Immunogenetic and molecular biomarkers in COVID-19 and hepatitis C virus infection: Evaluating the diagnostic potential of HLA (rs1131500), IGF-2, and I-FABP

Table 1 Baseline characteristics of the study cohorts (n = 57 per group), n (%)/mean ± SD

Characteristic	Control (n = 57)	HCV (n = 57)	COVID-19 (n = 57)	HCV-COVID-19 (n = 57)	P
Age (years)	46.2 ± 10.5	45.6 ± 11.2	47.8 ± 9.8	48.2 ± 10.1	> 0.05
Male	28 (49.1)	29 (50.9)	27 (47.4)	30 (52.6)	> 0.05
Female	29 (50.9)	28 (49.1)	30 (52.6)	27 (47.4)	> 0.05
Major comorbidities	6 (10.5)	7 (12.3)	8 (14.0)	9 (15.8)	> 0.05

HCV: Hepatitis C virus; COVID-19: Coronavirus disease 2019.

Table 2 Comparison among the groups studied regarding insulin-like growth factor 2, intestinal fatty-acid-binding protein, and interferon-gamma

Markers	HCV-COVID-19 group		COVID group		HCV group		Control group
	mean ± SD	P	mean ± SD	P	mean ± SD	P	mean ± SD
IGF-2 (ng/L)	121 ± 12.7	< 0.0001	98.46 ± 10.25	< 0.0001	77.91 ± 12.04	< 0.0001	32.67 ± 10.62
I-FABP (ng/L)	132.42 ± 31	< 0.0001	45.21 ± 8.46	< 0.0001	33.16 ± 9	< 0.0001	31.46 ± 9.04
IFN-γ (ng/L)	166.18 ± 41.86	< 0.0001	116.81 ± 18.61	< 0.0001	101 ± 14.41	0.315	95.23 ± 12.92

IFN: Interferon; IGF: Insulin-like growth factor; I-FABP: Intestinal fatty-acid-binding protein; HCV: Hepatitis C virus; COVID-19: Coronavirus disease 2019.

Table 3 Logistic regression analysis of sex, age, and cytokine levels (insulin-like growth factor 2, intestinal fatty-acid-binding protein, interferon-gamma) as predictors for distinguishing hepatitis C virus-coronavirus disease 2019 co-infection

Variables	B	SE	P	OR	95%CI for OR
					Lower	Upper
Sex	0.292	0.383	0.446	1.339	0.632	2.837
Age (years)	0.004	0.018	0.833	1.004	0.97	1.039
IGF-2	0.367	0.472	0.041	3.924	1.56	4.736
I-FABP	0.847	87.117	0.992	2.332	0.154	3.328
IFN-γ	0.101	0.024	< 0.001	1.107	1.056	1.16

IFN: Interferon; IGF: Insulin-like growth factor; I-FABP: Intestinal fatty-acid-binding protein; OR: Odds ratio.

Table 4 Logistic regression analysis of sex, age, and cytokine levels (insulin-like growth factor 2, intestinal fatty-acid-binding protein, interferon-gamma) as predictors for distinguishing coronavirus disease 2019

Variables	B	SE	P	OR	95%CI for OR
					Lower	Upper
Sex	0.221	0.384	0.566	1.247	0.588	2.646
Age	-0.027	0.018	0.138	0.973	0.939	1.009
IGF-2	0.41	0.586	0.037	4.489	1.48	5.772
I-FABP	0.193	0.037	< 0.001	1.213	1.129	1.303
IFN-γ	0.102	0.021	< 0.001	1.107	1.062	1.154

IFN: Interferon; IGF: Insulin-like growth factor; I-FABP: Intestinal fatty-acid-binding protein; OR: Odds ratio.

Table 5 Logistic regression analysis of sex, age, and cytokine levels (insulin-like growth factor 2, intestinal fatty-acid-binding protein, interferon-gamma) as predictors for distinguishing hepatitis C virus infection

Variables	B	SE	Sig.	OR	95%CI for OR
					Lower	Upper
Sex	0.148	0.385	0.7	1.160	0.545	2.467
Age	-0.012	0.017	0.484	0.988	0.956	1.022
IGF-2	0.354	0.125	0.005	1.425	1.114	1.822
I-FABP	0.021	0.021	0.313	1.022	0.98	1.065
IFN-γ	0.031	0.014	0.03	1.032	1.003	1.061

IFN: Interferon; IGF: Insulin-like growth factor; I-FABP: Intestinal fatty-acid-binding protein; OR: Odds ratio.

Table 6 Post hoc power analysis for logistic regression of cytokine biomarkers (insulin-like growth factor 2, intestinal fatty-acid-binding protein, interferon-gamma) across hepatitis C virus, coronavirus disease 2019, and hepatitis C virus-coronavirus disease 2019 co-infection groups

Groups	Variables	SE	Z	Achieved power	Approx. N per group for 80% power
HCV-COVID-19	IGF-2	0.283	4.826	0.998	20
	I-FABP	0.024	4.242	0.989	25
	IFN-γ	0.936	0.919	0.16	456
COVID-19	IGF-2	0.347	4.325	0.991	24
	I-FABP	0.037	5.281	0.999	17
	IFN-γ	0.021	4.796	0.998	20
HCV	IGF-2	0.126	2.822	0.806	57
	I-FABP	0.014	2.196	0.593	93
	IFN-γ	0.021	1.026	0.175	426

IFN: Interferon; IGF: Insulin-like growth factor; I-FABP: Intestinal fatty-acid-binding protein; HCV: Hepatitis C virus; COVID-19: Coronavirus disease 2019.