Excretion of urinary histamine and N-tele methylhistamine in patients with gastrointestinal food allergy compared to non-allergic controls during an unrestricted diet and a hypoallergenic diet

Table 5 Sensitivity, specificity, positive and negative predictive values for the detection of urinary histamine (UH) or urinary N - methylhistamine (UMH) as non-invasive markers of gastrointestinally mediated allergy (GMA)

Urinary histamine (UH) [μg/mmol creatinine x m²BSA]	Control group	Gastrointestinally mediated allergy (GMA)
>1.67*	13	50
≤1.67*	75	62
Total	88	112

*The significance level of 1.67 μg/mmol creatinine x m² BSA was calculated from the mean + 1SD of controls during unrestricted diet. Using this criterion UH was found to reach following test characteristics:
UH sensitivity 50/112 = 44.6%; specificity 75/88 = 85.2%; positive predictive value 50/63 = 79.3%, negative predictive value 75/137 = 54.7%.

ISSN: 1471-230X