Introduction Food allergy affects 6% of children and causes 85% of childhood anaphylaxis. It is a public health concern as anaphylaxis hospitalisation rates multiplied sevenfold between 1990 and 2000 in England. New-onset food allergy after liver, cardiac and intestinal transplantation has been reported but it is unknown if it is increased in paediatric renal transplant recipients (RTR).
Methods We investigated whether new-onset allergy development occurred in RTR, using three questionnaires regarding general health, food allergy and atopy, by patient and/or parent interview. We obtained blood samples from children under 18 years who had undergone renal transplantation, from our single centre and analysed for eosinophilia, total-IgE, and cow's milk, egg and peanut-specific IgE. Questionnaire and IgE results were presented to a blinded allergist to determine allergic status.
Results Seventy (60% male) children aged 30-207 (median 161) months and 0-161 (median 37) months post-renal transplantation were included. The primary renal disease was non-immunologically based (62% congenital abnormalities of the kidneys and urinary tract). Our cohort were compared to healthy controls in the normal population. Eleven (16%) RTR were sensitised to at least one food (cow's milk , egg , peanut ), eight (11%) were clinically ‘allergic’ (table 1, figure 1).
Total-IgE results ranged 1.0 to 2872.0 (median 16.5 kUIgE/L). Eosinophil counts ranged 0.0 to 1.07 (median 0.14 x109/L). Nine (13%) participants reported experiencing food allergy symptoms by questionnaire. Six (9%) reported parental food allergy history.
There was a significantly low breastfeeding rate (61%) and duration, range 0-26 (median 0) weeks, in RTR. There was a significant difference in gestation, range 24-43 (median 40) weeks (p=0.05), and birthweight, range 0.7-5.7 (median 3.2) kilograms (p=0.03), between sensitised and non-sensitised children (table 2).
Discussion Food allergy prevalence in paediatric RTR was not increased to the general population (rates of 6-22%) with no clear evidence of allergy being passively transferred from donor to recipient. There was no association with recipient-specific factors, such as immunological cause of renal disease, post-transplantation immunosuppression (tacrolimus has been implicated) or degree of renal function (figure 2).