Comparison of Antibody Identification by Gel Test and Conventional Tube Test

Abstract

Comparison of Antibody Identification by Gel Test and Conventional Tube Test

Sirina Pongtintongngam BSc (Med Tech), MSc (Microbiology)

Department of Blood Bank, BMA Medical College and Vajira Hospital

Objective : To compare antibody identification of the patients by gel test (GT) and conventional tube test (CTT).

Study design : Experimental research.

Subjects : Blood sample from 34 patients were sent to department of blood bank for blood transfusion requirement and result of antibody screening were positive since April 1, 2001 to May 31, 2001,  BMA Medical College and Vajira Hospital.

Methods : Positive antibody screening serum from the patients were detected by O cells carrying those blood group antigens necessary for detecting the most important clinically significant unexpected antibodies

(prepared by Department of Transfusion Medicine, Faculty of Medicine, Siriraj Hospital). Antibody identification  was performed using gel test compare to conventional tube test. The panel cells were prepared by National Blood Center.  Thai Red Cross Society.

Main outcome measures : Types of antibody were identified from GT and CTT.

Results : Types of antibody were identified by both GT and CTT in 27 cases (79.4 %) from total 34 cases (by indirect antiglobulin test). Only 1 case was found by only GT (anti E). Six cases were found by only CTT (one case of anti P, one case of anti Le^a and four cases of anti Le^a-b). Anti E was identified by  both methods in 4 cases but in 1 case can be identified by only GT. Anti P can not be identified by GT. Anti Le^a and anti Le^a-b can not be founded by GT, however when using enzyme the result gets along with CTT.

Conclusion : GT  was more sensitive to detect anti E than CTT. But GT was less sensitive than CTT for anti P detection.

Key words : antibody identification, gel test, conventional tube test

Vajira Med J 2001 ; 45 : 231 - 235