Rapid simultaneous measurement of multiple cytokines in childhood oncology patients with febrile neutropenia: increased interleukin (IL)-8 or IL-5 correlates with culture-positive

analysis with all testsbeing two-sided andsignificance taken forvalues P <0AE05.The JAK2 mutation was identified in 48% of our ETpopulation, which is a similar frequency to those reported byothers. There was no difference in age at diagnosis, gender ordisease duration between those with and those without themutation. The proportion of patients receiving some form ofcytoreductive therapy was also similar in both the groups.However, we found a significantly higher haemoglobinconcentration at diagnosis in ET patients with the muta-tion (median 14AE2±1AE5 g/dl vs. 13 ± 1AE7 g/dl, P ¼ 0AE0426)although no differences were seen in the packed cell volume,white cell or platelet counts. Thrombotic complications weremore common in patients with the JAK2 mutation; 18 (62%)vs. 8 (26%), P ¼ 0AE009. Although arterial events were morecommon, overall there was no statistical difference betweenthe two groups, as defined by JAK2 mutational status, foreither the type or timing of the thrombotic event.Our data therefore suggests that the presence of the JAK2mutation in ET defines a subgroup of patients with both apolycythaemic and thrombotic tendency, confirming theresults of recent studies. The ease of screening for the V617Fmutation makes it a very attractive tool for diagnosticpurposes but its role in risk stratification for therapy remainsto be further evaluated.Betty CheungDeepti RadiaPanagiotis PantelidisGhasem YadegarfarClaire Harrison