Table 3

Comparison of MFI ratios between mixed serum and diluted serum in inhibition FCXM, Wilcoxon signed-rank test.

Donor	N	T cell MFI ratio, mean±SD, median(range)				B cell MFI ratio, mean±SD, median(range)

		Inhibition FCXM			Conventional FCXM(neat recipient serum)	Inhibition FCXM			Conventional FCXM(neat recipient serum)

		Recipient serum diluted with		Mixed serum(recipient+donor)		Recipient serum diluted with		Mixed serum(recipient+donor)

		RPMI	Third-party serum			RPMI	Third-party serum
Previous sensitizer
Negative DSA	69	0.97±0.09	1.01±0.11	1.03±0.15	1.05±0.20	0.96±0.13	1.09±0.18	1.10±0.21	1.14±0.30
		0.98▼^a)(0.66–1.25)	1.00(0.79–1.50)	1.03(0.67–1.44)	1.00(0.11–1.63)	0.95▼(0.73–1.37)	1.04(0.79–1.95)	1.06(0.81–1.93)	1.05(0.75–2.20)
		P<0.00005	P=0.0894			P<0.0000001	P=0.5757
DSA class I alone	14	15.13±33.76	6.93^b)±10.01	6.74±10.50	13.38±20.58	17.84±26.92	11.74±14.01	10.87±14.26	22.38±25.20
		3.04▲(1.33–125.39)	2.88(1.23–30.81)	2.25(1.31–32.51)	5.28(1.95–77.68)	5.48▼(1.16–85.62)	6.00(1.23–49.33)	5.76(1.16–52.46)	13.54(1.61–94.26)
		P<0.01	P=0.1671			P<0.05	P=0.0962
DSA class II alone	27	1.07±0.18	1.07±0.17	1.14±0.25	1.24±0.27	18.99±33.19	18.94±32.01	16.56±24.90	26.10±36.15
		1.07(0.59–1.39)	1.04▼(0.79–1.42)	1.06(0.54–1.67)	1.16(0.71–1.83)	4.50(1.34–145.98)	5.08(1.44–138.47)	5.03(1.41–103.53)	8.14(2.06–144.92)
		P=0.0652	P<0.05			P=0.5561	P=0.2276
Both DSA classes(class I and II)	33	4.32±5.78	4.13±5.61	3.60±4.53	6.38±9.06	21.40±29.51	20.57±28.98	18.88±26.14	32.39±40.12
		1.97▲(0.99–24.77)	1.96▲(1.00–23.41)	1.55(1.01–18.10)	3.09(1.65–45.78)	7.49▲(2.15–114.56)	7.16▲(1.60–114.28)	6.19(1.46–91.02)	16.19(3.74–173.15)
		P<0.00001	P<0.0005			P<0.0005	P<0.005
Any DSA(class I or II)	74	5.18±15.60	3.54±6.02	3.30±5.72	5.83±11.42	19.85±30.09	18.30±27.91	16.52±23.78	28.20±36.06
		1.40▼(0.59–125.39)	1.40▲(0.79–30.81)	1.46(0.54–32.51)	1.99(0.71–77.68)	6.17▲(1.16–145.98)	6.80▲(1.23–138.47)	5.60(1.16–103.53)	12.09(1.61–173.15)
		P<0.0001	P<0.05			P<0.0005	P<0.0005
Total	143	3.15±11.38	2.32±4.50	2.20±4.26	3.52±8.53	10.73±23.56	10.00±21.79	9.08±18.72	15.24±29.55
		1.04(0.59–125.39)	1.06(0.79–30.81)	1.11(0.54–32.51)	1.18(0.11–77.68)	1.40(0.73–145.98)	1.56▼(0.79–138.47)	1.60(0.81–103.53)	2.11(0.10–173.15)
		P=0.4435	P=0.2897			P=0.5126	P<0.001
Non-sensitizer	6	1.00±0.13	1.05±0.08	1.03±0.13	1.14±0.25	1.62±0.78	1.79±0.75	1.71±0.78	1.14±0.19
		0.99(0.84–1.18)	1.03(0.97–1.18)	1.00(0.90–1.18)	1.01(0.95–1.59)	1.68(0.64–2.91)	1.72(1.04–3.17)	1.65(0.92–3.12)	1.13(0.83–1.42)
		P=0.1441	P=0.2785			P=0.2476	P=0.1411

^a)The symbols ▼and ▲indicate a significantly decreased or increased median value, respectively, when the MFI ratios of diluted sera were compared to those of mixed sera. ^b)Bold fonts indicate the most efficient comparisons between the diluted serum and the mixed serum to reveal neutralization effects with minimal matrix effects.

Abbreviations: DSA, donor-specific HLA alloantibody; MFI, mean fluorescence intensity; RPMI, Roswell Park Memorial Institute medium; SD, standard deviation.

Blood Res 2020;55:91~98 https://doi.org/10.5045/br.2020.2020031