Development of Immunocapture-LC/MS Assay for Simultaneous ADA Isotyping and Semiquantitation

Table 2

LC/MS peak area ratio response and cut-points of ADA isotopes/subclasses in PEA negative human plasma with drug as ADA capture reagent.

Plasma lot #	IgG1	IgG2	IgG3	IG4	IgE	IgM	IgA1 + IgA2
1	0.0277	0.0099	—	0.0107	—	0.1130	0.0041
2	0.0107	0.0008	—	0.0019	—	—	0.0059
3	0.0263	—	—	0.0012	0.0150	0.0084	0.0078
4	0.0093	0.0023	—	0.0053	—	0.0072	0.0057
5	0.0249	0.0244	0.0210	0.0099	0.0110	0.0474	0.0136
6	0.0060	0.0044	0.0110	0.0035	—	0.0326	—
7	0.0129	—	—	0.0037	0.0160	0.0159	0.0062
8	0.0637	0.0205	0.0570	0.0353	0.0140	0.0066	0.0174
9	0.0127	0.0008	—	0.0111	—	0.0035	0.0075
Mean	0.0216	0.0070	0.0099	0.0092	0.0061	0.0261	0.0086
SD	0.0177	0.0093	0.0192	0.0105	0.0074	0.0361	0.0043
Cut-point (95%)	0.0507	0.0224	0.0416	0.0265	0.0183	0.0854	0.0156

—: no LC/MS response was detected.