Table 4.

Laboratory Testing in AL Amyloidosis

Test	Ordered to Test for	Normal Range∗
SPIE†	Clonal immunoglobulin production	No M spike present
UPIE†	Clonal light chain production	No M spike present
Serum FLC assay	Detecting low-level clonal light chain production; clonality assumed if ratio is far from 1:1	Kappa:lambda ratio = 0.26-1.65‡
Cardiac troponin	Cardiomyocyte injury	Troponin I: <0.055 ng/ml Troponin T: <0.025 ng/ml
BNP or NT-proBNP	Abnormal cardiac function/heart failure (clinical or subclinical)	NT-proBNP: <300 pg/ml BNP: <100 pg/ml
Urine albumin:creatinine ratio§	Renal injury/proteinuria	<30 mg albumin/g creatinine
Alkaline phosphatase	Hepatic infiltration	35-105 U/l

Abbreviations as in Tables 1 and 3.

^∗Normal ranges may vary slightly according to local laboratory standards.

^†SPIE and UPIE are more sensitive than protein electrophoresis without immunofixation and should be ordered as the preferred tests.

^‡In patients with kidney disease, mild elevations in the kappa:lambda ratio are frequently encountered. In the setting of a normal SPIE/UPIE, a kappa:lambda ratio up to 2.5 can typically be considered normal.

^§Urine albumin:creatinine ratio is preferred over urine protein:creatinine ratio because the latter can detect light chain excretion, which is not itself a sign of renal injury; 24-h urine collection for albuminuria is a reasonable alternative test.