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PubMed1980

Erythema nodosum in chlamydial infections.

Twelve patients suffering from erythema nodosum who had diagnostic titres or seroconversions in chlamydial complement fixation test are described. Eleven had respiratory infections. The twelfth had sterile pyuria, symptoms of pelvic inflammatory disease and exceptionally high antibody titres against Chlamydia trachomatis in an immunofluorescence test. The simple chlamydial complement fixation test is recommended for the screening of cases of erythema nodosum.

Adolescent↗
PubMed1995

Prevalence and development of antibodies neutralizing the haemolysin and cytotoxin of Actinobacillus pleuropneumoniae in three infected pig herds.

Sero-epidemiological studies were carried out in pigs aged 1 to 24 weeks in three herds in which Actinobacillus pleuropneumoniae was endemic. The sera were tested in the complement-fixation test and for their ability to neutralize the haemolytic and cytotoxic activities of the A. pleuropneumoniae serotypes isolated from the herds. Almost all (98%) sera from 1-week-old piglets neutralized the haemolytic and cytotoxic activities but only 21% fixed complement. At the end of the finishing period, most pigs (82%) had sera that neutralized haemolytic and cytotoxic activities and only 22% fixed complement. In longitudinal studies the neutralization titres decreased during the first 12-13 weeks of age. Thereafter, 75% of the pigs had increased titres in the haemolysin- and cytotoxin-neutralization tests and only 5% of the pigs had increased titres in the complement-fixation test. In none of these pigs were clinical signs of pleuropneumonia seen. Thus in these endemically infected herds the prevalence of complement-fixing antibodies was low, whereas the prevalence of neutralizing antibodies was high. The fact that serum-neutralizing titres are low in 12-week-old pigs might be the reason that pigs of this age are the most vulnerable to the disease.

Actinobacillus Infections↗
PubMed1976

[Influence of standardization upon the results of serological analysis of toxoplasmosis (author's transl)].

It is the purpose of this paper to determine whether the decline of the serologically verified acute Toxoplasma gondii infections observed since the late sixties and found in literature has been caused by epidemiological factors or whether the standardization of serological methods (10) introducted in 1966/66 for the determination of antibodies specific to Toxoplasma gondii has been responsible. The paper is based on material of the prospective study, "Pregnancy and child development" supported by the Deutsche Forschungsgemeinschaft (DFG). Mainly six laboratories did the serological analysis for antibodies against T. gondii from 1964 to 1970. The following results were obtained: 1. Laboratories using the standardization observed a decline of the highly positive dilution starting in 1968 (Fig. 1, Table 1). 2. The proportion of the samples positive in the dye test did not change (Fig. 1). 3. The proportion of sera reacting in the complement fixation test (CFT) with a dilution of 1:5 increased. But after introduction of the standardization more sera were analyzed by both the dye and complement fixation tests than before (Table 2, Fig. 2). 4. The proportion of sera found positive by the complement fixation test increased slightly up to 1968 (Fig. 3). 5. Differences in the age structure (Fig. 4) or dietary habits of the group (Fig. 5) did not cause the changes in titer. 6. Therefore the standardization was introduced a considerable proportion of the sera showing dye test results of more than 1:1000 reacted negatively to the complement fixation test (Table 4). These cases were probably not acute infections. 7. When the standardization was introduced the difference between results of first and second analysis decreased for sera with titers smaller then 1:256 (increased of reliability) (Table 5, Fig. 7). 8. Complement fixation titer show an analogous behavior. (Table 7 and 8). The results detained above show that the decrease, observed since 1969, of the cases of acute Toxoplasma infections verified by serological methods is not caused by epidemiological but rather by methodical factors.

Adult↗
PubMed1990

A rapid cold agglutinin test in Mycoplasma pneumoniae infection.

A definite diagnosis of Mycoplasma pneumoniae infection is currently based on cultural method or complement fixation test which is usually retrospective. A rapid cold agglutinin test was developed to determine its value on the early diagnosis of M. Pneumoniae infection. One hundred and thirty patients with pneumonia aged between 5 and 14 years were studied. Blood specimens from all the patients were collected for rapid cold agglutinin test, cold hemagglutination test, and complement fixation test. Thirty patients showed positive, rapid cold agglutinin test. All the patients with positive rapid cold agglutinin test had higher (greater than or equal to 1:32) cold agglutinin titers which were simultaneously performed. The rapid cold agglutinin test had 100% sensitivity and 97% specificity when a cut-off criterion was set at cold agglutinin titer greater than or equal to 1:64. Twenty-five of the 130 cases were serologically proven to have M. pneumoniae infection using complement fixation test or/and cold agglutinin titer. M. pneumoniae was a major cause (21/28) in cold agglutinin-positive pneumonic patients. The positive predictive value of the rapid cold agglutinin test is 70% (21/30). Only 28% (7/25) of the patients with M. pneumoniae infection were diagnosed at acute stage with serological method. We conclude that the rapid cold agglutinin test is of much value in the early detection of M. pneumoniae infection in office or hospital practice in children with pneumonia.

Adolescent↗
PubMed1984

Single radial hemolysis test for quantitation of complement-fixing antibodies to non-hemagglutinating viruses.

A single radial hemolysis test, which overcomes many of the problems of conventional complement fixation tests, was developed for the quantitation of virus complement-fixing antibodies. The test procedure utilized staphylococcal protein A-coated sheep erythrocytes immobilized in agarose into which antigen was incorporated. Undiluted heat-inactivated serum samples were allowed to diffuse radially from wells punched in the agarose. Protein A served to concentrate the subsequent antigen-antibody reaction on the surface of the erythrocytes. Zones of hemolysis were developed by flooding with complement. With adenovirus as a model, basic test parameters were defined, and optimum reagent concentrations and diffusion conditions were determined. A positive linear relationship was found to exist between zone diameter and increasing log concentration of specific antiserum. No correlation was found between zone diameter and total concentration of immunoglobulin G in test sera. Sera rendered anticomplementary by the addition of carrageenan produced hemolytic zones equal to diameter to those observed with untreated sera. Seventy-seven human sera with known complement fixation titers were tested by this method. Good correlation (r = 0.74) between the complement fixation test and single radial hemolysis was observed. This test was highly reproducible and more sensitive than the conventional complement fixation test.

Adenovirus Infections, Human↗
PubMed1982

Vaccination of cattle against experimentally induced thromboembolic meningoencephalitis with a Haemophilus somnus bacterin.

The capability of a commercial Haemophilus somnus bacterin to protect cattle against experimentally induced thromboembolic meningoencephalitis was examined. Eighteen cattle were vaccinated twice, 8 were vaccinated once, and 14 were nonvaccinated controls. Serum antibody responses to vaccination were measured by gel immunodiffusion, bacterial agglutination test, and complement-fixation test. Deaths occurred in 8 of the 14 controls, 3 of the cattle vaccinated once, and 3 of the cattle vaccinated twice. Two vaccinations were found to give significant protection against challenge exposure (P less than 0.05). There were no cattle which gave positive reactions in the gel immunodiffusion test, and significant changes in bacterial agglutination test titers were not seen in the cattle after vaccination. There was a significant (P less than 0.01) increase in the complement-fixation test titers of cattle vaccinated twice. Serum antibody titers were unrelated to the outcome of challenge infection, regardless of vaccination status, in any of the serotests.

Animals↗
PubMed1995

Internal quality assurance in a clinical virology laboratory. II. Internal quality control.

AIMS: In April 1991 additional quality control procedures were introduced into the virology section of the Clinical Microbiology and Public Health Laboratory, Cambridge. Internal quality control (IQC) samples were gradually included in the serological assays performed in the laboratory and supplemented kit controls and standard sera. METHODS: From April 1991 to December 1993, 2421 IQC procedures were carried out with reference sera. RESULTS: The IQC samples were evaluated according to the Westgard rules. Violations were recorded in 60 of 1808 (3.3%) controls and were highest in the IQC samples of complement fixation tests (25/312 (8%) of controls submitted for complement fixation tests). CONCLUSIONS: The inclusion of IQC samples in the serological assays performed in the laboratory has highlighted batch to batch variation in commercial assays. The setting of acceptable limits for the IQC samples has increased confidence in the validity of assay results.

Complement Fixation Tests↗
PubMed1994

Evaluation of the one-point microcapsule agglutination test for diagnosis of leptospirosis.

We have developed a one-point microcapsule agglutination test (MCAT) for the serodiagnosis of leptospirosis. The MCAT kit was evaluated for use in humans by six WHO Collaborating Centres for Reference and Research on Leptospirosis. The laboratories classified their serum samples on the basis of the microscopic agglutination test (MAT) and the following screening tests: enzyme-linked immunosorbent assay (ELISA), macroscopic (slide) agglutination test, or the complement fixation test. The MCAT may in some instances give a positive result earlier in the course of the disease than MAT or the ELISA IgM; on the other hand, it did not detect antibodies against some serovars, for example, those of the Sejroe or Australis serogroup in Slovakia. In contrast, however, the MCAT detected antibodies to serovar hardjo (the same serogroup as Sejroe) in patients from the United Kingdom and the Russian Federation.

Agglutination Tests↗
PubMed1994

Latent Q fever in cattle in southern Moravia (Czech Republic).

In 1991-92, a complement fixation test technique (titre > or = 8) was used in serological assays of antibodies to Coxiella burnetti performed in cattle in southern Moravia. Antibodies were ascertained in 6.1% to 213 aborting cows. The cows with a positive finding after abortion came from 13 different farms. On two of the farms (H. V. and P.), all the cattle were tested. On the H. V. farm, antibodies were ascertained in 4.2% of 120 cows, in 1 of 36 calves and in none of 93 heifers. On the P. farm, antibodies were ascertained in 14.1% of 519 cows and 15.2% of 521 cows in 1991 and 1992 respectively, in 17.4% of 190 calves and in none of 40 heifers. C. burnetii was ascertained in the milk of 9 of 15 seropositive cows from the P. farm, in all cows with the titre > or = 64. On the P. farm, reproduction characteristics of cows were monitored to ascertain possible links with the latent Q fever infection, but no relationship was found in this case. In 1991, sera of 56 employees from farms with seropositive cattle (in H. V. and P. and from another farm) and 26 employees from an industrial company were tested but the complement fixation tests failed to detect any antibodies. The C. burnetii strain circulating in south Moravian herds at present may be described as little virulent or avirulent.

Abortion, Veterinary↗
PubMed1980

[Antigenic similarity between stimulators of immunogenesis of a polypeptide nature from the thymus and cerebral cortex].

Rabbit antisera against low molecular weight polypeptides from the thymus (thymosin and thymarin), cortex (cortexin) and white matter of the brain of the calves were cross-absorbed with these polypeptides and tested in the complement fixation test with these preparations and in the complement-dependent cytotoxicity test with thymic and bone marrow cells. The results showed that thymosin, thymarin and cortexin are antigenically similar, but differ in antigenic structure from polypeptide from white matter of the brain. Biological effect of polypeptides from the thymus and brain cortex is connected with thymus-depending lymphocytes and does not depend on B-cells. Cross absorbtion revealed that antisera against polypeptides from thymus and cortex of the brain contain antibody both against common antigens and antigens specific for appropriate preparation only. Antigenic set of polypeptide from the thymus (thymarin) corresponds more closely to thymic antigen as compared to polypeptide from the brain cortex (cortexin).

Adjuvants, Immunologic↗
PubMed1965

STUDIES ON BLUETONGUE II. COMPLEMENT-FIXING ACTIVITY OF OVINE AND BOVINE SERA.

Sera of sheep and calves infected with the California type 10 and Cyprus type 3 viruses of bluetongue were tested by the regular and modified direct complement-fixation tests. To obtain satisfactory complement fixation it was necessary to use the latter test. Cross reactivity was found, therefore, the California type 10 antigen could be used in testing sera of animals infected with the Cyprus virus.

Animals↗
PubMed1959

Reactivity of a lecithin-free cardiolipin preparation (cardchol) in leprosy sera.

Previous experiments have shown that a mixture of cardiolipin and cholesterol in absolute ethanol (named "cardchol") might be used as an antigen in complement-fixation tests. The reactivity in the complement-fixation test of CWRM (an "ordinary" cardiolipin antigen) was compared with that of cardchol in several experiments, and it could be demonstrated that the reactivity of cardchol was especially pronounced in sera from false-positive reactors. In about 50% of such cases, quantitative determination of the antibody content showed that cardchol was more reactive than CWRM, whereas in syphilitic cases the reactivity of cardchol was inferior to that of CWRM. An exception was primary syphilis, which showed a reactivity level with cardchol equal to or even superior to that of CWRM.Examinations of a certain number of sera from leprosy patients had shown them to be highly reactive with cardchol and non-reactive or weakly reactive with CWRM; this observation is fully confirmed by examination of a larger number of leprosy sera, on which this paper reports. These sera were examined with a battery of tests using lipoidal antigens and with the TPI test. Testing with cardchol proved to give the highest reactivity with these sera, which were mostly non-treponemal.Subdivision of the material according to the clinical stage of leprosy showed that the highest reactivity of cardchol occurred in patients with lepromatous leprosy, particularly in those with leprosy of relatively short duration.Electrophoretic fractionation of these sera demonstrated that the substances reacting with cardchol were situated in the gamma-globulin or gamma- and beta-globulin serum fractions.

Antibodies↗
PubMed1991

Detection of equine antibody to Babesia equi merozoite proteins by a monoclonal antibody-based competitive inhibition enzyme-linked immunosorbent assay.

A competitive inhibition enzyme-linked immunosorbent assay (CI ELISA) was developed to detect antibody to Babesia equi. One hundred fifty-four equine serum samples from 19 countries were tested for antibody to B. equi by the complement fixation test and by CI ELISA. The CI ELISA and complement fixation test results agreed in 94% (144) of the serum samples tested. The 10 discrepant serum samples were retested and analyzed for ability to immunoprecipitate in vitro translation products from B. equi merozoite mRNA. Five discrepant results were clearly resolved in favor of the CI ELISA, and the remaining five discrepancies were not definitively resolved.

Animals↗
PubMed1984

[Validity of syphilis serodiagnosis in its prevention in apparently healthy workers applying for health certificates according to Law No. 837 of 25 July 1956].

The law 837/1956 establishes the right to subject the applicants for a certificate of health to serological tests for syphilis. Two Ministerial decrees establish that the first laboratory should carry out these tests using a fast test (VDRL) and should use the Complement fixation test as a control. This criterion of research does not correspond to the aims of the law. In fact the Complement fixation tests are not very sensitive and specific when used on the unknown luetic population. The positive diagnosis can be formulated by the first laboratory only using more sensitive and specific tests. The control laboratory, in this case, has succeeded in singling out the true luetics by using different serological tests (FTA-ABS, TPI).

Complement Fixation Tests↗