BACKGROUND: Numerous studies have reported an atopic background in patients suffering from idiopathic nephrotic syndrome. Proteinuria has also been reported in allergic patients, but in a limited number of studies with, for most of them, a low level of evidence. If confirmed, the presence of proteinuria in allergic children could be a clue that could help to understand idiopathic nephrotic syndrome pathophysiology. We conducted a prospective study to compare the urine protein levels in allergic and non- allergic children.
METHODS Urine samples were collected from 196 children with a suspicion of allergy. Total protein, albumin, and creatinine were measured in urine. Included patients were secondary dispatched in allergic and non-allergic groups.
RESULTS In the allergic group (n=99), six children (6%) were proteinuric (proteinuria/creatinuria ratio ranging from 20 to 1449 mg/mmol versus eight (8%) (21 to 219 mg/mmol) among the non-allergic patients (n=97). There was no significant difference between allergic and non-allergic patients either for proteinuria/creatininuria ratio (mean 28.13 and 18.18 mg/mmol respectively) or albuminuria/creatininuria ratio (mean 9.84 and 3.04 mg/mmol respectively).
CONCLUSION Allergic patients do not present proteinuria more frequently than non- allergic patients. These results do not support a pathophysiological link that could lead from allergy to idiopathic nephrotic syndrome through the presence of pathologic proteinuria in allergic patients.