Presentation on theme: "Serum Protein Electrophoresis with Immunofixation"— Presentation transcript:
1 Serum Protein Electrophoresis with Immunofixation Dr.Ajay PhadkeCentre HeadSRL Diagnostics-Dr.Avinash Phadke’s Lab
2 What is electrophoresis? Electrophoresis is a method of separating proteins based on their physical properties.Proteins can be separated using a buffered solid medium (agarose electrophoresis ) or using only the liquid phase (capillary electrophoresis)The net charge (positive or negative) and the size and shape of the protein commonly are used in differentiating various serum proteins.A negatively charged particle usually travels to the positively charged electrode(Gel EP)In Capillary EP ? Negatively charged particle travels to the negatively charged electrode(Cathode)WHY?
3 Capillary Electrophoresis in Minicap/Capillarys Anode +Cathode -Protein migrationEOFElectro migrationDETECTION OFPROTEINSINJECTION OFSERUMThe Electro-Osmotic Flow (EOF) is a stronger force than the Electrical Field.As a result, all proteins are carriedtowards the cathodic end of the capillary.Positive charges of the buffer solutionNegative charges of capillarywall
4 The complementary positively charged ions in the surrounding buffer are free to move under the electromotive force, and they carry with them molecules of the solvent water.This buffer flow is termed electro-osmosis or endosmosis, which also carries the proteins with it to some extent by mechanical flow, not by charge.The actual distance traveled by a particular protein migrating in an electrical field is determined by the elec- tromotive force (a feature of the protein itself and the pH) and the electro- osmotic force (a function primarily of the support medium).When the electro-osmotic force is greater than the electrophoretic force acting on weakly anionic proteins (e.g., γ-globulins), those proteins move from the application point toward the cathode, even though their charge is slightly negative.
5 Electrophoretic System in Minicap/Capillarys Capillarys Electrophoresis PrincipleThermic bridgeTemperatureControlled byPeltier deviceMigrationCapillary in thermo-conductive resinDetectorDeuterium lampHigh VoltageCathode -Anode +
6 When do doctors ask for SPE? Unexplained anemia / weakness / fatigue / ↑ ESRUnexplained renal insufficiencyHeavy proteinuria in patient >40yrsBence Jones proteinuriaHypercalcaemiaHypergammaglobulinemiaImmunoglobulin deficiencyPeripheral neuropathy (5% will have MGUS)Recurrent infectionsUnexplained bone pain / pathologic fracture / lytic lesion-
7 1.Elderly patient with suspicion for MM i.e bone pain, lytic lesion 2. fever for >1 month3. ESR increase, persistent anemia, fatigue4. CRP high5.Heavy proteinuria in adults6.persistent increase in calcium7.Peripheral neuropathy since a percentage have MGUS
15 In diabetes mellitus, patients with Type 2-2 haptoglobin have shown higher risk for vascular complications, perhaps owing to different ability to clear hemoglobin, thus leading to altered iron handling and heightened oxidative loadSerum haptoglobin rises in response to stress, infection, acute inflam- mation, or tissue necrosis,
16 Fibrinogen levels become elevated with the other acute phase reactants, occasionally to over 1.0 g/L.In such instances, the erythrocyte sedimentation rate (ESR) is also markedly elevated owing to fibrinogen content directly.Fibrinogen levels also rise with pregnancy and use of contraceptive medications.Low levels generally indicate extensive activation of coagulation with consumption of fibrinogen.
18 Because of the rapid dynamics of its synthesis and clearance, prealbumin is considered to be a better early indicator of change in nutritional statusPresence of a distinct band of prealbumin is used only as a landmark to confirm that the specimen was likely CSF.A protein band frequently appears in the pre-albumin position of of serum from patients who have had heparin therapy. In the circulation, heparin activates and releases lipoprotein lipase activity, which attacks triglycerides in lipoprotein fractions.
20 AlbuminAlbumin concentrations are vital to the understanding and interpretation of calcium and magnesium levels because these ions are bound to albumin, and so decreases in albumin are directly responsible for depression of their concentrations
21 C3 (and also C4) concentration is a convenient marker for assessing disease activity in rheumatic disorders such as lupus erythematosus and rheumatoid arthritis.C4 is not appreciated on serum protein electrophoresis because its concentration is normally only about one-fifth that of C3.Both C3 and C4 are now easily quantitated by nephelometry for monitoring rheumatic disease activity
30 Immunofixation & immunotyping Principle: Apply the patients sample on gel. Separate the sample. Add antibody . If positive = on washing this sample remains because of large size of complex.Immunotyping : similar principle. Automated, not labour intensive.BASIC DIFFERENCE: way how sample is processed. WE MIX sample with antibody before processing.Complex is made EVEN BEFORE SEPERATION TAKES PLACE. Then injected into capillary. Monoclonal complex will MIGRATE SLOWLY and will NOT form a peak.THEREFORE, in IF you are looking for the band to be PRESENT. While in IT you are looking for it to be ABSENT!IFE is Very labour intensive
31 IEP: serum applied to aggel in wells. EP. Antisera added IEP: serum applied to aggel in wells. EP . Antisera added. 24 hr incubation. ARCS formedIFE:Sample on solid matrixIT: NO GEL. Migration in buffered medium. Mono-specific antisera. REDUCTION technique. Antisera binds to Immunoglobulin. Heavy, large molecule created. Pulled OUT of viewing area.If PEAK DETECTEd, just click on immunotyping after selecting dilution.Hypgogamma : Ig<0.8g/L(1/10)Std :Ig g/L(1/20)Hypergamma: Ig >2.0g/L(1/40)
32 Monoclonal peak or polyclonal increase in gamma? PointedpeakRounded topNarrowbasementLargebasementMonoclonal peakPolyclonalincreaseITITComplete substractionwith the antiserumagainst a heavychain and partial substractionwith the antiseraagainst kappa and lambdaComplete substraction of the peakwith one antiserumagainst a heavychain and a light chain
45 When interpreting IT, always consider: « If removingsomething, whatisremaining? »In eachwindow, removing one specific class of IgG highlights what is happening with the residual immunoglobulins that remain after substraction
46 When removing the IgM, the whole peak disappears When removing the Kappa → a slight peak in the residual Lambda remainsWhen removing the Lambda → a peak in the residual Kappa remainsIg M Kappa + Ig M LambdaThere are 2 monoclonal peaks, one Kappa and one Lambda. Both disappear when removing the IgM…
52 Treatment with Beta Mercaptoethanol (BME) to depolymerize a monoclonal Ig : * Prepare a 1% BME reducing solution :1) 90µL H2O + 10µL BME2) 10µL 1/10 diluted BME + 90µL Fluidil (ref 4587)* 100µL of 1% BME reducing solution + 300µL serum* Incubate 10 mn at room temperatureAnalyze immediately the treated sample in Capillarysor Minicap without any delay To separate co-migrating Igs of different types (Ig M vs Ig G)
53 IgG kappa + IgM LambdaIgM LIgG KAfter BME treatment
60 Oligoclonal profileOligoclonal: Presence of multiple faint peaks or distorsionsThis profile is observed in:Autoimmune diseases (Rheumatoid arthritis, Gougerot Sjögren syndrome, Lupus erythematosus)Infectious (viral, bacterial, parasitic) diseasesAutoimmune reactions (Patients with transplants or patients under immuno- suppressive treatments)Oligoclonal profile is linked with a dysregulation of immune system
65 Hints and tips for IT interpretation Examine carefully all IT curves without a zoom to verify the correct overlapping on albumin and the zone of interest between ELP and antisera curvesVerify that the correct sample dilution has been usedCompare the residual heavy and light chains after substraction and their position to verify additional presence of other monoclonal IgIf there is no correspondence between heavy and light chains, complete the test with an immunofixation to check for free light chains and/or IgD, IgE
66 Once a monoclonal gammopathy is identified by serum protein electrophoresis, multiple myeloma must be differentiated from other causes of this type of gammopathy. (Waldenström’smacroglobulinemia, smoldering multiple myeloma, monoclonal gammopathy of undetermined significance, plasma cell leukemia, heavy chain disease)
67 sizeof the M-protein spike sizeof the M-protein spike. Although this spike is usually greater than 3 g per dL in patients with multiple myeloma, up to one fifth of patients with this tumor may have an M-protein spike of less than 1 g per dL.10Hypogammaglobulinemia on serum protein electrophoresis occurs in about 10 percent of patients with multiple myeloma who do not have a serum M-protein spike.11 Most of these patients have a large amount of Bence Jones protein (monoclonal free kappa or lambda chain) in their urine.11 Thus, the size of the M-protein spike is not helpful in excluding multiple myeloma.If multiple myeloma still is considered clinically in a patient who does not have an M-protein spike on serum protein electrophoresis, urine protein electrophoresis should be performed.
68 With the addition of sodium sulfate, sodium sulfite, ammonium sulfate, or methanol, the globulins tend to precipitate, leaving albumin in solution. By measuring total protein in the original serum and protein in the precipitate or the supernatant, values for albumin and globulin can be derived.
69 1.Elderly patient with suspicion for MM i.e bone pain, lytic lesion 2. fever for >1 month3. ESR increase, persistent anemia, fatigue4. CRP high5.Heavy proteinuria in adults6.persistent increase in calcium7.Peripheral neuropathy since a percentage have MGUS
71 When does one advise urine EP The following conditions (to list a few) warrant urine protein electrophoresis: 1) monoclonal protein in serum is >1.5 g/dL, 2) monoclonal free light chains are detected in serum, 3) hypogammaglobulinemia is present in serum; 4) serum electrophoresis shows nephrotic pattern.“In the context of screening, the serum FLC assay in combination with serum protein electrophoresis (PEL) and immunofixation yields high sensitivity, and negates the need for 24-h urine studies for diagnoses other than light chain amyloidosis (AL).”• “...once diagnosis of a plasma cell disorder is made, 24-h urine studies are required for all patients.”• “For AL screening, however, the urine IFE should still be done in addition to the serum tests including the serum FLC.”• “The FLC assay cannot replace the 24-h urine protein electrophoresis for monitoring myeloma patients with measurable urinary M proteins”.