Specificity of the IgG antibody response to Plasmodium falciparum, Plasmodium vivax, Plasmodium malariae, and Plasmodium ovale MSP119 subunit proteins in multiplexed serologic assays

Table 3 Representative MSP1₁₉ competition assay results using sera from low incidence settings

Sample	Competitor added	Pf MSP1₁₉ (MFI-bg)	Pm MSP1₁₉ (MFI-bg)	Po MSP1₁₉ (MFI-bg)	Pv MSP1₁₉ (MFI-bg)	Pf CSP (MFI-bg)	GST (MFI-bg)
Haiti 1	PBS buffer only	25,260	15	21	9	65	1
	GST	25,473	16	21	11	65	4
	Pf MSP1₁₉	13 ^a	14	21	9	70	3
	Pm MSP1₁₉	25,058	6	17	8	63	3
	Po MSP1₁₉	25,344	12	6	7	62	2
	Pv MSP1₁₉	25,181	11	18	4	65	3
Cambodia 2	PBS buffer only	35	21	15	23,836	64	1
	GST	37	22	17	23,623	66	1
	Pf MSP1₁₉	28	24	11	21,057	70	1
	Pm MSP1₁₉	40	13	17	23,348	61	2
	Po MSP1₁₉	41	23	13	23,662	67	1
	Pv MSP1₁₉	36	22	14	9	61	2
Cambodia 3	PBS buffer only	29,763	3177	10	9	2871	0
	GST	30,461	3443	12	14	2909	1
	Pf MSP1₁₉	32	3428	11	15	2821	1
	Pm MSP1₁₉	30,233	9	14	13	2817	0
	Po MSP1₁₉	30,352	3480	10	12	3041	1
	Pv MSP1₁₉	30,129	3043	12	4	2879	2
Cambodia 4	PBS buffer only	15	6	13	20,899	17	0
	GST	15	7	13	20,930	13	1
	Pf MSP1₁₉	9	6	14	15,929	14	0
	Pm MSP1₁₉	12	2	12	20,382	16	0
	Po MSP1₁₉	11	5	2	20,177	15	0
	Pv MSP1₁₉	13	6	12	1	13	0
Cambodia 9	PBS buffer only	1882	21	17	12,439	22	3
	GST	2023	23	21	13,095	21	4
	Pf MSP1₁₉	31	22	23	9347	21	4
	Pm MSP1₁₉	1877	13	23	12,075	20	4
	Po MSP1₁₉	1854	24	17	12,679	21	2
	Pv MSP1₁₉	1725	22	21	4	22	3
Cambodia 5	PBS buffer only	28,405	743	39	24,051	1072	800
	GST	28,084	799	44	24,307	1143	911
	Pf MSP1₁₉	50	*439* ^b	34	23,510	1160	881
	Pm MSP1₁₉	26,098	31	34	23,646	1136	839
	Po MSP1₁₉	27,871	737	32	23,808	1103	861
	Pv MSP1₁₉	27,620	617	33	19	1090	828

^aMultiplex bead assay responses that were completely suppressed by homologous protein competition are indicated in italics cells. These responses were below the respective cut-off values
^bMultiplex bead assay responses that, as a result of heterologous competition, decreased more than 30% compared to the PBS control but remained above the respective cut-off values are indicated in bold italics cells. These values indicate some level of cross-reactivity

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