Counterelectrophoresis Research Articles

Evaluation of hepatitis B antigen testing in federally licensed blood banks in the United States.

Between August 1972 and January 1974, the Burear of Biologics distributed four panels of 20 coded serum samples to all federally licensed blood banks for hepatitis B antigen testing. Initially, all but six blood banks reported results by counterelectrophoresis (CEP) only, but by January 1974, 152 of 247 banks reported results by radioimmunoassay (RIA). On the four panels distributed, correct results were reported for 63 to 83% of all potentially detectable samples by CEP and for 98 to 100% of all samples potentially detectable by RIA. Perfect scores were obtained by only 5 to 25% of blood banks using CEP but by 77 to 100% using RIA. Nonreproducible results on duplicate reactive samples, included to evaluate internal consistency, ranged from 0.5 to 25% by CEP and from zero to 5% by RIA. These results demonstrate greater reliability in addition to greater sensitivity of "third generation" RIA testing in comparison with "second generation" CEP testing.

"Hippie" hepatitis: an epidemiologic investigation conducted within a population of "street-people".

An epidemiologic investigation of viral hepatitis among "street-people" was conducted in Pittsburgh, PA in 1971. Among 146 individuals, 100 admitted to parenteral drug use and 73 (50%) had evidence of acute viral hepatitis. Counterelectrophoresis (CEP) and complement-fixation (CF) were used to test for type B antigen (HBS AG). Seventeen individuals (22%) had detectable HBSAG; 13 of these were clinically ill and admitted to drug use, Type B antibody (anti-HBS) was tested for by CEP and radioimmunoprecipitation (RIP). Thirty-five persons (29%), 15 of whom admitted to drug use and were ill, had detectable antibody by RIP; none had detectable antibody by CEP. None of those tested had both HBSAB and anti-HBS Evidence to support the hypothesis of sexual transmission of type B virus was found. Use of prophylactic gamma globulin in street-people populations is recommended.

HBs antigen in human plasma fractions.

Therapeutic fractions were obtained by fractionating human plasma containing HBs antigen, by the Cohn ethanol technique modified by Nitschmann. Plasmas with various HBs antigen titers were selected. The antigen was sought in each fraction by the techniques of counterelectrophoresis and radioimmunological detection in liquid phase. With the exception of very pure albumins, all fractions were found to contain the HBs antigen, though in variable proportions. A technique for the purification of albumin, applicable on an industrial scale, is proposed. It makes it possible to obtain an albumin fraction in which the HBs antigen cannot be detected by the most sensitive techniques, even starting with a plasma which is very rich in HBs antigen (titer 1/64 by counterelectrophoresis).

Etude comparative de trois réactifs commercialisés de détection de l'antigène HB

2,944 sera from blood donors (420 of them being new donors) were tested in four techniques: Counterelectrophoresis (CEP) and three commercial tests: Ausria II, Auscell and Hepanosticon. Over 10 HBs Ag detected by RIA, 8 were evidenced by the Auscell test and 6 by the Hepanosticon Test. False positive results (approximately 3%) represent a disadvantage to the reverse hemagglutination method; this rate increased considerably in a group of 386 patients sera also tested. The authors conclude that the results obtained with the reverse hemagglutination technique are nearing those of RIA.

Diagnosis of California (La Crosse) Encephalitis by Precipitin Techniques: a Prospective Study

Counterelectrophoresis (CEP) and immunodiffusion (ID) were evaluated prospectively as methods for the early and rapid laboratory diagnosis of California encephalitis (CE). CEP and ID studies were done on paired sera from 127 patients with acute central nervous system infections. After the precipitin tests were completed, conventional hemagglutination-inhibition, neutralizing, and complement fixing antibody titers were measured. The CEP system detected antibodies in 7 (41%) of 17 CE patients during their acute illness and in all 17 patients during convalescence. The ID method was less sensitive; 3 of 17 acute sera and 16 of 17 convalescent sera were ID positive. Comparative precipitin studies indicated that La Crosse virus was the infecting California group subtype in all 17 CE patients. Because CEP can be performed in 1.5 h, is at least as sensitive as hemagglutination-inhibition, neutralizing, and complement fixing tests, and can detect prospectively 41% of CE patients during their acute illness, it is recommended as a rapid diagnostic test for CE.

POST-TRANSFUSION HEPATITIS IN RECIPIENTS OF BLOOD SCREENED BY NEWER ASSAYS

To assess the efficacy of screening blood with sensitive hepatitis-B-antigen (HBAg) assays to reduce the incidence of post-transfusion hepatitis, 6399 units of blood, previously found to be negative for HBAg when tested by counterelectrophoresis (C.E.P.), were rescreened for HBAg by red-blood-cell agglutination (R.C.A.) and radioimmunoassay (R.I.A.). Of these units, 2·2% were positive. The recipients of these HBAg-positive units were followed, as were 19 age and sex matched controls who received the same number of units of HBAg-negative blood. Among 63 recipients of HBAg-positive blood (C.E.P. negative, R.I.A. or R.C.A. positive), 24 (38%) developed hepatitis. In addition, 5 others developed hepatitis-B antibody (HBAb) (8%), and 1 other became an HBAg carrier without evidence of hepatitis. 1 control patient developed HBAb without hepatitis, and 9 (47%) control recipients developed hepatitis. The R.I.A. test was frequently associated with false-positive results (no hepatitis, HBAg carrier state, or HBAb seroconversion resulting), and was not more sensitive that R.C.A. in predicting the occurrence of hepatitis or seroconversion. When each test (R.C.A. or R.I.A.) was compared to the clinical outcome, a positive R.C.A. test correlated more closely with the development of hepatitis or seroconversion (94%).

Detection and identification of diagnostic Histoplasma capsulatum precipitates by counterelectrophoresis.

Studies were carried out to develop and evaluate a counterelectrophoresis (CEP) technique for the rapid and specific identification of the diagnostically important histoplasmosis H and M precipitin bands. Well-defined and centrally located precipitin bands were produced by using a discontinuous buffer system and a gel matrix composed of agarose and ionagar no. 2. A template was devised which allowed the selective identification of the H and M precipitins. Comparative evaluations were performed with the microimmunodiffusion (ID) and complement fixation tests. In 52 sera from persons with histoplasmosis, either the H or M precipitin, or both, were identified in 42 (81%) of the cases with the CEP technique and in 43 (83%) with the ID test. With sera from 28 persons with heterologous diseases, the CEP technique, like the ID test, failed to react. The specificity of the CEP technique was dependent upon the use of the identity template. The CEP technique is recommended for routine use in laboratories testing moderate numbers of sera. It provides accurate and reproducible results within 90 min, in contrast to the ID test, which requires 18 to 24 h.

Automated continuous-flow hemagglutination inhibition test for hepatitis B antigen in blood.

Abstract. An automated continuous‐flow hemagglutination inhibition (HI) method for hepatitis B antigen using purified HAA‐conjugated red cells has been developed in these laboratories and has been used to test 497 blood donors. For comparison, counter electrophoresis (CEP) and microtiter complement fixation (CF) tests were done concurrently. 14 samples were found to be HAA‐positive by all three tests. One additional sample was negative by CF but HI and CEP positive. The automated HI test proved very simple to operate. The results are available in 27 min at the rate of 60 samples/h.

Australia antigen in collagen disease.

To the Editor.— The work of Burrell and colleagues 1 and Miller's group 2 would indicate that Australia antigen is not found in rheumatoid arthritis, but is found in systemic lupus erythematosus (SLE). It is true that a high percentage of SLE and periarteritis patients have Australia antigen, 3-6 but Australia antigen is found in rheumatoid arthritis patients and, especially interesting, is the finding that antibody to Australia antigen can be found in rheumatoid arthritis patients in a high frequency by comparison with volunteer blood donors. We have studied sera from 27 patients with diagnosed rheumatoid arthritis confirmed by laboratory findings and consistent with their clinical picture. Three of the 27 patients had antibody to Australia antigen, and one had Australia antigen in his serum. The method of testing was that of sandwich counter electrophoresis. Treating the sera with mercaptoethanol 6,7 revealed two sera containing Australia antigen and no sera positive

Detection of Vaccinia Antigen and Antibody by Counterelectrophoresis

Counterelectrophoresis (CEP) for detection of vaccinia antigen and antibody is described. This method gives precipitation lines and reactions of immunological identity in less than 1 h. Moreover it is 5 times more sensitive than immunodiffusion (ID). CEP as well as ID are not sensitive enough to be used for the demonstration of vaccinia antibody in vaccinated persons.

Detection and Identification of Diagnostic Histoplasma capsulatum Precipitates by Counterelectrophoresis

Studies were carried out to develop and evaluate a counterelectrophoresis (CEP) technique for the rapid and specific identification of the diagnostically important histoplasmosis H and M precipitin bands. Well-defined and centrally located precipitin bands were produced by using a discontinuous buffer system and a gel matrix composed of agarose and ionagar no. 2. A template was devised which allowed the selective identification of the H and M precipitins. Comparative evaluations were performed with the microimmunodiffusion (ID) and complement fixation tests. In 52 sera from persons with histoplasmosis, either the H or M precipitin, or both, were identified in 42 (81%) of the cases with the CEP technique and in 43 (83%) with the ID test. With sera from 28 persons with heterologous diseases, the CEP technique, like the ID test, failed to react. The specificity of the CEP technique was dependent upon the use of the identity template. The CEP technique is recommended for routine use in laboratories testing moderate numbers of sera. It provides accurate and reproducible results within 90 min, in contrast to the ID test, which requires 18 to 24 h.

Evaluation of a Red Cell Agglutination Test for Detection of Australia Antigen (HB Ag)

An investigational red cell agglutination (RCA) test was evaluated for sensitivity in detecting and titering hepatitis B antigen (HB Ag) in comparison with two counterelectrophoresis (CEP) systems and a solid-phase radioimmunoassay (RIA). The RCA procedure was found to be significantly more sensitive than the CEP methods and compares favorably in sensitivity with the solid-phase RIA, detecting even lower concentrations of the HB Ag. Since the RCA test can be completed in 2 to 3 h and requires relatively inexpensive equipment, it offers a highly sensitive and rapid procedure suitable for use in blood banks to screen donors or detect low levels of antigen in serum of patients.

Evaluation of assay methods for hepatitis-associated antigen.

Assay methods for hepatitis-associated antigen (HAA) were evaluated for sensitivity, or reproducibility, or both in a series of three trials in which both research and service-oriented laboratories participated. Agar-gel diffusion (AGD) methods were found to be the least sensitive and reproducible of the commonly employed assay methods. Complement fixation (CF) tests were consistently more sensitive than either AGD or counterelectrophoresis (CEP) methods for detection of HAA. With judicious choice of the antibody reagent, sensitivity of CEP techniques was equivalent to CF methods of HAA detection. None of the three major assay methods (AGD, CEP, or CF) compared in this study were capable of consistently detecting HAA when it was present in relatively low concentrations in human serum.

Australia antigen detection by "sandwich" counterelectrophoresis.

To the Editor.— Detection of Australia antigen is performed in many clinical laboratories by counterelectrophoresis (CEP). Recently J. B. Smith described a sandwich counterelectrophoresis (SCEP) technique which is very sensitive for the detection of alpha-fetoprotein. 1 In a pilot experiment with the use of SCEP, we found that Australia antigen in the serum of a carrier could be detected at higher dilutions than by our regular CEP method. We have used a Shandon electrophoresis unit with a cooling apparatus operated at 200 m and 60 to 80 ma thus permitting completion of a run in 30 minutes. Barbital buffer at pH 8.6 is used to make 0.6% agarose plates. 2 Because we have found that certain sera contain a heat labile factor, probably Clq, that can mask Australia antigen just as rheumatoid factor can, all fresh specimens are heat inactivated for 30 minutes at 56 C. 3 Human rather than

Evaluation of Assay Methods for Hepatitis-Associated Antigen

Assay methods for hepatitis-associated antigen (HAA) were evaluated for sensitivity, or reproducibility, or both in a series of three trials in which both research and service-oriented laboratories participated. Agar-gel diffusion (AGD) methods were found to be the least sensitive and reproducible of the commonly employed assay methods. Complement fixation (CF) tests were consistently more sensitive than either AGD or counterelectrophoresis (CEP) methods for detection of HAA. With judicious choice of the antibody reagent, sensitivity of CEP techniques was equivalent to CF methods of HAA detection. None of the three major assay methods (AGD, CEP, or CF) compared in this study were capable of consistently detecting HAA when it was present in relatively low concentrations in human serum.