scholarly journals Elevation of Plasmin-α2-plasmin Inhibitor Complex Predicts the Diagnosis of Systemic AL Amyloidosis in Patients with Monoclonal Protein

2018 ◽  
Vol 57 (6) ◽  
pp. 783-788 ◽  
Author(s):  
Kazuya Ishiguro ◽  
Toshiaki Hayashi ◽  
Yoshihiro Yokoyama ◽  
Yuka Aoki ◽  
Kei Onodera ◽  
...  
Keyword(s):  
Al Amyloidosis ◽  
Monoclonal Protein ◽  
Inhibitor Complex ◽  
Plasmin Inhibitor

scholarly journals Kinetic properties of the primary inhibitor of plasmin from human plasma

1977 ◽  
Vol 163 (2) ◽  
pp. 389-391 ◽  
Author(s):  
U Christensen ◽  
I Clemmensen
Keyword(s):  
Human Plasma ◽  
Enzyme Inhibitor ◽  
Kinetic Properties ◽  
Inhibitor Complex ◽  
Rapid Formation ◽  
Plasmin Inhibitor

The interaction of human plasmin with the newly discovered alpha2-plasmin inhibitor was investigated. It was found from rate measurements that the reaction involves the rapid formation of a first enzyme-inhibitor complex, followed by the slow irreversible transition to another complex. L-Lysine influences the first step, but not the second.

scholarly journals Quantitative Immunoprecipitation Free Light Chain Mass Spectrometry (QIP-FLC-MS) Simplifies Monoclonal Protein Assessment and Provides Added Clinical Value in Systemic AL Amyloidosis

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 4375-4375 ◽  
Author(s):  
Faye Amelia Sharpley ◽  
Hannah Victoria Giles ◽  
Richa Manwani ◽  
Shameem Mahmood ◽  
Sajitha Sachchithanantham ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Light Chain ◽  
Residual Disease ◽  
Renal Involvement ◽  
Light Chains ◽  
Al Amyloidosis ◽  
Free Light Chains ◽  
Accurate Identification ◽  
Monoclonal Protein ◽  
Serum And Urine

Introduction Early diagnosis, effective therapy and precise monitoring are central for improving clinical outcomes in systemic light chain (AL) amyloidosis. Diagnosis and disease response assessment is primarily based on the presence of monoclonal immunoglobulins and free light chains (FLC). The ideal goal of therapy associated with best outcomes is a complete responses (CR), defined by the absence of serological clonal markers. In both instances, detection of the monoclonal component (M-component) is based on serum FLC assessment together with traditional serum and urine electrophoretic approaches, which present inherent limitations and lack sensitivity particularly in AL where the levels are typically low. Novel mass spectrometry methods provide sensitive, accurate identification of the M-component and may prove instrumental in the timely management of patients with low-level amyloidogenic light chain production. Here we assess the performance of quantitative immunoprecipitation FLC mass spectrometry (QIP-FLC-MS) at diagnosis and during monitoring of AL amyloidosis patients treated with bortezomib-based regimens. Methods We included 46 serial patients with systemic AL amyloidosis diagnosed and treated at the UK National Amyloidosis Centre (UK-NAC). All patients had detailed baseline assessments of organ function and serum FLC measurements. Baseline, +6- and +12-month serum samples were retrospectively analysed by QIP-FLC-MS. Briefly, magnetic microparticles were covalently coated with modified polyclonal sheep antibodies monospecific for free kappa light chains (anti-free κ) and free lambda light chains (anti-free λ). The microparticles were incubated with patient sera, washed and treated with acetic acid (5% v/v) containing TCEP (20 mM) in order to elute FLC in monomeric form. Mass spectra were acquired on a MALDI-TOF-MS system (Bruker, GmbH). Results were compared to serum FLC measurements (Freelite®, The Binding Site Group Ltd), as well as electrophoretic assessment of serum and urine proteins (SPE, sIFE, UPE and uIFE). Results Cardiac (37(80%) patients) and renal (31(67%) patients) involvement were most common; 25(54%) patients presented with both. Other organs involved included liver (n=12), soft tissue (n=4), gastrointestinal tract (n=3) and peripheral nervous system (n=2). Baseline Freelite, SPE, sIFE and uIFE measurements identified a monoclonal protein in 42(91%), 22(48%), 34(74%) and 21(46%) patients, respectively. A panel consisting of Freelite + sIFE identified the M-component in 100% of the samples. QIP-FLC-MS alone also identified an M-component in 100% of the samples and was 100% concordant with Freelite for typing the monoclonal FLC (8 kappa, 34 lambda). In 4 patients, QIP-FLC-MS identified an additional M-protein that was not detected by the other techniques. In addition, 4/8(50%) kappa and 4/38(11%) lambda patients showed a glycosylation pattern of monoclonal FLCs at baseline by mass spectrometry. Interestingly, the frequency of renal involvement was significantly lower for patients with non-glycosylated forms (25% vs 76%, p=0.01), while no similar relationship was found for any other organs. During the 1-year follow-up period, 17 patients achieved a CR; QIP-FLC-MS identified serum residual disease in 13(76%) of these patients. Conclusion In our series, QIP-FLC-MS was concordant with current serum methods for identifying the amyloidogenic light chain type and provided, against all other individual tests, improved sensitivity for the detection of the monoclonal protein at diagnosis and during monitoring. The ability to measure the unique molecular mass of each monoclonal protein offers clone-specific tracking over time. Glycosylation of free light chains is over-represented in AL patients which may allow earlier diagnosis and better risk-assessment of organ involvement. Persistence of QIP-FLC-MS positive M component in patients otherwise in CR may allow targeted therapy. Overall, QIP-FLC-MS demonstrates potential to be exploited as a single serum test for precise serial assessment of monoclonal proteins in patients with AL amyloidosis. Disclosures Wechalekar: GSK: Honoraria; Janssen-Cilag: Honoraria; Amgen: Research Funding; Takeda: Honoraria; Celgene: Honoraria.

scholarly journals Differential diagnosis of monoclonal gammopathy of undetermined significance

Hematology ◽  
2012 ◽  
Vol 2012 (1) ◽  
pp. 595-603 ◽  
Author(s):  
Giampaolo Merlini ◽  
Giovanni Palladini
Keyword(s):  
Differential Diagnosis ◽  
Plasma Cell ◽  
Monoclonal Gammopathy ◽  
Cell Clone ◽  
Organ Damage ◽  
Organ Injury ◽  
Al Amyloidosis ◽  
Monoclonal Protein ◽  
Undetermined Significance

Abstract Monoclonal gammopathy of undetermined significance (MGUS) is an asymptomatic plasma cell disorder occurring in 4.2% of adults > 50 years of age, which can progress into symptomatic diseases either through proliferation of the plasma cell clone, giving rise to multiple myeloma and other lymphoplasmacellular neoplasms, or through organ damage caused by the monoclonal protein, as seen in light-chain amyloidosis and related conditions. Differential diagnosis of asymptomatic and symptomatic monoclonal gammopathies is the determinant for starting therapy. The criteria for determining end-organ damage should include markers of organ injury caused by the monoclonal protein. Patient assessment and optimal follow-up are now performed using risk stratification models that should also take into account the risk of developing AL amyloidosis. Patients with low-risk MGUS (approximately 40% of all MGUS patients) need limited assessment and very infrequent follow-up. The ongoing development of novel molecular biomarkers and advanced imaging techniques will improve the identification of high-risk patients who may benefit from early therapeutic intervention through innovative clinical trials.

Baseline Serum Albumin and Proteinuria Predict Renal Response after Autologous Stem Cell Transplantation in AL Amyloidosis.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 1166-1166
Author(s):  
Nelson Leung ◽  
Angela Dispenzieri ◽  
Martha Q. Lacy ◽  
Mark R. Litzow ◽  
Shaji K. Kumar ◽  
...  
Keyword(s):  
Multivariate Analysis ◽  
Stem Cell ◽  
Stem Cell Transplantation ◽  
Light Chain ◽  
Al Amyloidosis ◽  
Baseline Serum ◽  
Monoclonal Protein ◽  
Renal Response ◽  
Hematologic Response ◽  
Organ Response

Abstract Introduction: High dose melphalan followed by autologous stem cell transplantation (ASCT) is an effective treatment for patients with light chain associated (AL) amyloidosis. Longer patient survival and higher rates of organ response have now been documented by multiple studies. However, predictors of organ response remain unknown. Previously, we have reported the benefits of renal response after ASCT in this population. This study was conducted to investigate the characteristics that would predict renal response after ASCT. Methods: The study was performed retrospectively on consecutive patients that underwent ASCT at our institution from March of 1996 to December of 2004. Exclusion criteria include baseline proteinuria < 1 g/d, dialysis prior to ASCT and lack of laboratory data at follow up to determine renal response. Renal response was defined by > 50% reduction in baseline proteinuria with < 25% decline in renal function as measured by serum creatinine. Treatment related mortality and dialysis dependence prior to meeting criteria of response were viewed as treatment failures. Hematologic response was determined by 50% reduction of monoclonal protein (free light chain) or complete eradication if the monoclonal protein was too small to be quantified. Results: A total of 135 patients met criteria for study. Median age was 56.2 years at the time of transplant, 53.7% were male. Median baseline proteinuria and GFR were 6.4 g/d and 70 ml/min/1.73m2 respectively. Renal response was achieved in 35.6% of the patients while hematologic response was 71.1% in the 128 patients evaluated. Patient’s age, sex, albumin, GFR, proteinuria, conditioning regimen, and hematologic response were evaluated and the following were found to be associated with renal response: albumin (p = 0.001), proteinuria (p = 0.008), and hematologic response (p = 0.0002). The cutoff for albumin was found to be 1.6 mg/dl and proteinuria was 3.5 g/d. Multivariate analysis using a logistic regression model showed hematologic response and proteinuria to be independent predictors of renal response. The impact of proteinuria and hypoalbuminemia was then investigated together (Table 1). When combined, they were a better predictor then either one alone (Hazard ratio = 6.34 for combined, 3.43 for proteinuria, 3.32 for hypoalbuminemia). The combination was also a better independent predictor of renal response in the multivariate analysis. In this group of patients, renal response was associated with longer survival but hematologic response was not (p = 0.02). Discussion: Our study showed that besides hematologic response, baseline serum albumin and proteinuria are independent predictors of renal response in AL patients after ASCT. Hypoalbuminemia and nephrotic range proteinuria, both markers of the severity of renal disease, have strong negative impact on response. This implies that there may be a limit to the reversibility of organ damage even when hematologic response is achieved. This study also points out the importance of organ (renal) response in this disease as hematologic response alone did not predict long term outcome. Our results suggest ASCT should be done early for AL to insure optimal organ response and patient outcome. Table 1 The Effects of Hypoalbuminemia and Proteinuria on Renal Response after ASCT Hypoalbuminemia & Proteinuria No Renal Response Renal Response None 39.3% 60.7% One 66.2% 33.8% Both 81.8% 18.2%

A300 Monoclonal Protein Detection in AL Amyloidosis Revisited: Analysis of 642 Patients

2009 ◽  
Vol 9 ◽  
pp. S49
Author(s):  
A Wechalekar ◽  
PN Hawkins ◽  
NJ Wassef ◽  
ND Gillmore ◽  
HJ Lachmann ◽  
...  
Keyword(s):  
Protein Detection ◽  
Al Amyloidosis ◽  
Monoclonal Protein

Modifications of α2-Plasmin Inhibitor During Treatments by a Defibrinating Agent

1979 ◽  
Author(s):  
M. Samama ◽  
J. Conard ◽  
B. Cazenave ◽  
A. Derlon ◽  
A. Gaudric ◽  
...  
Keyword(s):  
Retinal Vein Occlusion ◽  
Antithrombin Iii ◽  
Fibrinogen Level ◽  
Plasma Viscosity ◽  
Inhibitor Complex ◽  
Vein Occlusion ◽  
Crossed Immunoelectrophoresis ◽  
Α2 Macroglobulin ◽  
Plasmin Inhibitor ◽  
Soluble Complexes

A defibrination agent (Defibrase®) has been administered to 8 patients with retinal vein occlusion. Defibrase has been infused sub-cutaneously at a dose of 0.5 B. U./kg/day for 5 days followed by 1 to 2 B.U./kg twice a week, for 2 other weeks, so that fibrinogen level was maintained below 100 mg/100 ml. The tests performed were the following : fibrinogen, FDP, soluble complexes, plasminogen, α2 macroglobulin, antithrombin III, α2-plasmin inhibitor (amidolytic and Laurell methods), blood and plasma viscosity. They have been done before treatment and repeated daily for 5 days and then on the 8th, 11th, 14th and 21st day.A decrease in fibrinogen, viscosity, plasminogen and an increase in FDP and soluble complexes have been observed, as already described. The results of the α2- plasmin inhibitor shows a decrease of about 50 % that is slightly more pronounced by the Laurell method than the amidolytic method. The plasmin-α2 plasmin inhibitor complex detected by crossed immunoelectrophoresis is present in various amounts.

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