신기능저하 환자에서 혈청 유리형경쇄 kappa/lambda 비의 증가
Increment of Serum Free Light Chain Kappa/Lambda Ratio in Patients with Renal Dysfunction
5
조회
0
다운로드
0
인용
0
참고문헌
키워드
초록
배경: 혈청 유리형경쇄 (free light chain, FLC) 는 신장에서 대사되므로, 신기능이 저하된 환자에서는 단클론단백이 존재하지 않는 상태에서도 혈청 FLC 농도가 상승하고 kappa/lambda비도 증가하는 것으로 알려져 있다. 본 연구에서는 신기능저하 환자에 대해 혈중 FLC 및 kappa/lambda 비를 측정하고, 신기능저하의 정도에 따른kappa/lambda 비의 연관성에 대해 분석하고자 하였다. 방법: 한국인 만성신질환 환자 92 명의 보관된 혈청 검체를 대상으로 Freelite 검사 (The Binding Site Group Ltd., UK) 를 사용하여 kappa FLC, lambda FLC 를 정량하였고, kappa/lambda 비를 구하였다. 혈청 크레아티닌 측정값을 이용하여 사구체여과율 추정값(estimated glomerular fltration rate, eGFR) 을 계산하였고, 미국 National Kidney Foundation 의 Kidney Disease Improving Global Outcomes (KDIGO) 지침의 분류에 따라 신기능 경도 감소군, 중등도 감소군, 중증 감소군, 신부전군으로 분류하였고, 그룹 간 kappa FLC, lambda FLC 및kappa/lambda 비의 차이가 있는지 분석하였다. 결과: 신기능감소의 정도가 심할수록 혈중 FLC 및 kappa/lambda비가 높았으며, eGFR 60 mL/min/1.73 m 2 를 기준으로 환자를 분류하였을 때 (그룹 A: eGFR ≥ 60 mL/min/1.73 m2, 그룹 B: < 60 mL/min/1.73 m2) 그룹 B 의 kappa/lambda 비가 그룹 A 에 비해 유의하게 높았다(그룹 B: 1.60 ± 0.46 vs 그룹 A: 1.35 ± 0.27, P = 0.018). 신기능저하 환자에서의 혈청 FLC kappa/lambda 비 참고범위 검증결과 모든 환자에서 기존 참고범위 (0.37–3.1) 내의 값을 보였다. 결론: 혈청 FLC kappa/lambda 비 결과를 해석할 때에는 혈액학적 소견 외에도 환자의 신기능을 반드시 참조하여야 하며, 신기능이 저하되어 있는 경우에는 기존의 참고범위에 비해 넓게 설정된 kappa/lambda 비 참고범위를 적용하는 것이 바람직할 것으로 생각된다.
Abstract
Background: Since free light chain (FLC) is metabolized in the kidney, serum FLC concentration and kappa/lambda ratio are increased in patients with decreased renal function, even in the absence of monoclonal protein. In this study, we measured serum FLC levels to investigate the change in kappa/lambda ratios in relation to the severity of renal dysfunction. Methods: Serum FLC concentrations were measured in 92 archived serum samples from patients diagnosed with chronic kidney disease using the Freelite assay (The Binding Site Group Ltd., UK), and kappa/lambda ratios were calculated. Serum creatinine levels were assayed to calculate estimated glomerular filtration rate (eGFR), and patients were divided into subgroups according to Kidney Disease Improving Global Outcomes (KDIGO) guidelines. We analyzed the difference in serum FLC levels and kappa/lambda ratios between subgroups. Results: Serum FLC levels and kappa/lambda ratios increased depending on the severity of renal dysfunction. When patients were classified by setting cut-off value of eGFR as 60 mL/min/1.73 m2 (group A: eGFR ≥60 mL/min/1.73 m2, group B: <60 mL/min/1.73 m2), the kappa/lambda ratio of group B was significantly higher than that of group A (group B: 1.60±0.46 vs. group A: 1.35±0.27, P=0.018). Serum FLC kappa/lambda ratios were within the previously determined renal reference interval (0.37–3.1). Conclusions: When interpreting results of serum FLC kappa/lambda ratio, renal function status should be considered in addition to hematological findings. If renal function deteriorates, a wider renal reference interval is preferred instead of the usual reference interval.
참고문헌 (18)
- Bradwell AR, "Serum test for assessment of patients with Bence Jones myeloma", Lancet, 361, pp.489~491 (2003)
- Bradwell AR, "Serum free light chain measurements move to center stage", Clin Chem, 51, pp.805~807 (2005)
- Heher EC, "Kidney disease and multiple myeloma", Clin J Am Soc Nephrol, 8, pp.2007~2017 (2013)
- Finkel KW, "Paraprotein–related kidney disease : evaluation and treatment of myeloma cast nephropathy", Clin J Am Soc Nephrol, 11, pp.2273~2279 (2016)
- Katzmann JA, "Screening panels for detection of monoclonal gammopathies", Clin Chem, 55, pp.1517~1522 (2009)
- Rajkumar SV, "International Myeloma Working Group updated criteria for the diagnosis of multiple myeloma", Lancet Oncol, 15, pp.e538~48 (2014)
- Kumar S, "International Myeloma Working Group consensus criteria for response and minimal residual disease assessment in multiple myeloma", Lancet Oncol, 17, pp.e328~46 (2016)
- Nowrousian MR, "Serum free light chain analysis and urine immunofixation electrophoresis in patients with multiple myeloma", Clin Cancer Res, 11, pp.8706~8714 (2005)
- Hutchison CA, "Quantitative assessment of serum and urinary polyclonal free light chains in patients with chronic kidney disease", Clin J Am Soc Nephrol, 3, pp.1684~1690 (2008)
- Katzmann JA, "Serum reference intervals and diagnostic ranges for free kappa and free lambda immunoglobulin light chains : relative sensitivity for detection of monoclonal light chains", Clin Chem, 48, pp.1437~1444 (2002)
- Hutchison CA, "Serum free light chain measurement aids the diagnosis of myeloma in patients with severe renal failure", BMC Nephrol, 9, pp.11~ (2008)
- Abadie JM, "Are renal reference intervals required when screening for plasma cell disorders with serum free light chains and serum protein electrophoresis?", Am J Clin Pathol, 131, pp.166~171 (2009)
- Diamantidis MD, "Novel extended reference range for serum kappa", lambda free light chain ratio in diagnosing monoclonal gammopathies in renal insufficient patients, 2009, pp.42, 1202~1203
- Park JW, "Combined analysis using extended renal reference range of serum free light chain ratio and serum protein electrophoresis improves the diagnostic accuracy of multiple myeloma in renal insufficiency", Clin Biochem, 45, pp.740~744 (2012)
- Levey AS, "A new equation to estimate glomerular filtration rate", Ann Intern Med, 150, pp.604~612 (2009)
- Kidney Disease : Improving Global Outcomes(KDIGO)CKD Work Group, "KDIGO 2012 clinical practice guideline for the evaluation and management of chronic kidney disease", Kidney Int Suppl, 3, pp.1~150 (2013)
- Leung N, "Laboratory testing in monoclonal gammopathy of renal significance(MGRS)", Clin Chem Lab Med, 54, pp.929~937 (2016)
- Hutchison CA, "Polyclonal immunoglobulin free light chains as a potential biomarker of immune stimulation and inflammation", Clin Chem, 57, pp.1387~1389 (2011)