Serum Protein Immunofixation Electrophoresis Research Articles

Light chain only variant of proliferative glomerulonephritis with monoclonal immunoglobulin deposits: a clinicopathological study of three cases

AimsTo explore the clinical and pathological features of light chain only variant of proliferative glomerulonephritis with monoclonal immunoglobulin deposits (PGNMID-LC).MethodsFrom January 2010 to December 2022, patients who were diagnosed with...

MO182CRYSTALLINE LIGHT CHAIN CAST NEPHROPATHY IS ASSOCIATED WITH EARLY MORTALITY IN PATIENTS WITH MULTIPLE MYELOMA

Abstract Background and Aims Light chain cast nephropathy is the most common paraprotein-associated kidney lesion in patients with multiple myeloma (MM). Rarely, light chain cast nephropathy could show crystalline appearance in patients with multiple myeloma, also known as crystalline light chain cast nephropathy. We here report the first retrospective study of crystalline light chain cast from a single centre. Method All native kidney biopsies were retrospectively studied in the Peking University First Hospital from 2000 to 2020. Newly diagnosed MM patients with were enrolled. Patients with light chain cast nephropathy at least one cast with crystalline appearance were identified as crystalline light chain cast nephropathy (Figure 1, n = 8), others were identified as ordinary light chain cast nephropathy (n = 18). Results The cohort of crystalline light chain cast nephropathy consisted of 6 men and 2 women with a median age of 59.5 (range, 41-73) years. All patients suffered from advanced multiple myeloma (1 with ISS staging II, 7 with ISS staging III) and acute kidney injury with a median eGFR of 5.59 (range, 2.27-26.04) mL/min/1.73m2. All patients except 1 required emergency dialysis at admission. Microhematuria was presented in 3 patients. Median proteinuria was 2.13 (rang, 0.83-3.59) g/24h and median serum albumin was 38.2 (30.7-46.7) g/L. No one presented with nephrotic syndrome. Monoclonal immunoglobulin, detected in all patients on serum protein immunofixation electrophoresis, was λ alone in 5 patients, κ alone in 1 patient, IgG λ in 1 patient, IgA λ in 1 patient. The 8 patients were followed up with a median time of 8 (range, 2-24) months. Three patients received VAD chemotherapy and 5 patients received bortezomib based regimens. At the time of last follow-up, 2 of 7 patients who needed emergency dialysis got rid of dialysis and the rest remained dialysis-dependent. Five patients died with a median time of 5 (range, 2-19) months, 2 patients achieved partial remission and 1 patient achieved complete remission. There was no significant difference in clinical features, treatments and main outcomes between crystalline light chain cast nephropathy patients and ordinary light chain cast nephropathy patients (Table 1). However, crystalline light chain cast nephropathy patients had higher early mortality than ordinary light chain cast nephropathy patients (50.0% vs 11.1%, p = 0.03). Conclusion Crystalline light chain cast nephropathy patients usually presented with acute kidney injury requiring emergency dialysis. Although various types of monoclonal immunoglobulin were detected, there was a dominance of the λ isotype. Compared to ordinary light chain cast nephropathy patients, crystalline light chain cast nephropathy patients had higher early mortality.

Optimization of workflow and screening panels for the detection of malignant monoclonal gammopathies.

Multiple myeloma (MM) is one of the hematologic malignancies with a greater delay in diagnosis. Laboratories receive numerous MM screening test requests without a specific suspicion, which entails a substantial workload and reduces the efficiency of laboratories. Objective: to increase the efficacy of MM screening protocols. The results of serum protein electrophoresis (SPEP), serum protein immunofixation electrophoresis (SIFE), urine protein immunofixation electrophoresis, and serum free light chain assays of 75 patients with MM, three with amyloidosis, and a patient with solitary plasmocytoma were collected. The frequency of a set of biochemical alterations in these patients was compared with that in controls (n=120). A validation of the screening algorithm was carried out in 261 consecutive patients with a clinical or analytical suspicion of MM. SPEP+SFLC or SIFE+SFLC (98% sensitivity) were the screening algorithms with the highest sensitivity. Prospectively, the SPEP+SFLC detected 27 of the 28 confirmed cases of MG and saved 15h of work. Alterations in five of the six parameters studied were more frequent in the study group, with a cumulative value of≥3 parameters altered (61.1 vs. 1.7%) (positive predictive value: 85%; negative predictive value: 94%). The SPEP+SFLC screening protocol demonstrated the highest sensitivity and was the least time-consuming protocol. In addition, this protocol improves diagnostic sensitivity and laboratory performance.

Serum Free Light Chains in Neoplastic Monoclonal Gammopathies: Relative Under-Detection of Lambda Dominant Kappa/Lambda Ratio, and Underproduction of Free Lambda Light Chains, as Compared to Kappa Light Chains, in Patients With Neoplastic Monoclonal Gammopathies

BackgroundQuantitative evaluation of serum free light chains is recommended for the work up of monoclonal gammopathies. Immunoglobulin light chains are generally produced in excess of heavy chains. In patients with monoclonal gammopathy, κ/λ ratio is abnormal less frequently with lambda chain lesions. This study was undertaken to ascertain if the levels of overproduction of the two light chain types and their detection rates are different in patients with neoplastic monoclonal gammopathies.MethodsResults of serum protein electrophoresis (SPEP), serum protein immunofixation electrophoresis (SIFE), urine protein electrophoresis (UPEP), urine protein immunofixation electrophoresis (UIFE), and serum free light chain assay (SFLCA) in patients with monoclonal gammopathies were examined retrospectively.ResultsThe κ/λ ratios were appropriately abnormal more often in kappa chain lesions. Ratios of κ/λ were normal in about 25% of patients with lambda chain lesions in whom free homogenous lambda light chains were detectable in urine. An illustrative case suggests underproduction of free lambda light chains, in some instances.ConclusionsThe lower prevalence of lambda dominant κ/λ ratio in lesions with lambda light chains is estimated to be due to relative under-detection of lambda dominant κ/λ ratio in about 25% of the patients and because lambda chains are not produced in as much excess of heavy chains as are kappa chains, in about 5% of the patients. The results question the medical necessity and clinical usefulness of the serum free light chain assay. UPEP/UIFE is under-utilized.

Prospective Identification of Oligoclonal/Abnormal Band of the Same Immunoglobulin Type as the Malignant Clone by Differential Location of M-Spike and Oligoclonal Band.

BackgroundSerum and urine protein electrophoreses and immunofixation electrophoreses are the gold standards in diagnosing monoclonal gammopathy. Identification of oligoclonal bands in post-treatment patients has emerged as an important issue and recording the location of the malignant monoclonal peak may facilitate prospective identification of a new “monoclonal” spike as being distinct from the malignant peak.MethodsWe recorded the locations of monoclonal spikes in descriptive terms, such as being in the cathodal region, mid-gamma region, anodal region, and beta region. The location of monoclonal or restricted heterogeneity bands in subsequent protein electrophoreses was compared to the location of the original malignant spike.ResultsIn a patient with plasma cell myeloma, the original monoclonal IgG kappa band was located at the anodal end of gamma region. Post-treatment, an IgG kappa band was noted in mid-gamma region and the primary malignant clone was not detectable by serum protein immunofixation electrophoresis (SIFE) in post-treatment sample. Even though the κ/λ ratio remained abnormal, we were able to recognize stringent complete response by noting the different location of the new IgG kappa band as a benign regenerative process.ConclusionsRecording the location of the malignant monoclonal spike facilitates the identification of post-treatment oligoclonal bands, prospectively. Recognizing the regenerative, benign, bands in post-transplant patients facilitates the determination of stringent complete response despite an abnormal κ/λ ratio.

45. Evidence-based guidelines regarding the role of laboratory and genetic test for the assessment of DSP. What is the perspective in 2016?

Distal symmetric polyneuropathy (DSP) is a relatively common variety of neuropathy. The AAN, AANEM and AAPMR the recommendations where: (1) Screening laboratory tests may be considered for all patients with polyneuropathy (Level C). The highest yield of abnormality were found in blood glucose, serum B12 with metabolites and serum protein immunofixation electrophoresis (Level C). If there is no definite evidence of diabetes mellitus on routine testing of blood glucose, testing for impaired glucose tolerance may be considered in DSP (Level C). (2) Genetic testing should be conducted for the accurate diagnosis and classification of hereditary neuropathies (Level A). Also, in patients with cryptogenic polyneuropathy who exhibit an hereditary neuropathy phenotype (Level C). Initial genetic testing should be guided by the clinical phenotype, inheritance pattern, and electrodiagnostic features and should focus on the most common abnormalities which are CMT1A duplication/HNPP deletion, Cx32 (GJB1), and MFN2 mutation screening. There is insufficient evidence to determine the usefulness of routine genetic testing in patients with cryptogenic polyneuropathy who do not exhibit a hereditary neuropathy phenotype (Level U).

Audit of Use and Overuse of Serum Protein Immunofixation Electrophoresis and Serum Free Light Chain Assay in Tertiary Health Care: A Case for Algorithmic Testing to Optimize Laboratory Utilization.

Overuse of laboratory tests is a persistent issue. We examined the use and overuse of serum immunofixation electrophoresis and serum free light chain assays to develop an algorithm for optimizing utilization. A retrospective review of all tests, for investigation of monoclonal gammopathies, for all patients who had any of these tests done from April 24, 2014, through July 25, 2014, was carried out. The test orders were categorized as warranted or not warranted according to criteria presented in the article. A total of 237 patients were tested, and their historical records included 1,503 episodes of testing for one or more of serum protein electrophoresis, serum immunofixation electrophoresis, and serum free light chain assays. Only 46% of the serum immunofixation and 42% serum free light chain assays were warranted. Proper utilization, at our institution alone, would have obviated $64,182.95/year in health care costs, reduced laboratory cost of reagent alone by $26,436.04/year, and put $21,904.92/year of part B reimbursement at risk. Fewer than half of the serum immunofixation and serum free light chain assays added value. The proposed algorithm for testing should improve utilization. Risk to part B billing may be a disincentive to reducing test utilization.

Practice Parameter: The Evaluation of Distal Symmetric Polyneuropathy: The Role ofLaboratory and Genetic Testing (An Evidence-Based Review): Report of the American Academy of Neurology, the American Association of Neuromuscular and Electrodiagnostic Medicine, and the American Academy of Physical Medicine and Rehabilitation

BackgroundDistal symmetric polyneuropathy (DSP) is the most common variety of neuropathy. Since the evaluation of this disorder is not standardized, the available literature was reviewed to provide evidence‐based guidelines regarding the role of laboratory and genetic tests for the assessment of DSP.MethodsA literature review using MEDLINE, EMBASE, Science Citation Index and Current Contents was performed to identify the best evidence regarding the evaluation of polyneuropathy published between 1980 and March 2007. Articles were classified according to a four‐tiered level of evidence scheme and recommendations were based upon the level of evidence.Results and Conclusions1. Screening laboratory tests may be considered for all patients with polyneuropathy (Level C). Those tests that provide the highest yield of abnormality are blood glucose, serum B12 with metabolites (methylmalonic acid with or without homocysteine) and serum protein immunofixation electrophoresis (Level C). If there is no definite evidence of diabetes mellitus by routine testing of blood glucose, testing for impaired glucose tolerance may be considered in distal symmetric sensory polyneuropathy (Level C). 2. Genetic testing is established as useful for the accurate diagnosis and classification of hereditary neuropathies (Level A). Genetic testing may be considered in patients with cryptogenic polyneuropathy who exhibit a hereditary neuropathy phenotype (Level C). Initial genetic testing should be guided by the clinical phenotype, inheritance pattern, and electrodiagnostic (EDX) features and should focus on the most common abnormalities which are CMT1A duplication/HNPP deletion, Cx32 (GJB1), and MFN2 mutation screening. There is insufficient evidence to determine the usefulness of routine genetic testing in patients with cryptogenic polyneuropathy who do not exhibit a hereditary neuropathy phenotype (Level U).

Evaluation of distal symmetric polyneuropathy: The role of laboratory and genetic testing (an evidence‐based review)

Distal symmetric polyneuropathy (DSP) is the most common variety of neuropathy. Since the evaluation of this disorder is not standardized, the available literature was reviewed to provide evidence-based guidelines regarding the role of laboratory and genetic tests for the assessment of DSP. A literature review using MEDLINE, EMBASE, Science Citation Index, and Current Contents was performed to identify the best evidence regarding the evaluation of polyneuropathy published between 1980 and March 2007. Articles were classified according to a four-tiered level of evidence scheme and recommendations were based on the level of evidence. (1) Screening laboratory tests may be considered for all patients with polyneuropathy (Level C). Those tests that provide the highest yield of abnormality are blood glucose, serum B(12) with metabolites (methylmalonic acid with or without homocysteine), and serum protein immunofixation electrophoresis (Level C). If there is no definite evidence of diabetes mellitus by routine testing of blood glucose, testing for impaired glucose tolerance may be considered in distal symmetric sensory polyneuropathy (Level C). (2) Genetic testing is established as useful for the accurate diagnosis and classification of hereditary neuropathies (Level A). Genetic testing may be considered in patients with cryptogenic polyneuropathy who exhibit a hereditary neuropathy phenotype (Level C). Initial genetic testing should be guided by the clinical phenotype, inheritance pattern, and electrodiagnostic (EDX) features and should focus on the most common abnormalities, which are CMT1A duplication/HNPP deletion, Cx32 (GJB1), and MFN2 mutation screening. There is insufficient evidence to determine the usefulness of routine genetic testing in patients with cryptogenic polyneuropathy who do not exhibit a hereditary neuropathy phenotype (Level U).

Practice Parameter: Evaluation of distal symmetric polyneuropathy: Role of laboratory and genetic testing (an evidence-based review)

Distal symmetric polyneuropathy (DSP) is the most common variety of neuropathy. Since the evaluation of this disorder is not standardized, the available literature was reviewed to provide evidence-based guidelines regarding the role of laboratory and genetic tests for the assessment of DSP. A literature review using MEDLINE, EMBASE, and Current Contents was performed to identify the best evidence regarding the evaluation of polyneuropathy published between 1980 and March 2007. Articles were classified according to a four-tiered level of evidence scheme and recommendations were based upon the level of evidence. 1) Screening laboratory tests may be considered for all patients with polyneuropathy (Level C). Those tests that provide the highest yield of abnormality are blood glucose, serum B12 with metabolites (methylmalonic acid with or without homocysteine), and serum protein immunofixation electrophoresis (Level C). If there is no definite evidence of diabetes mellitus by routine testing of blood glucose, testing for impaired glucose tolerance may be considered in distal symmetric sensory polyneuropathy (Level C). 2) Genetic testing should be conducted for the accurate diagnosis and classification of hereditary neuropathies (Level A). Genetic testing may be considered in patients with cryptogenic polyneuropathy who exhibit a hereditary neuropathy phenotype (Level C). Initial genetic testing should be guided by the clinical phenotype, inheritance pattern, and electrodiagnostic features and should focus on the most common abnormalities which are CMT1A duplication/HNPP deletion, Cx32 (GJB1), and MFN2 mutation screening. There is insufficient evidence to determine the usefulness of routine genetic testing in patients with cryptogenic polyneuropathy who do not exhibit a hereditary neuropathy phenotype (Level U).