Comparison of Free Light Chain Assays: Freelite and N Latex in Diagnosis, Monitoring, and Predicting Survival in Light Chain Amyloidosis.

OBJECTIVES: Measurement of serum free light chains (FLCs) is critical in diagnosis, prognosis, and monitoring treatment responses in light chain (AL) amyloidosis. We compare the Freelite assay (polyclonal antibodies to hidden light chain epitopes), which is the current gold standard, with a new assay: a mixture of monoclonal antibodies to light chain epitopes (N Latex). METHODS: We collected 240 serum samples from 94 consecutive patients with newly diagnosed AL amyloidosis (at least three serial serum samples during the first 6 months) analyzed at the National Amyloidosis Centre, London, from January 2011 to April 2012. Concordance in detecting abnormal light chain components and hematologic response was assessed at 2, 4, and 6 months. RESULTS: The κ and λ clonal light chain involvement was 21% and 79%, respectively, with an abnormal κ/λ ratio or detectable protein in 78.7%. Median κ, λ, and difference in involved and uninvolved FLCs by Freelite and N Latex assays were 17.3 vs 16 mg/L (R(2 ) = 0.91), 48.8 vs 52.6 mg/L (R(2) = 0.52), and 43.2 vs 39.1 mg/L, respectively. Discordant κ/λ ratios at presentation were as follows: 10 of 90 abnormal by Freelite/normal by N Latex and 11 of 90 abnormal by N Latex/normal by Freelite. CONCLUSIONS: Both FLC assays show good correlation in detecting the abnormal light chain subtype with discordance in absolute values and thus are not interchangeable.

A matched comparison of cyclophosphamide, bortezomib and dexamethasone (CVD) versus risk-adapted cyclophosphamide, thalidomide and dexamethasone (CTD) in AL amyloidosis.

Despite improvements in therapy amyloid light-chain (AL) amyloidosis, there are few studies comparing different regimens. Here we present a matched comparison with 69 patients in each cohort examining upfront therapy with cyclophosphamide, bortezomib and dexamethasone (CVD) vs cyclophosphamide, thalidomide and dexamethasone (CTD). On an intention-to-treat basis, the overall response rates were 71.0% vs 79.7% in the CVD and CTD arms, respectively, (P=0.32). A higher complete response (CR) rate was observed in the CVD arm (40.5%) vs CTD (24.6%), P=0.046. One-year overall survival (OS) was 65.2% and 66.7% for CVD and CTD, respectively (P=0.87). The median progression-free survival (PFS) was 28.0 and 14.0 m for CVD and CTD, respectively (P=0.039). In a landmark analysis assessing outcomes performed at 6 months, the CR rate with CVD was 59.6% vs 34.0% for CTD (P=0.03). The 1-year OS was 96% with CVD and 92% with CTD (P=0.40). The median PFS with CVD was not reached and was 19.2 m with CTD, P=0.028). In summary, both regimens are unable to overcome the high rate of early deaths in AL amyloidosis. However, CVD correlates with improved depth of response and superior PFS supporting its use in the frontline setting. Further optimisation and better supportive-care strategies are required to increase the proportion of patients fully benefiting from therapy.

Isolation and sequence of cDNA encoding the soybean protease inhibitors PI IV and C-II.

Two full-length (or nearly so) cDNA clones containing information for the protease inhibitors PI IV and C-II from soybean seeds were identified by means of a synthetic probe. DNA sequencing revealed that the two protease inhibitors are synthesized as precursors with a short peptide leader. The coding regions of the two clones show 80% homology, wheraes the 5' non-coding regions are 90% homologous. Homology of 75% is found in the region extending beyond the stop codons.

Molecular cloning and analysis of a gene coding for the Bowman-Birk protease inhibitor in soybean.

We have constructed cDNA clones from size-selected mRNA of developing soybean seeds to identify genes encoding the Bowman-Birk protease inhibitor. Recombinant clones containing sequences coding for the Bowman-Birk inhibitor were identified by mRNA hybrid selected translation and immunoprecipitation. The nucleotide sequence of the insert of plasmid pB38 corresponds to the mRNA for the Bowman-Birk inhibitor, although it is missing a portion of the coding sequence at the 5' end. Northern hybridization analysis of total RNA isolated from developing soybean seeds showed that the mRNA for the inhibitor is approximately 450 nucleotides long and that it accumulates early in embryogeny. Southern hybridization analysis of restriction enzyme-digested soybean nuclear DNA indicated that the gene encoding the Bowman-Birk inhibitor is not highly reiterated in the genome. We have isolated a gene encoding the Bowman-Birk inhibitor from a soybean genomic library constructed in Charon 4A. DNA sequence analysis of the genomic clone reveals that it is similar, although not identical, to the cDNA clone and that it contains no intervening sequences.

In vitro synthesis of the Bowman-Birk and related soybean protease inhibitors.

Poly (A)(+) RNAs from immature soybean seeds were size fractionated in denaturing sucrose gradients to identify mRNA that directs the cell-free synthesis of the Bowman-Birk protease inhibitor and the related inhibitors PI I-IV. Polypeptides synthesized in vitro were labeled with ((35)S)-cysteine and ((3)H)-serine and detected by immunoprecipitation with anti Bowman-Birk and anti PI I-IV sera. Immunoprecipitates of the translation products comigrated on SDS-polyacrylamide gels with the dimeric or trimeric aggregates of the authentic inhibitor proteins, which self-associate under certain conditions. Further evidence that these immunoprecipitates contained authentic polypeptides corresponding to the Bowman-Birk or PI IV inhibitor was shown by sequential amino acid analyses of peptides generated by cleavage with cyanogen bromide.

Rapid release of protease inhibitors from soybeans: immunochemical quantitation and parallels with lectins.

Specific antisera were prepared against the Bowman-Birk trypsin inhibitor and four other trypsin inhibitors of low molecular weight isolated from soybeans (Glycine max L. cv. Tracy). These antisera were used to detect the presence and amount of the inhibitors in: (a) seeds and protein extracts of soybean meal; (b) seedlings; and (c) the water surrounding the seeds and roots of seedlings. Lectin activities in seeds, seedlings, and water were also determined at the same time as the protease inhibitor activities. By competitive inhibition of immunoprecipitation, the combined five low molecular weight protease inhibitors were found to constitute the following percentages of proteins (w/w): 6.3% in defatted soybean meal; 8.1% of the protein extracted from the meal by a buffer of pH 8.6; 8.3, 14.7, 15.2, 16.1, 17.2, and 18.9% of the protein in a lyophilisate of water in which seeds were incubated for 4, 8, 12, 16, 20, and 24 hours, respectively; 8.2% in a lyophilisate of water in which roots of seedlings grew for 20 days; 1.5% in cotyledons; and less than 0.1% in epicotyls, hypocotyls, and roots of 12-day-old seedlings. Hemagglutination activities, expressed as the lowest amount of protein required to give a positive agglutination of 0.2 ml of 2% rabbit red blood cells, were as follows: purified soybean lectin, 0.08 mug; lyophilisate of water in which seeds were incubated for 4, 8, 12, 16, 20, and 24 hours, 10, 2.5, 5, 5, and 2.5 mug, respectively; lyophilisate of water in which roots grew for 20 days, 5 mug; 12-day-old cotyledons, roots, epicotyls, and hypocotyls, 12.5, 100, >1,000, and >500 mug, respectively. The results indicate that a large amount of protease inhibitors as well as lectins are released from seeds during the first 8 hours of imbibition. Neither lima bean trypsin inhibitor (mol wt, 10,000) nor Kunitz soybean trypsin inhibitor (mol wt, 21,500) showed competitive inhibition in tests with antisera against low molecular weight soybean protease inhibitors.

Purification, partial characterization, and immunological relationships of multiple low molecular weight protease inhibitors of soybean.

Five protease inhibitors, I--V, in the molecular weight range 7000--8000 were purified from Tracy soybeans by ammonium sulfate precipitation, gel filtration on Sephadex G-100 and G-75, and column chromatography on DEAE-cellulose. In common with previously described trypsin inhibitors from legumes, I--V have a high content of half-cystine and lack tryptophan. By contrast with other legume inhibitors, inhibitor II contains 3 methionine residues. Isoelectric points range from 6.2 to 4.2 in order from inhibitor I to V. Molar ratios (inhibitor/enzyme) for 50% trypsin inhibition are I = 4.76, II = 1.32, III = 3.22, IV = 2.17, V = 0.97. Only V inhibit chymotrypsin significantly (molar ratio = 1.33 for 50% inhibition). The sequence of the first 16 N-terminal amino acid residued of inhibitor V is identical to that of the Bowman-Birk inhibitor; all other observations also indicate that inhibitor V and Bowman-Birk are identical. The first 20 N-terminal amino acid residues of inhibitor II show high homology to those of Bowman-Birk inhibitor, differing by 1 deletion and 5 substitutions. Immunological tests show that inhibitors I through IV are fully cross-reactive with each other but are distinct from inhibitor V.

Lectin release by soybean seeds.

Lectin is released from soybean seeds during water uptake. Hemagglutination activity data show that the lectin is a preferential release product within the first 8 hours of hydration. A qualitative filter-paper assay for detection of lectin released by single seeds is used to show that the release phenomenon is independent of seed viability and insensitive to azide.

A soybean trypsin inhibitor. Crystallization and x-ray crystallographic study.

Five trypsin and alpha-chymotrypsin inhibitors which have low molecular weights (ranging from 6800 to 8600) and are present in soybean seeds of the Tracy variety have been isolated and purified, and single crystals which give x-ray diffraction data beyond 3-A spacings have been obtained from one of them. The trypsin inhibitor crystallizes in a monoclinic unit cell of symmetry P2(1) and dimensions a = 25.919(7) A, b = 43.23(1) A, c = 19.905(5) A, and beta = 103.63(2) degrees. The assymmetric unit contains 1 molecule of molecular weight 6800. The crystal, which has been found to be unusually stable to x-radiation, has solvent content of approximately 26% by volume.

Mitoses in thermodormant lettuce seeds with reference to histological location, localized expansion, and seed storage.

Seeds from one lot of "New York" lettuce were sown in each of 5 successive years to compare the effect of duration of storage on the capacity for mitosis in thermodormant seeds with the effect of storage on the capacity for germination under conditions favorable for germination. Whereas the capacity for mitosis in absence of germination increased as a function of duration of seed storage, the capacity for germination itself decreased steadily over the period studied. Thus, the apparent "deterioration" of stored seed, as measured by decreased germination, does not necessarily indicate a general deterioration of all cytologic processes. Histological study of thermodormant lettuce seeds demonstrated that in some seeds mitosis and cytokinesis can occur without either overall or localized expansion of the embryo-axis. Although localized expansion occurred in some seeds, there was no expansion of the embryo-axis as a whole in any of the seeds, the localized expansion being accompanied always by localized compression elsewhere in the axis. Restraint of the embryo by the endosperm, which remained intact, could account for the prevention of overall expansion of those embryos in which localized expansion and compression occurred. Mitoses in such embryos occurred both within and outside the regions of localized expansion. Thus, even in those embryos with localized expansion, mitotic activity is not necessarily correlated with expansion. Mitoses occurred in each of the primary tissue meristems of the hypocotyl-radicle, mainly within the apical 0.5 mm of the radicle. In this regard, thermodormant embryos resemble growing roots of lettuce seedlings. These findings demonstrate that mitotic activity and localized expansion, either separately or together, can occur in the embryo without germination.