Table 1.

The comparison of methods for IMA measuring.

Method	Average content in control	Advantages	Limitations	Ref.
Colorimetric methods
ACB	0.39-0.43 ABSU 79 ± 6.3 U/mL	Simple, low cost, automation possibility	Dependent on pH, temperature, level of HSA and free FA, the proportion of the intact HSA N-terminus, the state of cys34 oxidation in HSA, lack of standardization	[23, 29, 51, 52, 54]
CAB	0.53 ± 0.04 ABSU	Affordable and simple, small sample volume, the possibility to analyze the structural differences of HSA, independent of HSA concentration	Dependent on HSA and free FA concentrations, on the proportion of the intact N-terminus of HSA, lack of standardization	[53]
NAB	0.415 ± 0.084 ABSU	More sensitivity than ACB	Not widespread, not enough information	[48, 49]
ACuB	There is no data	More accurate than ACB, highly reliable, and highly sensitive	Poorly developed not enough information	[50]
Immunochemical methods
ELISA	45.7 ± 23.9 ng/mL 62.21 ± 21.47 ng/mL 43.4 ng/mL (1.1–320.3)	High sensitivity and specificity for NTS	Cost analysis, high antibody affinity	[55] [56] [57]
LCB	50 μg/mL	Simple, does not require measuring technology	The high cost of the biosensor and the lack of its production, low sensitivity and accuracy	[58]
SPRI	10-100 ng/L	High sensitivity and specificity	Availability of appropriate equipment, no clinical trials	[59]
Q-XRF	0.05 U/mL		Availability of appropriate equipment, no clinical trials	[60, 61]

Note: ACB: Albumin Cobalt Binding test; ACuB: Albumin Copper Binding assay; CAB: Cobalt-Albumin Binding test; ELISA: enzyme-linked immunosorbent assay; FA: fatty acids; LCB: liquid crystal biosensor; NAB: nickel-albumin binding assay; SPRI: surface plasmon resonance immunosensor; Q-XRF: X-ray fluorescence spectroscopy; ABSU: absorbance units; U/mL: units in liter (one unit was defined as of free Co²⁺ in the reaction mixture per mL of serum sample.