Defect in Automated Antigen Excess Detection Discovered after Reviewing Serum Free Light Chain Results in Context with Clinical Findings.
Lab Med
; 55(1): 106-108, 2024 Jan 06.
Article
en En
| MEDLINE
| ID: mdl-37285521
Serum κ and λ free light chains can be markedly elevated in monoclonal gammopathies; consequently, serum free light chain (sFLC) immunoassays are susceptible to inaccuracies caused by antigen excess. As a result, diagnostics manufacturers have attempted to automate antigen excess detection. A 75-year-old African-American woman had laboratory findings consistent with severe anemia, acute kidney injury, and moderate hypercalcemia. Serum and urine protein electrophoresis and sFLC testing were ordered. The sFLC results initially showed mildly elevated free λ light chains and normal free κ. The pathologist noted that sFLC results were discrepant with the bone marrow biopsy, electrophoresis, and immunofixation results. After manual dilution of the serum, repeat sFLC testing revealed significantly higher λ sFLC results. Antigen excess causing falsely low sFLC quantitation may not be detected by immunoassay instruments as intended. Correlation with clinical history, serum and urine protein electrophoresis results, and other laboratory findings is essential when interpreting sFLC results.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Paraproteinemias
/
Cadenas Ligeras de Inmunoglobulina
Tipo de estudio:
Diagnostic_studies
/
Guideline
Límite:
Aged
/
Female
/
Humans
Idioma:
En
Revista:
Lab Med
Año:
2024
Tipo del documento:
Article
Pais de publicación:
Reino Unido