Clinical Comparisons of Two Free Light Chain Assays to Immunofixation Electrophoresis for Detecting Monoclonal Gammopathy

Table 2

Method comparison between the N Latex FLC assays and the Freelite assays.

Group	𝑁	N Latex FLC, mg/L	Freelite FLC, mg/L	Pearson’s correlation (𝑟)	Passing-Bablok slope (95% CI)	Normalized difference (%)
All
FLC 𝜅	157	2.3–8920.0	6.0–29200.0	0.9792	0.76 (0.71–0.80)	−4.6
FLC 𝜆	157	2.6–599.0	1.0–2590.0	0.8264	1.18 (0.99–1.35)	5.3
𝜅/𝜆 ratio	157	0.004–323.2	0.008–4687.0	0.9064	0.45 (0.37–0.51)	−10.1
Monoclonal gammopathy
FLC 𝜅	100	2.3–8920.0	6.0–29200.0	0.9793	0.67 (0.61–0.75)	−5.2
FLC 𝜆	100	2.6–599.0	1.0–2590.0	0.8388	0.78 (0.69–0.92)	0.43
𝜅/𝜆 ratio	100	0.004–323.2	0.008–4687.0	0.9065	0.43 (0.35–0.53)	−8.0
No monoclonal gammopathy
FLC 𝜅	57	7.2–222.0	9.5–269.0	0.9867	0.78 (0.73–0.82)	−4.0
FLC 𝜆	57	11.4–358.0	13.9–213.0	0.9286	1.72 (1.53–1.94)	8.15
𝜅/𝜆 ratio	57	0.261–1.243	0.646–4.347	0.5168	0.47 (0.28–0.71)	−11.2