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

Early M-protein immune reconstitution after autologous haematopoietic stem cell transplantation is a good prognostic marker for patients with high-risk cytogenetic multiple myeloma

The presence of transient abnormal protein banding (M-protein immune reconstitution) in serum immunofixation electrophoresis after autologous haematopoietic stem cell transplantation in patients with multiple myeloma has been reported. The purpose of this study was to investigate the impact of post-transplant M-protein immune reconstitution on the prognosis of patients with multiple myeloma. M-protein immune reconstitution was observed in 25.9% (75/290) of patients. The CR rate and MRD negativity were higher in the M-protein immune reconstitution group (85.3% vs. 69.3%, p = 0.013, 81.9% vs. 66.5%, p = 0.014). Although there were no significant differences between the groups, the overall median survival time was longer in the M-protein immune reconstruction group (80 vs. 72 m, p = 0.076; not reached vs. 105 m, p = 0.312). Among patients in the cytogenetic high-risk group, the occurrence of M-protein immune reconstitution predicted better PFS and OS (80 vs. 31 m, p = 0.010; not reached vs. 91 m, p = 0.026). Additionally, in revised-International Staging System stage III patients, PFS and OS were better in those who achieved M-protein immune reconstitution (80 vs. 20 m, p = 0.025; 57 vs. 32 m, p = 0.103). The better prognosis of M-protein immune reconstitution patients may be associated with the acquisition of a deeper response. In high-risk patients, early acquisition of M-protein immune reconstitution may suggest a better prognosis.

Isoelectric focusing followed by affinity immunoblotting to detect monoclonal free light chains in monoclonal gammopathies: Comparison with immunofixation electrophoresis and free light chain ratio

BACKGROUND

Isoelectric focusing (IEF) is a method with an exquisite resolution, and coupled with affinity immunoblotting (AIB), it can provide superior sensitivity to detect monoclonal free light chains (FLC).

METHODS

We tested the hypothesis that IEF/AIB is more sensitive and specific for monoclonal FLC detection in serum and urine samples than conventional methods, that is, electrophoresis (ELP), immunofixation (IF) and serum FLC ratio assessment. Investigation included 107 samples of 68 patients, among which 21 multiple myeloma patients were recently tested for minimal residual disease and 18 patients with AL amyloidosis.

RESULTS

Monoclonal FLC were detected by IEF/AIB in 37% of serum samples negative for monoclonal FLC on ELP/IF. As for urine samples, significant advantage of the IEF/AIB over ELP/IF was not demonstrated. Considering both serum and urine results, IEF/AIB definitely revealed monoclonal FLC in 20/83 (24%) of ELP/IF-negative samples. FLC ratio was abnormally high (>1.65) in all 11 patients definitely positive for monoclonal FLC kappa by IEF/AIB but also in 16/47 (34%) IEF/AIB-negative samples. Abnormally low values (<0.26) were found only in 10/28 samples (36%) positive for monoclonal FLC lambda. Appropriate use of renal FLC ratio reference range reduced the number of presumably false positives (6/47, i.e. 13%) but not false negatives (17/28, i.e. 61%).

CONCLUSIONS

The IEF/AIB method is more sensitive than IF and might be used in patients with negative IF results before deciding whether to proceed to minimal residual disease testing.

Engaging Pathology Residents in Clinical Chemistry: The Essential Ingredient Is a Committed Teacher

BACKGROUND

Pathology residents are thought to show a lack of interest in clinical chemistry, therefore potentially graduating from training programs unprepared to function as laboratory directors and clinical consultants.

METHODS

A structured program of tutorials based primarily on Henry's textbook, supplemented by recent review articles; a question bank of about 600 questions to emphasize key concepts; requirement for performing and presenting quality improvement projects; participation in on-site CAP inspections; review of reference laboratory test requests; and involving residents in scholarly activity have resulted in sustained, transferable, and significant improvements in engagement, knowledge, competence, and examination scores.

RESULTS

The primary parameter for measuring change in resident competence and engagement were improvements in resident in-service examination (RISE) scores, publications in peer-reviewed journals, and receipt of awards. The revised program produced significant improvement in RISE scores in clinical chemistry, over and above the improvements in the general residency program. The residents were authors on 12 publications in peer-reviewed PubMed listed journals in the 5-year period since revision in the clinical chemistry curriculum compared to no publications in clinical chemistry in the 5-year period before the new curriculum. Over the past 2 years, 6 of the 11 publications by graduating residents were in clinical chemistry, and 6 of 7 awards for research were garnered by residents engaged in clinical chemistry investigations. All of the residents passed their clinical pathology boards on first attempt since the change compared to 2 failures in the prior 5-year period.

CONCLUSIONS

The structured program described here is important as a template that could be adopted by any pathology training program. The question bank developed by this program is a valuable and transferable aid. However, success of such a program is dependent on the commitment of a knowledgeable, dedicated, and passionate teacher.

Serum and Urine Protein Electrophoresis and Serum-Free Light Chain Assays in the Diagnosis and Monitoring of Monoclonal Gammopathies

BACKGROUND

Laboratory methods for diagnosis and monitoring of monoclonal gammopathies have evolved to include serum and urine protein electrophoresis, immunofixation electrophoresis, capillary zone electrophoresis, and immunosubtraction, serum-free light chain assay, mass spectrometry, and newly described QUIET.

CONTENT

This review presents a critical appraisal of the test methods and reporting practices for the findings generated by the tests for monoclonal gammopathies. Recommendations for desirable practices to optimize test selection and provide value-added reports are presented. The shortcomings of the serum-free light chain assay are highlighted, and new assays for measuring monoclonal serum free light chains are addressed.

SUMMARY

The various assays for screening, diagnosis, and monitoring of monoclonal gammopathies should be used in an algorithmic approach to avoid unnecessary testing. Reporting of the test results should be tailored to the clinical context of each individual patient to add value. Caution is urged in the interpretation of results of serum-free light chain assay, kappa/lambda ratio, and myeloma defining conditions. The distortions in serum-free light chain assay and development of oligoclonal bands in patients' status post hematopoietic stem cell transplants is emphasized and the need to note the location of original monoclonal Ig is stressed. The need for developing criteria that consider the differences in the biology of kappa and lambda light chain associated lesions is stressed. A new method of measuring monoclonal serum-free light chains is introduced. Reference is also made to a newly defined entity of light chain predominant intact immunoglobulin monoclonal gammopathy. The utility of urine testing in the diagnosis and monitoring of light chain only lesions is emphasized.