3 of these tests was higher at 100%. CONCLUSIONS: A combination of protein electrophoresis with immunotyping and serum free-light-chain assay may be the best screening method for detecting monoclonal proteins since its non-invasiveness.

Síndrome de POEMS (mieloma osteoesclerótico) / POEMS syndrome (osteosclerotic myeloma)

A síndrome de POEMS é uma entidade clínica única definida pela presença concomitante de doença monoclonal de plasmócitos, polineuropatia periférica e outras manifestações paraneoplásicas tais como organomegalias, endocrinopatias, alterações cutâneas, papiledema, lesões osteoescleróticas e sobrecarga de volume extravascular. Para o diagnóstico da doença não é necessária a presença de todas as manifestações relacionadas e o reconhecimento precoce desta patologia é importante para reduzir a morbidade. A síndrome de POEMS também é conhecida como Mieloma Osteoesclerótico, síndrome de Crow-Fukase e síndrome de Takatsuki. A sobrevida média dos pacientes com síndrome de POEMS é significativamente superior àquela esperada para os portadores de mieloma múltiplo (165 e 38 meses, respectivamente), independente do número de manifestações presentes ao diagnóstico e da intensidade de infiltração da medula óssea por plasmócitos. O tratamento padrão da síndrome de POEMS ainda não está estabelecido e as principais opções são radioterapia, corticosteróides e agentes alquilantes, inclusive na forma de quimioterapia de altas doses com transplante autólogo de células-tronco hematopoiéticas.

POEMS syndrome is a unique clinical entity defined by the presence of a monoclonal plasma cell disorder, peripheral neuropathy, and other paraneoplastic features such as organomegaly, endocrinopathy, skin changes, papilledema, sclerotic bone lesions, extravascular volume overload. Not all features of the disease are required to make the diagnosis, and early recognition is important to reduce morbidity. Other names for the syndrome include ostesclerotic myeloma, Crow-Fukase syndrome, or Takatsuki syndrome. The median survival of patients with POEMS syndrome is superior to those with multiple myeloma (165 and 38 months, respectively), independent of the number of presenting features, bone lesions, or plasma cells at diagnosis. There is no standard treatment for this disorder, the mainstays of therapy for patients with POEMS include irradiation, corticosteroids, and alkylator-based therapy, including high-dose chemotherapy with peripheral blood stem cell transplantation.

POEMS syndrome: a case report

POEMS syndrome is a multisystem disorder associated with polyneuropathy, organomegaly, endocrinopathy, a monoclonal protein (M-protein), and skin changes. The authors describe a patient with POEMS syndrome who had osteosclerotic myeloma confirmed by open bone biopsy. Magnetic resonance imaging (MRI) showed discrete lesions of low signal intensity in both T1 and T2-weighted images. This patient is now being successfully treated with melphalan and prednisone with much improvement in skin thickening and sensory change in the lower extremities.