Basophil activation test in the diagnosis of gadobutrol anaphylaxis

2 ) was recorded in 11 children (42%) with positive OFC results and in 28 children (51%) with negative OFC results (P .05). In reactive children, low SBPs for age were measured in 3 children when anaphylactic symptoms occurred and in 8 children only in the absence of symptoms. A SBP below the mean minus 3 SDs (57.44 mm Hg) was reached in 2 children during reaction and in 1 tolerant child. In summary, decreased SBP was not associated with the outcomes of OFCs. Furthermore, we have not found anaphylactic reactions characterized only by low SBP. 2 On the contrary, the criterion of isolated SBP decrease was satisfied during anaphylaxis to antibiotics or contrast media in adults. 6 This finding may suggest that a SBP decrease is probably not caused by an inflammatory reaction. Our findings showed that symptoms characteristic of anaphylaxis 2 induced by OFCs were associated with low SBP. Therefore, monitoring blood pressure is helpful when systemic reactions occur. 7 The SBP decrease in tolerant children may suggest inaccurate measuring. However, we found small SBP variability, indicating good method precision. A limitation of this study is the low number of children developing anaphylaxis, which may depend on stopping OFC at the onset of symptoms to avoid anaphylaxis. Another weakness is that our results may be due to selection bias. However, no patient refused blood pressure measurement; therefore, we think that our findings are generalizable to a tertiary care setting. Despite these limitations, our study suggests that decreased SBP 2 appears unhelpful in diagnosing anaphylaxis during OFCs in asymptomatic children. Larger studies and comparable data for other agents (ie, drugs) are needed to extend our findings.