Table 4. Quantitative Comparison between ImmunoCAP® and PROTIA™ Specific IgG4®.

Allergens	Number of cases	Correlation coefficient value	Degree of correlation	p value
Dermatophagoides pteronyssinus	69	0.9651	Very strong	<0.001
Dermatophagoides farinae	89	0.9582	Very strong	<0.001
Cat dander	16	0.8400	Strong	<0.001
Dog dander	20	0.8014	Strong	<0.001
Birch pollen	5	1.0000	Very strong	0.017
Ragweed pollen	6	0.9856	Very strong	0.006
Egg white	12	0.9441	Very strong	<0.001
Casein	21	0.9494	Very strong	<0.001
Wheat	15	0.8097	Strong	<0.001
Peanut	7	0.9643	Very strong	0.003
Walnut	12	0.9037	Very strong	<0.001
Apple	6	0.6571	Moderate	0.175
Peach	10	0.8811	Strong	0.001

Positive results in both tests were compared through correlation analysis. A sIgG4 value ≥0.50 mg/L was considered a positive result. Correlation coefficient values were categorized as very strong (0.90–1.00), strong (0.70–0.89), moderate (0.40–0.69), weak (0.10–0.39), or negligible correlations (0.00–0.09).