Allergy is a protective factor against age-related macular degeneration.
OBJECTIVE
To investigate the role of allergy on AMD.


METHODS
Age-related macular degeneration staging was performed for 3585 individuals (1878 from Cologne, Germany, and 1707 from Nijmegen, The Netherlands). Interviewer-assisted questionnaires were evaluated for the factors smoking, use of corticosteroids, and history of allergy, including causative allergens. Serum complement component C3d and C3 levels were measured and the C3d:C3 ratio was calculated. Associations of allergy with AMD/late AMD were assessed by logistic regression analysis; C3d:C3 ratio was compared between groups.


RESULTS
The discovery cohort from Cologne included 864 AMD patients and 1014 controls; 495 patients had late AMD. Positive history of allergy showed strong protective effects on the phenotype AMD (OR 0.52; P = 3.42 × 10(-9)) and late AMD (OR 0.32; P = 2.57 × 10(-13)). Subclassification in allergy-provoking agents showed significant protective effects in all groups. After adjustment for age, sex, smoking, and corticosteroid use, protective effects for AMD (OR 0.75; P = 0.018) and late AMD (OR 0.49; P = 2.87 × 10(-5)) were confirmed. Although the C3d:C3 ratio was higher in AMD/late AMD patients (both P < 0.001), there was no association with allergy in AMD (P = 0.22). The protective effect of allergy on AMD was confirmed in the replication cohort from Nijmegen (P = 0.002 for AMD; P = 0.0001 for late AMD).


CONCLUSIONS
Allergy has a protective effect on the development of AMD independent of the provoking allergen, which cannot be explained by complement activation. Further investigations are necessary to elucidate the molecular mechanisms underlying the protective effect of allergy on AMD.
Department of Ophthalmology, University Hospital of Cologne, Cologne, Germany.
Tina
T
Ristau
Lebriz
L
Ersoy
Yara
Y
Lechanteur
Anneke I
AI
den Hollander
Mohamed R
MR
Daha
Moritz
M
Hahn
Carel B
CB
Hoyng
Sascha
S
Fauser
D000368:Aged; D003167:Complement Activation; D003165:Complement System Proteins / Q000378:metabolism*; D005260:Female; D005451:Fluorescein Angiography; D005654:Fundus Oculi; D006801:Humans; D006967:Hypersensitivity / Q000150:complications* / Q000175:diagnosis / Q000378:metabolism; D008268:Macular Degeneration / Q000175:diagnosis / Q000209:etiology* / Q000378:metabolism; D008297:Male; D012189:Retrospective Studies; D012307:Risk Factors
D003165:Complement System Proteins
age-related macular degeneration; allergy; risk factor