Assessment of serum angiogenic factors as a diagnostic aid for small bowel angiodysplasia in patients with obscure gastrointestinal bleeding and anaemia

Table 1 Levels of serum angiogenic factors, ranges and P values compared to the small bowel angiodysplasia group for all 3 groups

	SBA (n = 40)	Abnormal (n = 40)	Normal (n = 40)
Ang1 (pg/mL)
Median (range)	40976 (974-97511)	44770 (2660-101930)	47639 (17899-95173)
P value vs SBA		0.33	0.04
Ang2 (pg/mL)
Median (range)	3759 (1915-14731)	2261 (842-14000)	2620 (686-8850)
P value vs SBA		< 0.004	< 0.003
Ratio of Ang1/Ang2
Median	11.4	20.2	19
P value vs SBA		< 0.006	< 0.001
TNFα (pg/mL)
Median (range)	5.76 (0.35-40)	9.76 (0.46-58)	10.14 (0.35-38)
P value vs SBA		0.12	0.13

SBA: Small bowel angiodysplasia; TNF: Tumor necrosis factor; Ang1: Angiopoietin-1.

Table 2 Analysis of sensitivity, specificity and predictive values of a cut-off serum level of Ang2 of 2600 pg/mL

True positive n = 33	False positive n = 40	Sensitivity = 85%
		Specificity = 50%
False negative n = 7	False negative n = 40	Positive predictive value = 45%
		Negative predictive value = 85%