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The presence of IgM, IgA and IgG antibodies against chlamydiallipopolysaccharide in circulating blood immunocomplexes

Abstract number: 1134_03_264

Medkova Z., Hejnar P.

Objectives:  

The aim of the study was to evaluate 1. the presence of different isotypes of antibodies (IgA, IgG, IgM) against chlamydial lipopolysaccharide (LPS) in blood circulating immunocomplexes; 2. the influence of freezing and defreezing on the blood levels of the described isotypes of antibodies (Abs).

Methods:  

100 human sera showing the presence of specific anti-chlamydial LPS IgA and the absence of the IgG in the initial testing (the same specificity; 21 sera were anti-LPS IgM positive) were collected. The sera were stored at -20 degrees of Celsius temperature, defrosted at room temperature and divided into two halves.In one aliquot the Abs were unbound from circulating blood immunocomplexes (CIC) by polyethylenglycol precipitation (PEGP) and the both aliquoths were then tested for the presence of anti-chlamydial LPS IgA,IgG and IgM respectively. The diagnostic sets Chlamydia-rELISA IgA, IgG, IgM (medac, Wedel) were used.

Results:  

With a mere defreezing IgG developed in 23 and IgM in 24 sera, whereas IgA developed only in 72 samples. After completion of PEGP IgG were demonstrated in 21 sera, IgM in 18 and IgA only in eight. On the whole, after a mere defreezing and PEGP IgG Abs developed in 34 blood samples (29,4% correspondence between methods), IgM in 30 (40% correspondence) and IgA in 72 (only 11,1% correspondence).

Conclusions:  

With the use of the presented method the specific IgG bound in CIC were demonstrated in about one third of the samples (and IgM bound in CIC in one tenth of sera). A mere freezing and defreezing caused destruction of free IgA and IgM in about 30% sera. PEGP resulted in destruction of free IgA and IgM in about 90% and 40% tested samples, respectively. Thus, the interpretation of the chlamydial serology is more complicated then we could expect, and next research in that area is needed.

Session Details

Date: 01/08/2007
Time: 00:00-00:00
Session name: XXIst ISTH Congress
Subject:
Location: Oxford, UK
Presentation type:
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