Bence-Jones, globulin

On examination of the urine and serum of numerous patients with suspected paraproteinemia in both Jamaicans and Africans between 1962 and 1966, it was concluded that whenever a low total serum y-globulin level with a normal serum electrophoretic pattern were encountered in a suspected case of multiple myelomatosis, it was then essential to obtain also a specimen of urine from such a patient for further electrophoretic examination. Invariably simultaneous electrophoresis of such sera and urines proved to be diagnostic, even when the classical heat test for Bence Jones protein was negative. Consequently it was found that concurrent electrophoresis of scrum and urine was the first means of detecting multiple myelomatosis in no less than 20% of the patients, which were subsequently confirmed either by bone marrow biopsy or X-ray examination or both (M3). 

Figure 1 shows diagrammatically the arrangement of the proteins of the serum in accordance with their mobilities, as would be found in a classical electrophoretical pattern obtained by electrophoresis of normal serum at pH 8.6 in veronal buffer. The Bence-Jones and myeloma globulins are also placed in areas where they were found in respect to the serum proteins indicated (see Table V for other data on these proteins). In each system, in both the hepatic and extrahepatic proteins (26), the ala-thr ratios change in the same direction as the... 

The remarkable similarity in the molar ratios of the amino acids offers encouragement to the proposition that common peptides will be found in the electrophoretic components of the serum proteins. The peptide of spot 7 probably differs from spot 8 in leucine content, which would account for the higher Rf of spot 8. More encouraging are the recent reports of Edelman (2, 13) who found that gamma-globulin, the Bence-Jones proteins, and the myeloma proteins have a peptide unit of common amino acid composition. 

The dipstick test for total protein includes a cellulose test pad impregnated with tetrabromphenol blue and a citrate pH 3 buffer. The reaction is based on the protein error of indicators phenomenon in which certain chemical indicators demonstrate one color in the presence of protein and another in its absence. Thus tetrabromphenol blue is green in the presence of protem at pH 3 but yellow in its absence. The color is read after exactly 60s and the test has a lower detection limit of 150 to 300mg/L, depending on the type and proportions of protein present. The reagent is most sensitive to albumin and less sensitive to globulins, Bence Jones protein, mucoproteins, and hemoglobin. 

Fig. 14. Malignant paraproteinemia. Electrophoresis on cellulose acetate of serum (above) and concentrated urine (below) reveals (i) Bence Jones proteinuria. In this case monoclonal bands are seen of each type. For L the relevant concentration to albumin indicates which are IgGL, L dimer, and L monomer (ii) loss of normal y-globulin (iii) a high serum level of paraprotein. Immunoelectrophoresis of urine reveals paraprotein bows of k, and X, yaXj and X2.

Fig. 15. Benign paraproteinemia. Electrophoresis on cellulose acetate of serum and concentrated urine reveals (i) no Bence Jones proteinuria (ii) no loss of normal y-globulin (iii) a low level of serum paraprotein. In this case the paraprotein is of post-y-mobility, is type GL, and is typically (but not exclusively) found in lichen myxedematosus. Reproduced by courtesy of the Proceedings of the Royal Society of Medicine (H30).

The same investigators studied the antigenic relationship between purified Bence Jones uroproteins, multiple myeloma globulins, and normal y-globulin. All 18 Bence Jones proteins cross-reacted with anti-y-globulin sera they showed mobilities between 1.4 and 4.7 cm volt sec X 10 and S2o-values from 2.14 to 4.60. Bence Jones proteins were found to be antigenically more deficient than either myeloma globulins... 

Development of electrophoretic protein separation techniques have been paralleled by improvements in protein detection methods. Protein detection in early electrophoretic applications, utilizing electrophoretic separations of solutions or colloidal suspensions from about 1816 to 1937, was limited to direct visualization of proteins coated onto microspheres, or studies of naturally colored proteins such as hemoglobin, myoglobin, or ferritin <1-4). An increase in sensitivity and the ability to detect non-colored proteins was achieved by the use of the specific absorption, by proteins, of ultraviolet light. This detection technique permitted Tiselius,in 1937, to demonstrate the quantitative electrophoretic separation of ovalbumin, serum globulin fractions and Bence Jones proteins (S). Tiselius also employed the shadows, or schlieren, created by the boundaries, due to the different concentrations of proteins in the electrophoretic system to detect protein position and concentration ( ). These detection methods served as the main methods for protein detection in the liquid electrophoresis systems. However,... 

Known P. are Bence-Jones proteins, amyloid proteins, Waldenstrbm-type IgM and cryoglobulin (a 7S globulin). Owing to their homogeneous character and relative ease of isolation on a preparative scale, P. are among the best studied immuno obulins... 

A small molecular weight protein produced in large amounts in monocytic leukaemia. It passes into the urine where it can form a discrete band on protein electrophoresis. It is therefore sometimes mistaken for Bence-Jones protein. It has post-7 mobility and is well separated from the 7-globulin fraction. 

The sensitivity and specificity of the quantitative precipitin method make it applicable to the identification and estimation of abnormal plasma proteins in certain diseases, particularly when present in concentrations too low to be detected by other methods. Goettsch and her associates (103, 104) and Kendall (181) employed immunochemical techniques in the study of nephrotic sera Kendall (181) also investigated the distribution of his immunologically distinct globulin subfractions in hyperglobulinemia due to lymphogranuloma venereum, cirrhosis of the liver, and rheumatoid arthritis Kabat (261) was able to demonstrate the presence of as little as 0.15 gram per cent Bence-Jones protein in the serum of a patient with multiple myeloma. Many other applications of immunochemical techniques are noted by Kabat (167) and Treffers (358) in recent reviews. 

Occasionally, sera which appear to be quite normal when examined by Howe s method, including globulin subfractionation, give distinctly abnormal electrophoretic patterns, as in case 27 of Table VII (see Blackman et al., 22). In cases 25, 28, and 43 both Howe and electrophoretic fractionation gave essentially normal results. Such normal findings do not exclude the presence in the blood of small amounts of Bence-Jones protein, which appeared in quantity in the urine of cases 25 and 43. 

Blackman et al. (22) reported that the Bence-Jones protein in the urine of their case migrated with the mobility of /3-globulins, the major abnormal serum component also appearing as a large /3 peak. Malmros and Blix (231) foimd that the urinary Bence-Jones protein in the one case examined appeared to move with a mobility intermediate between /3- and y-globulins, the major abnormal serum protein component appearing as a large /3 peak. 

In 1943 Moore and associates (251) reported sedimentation constants for Bence-Jones proteins obtained from the urine of four cases of multiple myeloma, S20 = 2.8 S, 3.4 S, 3.4 S, and 3.4 S, respectively. The sedimentation constant of the electrophoretically separated main abnormal component of the serum proteins was also determined in six cases of multiple myeloma. In cases 1 and 39 of Table VII (page 197), the chief components in both instances were 7-globulins with Sao = 7.1 S. In cases 40 and 42 the chief components with electrophoretic mobilities between /5- and 7-globulins had sedimentation constants S20 = 6.5 S and 7.0 S, respectively. These four abnormal serum proteins clearly were not Bence-Jones proteins. The abnormal component in case 42 was studied further by Shapiro, Ross, and Moore (319), who found it to be a very viscous protein, molecular weight about 160,000. In cases 11 and 41 (the chief component of the first with an electrophoretic mobility between 3- and 7-globulins and of the second corresponding with 3-globulins) sedimentation constants of 820 = 4.0 S and 3.0 S, respectively, were... 

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