title: Plasma levels of polyunsaturated fatty acids in children with atopic dermatitis and in atopic and nonatopic controls.
abstract: BACKGROUND
  Atopic dermatitis has been thought to be associated with a disturbance in n-6 polyunsaturated fatty acid (PUFA) metabolism, but randomized trials investigating the clinical efficacy of oral supplementation with gammalinolenic acid have revealed conflicting results.
  
  
  OBJECTIVE
  To re-investigate the proposed linkage between PUFA dysregulation and atopic dermatitis.
  
  
  METHODS
  Plasma levels of linoleic acid (LA), gammalinolenic acid (GLA), dihomogammalinolenic acid (DGLA) and arachidonic acid (AA) were measured using HPLC in 22 children with atopic dermatitis. Patients were subdivided into those with elevated total serum IgE (group A, n = 15, IgE > +1 SD of age-specific normal values) and those with normal IgE (group B, n = 7) and compared with children suffering from allergic rhinitis/asthma (group C, n = 8) and with non-atopic controls (group D, n = 6).
  
  
  RESULTS
  GLA levels were significantly lower (p < 0.05) in eczema patients with elevated IgE (A, 0.19 +/- 0.06%) and in atopic controls (C, 0.23 +/- 0.06%) than in eczema patients with low IgE (B, 0.42 +/- 0.19%) and non-atopic controls (D, 0.43 +/- 0.16%). There were no significant differences between groups for LIN, DGLA and AA, except for lower LIN levels in atopic controls. Correlation of individual LA and GLA values showed significantly steeper regression lines in low-IgE responders (B and D, k(x) = 0.058) than in high-IgE responders (A and C, k(x) = 0.012; p < 0.02), suggesting impaired delta-6-desaturase function in the latter. For the study population as a whole, there was a clear negative correlation between total levels of IgE and GLA (r(s) = -0.64) and a moderate negative correlation between total IgE and AA (r(s) = -0.38).
  
  
  CONCLUSIONS
  Dysregulation of n-6 PUFA metabolism is neither consistently found in nor specifically associated with atopic dermatitis but rather appears to be associated with IgE production and atopy in general. The finding of decreased GLA levels in eczema patients with elevated total IgE and in children with allergic rhinitis and asthma but not in eczema patients with normal total IgE questions the proposed pathophysiologic role of fatty acid dysregulation in atopic dermatitis.
authors.affiliation: Floridsdorf Allergy Center, Vienna, Austria.
authors.forename: Margarete
authors.initials: M
authors.lastname: Focke
authors.forename: Gabriele
authors.initials: G
authors.lastname: Sesztak-Greinecker
authors.forename: Werner
authors.initials: W
authors.lastname: Brannath
authors.forename: Manfred
authors.initials: M
authors.lastname: Götz
authors.forename: Reinhart
authors.initials: R
authors.lastname: Jarisch
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Hemmer
mesh_terms: D001249:Asthma / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology; D015415:Biomarkers / Q000097:blood; D002648:Child; D003876:Dermatitis, Atopic / Q000097:blood* / Q000175:diagnosis / Q000453:epidemiology; D005231:Fatty Acids, Unsaturated / Q000097:blood*; D005260:Female; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood*; D008297:Male; D015995:Prevalence; D011379:Prognosis; D012221:Rhinitis, Allergic, Perennial / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors
chemical_list: D015415:Biomarkers; D005231:Fatty Acids, Unsaturated; D007073:Immunoglobulin E