%0 Journal Article
%T Lability of IgE Levels Early in Life
%A Koffi N'guessan
%A David Ternant
%A Fran£¿ois Labarthe
%A Herv¨¦ Watier
%J Journal of Allergy
%D 2011
%I Hindawi Publishing Corporation
%R 10.1155/2011/547389
%X We report a case of a very fast and intriguing decrease in IgE concentrations after exclusion from the diet of any CM lysate in an unusual clinical presentation of cow's milk allergy in an infant. Analysis of IgE kinetics after allergen elimination suggests rapid cessation of IgE biosynthesis and a short IgE half-life. 1. Introduction An unusual clinical presentation of cow's milk allergy (CMA) in an infant gave us the opportunity to observe a very fast and intriguing decrease of IgE concentrations after allergen withdrawal, raising new questions about IgE production and metabolism in newborns and infants. 2. Case Report A 17-day-old neonate, born to atopic parents at full term, was hospitalized in the children hospital of Tours (France) for poor feeding and increasing diarrhoea for 4 days, associated with a severe metabolic acidosis, after a symptom-free interval of 2 weeks. The diarrhoea ceased soon after admission. Erythema and a pustular rash of the face as well as a ¡°gloves and socks-¡± type skin rash were noted at 18 days of age, leading to the finding of very high concentrations of total IgE (1298£¿kIU/L) and IgE specific to cow¡¯s milk (CM) (83£¿kAU/L, Phadia) (Figure 1). First-stage formula milk had been introduced on day 11 in addition to breastfeeding according to the mother, although it is possible that this had been given since birth. Although the clinical presentation was very unusual and severe [1, 2], the diagnosis of CMA was confirmed by a rapid regression of all symptoms after withdrawal of CM proteins. Seven days later, total IgE fell to 121£¿kIU/L and specific IgE to 1.44£¿kAU/L, and total IgE returned to within the normal range (10.5£¿kIU/L) (Figure 1) five days later. Figure 1: Evolution of total IgE (¡ñ) and CM-specific IgE (¡ö). IgE levels were measured on D19, D26, and D31. Predicted IgE kinetics are indicated as a black bold line. Extrapolated IgE kinetics are shown as grey lines (median in bold, 5 and 95% CI as normal lines). With only two values available, calculations were not performed for specific IgE. 3. Discussion The IgE detected in the newborn had been self-produced since IgE did not cross the placenta and his mother had no CM-specific IgE (not shown). This IgE immune response thus probably reflected a rapid maturation of IgE+ B cells into plasmablasts, as recently evidenced in mice [3]. No less spectacular was the 100-fold decrease in IgE concentrations 12 days later (Figure 1), following exclusion of any CM lysate from the diet. High levels of both specific and total IgE are regularly observed in infant cow¡¯s milk allergy [4]
%U http://www.hindawi.com/journals/ja/2011/547389/