Assessment of Total Serum Immunoglobulin E and Eosinophilic Cationic Protein in Primary Mono-symptomatic Nocturnal Enuresis: Allergic Theory?

Introduction: The available evidences indicate that nocturnal enuresis has multi-factorial etiology and this may underlie the wide range of outcomes. Various pathophysiological mechanisms have been discussed and succeeded in defining many causes of enuresis such as disturbed functional bladder capacity, reversal of anti-diuretic hormone secretion rhythm and disturbed sleep architecture but still the cause could not be achieved in some enuretics. An association between allergic diseases and urinary tract disorders was reported by some authors and allergy was suggested to be one of the etiologies implicated in primary nocturnal enuresis (PNE).

Aim: is to negate or approve the allergic theory through assessment of serum level of total immunoglobulin E (IgE) and eosinophil cationic protein (ECP) in a sample of Egyptian children with primary mono-symptomatic nocturnal enuresis and correlate their levels with both bladder capacity and efficiency.

Patients and Methods: Seventy-three children aged 6-18 years (32 males & 41 females) complaining of primary mono-symptomatic nocturnal enuresis on ordinary diet (no restriction to any food) were recruited. Sixty-nine healthy children of the same age and sex with good toilet control day and night were also recruited. All children were evaluated by medical history, clinical examinations and assessment of total serum IgE and eosinophil cationic protein using ELISA technique. Bladder capacity and efficiency were assessed using abdominal and pelvic ultrasonography (for 44 patients and 21 controls).

Results: Serum levels of total IgE and ECP were higher in enuretics than controls but statistically insignificant. The bladder capacity of patients was significantly smaller than controls (p=.04) while no significant difference was found regarding bladder efficiency. Total serum IgE was significantly elevated in enuretics with small bladder capacity (p=0.01) compared to enuretics with normal bladder capacity. There was a significant negative correlation between total serum IgE and both bladder capacity (p=0.041, r=-0.3) and bladder efficiency (p=0.04, r= -0.27).

Conclusion: Immunoglobulin E induced hypersensitivity may be one of the pathophysiologic mechanisms involved in PNE through reduction of the bladder capacity and efficiency. Further proof studies on a large scale is recommended. Food elimination and challenge test could help if accused allergen is known.