Mohammad Reza Bonyadi; Mohammad Barzegar; Reza Badalzadeh; Mazyar Hashemilar
Volume 7, Issue 2 , June 2010, , Pages 117-123
Abstract
Background: Anti-ganglioside antibody assays are widely used for diagnosis of autoimmune peripheral neuropathies. Objective: This study aimed to determine serum levels of anti-ganglioside antibodies in children with Guillain-Barre syndrome by immunoblotting technique and compare the results with those ...
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Background: Anti-ganglioside antibody assays are widely used for diagnosis of autoimmune peripheral neuropathies. Objective: This study aimed to determine serum levels of anti-ganglioside antibodies in children with Guillain-Barre syndrome by immunoblotting technique and compare the results with those obtained by ELISA method. Method: In this investigation, 50 children with Guillain-Barre syndrome (GBS) who were admitted from July 2006 to July 2008, to Tabriz Children’s hospital in the northwest of Iran were studied. 30 children admitted for various other reasons than GBS were randomly selected as a control group. The levels of anti-ganglioside antibodies in serum were measured by ELISA and immunoblotting methods using commercial kits. Results: Anti-ganglioside antibodies (IgG) were detected in 16 (32%) GBS patients and in 1 (3.3%) control using ELISA assay. However, by employing immunoblotting technique, antibodies against seven gangliosides were found positive in 28 (56%) GBS patients and none in the control group. The sensitivities of immunoblotting and ELISA methods were 56% and 32% and their specificities were 100% and 97%, respectively (p<0.001). Conclusion: According to the clinical criteria of GBS, the specificity and sensitivity of immunoblotting was better than those of ELISA. It is important to notice that the immunoblotting method is able to measure the seven types of antibodies (GM1, GM2, GM3, GD1a, GD1b, GT1b, and GQ1b) simultaneously and it is an easy, routine method with a lower cost.
Fatemeh Hajighasemi; Soheila Gharagozlou; Nasrin Moheghi; Roya Ghods; Jalal Khoshnoodi; Fazel Shokri
Volume 2, Issue 3 , September 2005, , Pages 125-133
Abstract
Background: There are two subclasses of human IgA (IgA1 and IgA2) that differ in antigenic properties and in chemical composition. The constant domains of α1 and α2 heavy chains have >95% sequence homology though major structural differences exist in the hinge region. Quantitation of IgA ...
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Background: There are two subclasses of human IgA (IgA1 and IgA2) that differ in antigenic properties and in chemical composition. The constant domains of α1 and α2 heavy chains have >95% sequence homology though major structural differences exist in the hinge region. Quantitation of IgA subclass levels depends on the availability of monoclonal antibodies (MAbs) specific for conserved conformational or linear epitopes restricted to each subclass. Objective: To produce, select and characterize monoclonal antibodies specific for human IgA2. Methods: Splenocytes from BALB/C mice immunized with a human IgA2 myeloma protein were fused with SP2/0 myeloma cells. Fused cells were grown in hypoxanthine, aminopterine and thymidine (HAT) selective medium and cloned by limiting dilution assay. Antibody (Ab) secreting cells were screened by enzyme-linked immunosorbent assay (ELISA) and the specificity of secreted MAbs was further analyzed, using a panel of purified myeloma proteins and some animal sera by ELISA and immunoblotting. The affinity constant (Kaff) was also determined by ELISA. Results: Four murine hybridoma clones designated 2F20G5, 2F20B5, 3F20E3 and 6F20H11 were obtained that secreted MAbs specific for the human IgA2. 2F20G5 and 6F20H11 MAbs react with linear epitope(s) while 2F20B5 and 3F20E3 react with conformational epitope(s) located to human IgA2 subclass. 2F20G5 MAb displays a weak cross-reactivity with monkey and rabbit sera and a strong cross-reactivity with cat and dog sera while the other three MAbs showed no cross-reactivity with the animal sera tested. Conclusion: These MAbs, especially 6F20H11 with high affinity constant (6.03 ×109 M-1) are useful tools for quantitation of human IgA2 subclass levels in various diseases. Cross-reactivity of 2F20G5 MAb with some animalsera suggests phylogenic conservation ofthe epitope recognized by this MAb.
