Kappa and lambda light chain proteins--clinical and prognostic significance in patients with multiple myeloma.

In 76 patients with multiple myeloma an independent or combined light chain production at a ratio of kappa (kappa) to lambda (lambda) chains of 43:33 was proved. Two groups of patients were formed depending on the type of the light chain production. They were compared by a number of biological, clinical and biochemical parameters, which demonstrate the frequency and pathogenetic participation of the two light chains in the main syndromes of the disease. The therapeutic response and prognostic value were also estimated. Bence Jones (lambda) chains prevail in men, in the III clinical stage of the disease, in patients with tubular proteinuria and in syndromes indicating an advanced stage of evolution of the main process, in non-reversible azotaemia, hypercalcaemia and hypoalbuminemia. The survival rate in thus group of patients is an average of 7 months shorter in comparison with the BJ (kappa) group (the difference is non-significant). The median survival of patients with BJ (kappa) is 30 months and 21 months for BJ (lambda).

Production of the immunoglobulin variable domain REIv via a fusion protein synthesized and secreted by Staphylococcus carnosus.

REIv--the variable domain of an immunoglobulin x light chain--was produced by heterologous gene expression in a Gram-positive bacterium, purified to homogeneity and characterized. A host/vector combination based on secretion of Staphylococcus hyicus lipase by Staphylococcus carnosus was exploited. A gene encoding a fusion protein, composed of an aminoterminal portion of the pre-pro-peptide of S. hyicus lipase, a hexahistidine affinity tag, followed by the recognition sequence of IgA protease and REIv was constructed. Expression of the fusion gene in S. carnosus causes selective secretion and accumulation of a soluble fusion protein in the culture medium (5-10 mg/l), which can be purified from the supernatant by immobilized metal ion affinity chromatography (IMAC). REIv is released from the fusion protein with an additional threonine and proline residue at the aminoterminus (REIvTP) by site-specific cleavage with IgA protease and can be separated from the hexahistidine-tagged fusion partner and the protease by a second passage through an IMAC gel matrix. Like authentic REIv, the isolated protein (> 1 mg/l culture medium) migrates as a dimer in gel filtration chromatography and undergoes cooperative, reversible unfolding in urea. The isolated immunoglobulin REIvTP and authentic REIv have indistinguishable free energies of unfolding (approx. 26 kJ/mol, 6.3 kcal/mol).

Synthesis and metabolism of Bence Jones protein and calculation of tumour burden in patients with Bence Jones myeloma.

Synthesis and metabolism of Bence Jones protein was measured in seven patients with Bence Jones myeloma. Using the plasma and urine levels of 125I-labelled Bence Jones protein, it was possible to calculate the fractional catabolic rate (FCR), fractional proteinuric rate (FPR), and fractional metabolic rate (FMR) for the individual patients. There was a high degree of correlation between decreased metabolism and reduced creatinine clearance (P < 0.001). Ideal regression equations (linear and nonlinear) relating FCR, FPR and FMR with fractional creatinine clearance (FCC) were calculated. Using these regression equations plus measured values for the synthetic rates of light chain for bone marrow plasma cells, the myeloma cell mass or tumour burden was measured in each patient. Correlations between these measured cell mass values and those derived from clinical staging were reasonably good. However, for the lambda (gamma) Bence Jones myeloma patients, the measured cell mass values were significantly higher than predicted from clinical staging. Further studies will be necessary to validate this latter observation. It is hoped that this study will serve as a basis for a comprehensive schema allowing accurate cell mass measurement and staging of Bence Jones myeloma.

Extramedullary plasmacytoma of the oropharynx producing kappa-type Bence-Jonas protein.

A case of extramedullary plasmacytoma in the oropharynx of a 41 year-old woman is reported. Histologically, the tumor was plasmacytoma consisting mainly of matured plasma cells and showing a deposit of amyloid in the interstitial structure. Immunoelectrophoretic studies of the concentrated urine specimen revealed a kappa-type Bence-Jones protein even though there was no increase in blood M-protein. Lineac electron radiation of 5,100 rad was given over a period of eight weeks but no effect was noted. After the tumor was surgically removed, follow up of the patient was made for 2 years without evidence of recurrence or metastasis.

Immunoquantitation of free light chain immunoglobulins: applications in multiple myeloma.

A single radial immunodiffusion (RID) assay for the free lambda (lambda) and kappa (kappa) light chain (LC) immunoglobulins was developed for study of clinical samples of serum, urine, and bone marrow of patients with multiple myeloma. Using highly specific rabbit anti-LC sera, we were able to quantitate: (a) free serum LC after fractionating the serum sample using an Amicon ultrafiltration chamber equipped with an XM100A diaflow membrane and an 125I-LC standard for calculating filtration efficiencies, (b) directly, Bence Jones (BJ) proteins in the urine, and (c) the in vitro LC synthesis by myeloma plasma cells obtained from bone marrow aspirates. The median values of free LC levels in sera (n = 12), urines (n = 25), and marrow culture synthetic rates (n = 17) were 116.2 mg/dl, 0.775 g/day and 15.3 pg/plasma cell/day, respectively. These data were useful in initial evaluation of patients and serial follow-up studies. The assays have also been of use in our research on the determination of total body tumor mass in patients with BJ multiple myeloma.

Bence Jones proteins and light chains of immunoglobulins. XV. Effect of corticosteroids on synthesis and excretion of Bence Jones protein.

The effect of corticosteroids and cytotoxic chemotherapeutic agents on the excretion of Bence Jones protein was determined for periods of 1 - 62 mo in 29 patients with multiple myeloma and Bence Jones proteinuria. The amount of protein present in 24-h urine specimens collected before treatment and at frequent intervals during monthly treatment cycles was determined. Striking variations occurred in the amount of Bence Jones protein excretion; these changes were especially evident when 75 mg of prednisone were given daily for 7 days as part of a monthly chemotherapeutic regimen. Within the 7-day period seven patients showed essentially no decrease (<25%), whereas 13 and 9 patients had a moderate decrease (25-75%) or a marked decrease (>75%), respectively, in Bence Jones proteinuria as compared to pre-treatment values. The decrease in excretion of Bence Jones protein during this period was attributed mainly to corticosteroid therapy because of the transient nature of the response in most patients and the lack of such response in three patients when the hormone was omitted. Biosynthetic studies were performed to determine in vitro the effect of corticosteroids on Bence Jones protein synthesis. Plasma cells obtained from the bone marrow of 13 patients were incubated in a growth medium containing (14)C-labeled lysine and isoleucine and prednisone in concentrations up to 240 mug/ml, and the amount of Bence Jones protein synthesized was determined immunochemically. No differences in viability were apparent between untreated and prednisone-treated cells. The type of response exhibited by an individual patient in the percent decrease of Bence Jones protein excreted after 7 days of prednisone treatment was comparable to the percent decrease in newly-synthesized Bence Jones protein secreted by tumor cells when cultured in the presence of prednisone at a concentration of 120 mug/ml. The marked differences in the capacity of corticosteroids to affect Bence Jones protein synthesis appear to reflect a biochemical heterogeneity among plasma cell neoplasms.

Transplantable lymphoma producing type K Bence-Jones protein in NZB mouse.

Spontaneous lymphoma occurring in the retroperitoneum in a 13-month-old New Zealand Black female mouse, as transplantable to the same strain mice, was subjected to immunological studies by serial transplantation as subcutaneous solid tumor (66A) and bloody ascites tumor (66B). The transplanted tumor-bearing mice showed M component in the plasma, urine and ascites. It was confirmed as type K Bence-Jones protein. Speculations were made on the relation between abnormal immunity in NZB mice and lymphoma.

Bence Jones proteins and light chains of immunoglobulins. XI. A transient Bence Jones-related protein associated with corticosteroid therapy.

Urine specimens from patients with multiple myeloma and Bence Jones proteinuria frequently contain low molecular weight proteins which correspond either to the amino-terminal, variant half (VL) or to the carboxyl-terminal, constant half (CL) of the Bence Jones protein. Analyses of urine specimens from such patients who had received high doses of corticosteroids as part of their treatment regimen revealed that concomitantly with a decrease in Bence Jones protein excretion was the appearance of a low molecular weight protein related to the Bence Jones protein but not identical to the VL or to the CL. Analyses of daily urine specimens obtained from one such patient over an extended time period revealed that a reproducible chain of events occurred during a treatment regimen which included oral administration of 75 mg of prednisone daily for 7 consecutive days. The amount of Bence Jones protein excreted decreased progressively, and by the 5th day was usually less than 10% of the pretreatment value. The urine specimen obtained on the 6th day of treatment was virtually devoid of Bence Jones protein but contained a newly appearing protein whose electrophoretic mobility was distinct from that of the Bence Jones protein or its VL or CL. Cessation of corticosteroid therapy resulted in a prompt disappearance of the new protein and in a progressive increase in the amount of Bence Jones protein excreted. The new protein was isolated from the urine of this patient and was purified for comparative studies with Bence Jones protein and with the VL and CL prepared by specific enzymatic cleavage of the Bence Jones protein. These studies revealed that the new protein was most related antigenically to the CL, but could be distinguished immunochemically from the CL. This new protein, a component found in vivo related to the constant half of the light polypeptide chain, was designated CL, and was structurally 25 amino acid residues longer than the CL, that is, the amino-terminus of the enzymatically prepared CL was at position 117 whereas that of the transitory new Bence Jones-related protein was at position 92 of the light polypeptide chain. Biosynthetic studies were performed with plasma cells derived from the bone marrow of this patient at a time when both the CL and the Bence Jones protein were being excreted; both proteins were identified in extracellular culture fluid by immunochemical techniques. Whether the CL is of synthetic or catabolic origin is presently not known; however, the detection of the CL and the absence of any detectable protein related to the VL in the extracellular culture fluid might imply a synthetic origin of the CL and suggest a corticosteroid-induced alteration in light chain synthesis.

Synthesis and assembly of immunoglobulins by malignant human plasmacytes. I. Myelomas producing gamma-chains and light chains.

Three basic patterns of gamma-globulin synthesis are described in malignant human plasmacytes: extreme unbalanced synthesis where only L chains are synthesized; unbalanced synthesis in which intact gammaG globulin and an excess of free L chains are synthesized and secreted; and balanced synthesis where H and L chains appear to be synthesized in equimolar amounts. Studies of the cellular products appear to reflect the biosynthetic processes of the cells in a more reliable fashion than does analysis of serum or urinary proteins. The absence of Bence Jones proteins from the urine does not necessarily indicate that free L chains are not being synthesized and secreted at the cellular level. Similarly, the completed globulin molecule secreted by malignant plasma cells may not be demonstrable by examination of serum. Patterns of globulin synthesis in human myelomatous tissues vary as do patterns of globulin synthesis in mouse plasmacytomas. Pulse-chase studies of the cells from one patient showed that a gammaG myeloma protein was assembled via an HL (half molecule) intermediate.