Research

Circulating immune complexes and complement C3 and C4 levels in a selected group of patients with rhinitis in Lebanon

Alexander M Abdelnoor¹ , Firas Kobeissy^1,2 , Daad Farhat¹ and Usamah Hadi³

¹  Department of Microbiology & Immunology, Faculty of Medicine, American University of Beirut, P. O. Box 11-0236, Riad el-Solh, Beirut, 11072020, Lebanon

²  Department of Neuroscience, University of Florida, Gainsville, FL, 32608, USA

³  Department of Otolaryngology, Faculty of Medicine, American University of Beirut, P. O. Box 11-0236, Riad el-Solh, Beirut, 11072020, Lebanon

author email corresponding author email

Clinical and Molecular Allergy 2004, 2:6doi:10.1186/1476-7961-2-6

Published:	22 April 2004

Abstract

Background

A number of reports indicate that circulating immune complexes (CIC) and activation of the complement system contribute to the pathogenesis of Type I allergy. The aim of this study was to investigate the status of CIC in 113 patients with rhinitis in Lebanon and determine complement components C3 and C4 serum levels in the CIC-positive patients. Serum specific IgE antibodies were previously detected and reported in 74 of the 113 patients.

Methods

CIC were detected by polyethylene glycol precipitation and serum C3 and C4 levels quantified by radial immunodiffusion.

Results

CIC was positive in 20 of the specific IgE-positive and 13 of the specific IgE-negative patients. C3 and C4 levels were within the normal range in all the 33 CIC-positive patients.

Conclusions

The antibody class that constitutes the complexes does not seem to be IgG or IgM. Moreover, complement activation does not seem to be involved in the allergic reaction since both C3 and C4 levels were normal in all patients. The role of these complexes, if any, in the pathogenesis of rhinitis is yet to be determined.