Amylase-producing IgD-type multiple myeloma

Amylase: A disease activity index in multiple myeloma?

This study reports a case of a patient with lambda-light chain multiple myeloma who developed a high hyperamylasaemia of the salivary type during the disease and soon afterwards died. Ectopic production of amylase by myeloma cells has been described in a few cases and demonstrated by tissue culture and immunohistochemical techniques. The common characteristics of these cases were: salivary amylase isoenzyme increase, high tumor mass, extensive extra-medullary spread, extensive bone destruction and poor prognosis. In patients with amylase-producing multiple myeloma, the onset of hyperamylasaemia heralds a rapid disease progression; therefore, in these patients, a simple test such as serum amylase may represent a reliable disease activity index and provide an additional prognostic information.

Paraneoplastic hyperamylasaemia in association with multiple myeloma

Marked hyperamylasaemia associated with an amylase-producing multiple myeloma appears to be a fairly unusual phenomenon. The present report describes a fatal case of multiple myeloma associated with paraneoplastic hyperamylasaemia without evidence of pancreatic or salivary gland involvement. Serum and urine amylase levels paralleled the myeloma response to chemotherapy and disease progression. The importance of paraneoplastic hyperamylasaemia as a useful myeloma marker to monitor disease progression and treatment response is emphasized. Conventional chemotherapy at diagnosis and salvage treatment with bortezomib at relapse failed to achieve a long-term response and to decrease the serum amylase to a normal level.

Protein precipitation as a possible important pitfall in the clinical chemistry analysis of blood samples containing monoclonal immunoglobulins: 2 case reports and a review of the literature

Two case reports are presented, both illustrating an analytical interference caused by monoclonal immunoglobulins. Falsely low results were obtained in the routine analysis of glucose, CRP and HDL-cholesterol. When analysing samples containing paraproteins, various problems can be encountered in the clinical laboratory: next to the antibody effect, pseudohyponatraemia, hyperviscosity, cryoglobulinaemia and gel formation have to be taken into account. In our two cases the interference was caused by paraprotein precipitation, causing an increased turbidity and an apparent increase of light absorbance at every wavelength due to light scattering, including the wavelengths used in the clinical chemistry assays. We review the literature on this sometimes overlooked interference in photometric/turbidimetric assays. This reaction is based on the insolubility of these proteins in specific physico-chemical circumstances in which many variables are involved, among others: pH and ionic strength, presence of preservatives and surfactants in the assays, pI and other specific properties of the monoclonal immunoglobulins. The complexity of the problem makes predicting or preventing this probably infrequent interference usually impossible. This artifact can cause both false positive and false negative results in multiple parameters (e.g. bilirubin, creatinine, iron, urea, uric acid), the most frequently reported analyte being phosphate. The Sia water test (Sia euglobulin precipitation test) can provide a first clue to a paraprotein aggregation; confirmation can be obtained by observing the time/ absorbance curves of the analysis, performing the test manually or setting up a serial dilution of the sample. The problem can be solved by avoiding the presence of the proteins in the assay, performing the analysis using an alternative method or diluting out the interference. Both laboratorians and clinicians should be aware of interferences in the clinical laboratory since the clinical consequences could be important.

Hyperamylasaemia and multiple myeloma

This case report describes a 42-year-old Caucasian woman who presented with persistent hyperamylasaemia and no evidence of pancreatic pathology. Further investigations resulted in a diagnosis of light-chain multiple myeloma. Amylase production by epithelial tumours has been well documented but the association with multiple myeloma has only been described in a small number of cases. The link does not appear to be immunoglobulin class-specific but the association with Bence Jones myeloma is unusual. The common features in this group of patients have been extensive extramedullary spread with a high tumour mass and a poor prognosis. This case was similar in that the patient showed very rapid disease activity developing extensive metastatic lesions and treatment ultimately proved unsuccessful. The amylase concentrations have been shown to decrease in response to treatment and increase at times of relapse and it has been proposed that it may be useful as a tumour marker in these patients. This case study adds to the pool of patents with this unusual association.

Macroamylasemia in a patient with multiple myeloma

We report a rare case of a patient with multiple myeloma who developed hyperamylasemia not associated to hyperamylasuria and without symptoms of pancreatic or salivary disease. This condition suggested the occurrence of macroamylasemia, consisting of macromolecules of amylase bound with immunoglobulins, which are not filtered by the kidneys. Hyperamylasemia was not present at the diagnosis of myeloma and appeared at the relapse of the disease, simultaneously with the appearance of an additional gamma-chain oligoclonal component, suggesting a possible role of these chains in producing macroamylasemia. To our knowledge, this is the first report of macroamylasemia in a patient with multiple myeloma.

Recurrent chromosomal rearrangements involving breakpoints 3p21 and 19q13 in Chinese IgD multiple myeloma detected by G-banding and multicolor spectral karyotyping: a review of IgD karyotype literature

Immunoglobulin D multiple myeloma (IgD MM) is a rare subtype that accounts for 1% to 3% of MM and shows higher aggressiveness with distinctive clinical and laboratory features. However, there is little information in the literature on their karyotypes, which are mainly derived from G-banding results. Our current study on 2 Chinese IgD MM thus represents the first description of cytogenetic data on this subtype based on an integrated analysis with G-banding and multicolor spectral karyotyping (SKY). Both of our cases showed some usual features of MM, as well as a few novel translocations including t(3;22), t(6;19), t(X;19) and the 3 whole-arm translocations namely t(1;6)(q10;p10), t(4;9)(q10;p10), and t(16;18)(q10;q10). We also identified recurrent chromosomal rearrangements involving breakpoints 3p21 and 19q13, which may suggest to be unique aberrations that may underline the pathogenesis of this distinctive biological MM subtype.

Cytogenetic analysis and fluorescence in situ hybridization in a case of IgD multiple myeloma

Immunoglobulin D multiple myeloma (IgD MM) is a subentity of MM occurring in fewer than 2% of patients with distinct clinical pattern, dismal prognosis, and very little information about genetic abnormalities. The karyotype and the results of fluorescent interphase in situ hybridization analysis of a 62-year-old female patient with IgD MM are presented and show a complex hypodiploid karyotype with loss of an X chromosome and monosomy 13--very well known adverse prognostic factors in MM--but, in addition, several deletions of chromosomes 1, 6, 11, and 12, as well as translocations involving chromosomes 4, 9, 10, 15, 16, and 21 that underline the singularity of IgD MM.

Hydrolases acting on glycosidic bonds: chromatographic and electrophoretic separations

We describe analyses of unusual human alpha-amylase, performed in our laboratory and review available methods for amylase study. Electrophoretic and chromatographic methods provide an effective means for the analysis of amylase isoenzymes and unusual amylase. The recent identification of a selective inhibitor and a monoclonal antibody to amylase isoenzyme contributes to rapid routine clinical assays of amylase isoenzymes. However unusual amylases such as variants, macroamylasemia and sialyl salivary-type amylasemia cannot be detected by those conventional methods. The unusual amylases can only be detected by electrophoresis and can be easily characterized by combination study with chromatographic methods. Electrophoretic and chromatographic methods are universal means to validate unusual amylases found in patient sera. Further basal studies are needed to define the roles of salivary amylase in exocrine fluids using those separation techniques.