The serodiagnosis of human hydatid disease: 2. Additional studies on selected sera using indirect haemagglutination (IHA), enzyme linked immunosorbent assay (ELISA) and defined antigen substrate spheres (DASS).

Sixty-one serum samples selected on the basis of reactivity in the complement fixation (CF) and latex agglutination (LA) test, were further examined for sensitivity and specificity by indirect haemagglutination (IHA), enzyme linked immunosorbent assay (ELISA) and defined antigen substrate spheres (DASS). Twenty sera from healthy Europeans and 48 samples from patients with either schistosomiasis or trichinosis were also tested. Comparable levels of sensitivity were found between the CF and LA positive sera and IHA, ELISA and DASS. Of the CF positive LA negative group of sera, many were positive by DASS but only a few reacted in IHA and ELISA. Some cross reactivity was also observed in the schistosomiasis sera tested by IHA and ELISA.     

Serological diagnosis of brucellosis caused by Brucella canis

Blood serum samples from 2,328 dogs were tested to detect antibodies against Brucella canis with the agar gel immunodiffusion (AGID) and 2-mercaptoethanol slide agglutination test (ME-SAT) using Brucella ovis as the antigen. All blood serum samples were also evaluated for antibodies against Brucella abortus and Brucella melitensis using the Rose Bengal test. Twentyfive (1.07%) of the sera evaluated were considered positive with AGID test. Only 4 (16%) of these blood serum samples were positive when evaluated with ME-SAT. The 25 AGID positive samples and 25 AGID negative serum samples were also examined by: the complement fixation test (CFT) using B. ovis hot saline extract (HSE) as the antigen, indirect enzyme linked immunosorbent assay (ELISA) and immunoblotting (IB) using B. canis and B. ovis HSE antigens. Two positive canine sera from culture positive dogs and the serum of an experimentally RM6/66 B. canis-infected rabbit were employed as positive controls and one serum from a known uninfected dog as a negative control. ELISA with B. canis antigen gave 9 (18%) positive results (6 AGID-positive and 3 AGID-negative sera). ELISA performed with B. ovis antigen detected 15 (30%) positive samples (10 AGID-positive, 5 AGID-negative and 8 B. canis ELISA positive sera). IB analysis of known positive controls sera employing B. canis antigen detected bands with molecular weights of 94-80, 64-50, 35, 32-30, 28, 23, 20-18, 15-12 kDa. The same sera tested with B. ovis antigen revealed bands of 35, 32-30, 25, 23, 20-18, 15-12 kDa. No bands were observed with the negative control serum and the 50 canine tested sera.     

Circulating immune complexes as possible cause for anticomplementary activity in humans with malignant melanoma

Summary Sera from 98 melanoma patients, 20 noncancer patients with immune complex-associated diseases, and 90 normal donors were analyzed for anticomplementary (AC) activity by the complement consumption method. Some of these sera were also tested for immune complex-like materials by the Raji cell radioimmune assay. In addition, serum samples from ten melanoma patients were analyzed serially to correlate the AC activity with clinical course. Significant levels of Ac activity were found in 45% of melanoma sera, 75% of nonmalignant immune complex-associated disease sera, and 10% of normal donors' sera. In some patients, AC activity decreased and became undetectable as their disease progressed. AC-negative serum samples taken from melanoma patients late in the course of disease when the tumor burden was large became anticomplementary when mixed with autologous or allogeneic serum samples taken earlier at the time of little or no tumor burden. The early serum samples contained antibodies against autologous tumor extracts, as shown by a complement fixation test. Absorption of early serum samples with cultured allogeneic melanoma cells reduced their ability to consume complement when mixed with autologous late serum samples, suggesting the presence of free antigen in the latter. The mixed samples of early and late sera and the sera positive in the complement consumption test contained heavy nonmonomeric IgG. Therefore, the AC activity of melanoma sera could be due to tumor-associated antigen-antibody complexes.     

Antibodies to saline extractable tissue antigen in sera of patients with renal diseases

Multiple serum samples originating from 110 renal allograft recipients were examined against saline extract of normal human kidney by means of double diffusion gel precipitation. Eleven recipients were found to be positive; 99 of 106 sera from these patients were positive. Pretransplantation sera were available from 7 of these recipients and 6 patients were found "positive." The precipitation reaction was composed of one line. Identity reactions were formed between the lines produced by sera from all patients except 1. Sera of patients from end-stage renal disease produced similar reaction; however, only 3 of 234 sera from patients with nonrenal diseases precipitated the kidney extract. None of 154 normal sera were positive. Several positive sera also were positive in complement fixation tests with human kidney extract. Evidence was presented that the antibodies under study combined with a nonorgan-specific but species-restricted tissue antigen. The hypothesis was advanced that these antibodies are autoantibodies formed in response to a sequestered antigen released as a result of tissue damage. Apparently, the antigen is released frequently in immunogenic form from injury to kidney but infrequently from injury to other organs.     

A Comparative Examination of Swine Sera for Antibody To Aujeszky Virus with the Conventional and a Modified Virus-Serum Neutralization Test and a Modified Direct Complement Fixation Test

Sera of pigs from élite breeding herds, of boars and sows collected at slaughter-houses, and of pigs from herds known to be infected, were examined for antibody to Aujeszky virus. The conventional and a modified virus-neutralizing antibody (VNA) test and a modified direct complement fixation (CF) test were employed. In simultaneous titrations of positive sera the modified VNA test gave titers approx. 4 log2 units above the titers obtained by the conventional test. The conventional VNA test was found insufficiently sensitive. Unspecific neutralization in the modified VNA test was infrequent in serum dilution 1/2 and rare in dilution 1/4. The GF tests on sera of slaughter sows and animals from known infected herds showed a remarkable consistency with the VNA tests. Inconsistent results were obtained with but few sera. Abt. 5 % of the sera could not be examined because of complement fixation with control antigen.     

Brucellosis in elk I. Serologic and bacteriologic survey in Wyoming.

Incidence of brucellosis in elk (Cervus canadensis) on two winter feedgrounds in Wyoming was examined over a 5-year period by testing serum samples using the standard plate agglutination (SPT) buffered Brucella antigen (BBA), rivanol (Riv) and complement fixation (CFT) tests. Thirty-one percent of 1,165 elk were positive by defined criteria. Considering each test individually, only 29% (106) of 370 positive sera would have been classified as reactors by the SPT, 83% (307) by the BBA test and 86% (314) by the Riv test. The CFT would have identified 85% (267) of 332 positive samples on which it was used. Brucella abortus, type 1, was isolated from 17 of 45 elk necropsied. The SPT identified 59% (10) of these as reactors, the BBA test 94% (16) and the Riv test 88% (15). The CFT identified nine of nine (100%) on which it was used. Prevalence of sero-positive animals increased with age. Brucellosis has been present in one of the two elk herds since at least 1930, and the incidence of infection among mature females in both herds was approximately 50% during this study. No single serologic test should be relied upon to diagnose brucellosis in elk.     

Combined use of serological tests for the purpose of the diagnosis and study of Q-rickettsiosis

The combined use of the complement fixation test, the indirect immunofluorescent test and the ring precipitation test with C. burnetii antigen greatly enhances the effectiveness or serological study, as it allows not only to find out the spread of infection among population more completely, but also to differentiate, to a certain extent, "fresh" infectious process from immunological trace reaction. The arguments are presented in favor of introducing the antigen of C. burnetii, phase I, into practice, especially in surveying the sera of farm animals.     

Counter-immunoelectrophoresis for the detection of Brucella antigen and antibodies in the diagnosis of brucellosis in buffaloes

Counter-immunoelectrophoresis was employed for the detection of Brucella antigen in stomach contents of aborted buffalo fetuses and antibody in aborted as well as apparently healthy in contact buffaloes. Five of 16 aborted cases were serologically positive for brucellosis but isolation of Brucella abortus was successful in only two cases. By counter-immunoelectrophoresis, Brucella antigen was detected in the fetal stomach contents of four serologically positive cases. Of the 68 serum samples from in contact healthy buffaloes, 10 were positive with counter-immunoelectrophoresis: more than were detected by tube agglutination, Rose Bengal plate agglutination, complement fixation and agar gel precipitation test.     

Counter-immunoelectrophoresis for the detection of Brucella antigen and antibodies in the diagnosis of brucellosis in buffaloes

Counter-immunoelectrophoresis was employed for the detection of Brucella antigen in stomach contents of aborted buffalo fetuses and antibody in aborted as well as apparently healthy in contact buffaloes. Five of 16 aborted cases were serologically positive for brucellosis but isolation of Brucella abortus was successful in only two cases. By counter-immunoelectrophoresis, Brucella antigen was detected in the fetal stomach contents of four serologically positive cases.
Of the 68 serum samples from in contact healthy buffaloes, 10 were positive with counter-immunoelectrophoresis: more than were detected by tube agglutination, Rose Bengal plate agglutination, complement fixation and agar gel precipitation test.     

Immunological study of the occurrence of staphylococci with skin antigens in various experimental animals]

Experiments were conducted on rabbits; primary and secondary administration of staphylococcus vaccine was regularly accompanied by the production of antibodies not only to a staphylococcus antigen, but also of antibodies reacting with an extract of homologous kidneys, myocardium and the skin. The presence in the pathogenic staphylococcus of an antigen affiliated to proteins of the skin and kidneys of rabbits and mice was shown by the method of cross sorption of antistaphylococcus and antiskin sera by a suspension of the staphylococcus or skin antigen with the use of the complement fixation test. Indirect hemagglutination and immunofluorescence. Such antigen was absent in nonpathogenic bacteria isolated from the skin extracts.     

The application of a protein fraction derived fromTreponema Pallidum (reiter strain) as an antigen in the serodiagnosis of syphilis

Summary A comparison was made between the complement fixation test using a protein fraction derived fromTreponema pallidum (Reiter strain) as an antigen and theTreponema pallidum immobilization test. As appears from the results obtained with 116 syphilitic and 137 presumably non-syphilitic sera the complement fixation test with protein antigen showed an excellent sensitivity together with a satisfactory specificity.     

Comparison of the yield of indirect hemagglutination reaction and complement fixation reaction in the diagnosis of neurocysticercosis

Two variations of an indirect hemagglutination test (IHAT) and a complement fixation test (CFT) for the diagnosis of human cysticercosis were compared and evaluated. For the IHAT, a cysticerci crude total saline extract (SE) and a cysticerci lyophylized and delipidized veronal bicarbonate saline buffer (VBS) extract were used, comparing their diagnosis yieldings with that of a CFT in 57 confirmed cysticercosis patients: 45 serum samples and 32 cerebrospinal fluid (CSF). Sera and CSF from 29 patients with other neurological diseases and 25 sera from healthy volunteers were also compared. Both types of methods presented an overall average concordance of 91.5% and 97.0% with CSF and sera respectively. With respect to the sensitivity observed with CFT was 85.2% and 93.3% for CSF and sera, whereas that of IHAT was 96.9% in CSF and 97.8% in sera, when SE antigen was used; with the VBS antigen for IHAT 96.9% and 95.6% were detected in CSF and sera respectively. In order to determine the specificity of the IHAT, besides the study in healthy volunteers, in patients with other neurological diseases and in 156 serum samples from individuals with other parasitoses, such as hydatidosis (43), trichinosis (56), fascioliasis (31) and Chagas' disease (26) were also tested. A high reactivity with the hydatidosis group was found. The specificity, using a titre > or = 1:16 as a diagnostic value and without considering hydatidic sera was 99.4% for RHAI (SE), 100.0% for RHAI (VBS). The use of IHAT and CFT in diagnosis of human cysticercosis is discussed.     

Seroepidemiology of Anaplasma marginale in white-tailed deer (Odocoileus virginianus) from Louisiana

Antibodies to Anaplasma marginale were detected by the indirect fluorescent antibody test (IFA) in six of 331 (2%) serum samples of white-tailed deer (Odocoileus virginianus) from Louisiana. None of the serum samples were positive using the A. marginale modified rapid card agglutination test. Of the six IFA positive sera retested by the complement fixation test four sera gave anticomplementary and two gave seropositive reactions. The low A. marginale reactor rate in this white-tailed deer population was probably a reflection of the lack of cohabitation between cattle and deer and the fact that the primary arthropod vectors in Louisiana are tabanids. The validity of the indirect fluorescent antibody test for A. marginale antibodies in white-tailed deer should be evaluated.     

Indirect Hemagglutination Test for Chlamydial Antibodies

An indirect hemagglutination (IHA) test is described for chlamydial antibodies in psittacosis diagnostic sera; for this test tanned sheep erythrocytes sensitized with a deoxycholate extract of Chlamydia psittaci grown in Vero cell monolayers were used. Adaptation of the IHA test to the Microtiter system decreased sensitivity; nevertheless, the Microtiter-IHA test was more sensitive than the complement fixation test. Lymphogranuloma venereum antibodies also were detected by using antigen extracted from C. psittaci.     

Occurrence of Antirodies to Group Specific Chlamydia Antigen in Finnish Sheep,Cattle and Horse Sera

A serological survey on the occurrence of group-specific chlamydial antibodies in random sera of Finnish sheep, cattle and horses was performed. The whole material consisted of 1347 serum samples, including 432 ovine, 454 bovine and 461 equine sera. The sera were sent to the laboratory for various serological tests during 1968–1972. Of the ovine sera 9.5%, bovine 12.8 % and equine 7.1 % showed a titer ≥ 1:16 in the complement fixation test. No definite geographic differences could be found in the distribution of the herds which showed positive results. The ubiquity of chlamydial infections in domestic mammals and their role as a cause of clinical diseases is discussed.     

Commercially available histoplasmin sensitized latex particles in an agglutination test for histoplasmosis

Summary A commercial preparation of histoplasmin sensitized latex particles was tested in an agglutination test with sera from 50 culturally confirmed cases of histoplasmosis in varying stages of the infection. The reactions were superior to those obtained with collodion agglutination and complement fixation tests in which the antigen histoplasmin was also used. The latex agglutination test with the commercially available antigen is easy to do, and can be done in any laboratory equipped to carry out agglutination tests with the common bacterial antigens. It warrants more extensive trial in the general hospital laboratory as a screening test for histoplasmosis, especially the primary, pulmonary type.     

Evaluation of the sensitivity of selected serological tests and activity of Coxiella burnetii antigens in the diagnosis of Q fever]

Sensitivity of three serological tests: indirect immunofluorescence assay (If), complement fixation test (CF), and microagglutination test (MA) was evaluated. Sera (118 samples) of humans suspected of C. burnetii infection were tested. Phase II antibodies were detected in 68.6% of sera and phase I antibodies--in 38.2% of sera. Among seropositive to phase II antigen--93.8% of sera reacted in IF, 62.9% in MA, and 32.1% in CF; among seropositive to phase I antigens--100% of samples reacted in IF, 2.6% in MA and 2.6% in CF. Calculated sensitivity of above tests was as followed: IF-93.8%, MA-67.1%, CF-34.2%. Some human sera (6.1%) reacted with hen egg antigens in CF. Reactivity of diagnostic antigens prepared from reference Henzerling strain and four others isolated in Poland with rabbit immune sera and sera of individuals suspected of C. burnetii infection in IF was compared. Generally, the immune sera reacted in highest titres with homologous antigens derived from homologous strains. Human sera showed differentiated activity to particular antigens. The titres of phase I antibodies fluctuated from 0 to 16 depending on the antigen applied. Because of that fact diagnostic antigens should be prepared from the mixture of reference strains and isolates from a region under study.     

Interactions of Standard Antibody with Australia Antigens in Au Ag-Ab Radioimmunoassay

Human antisera against Australia (Au) antigen have been characterized by liquid-phase radioimmunoassay (RIA) for their precipitation of (125)I-labeled Au antigen. The end-point dilutions of sera (anti-Au) which precipitated 50% of (125)I-Au antigen by RIA correlated well with complement fixation titers but had a much wider range, indicating a greater precision and perhaps a better sensitivity of assay. Anti-Au serum diluted to precipitate 50% of (125)I-labeled Au antigen was used as standard antibody in RIA tests to detect either inhibition or enhancement of the reaction by preincubated mixtures of Au antigen and antibody specimens. Without free Au antigen or antibody in the resultant mixtures there was no inhibition or enhancement; the mixtures presumably contained immunoreactively equivalent proportions of Au antigen and antibody. RIA data for diagnostic specimens indicated an end-point sensitivity which was proportional to the dilution of the standard anti-Au sera used in the test. High concentrations of the standard antibody permitted detectable inhibition of (125)I-Au antigen precipitation at lower antigen specimen concentrations. Similarly, low concentrations of the standard antibody permitted detectable enhancement of (125)I-Au antigen precipitation at lower antibody specimen concentrations. Omitting the standard antibody altogether resulted in a more sensitive RIA for Au antibody in test sera.     

Detection of Coronavirus 229E Antibody by Indirect Hemagglutination

Tannic-acid treated sheep erythrocytes (fresh or glutaraldehyde preserved) were sensitized with 229E antigens from human embryonic lung (RU-1) cell cultures. Indirect hemagglutination (IHA) antigen titers in 229E-infected cell cultures paralleled virus infectivity and complement fixation (CF) antigen titers. The identity of the IHA antigen was confirmed by testing extracts from inoculated and control cell cultures for ability to inhibit IHA. Also, significant increases in IHA antibody were demonstrated with acute and convalescent serum pairs from patients with proven 229E infections. A comparison of IHA, neutralization and CF titers for 229E antibodies was made on human sera drawn from different populations. The IHA and neutralization results were in agreement on 93% of the 129 sera found to be positive by at least one of three tests. The number of antibody titers detected by the CF test was insufficient to permit comparison. Hyperimmune sera from animals immunized with OC 43 did not react with 229E by IHA. Also no increase in IHA antibody was demonstrated with acute and convalescent serum pairs from patients with seroconversions to OC 43. These findings suggest that the IHA test provides (i) a rapid and sensitive method for serodiagnosis of 229E infections and (ii) a simple and inexpensive method for seroepidemiological studies.     

Relative Sensitivity of Gel Diffusion, Complement Fixation, and Immunoelectroosmophoresis Tests for Detection of Hepatitis-Associated Antigen and Antibody

The immunoelectroosmophoresis (IEOP) test was compared with gel diffusion and complement fixation (CF) tests for sensitivity in detecting hepatitis-associated antigen (HAA) in the sera of hepatitis patients, for titration of HAA, and for detection of antibody to HAA. The IEOP test was found to be slightly more sensitive than either gel diffusion or CF tests for detection of antigen in the patients' sera. Titers of HAA demonstrated by IEOP were higher than those seen in gel diffusion tests but lower than CF titers. The gel diffusion test with an "enhancement" pattern was found to be more reliable than the other two procedures for detection of low levels of anti-HAA, due to the greater inhibitory effect of an antigen excess in the IEOP system and the possible masking of low levels of antibody by anticomplementary activity in the CF test system. Staining of immunoprecipitates in the IEOP test contributed little to the sensitivity of the test for detection of HAA.