Diagnostic accuracy of monoclonal antibody based serum immunoglobulin free light chain immunoassays in myeloma cast nephropathy

Table 2 Demographics of the 5 patients missed by the Siemens FLC assay

Patient	MM type	Freelite			Siemens			Missed FLC*	Misclassified FLC as <500 mg/L**
Patient	MM type	κ	λ	Ratio	κ	λ	Ratio	Missed FLC*	Misclassified FLC as <500 mg/L**
2	Free λ	2	7010	0.0003	1	322	0.003	No	Yes
7	IgA λ	8	1810	0.0044	4	1	8.058	Yes	Yes
10	IgG λ	8	1080	0.0078	9	64	0.134	No	Yes
13	IgG λ	9	572	0.0162	9	225	0.041	No	Yes
23	IgG κ	796	6	125.7	493	17	29.6	No	Yes

*Patients were classified as missed FLC if the new assays did not identify a monoclonal FLC.
**Patients were classified as misclassified if their monoclonal FLC level was reported as less than the nephrotoxic level of 500 mg/L (5 of 28 patients).

ISSN: 1472-6890