Table 2A.

Analytical evaluation of discrepant results (n = 49).

Case	TMA Procleix		RT-PCR Allplex™				Type of disagreement	RT-PCR Alinity m		Analytical result
		Ratioa		Ct				Result	Ctc
	Result	N	Result	E	RdRP	N			RdRP & N
1	P	4.18	N	NA	NA	NA	Major	N	NA	N
2	N	NA	P	NA	NA	37.59	Major	NDd	–	ND
3	P	3.92	N	NA	NA	NA	Major	P	40.99	P
4	P	3.81	N	NA	NA	NA	Major	P	39.53	P
5	P	3.81	Ib	37.96	NA	NA	Minor	P	40.94	P
6	P	4.00	N	NA	NA	NA	Major	N	NA	N
7	P	4.24	N	NA	NA	NA	Major	N	NA	N
8	P	4.24	Ib	38.02	NA	NA	Minor	P	40.03	P
9	P	4.18	N	NA	NA	NA	Major	NDd	–	ND
10	P	4.20	Ib	36.91	NA	NA	Minor	NDd	–	ND
11	P	3.73	N	NA	NA	NA	Major	N	NA	N
12	P	4.15	N	NA	NA	NA	Major	P	40.90	P
13	P	4.36	N	NA	NA	NA	Major	P	39.60	P
14	P	4.21	N	NA	NA	NA	Major	P	37.21	P
15	P	4.16	N	NA	NA	NA	Major	P	40.90	P
16	P	4.05	Ib	37.88	NA	NA	Minor	NDd	–	ND
17	N	NA	P	NA	NA	37.63	Major	NDd	–	ND
18	P	4.21	N	NA	NA	NA	Major	N	NA	N
19	P	4.23	Ib	38.06	NA	NA	Minor	P	40.99	P
20	P	4.50	N	NA	NA	NA	Major	P	40.99	P
21	P	4.46	N	NA	NA	NA	Major	N	NA	N
22	P	3.95	N	NA	NA	NA	Major	N	NA	N
23	P	3.97	N	NA	NA	NA	Major	N	NA	N
24	P	4.00	N	NA	NA	NA	Major	N	NA	N
25	P	4.12	I	38.23	NA	NA	Minor	P	40.99	P

Case	TMA Procleix SARS-CoV-2		RT-PCR Allplex™ SARS-CoV-2				Type of disagreement	RT-PCR cobas® SARS-CoV-2			Analytical result
	Result	Ratioa	Result	Ct				Result	Ct
		N		E	RdRP	N			ORF-1ab	E
26	P	4.17	N	NA	NA	NA	Major	N	NA	NA	N
27	P	3.78	N	NA	NA	NA	Major	Ib	NA	35.63	Ib
28	P	3.84	N	NA	NA	NA	Major	Ib	NA	37.73	Ib
29	P	4.16	N	NA	NA	NA	Major	N	NA	NA	N
30	P	3.93	N	NA	NA	NA	Major	P	32.4	34.98	P
31	P	3.90	N	NA	NA	NA	Major	N	NA	NA	N
32	P	4.22	N	NA	NA	NA	Major	Ib	NA	38.47	Ib
33	P	4.02	N	NA	NA	NA	Major	N	NA	NA	N
34	P	3.95	N	NA	NA	NA	Major	N	NA	NA	N
35	P	4.28	N	NA	NA	NA	Major	P	36.19	37.22	P
36	P	3.92	Ib	36.58	NA	NA	Minor	P	33.15	35.01	P
37	P	4.05	N	NA	NA	NA	Major	N	NA	NA	N
38	P	4.59	Ib	38.15	NA	NA	Minor	P	33.35	34.51	P
39	P	4.03	N	NA	NA	NA	Major	N	NA	NA	N
40	P	4.25	N	NA	NA	NA	Major	Ib	NA	38.01	Ib
41	P	4.22	N	NA	NA	NA	Major	P	35.58	35.87	P
42	P	3.99	N	NA	NA	NA	Major	N	NA	NA	N
43	P	3.84	N	NA	NA	NA	Major	N	NA	NA	N
44	P	4.04	Ib	38.18	NA	NA	Minor	N	NA	NA	Ib
45	P	4.46	Ib	38.26	NA	NA	Minor	N	NA	NA	Ib
46	P	4.04	N	NA	NA	NA	Major	Ib	NA	37.94	Ib
47	P	4.35	N	NA	NA	NA	Major	P	30.80	31.60	P
48	P	4.15	Ib	38.14	NA	NA	Minor	N	NA	NA	Ib
49	P	4.33	N	NA	NA	NA	Major	N	NA	NA	N

^aThe ratio provided by the instrument corresponds to an analytical parameter based on chemiluminescense with a qualitative interpretation. Values ≥1.00 are considered reactive/positive, according to the manufacturer's criteria.

^bInconclusive cases are considered: (i) those testing positive for the E target, but negative for both the N and the RdRP/S targets with the RT-PCR Allplex™ SARS-CoV-2 assay, according to the manufacturer's criteria, (ii) those testing positive for the E target, but negative for the ORF-1ab target with the RT-PCR cobas® SARS-CoV-2 assay, according to the manufacturer's criteria, and (iii) those unresolved after the discrepant analytical testing.

^cThe two SARS-CoV-2-specific probes are labelled with the same fluorophore, so the test provides a unique Ct value for both RdRP and N targets.

^dSpecimens unavailable for discrepant analytical testing.

A minor disagreement is considered that discrepancy testing positive with one assay but inconclusive with the other study technique. Contrary, a major disagreement is considered that reverting from positive to negative depending on the study assay.

Abbreviations: TMA: transcription-mediated amplification; RT-PCR: real-time reverse-transcriptase PCR; Ct: cycle-threshold; P: positive; N: negative; I: inconclusive; NA: not amplified; ND: not determined.