Journal of Medical Virology 3:17-18 (1978)
Enzyme-Linked lmmunoassay (ELISA): Its Practical Application to the Diagnosis of Hepatitis B Elise M. Vandervelde Virus Reference Laboratory, Central Public Health Laboratory, Colindale, England
The commercial ELISA test system (Hepanostika, Organon, BV, Oss, The Netherlands) was initially assessed by the Virus Reference Laboratory as part of an organized multi-centered study and the results published [Vandervelde et al, I9771 . Following this study the system and the accessory equipment have been modified and are now on sale. The Hepanostika kit now consists of five microtiter plates, each with I10 wells coated with sheep anti-HBs gamma globidin, all the reagents required (except sulphuric acid), arid control sera. A multi-channeled adjustable micropipette and an automatic washer are also available. This equipment was used t o compare this new method with some other readily available techniques - IEOP (using our own reagents), Hepanosticon, Hepatest, and Ausria 11. “High-risk’’ specimens were selected - eg, convalescent cases of acute hepatitis B, babies of HBsAg-positive mothers, and sera giving equivocal results in other tests. Most of these sera were HBsAg-negative when tested by immunoelectroosiiiophoresis (TEOP); some were HBsAg-positive by W I I A (Hepanosticon, Organon, BV). Table I shows the results of 354 such “high-risk” specimens compared with radioimmunoassay (KIA) (Ausria 11, Abbott Laboratories, North Chicago, Illinois). Only 17 specimens gave discrepant results; all were HBsAg-positive by RIA and negative by ELISA. However all had very low RIA readings. They included seven convalescent hepatitis B cases, three cord bloods, two babies of HBsAg-positive mothcrs, one commercial factor VTTT product, and one urine from a carrier. A comparison was also made with a more sensitive RPHA test (Hepatest). The 134 sera that were HBsAg-positive when tested with Hepanostika but negative with IEOP and Hepanosticon were then tested with a second RPHA test (Hepatest, Wellcome Reagents Limited, Beckenham, Kent). Of these, 108 were positive (many with only weak reactions), and 26 were negative. Address reprint requests to Dr. E. M. Vandervelde, Virus Reference Laboratory, Central Public Health Laboratory, Colindale Avenue, Colindale NW9, England.
0146-6615/78/0301-0017$00.80 0 1978 Alan R. Liss, Inc
18
Vandervelde TABLE I. Comparison of Ausria It and ELISA (354 “high-risk” specimens) ELISA+
ELISA-
143 0
17 194
RIA+ RIA-
TABLE 11. Comparison of ’Tests for HBsAg. Hepanosticon Sensitivity Number of‘ manipulations Equipment (expense) Radioactivity Shelf-life Number of tests/run Time
Hepatest
IIepanostika
Ausria I1
+
+t
+++
++++
+ +
+ +
++ ++
++
-
-
-
1 year 1 3 hours
1 pear 1 < 1 hour
1 year 90 6 or 24 hours
+++ + < 1 month 100 (2 X 50) 6 or 24 hours
Thus Hepanostika appeared to be more sensitive than Hepatest but a little less sensitive Lhaii Ausria TI (Table Ir). Both ELISA and KIA incorporate a number of manipulations within the test, fairly long incubation periods, and some expensive equipment. 1Iow. ever ELISA does not have the problems associated with the use of radioactive material, and the reagents themselves have a shelf-life of over a year, compared with less than one month for RIA. In their present form neither Hepanostika nor Ausria I1 is suitable for testing a few specimens on which urgent results are required. In comparison the RPHA tests are simple to perform, require minimal equipment, and the result is available after only a short incubation period (3 hours for Hepanosticon, l/i; to 1 hour for Hepatest). REFERENCES Vandervelde EM, Cohen RJ, Cossart YE (1 977): An enzyme-linked irnmunnsorbcnt-assay test fo: hepatitis €3 surfacc antigen. Journal of Clinical Pathology 30:714.
Enzyme-Linked lmmunoassay (ELISA): Its Practical Application to the Diagnosis of Hepatitis B Elise M. Vandervelde Virus Reference Laboratory, Central Public Health Laboratory, Colindale, England
The commercial ELISA test system (Hepanostika, Organon, BV, Oss, The Netherlands) was initially assessed by the Virus Reference Laboratory as part of an organized multi-centered study and the results published [Vandervelde et al, I9771 . Following this study the system and the accessory equipment have been modified and are now on sale. The Hepanostika kit now consists of five microtiter plates, each with I10 wells coated with sheep anti-HBs gamma globidin, all the reagents required (except sulphuric acid), arid control sera. A multi-channeled adjustable micropipette and an automatic washer are also available. This equipment was used t o compare this new method with some other readily available techniques - IEOP (using our own reagents), Hepanosticon, Hepatest, and Ausria 11. “High-risk’’ specimens were selected - eg, convalescent cases of acute hepatitis B, babies of HBsAg-positive mothers, and sera giving equivocal results in other tests. Most of these sera were HBsAg-negative when tested by immunoelectroosiiiophoresis (TEOP); some were HBsAg-positive by W I I A (Hepanosticon, Organon, BV). Table I shows the results of 354 such “high-risk” specimens compared with radioimmunoassay (KIA) (Ausria 11, Abbott Laboratories, North Chicago, Illinois). Only 17 specimens gave discrepant results; all were HBsAg-positive by RIA and negative by ELISA. However all had very low RIA readings. They included seven convalescent hepatitis B cases, three cord bloods, two babies of HBsAg-positive mothcrs, one commercial factor VTTT product, and one urine from a carrier. A comparison was also made with a more sensitive RPHA test (Hepatest). The 134 sera that were HBsAg-positive when tested with Hepanostika but negative with IEOP and Hepanosticon were then tested with a second RPHA test (Hepatest, Wellcome Reagents Limited, Beckenham, Kent). Of these, 108 were positive (many with only weak reactions), and 26 were negative. Address reprint requests to Dr. E. M. Vandervelde, Virus Reference Laboratory, Central Public Health Laboratory, Colindale Avenue, Colindale NW9, England.
0146-6615/78/0301-0017$00.80 0 1978 Alan R. Liss, Inc
18
Vandervelde TABLE I. Comparison of Ausria It and ELISA (354 “high-risk” specimens) ELISA+
ELISA-
143 0
17 194
RIA+ RIA-
TABLE 11. Comparison of ’Tests for HBsAg. Hepanosticon Sensitivity Number of‘ manipulations Equipment (expense) Radioactivity Shelf-life Number of tests/run Time
Hepatest
IIepanostika
Ausria I1
+
+t
+++
++++
+ +
+ +
++ ++
++
-
-
-
1 year 1 3 hours
1 pear 1 < 1 hour
1 year 90 6 or 24 hours
+++ + < 1 month 100 (2 X 50) 6 or 24 hours
Thus Hepanostika appeared to be more sensitive than Hepatest but a little less sensitive Lhaii Ausria TI (Table Ir). Both ELISA and KIA incorporate a number of manipulations within the test, fairly long incubation periods, and some expensive equipment. 1Iow. ever ELISA does not have the problems associated with the use of radioactive material, and the reagents themselves have a shelf-life of over a year, compared with less than one month for RIA. In their present form neither Hepanostika nor Ausria I1 is suitable for testing a few specimens on which urgent results are required. In comparison the RPHA tests are simple to perform, require minimal equipment, and the result is available after only a short incubation period (3 hours for Hepanosticon, l/i; to 1 hour for Hepatest). REFERENCES Vandervelde EM, Cohen RJ, Cossart YE (1 977): An enzyme-linked irnmunnsorbcnt-assay test fo: hepatitis €3 surfacc antigen. Journal of Clinical Pathology 30:714.
