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PubMed1991

Field evaluation of alternative HIV testing strategy with a rapid immunobinding assay and an agglutination assay.

A rapid immunobinding assay ('HIVCHEK', Ortho) and an agglutination assay ('Serodia-HIV', Fujirebio) were evaluated as an alternative to enzyme-linked immunosorbent assay (ELISA) and western blot under field conditions in Africa for detection of antibody to human immunodeficiency virus (HIV). 7106 specimens were tested at 25 laboratories in Kenya, Ghana, Senegal, and Zaire. HIVCHEK was used as a screening test, and serodia-HIV as a supplemental test to evaluate these assays in an alternative testing strategy to the standard ELISA/western blot testing procedure. In each country, HIVCHEK was more sensitive and specific than ELISA when compared with western blot. The sensitivity of HIVCHEK ranged from 87.0 to 96.3% and the specificity from 99.0 to 100%. The sensitivity and specificity of serodia-HIV ranged from 85 to 98% and from 88 to 98%, respectively. The sensitivity and specificity were affected by the presence of HIV-2 in Ghana and Senegal. Overall, with an HIV-1 prevalence of 14.8% in Kenya and 22.5% in Zaire, the sensitivities of the alternative strategy were 96.4% and 91.4%, the specificities 99.6% and 100%, the positive predictive values 97.6% and 100%, and the negative predictive values 99.3% and 97.9% for Kenya and Zaire, respectively. With this testing format there was an estimated average cost saving of up to 82% over the conventional strategy with ELISA/western blot. This procedure constitutes a reasonable alternative to the standard ELISA/western blot combination.

Africa↗
PubMed1985

Anti-sperm antibodies, detected by agglutination, immobilization, microcytotoxicity and immunobead-binding assays.

To determine the reliability of tests currently utilized in the detection of sperm-reactive antibodies, sera were provided as unknowns and studied without knowledge of the clinical histories. Four laboratories performed tray agglutination tests (TAT), three complement-dependent immobilization (SIT), and single laboratories sperm cytotoxicity (SCT), passive haemagglutination (PHA) and immunobead binding (IBB). Most investigators demonstrated an excellent correlation between duplicate sample results. Nearly all of the female sera were free of anti-sperm antibodies and positive results did not appear in greater frequency in women with unexplained infertility as compared with other categories. For the male sera, the highest incidence of anti-sperm antibodies in the infertile group (21% positive for sperm-reactive IgGs) was obtained by immunobead binding. The GAT and TAT results gave 7 and 12% positives, except for lower results in one laboratory. Sperm-reactive antibodies were detected most commonly in vasectomized men, with all assays except SCT and PHA. Of the newer techniques studied, IBB results correlated well with TAT, GAT and SIT, while SCT and PHA did not, suggesting that a different group of antibodies, perhaps directed against other sperm-associated antigens, was being detected by the latter procedures. In this light, emphasis was placed on the need to validate whether results of particular methodologies correlated with impaired sperm function and to develop methods that provided evidence for this premise, either on the basis of clinical criteria or altered gamete interaction in vitro.

Antibodies↗
PubMed1989

Detection of conglutinin in bovine serum by complement-dependent agglutination of Escherichia coli.

Agglutination of Escherichia coli (ECA) by normal bovine serum was shown to be prevented by heating serum to 56 degrees C for 30 min, but restored by normal horse, swine, rabbit or guinea pig sera. Further investigation of the ECA reaction using techniques to distinguish between conglutination and immunoconglutination indicated ECA to be a conglutination reaction. Testing of 264 sera obtained from 22 normal cattle over a period of 5 months did not show individual or seasonal variation in ECA. Changes in ECA and conglutination were detected in sera of periparturient cows. The ECA reaction is a simple technique for detecting conglutinin in bovine serum.

Agglutination↗
PubMed1996

Crowding stress induces changes in serum haemolytic and agglutinating activity in the gilthead sea bream Sparus aurata.

Sea bream Sparus aurata were subjected to crowding for 3 weeks and the levels of plasma cortisol and glucose were determined in order to ascertain the occurrence of stress. At the same time, selected indicators of the immune response were monitored through blood lymphocyte counting and selected humoral responses such as the haemagglutination activity (HA) of serum towards rabbit erythrocytes (RaRBC) and the alternative complement pathway (ACP) levels. The results show an initial moderate increase in cortisol followed by hyperglycaemia and recovery to basal levels. A pattern of immunodepression was detected afterwards as shown by decreases in ACP levels after 5 days and haemagglutination titre and circulating lymphocytes after 9 days. Nevertheless, ACP levels showed a significant increase after 9 days, and HA titres and circulating lymphocyte numbers also increased after 15 days. Normal values were recovered after 15 days for lymphocytes and ACP and 21 days for agglutination. Results are discussed in view of the incidence of stress on indicative parameters of endocrine and immune systems.

Agglutination↗
PubMed1987

Surface carbohydrates of procyclic forms of African trypanosomes studied using fluorescence activated cell sorter analysis and agglutination with lectins.

Living culture form procyclics of Trypanosoma brucei brucei, T.b. rhodesiense, T.b. gambiense, T. congolense and T. simiae were tested for binding of eight different lectins. The binding of fluorescein isothiocyanate (FITC)-conjugated lectins was measured using a fluorescence activated cell sorter (FACS) and by agglutination with unlabelled lectins. Five of the lectins failed to bind to any of the procyclic organisms in both tests. All parasites bound concanavalin A (Con A) and all T.b. brucei, T.b. rhodesiense and T. congolense procyclics bound Ricinus communis agglutinin 120 (RCA) and wheat germ agglutinin (WGA). Trypanosoma b. gambiense procyclics failed to bind RCA and thus could be easily discriminated from other subspecies of T. brucei. Similarly, T. simiae did not bind WGA, unlike T. congolense, the other species of the genus Nannomonas. All positive reactions were inhibited by 0.2 M concentrations of the relevant sugars. The results indicate that all species and subspecies of the procyclic culture forms tested have surface-exposed structures resembling alpha-D-mannose moieties and that T.b. brucei, T.b. rhodesiense and T. congolense have surface-exposed molecules resembling D-galactose and N-acetyl D-glucosamine (or sialic acid) moieties. Molecules resembling D-galactose and N-acetyl D-glucosamine residues are absent or inaccessible in T.b. gambiense and T. simiae respectively. A group of T. congolense clones of parasite stocks isolated at Kilifi on the Kenyan coast showed quantitatively different binding of RCA when compared to the other T. congolense clones tested indicating that these organisms differ in surface carbohydrate structure.

Agglutination↗
PubMed1975

The Concanavalin A agglutinating system of cell membranes.

The hopes raised by the finding of differential Concanavalin A (Con A) agglutinability of normal and transformed cells in efforts to quantify differences between these cell lines seem not to have been justified. In this paper, the development of information on the mechanism of action of Con A on the cell surface, as well as the theories put forward at each stage of this development are surveyed. In this respect, investigations on Con A constitute a case history in biological research. The involvement of glycoproteins and galactosyltransferases in cell-cell interactions and their relations to Con A are also reviewed.

Agglutination↗
PubMed1990

Induction of sexual agglutinability by unsaturated fatty acids in Saccharomyces cerevisiae.

Agglutinins in S. cerevisiae are necessary for mating, for recognition between cells of opposite mating type. The mode of agglutinin synthesis is altered by the growth temperature and by the carbon source, from constitutive to inducible synthesis and vice versa. Some of the unsaturated fatty acids tested induced synthesis of agglutinins in cells grown at an elevated temperature, even in the absence of the pheromone. However, synthesis of agglutinins in glycerol-grown cells, that are inducible by the pheromone, was not induced by linolenic acid. Hence, the change in the mechanism of regulation of agglutinability produced by differences in temperature probably differs from that produced by differences in carbon source.

Agglutination↗
PubMed1992

Development and evaluation of a rapid, simple, sensitive, monoclonal antibody-based co-agglutination test for direct detection of Vibrio cholerae 01.

Cholera epidemics caused by Vibrio cholerae 01 continue to represent a major public health concern in many developing countries. A rapid and simple test kit for the detection of V. cholerae 01 has been developed. The kit, CholeraScreen is a monoclonal antibody-based, co-agglutination test and is used directly with stool specimens. It does not include culturing the specimen and is performed without the need for sophisticated laboratory equipment. Specificity of the test was demonstrated, using 118 reference cultures, to which cross-reactions were not observed. Preliminary results of field trials carried out in Guatemala and Bangladesh demonstrated that the test is equally sensitive as conventional culture methods in detecting V. cholerae and, in many cases, more sensitive. The CholeraScreen test is simple, specific, and does not require culturing procedures, making it suitable for direct detection of cells of V. cholerae in clinical specimens, even in the field. Also, the test requires less than five minutes to complete.

Agglutination Tests↗
PubMed1991

The serological response of calves to Leptospira interrogans serovar hardjo vaccines and infection as measured by the microscopic agglutination test and anti-IgM and anti-IgG enzyme-linked immunosorbent assay.

The microscopic agglutination test (MAT) and the anti-IgM and anti-IgG enzyme-linked immunosorbent assays (ELISA) were used to examine sera taken over the course of 16 weeks from 35 calves vaccinated and/or infected with Leptospira interrogans serovar hardjo. The relationship between the IgM and IgG responses to vaccination and infection were determined. The rapid and high rise in IgM levels following challenge made the anti-IgM ELISA a potentially good indicator of recently established infection although some transitory high levels were seen where infection did not become established. The slow IgG response to infection made the anti-IgG ELISA of limited diagnostic use.

Agglutination Tests↗
PubMed1983

Comparison of coagglutination, latex agglutination, and enzyme-linked immunosorbent assay for detection of Haemophilus influenzae type b infection.

Two commercially available kits were compared to an enzyme-linked immunosorbent assay (ELISA) for detection of Haemophilus influenzae type b antigen polyribophosphate in clinical specimens with infections proved by culture. Methods employed by the kits were latex agglutination (LA) and staphylococcal coagglutination (COA). The COA kit detects H. influenzae type b and types a and c-f with a polyvalent antiserum, whereas the ELISA assay and the LA kit detect only type b. A total of 139 specimens (41 spinal fluid, 35 urine, 25 serum, and 38 sputum) were tested. All spinal fluid samples positive by culture were positive by all three procedures. Of urine specimens from patients with a variety of H. influenzae type b infections, 13 of 15 were positive by ELISA, 8 of 15 by COA, and 8 of 14 by LA. Of serum samples collected from the same patients at various times during their illness, 8 of 15 were positive by ELISA, 6 of 15 by COA, and 10 of 15 by LA. Of sputum samples positive by culture for H. influenzae type b, 14 of 17 were positive by ELISA, 9 of 17 by COA, and 4 of 16 by LA. The ability to detect additional serotypes of H. influenzae was shown by the COA kit, which detected H. influenzae type a in spinal fluid from a patient with type a meningitis proved by culture.

Agglutination Tests↗
PubMed1993

Serodiagnosis of tuberculosis: assessment of kaolin agglutination test.

Kaolin agglutination test (KAT), for the detection of anti-tuberculophospholipid antibodies for the serodiagnosis of tuberculosis, was performed on the sera of 137 pulmonary and 276 extra pulmonary tuberculosis patients and 140 controls. The sensitivity and specificity of KAT was 86.9% and 100%, respectively, at the titre of 1:128 and more.

Agglutination Tests↗
PubMed2005

Serological diagnosis of Indian visceral leishmaniasis: direct agglutination test versus rK39 strip test.

We evaluated the direct agglutination test (DAT), using freeze-dried (FD) and aqueous (AQ) antigen, and the rK39 immunochromatographic strip test in the diagnosis of Indian visceral leishmaniasis (VL). Sera from 508 subjects (150 parasitologically confirmed patients with VL, 100 and 153 healthy controls drawn from non-endemic and endemic regions, respectively, and 105 patients with other diseases presenting with fever and/or splenomegaly) were tested. The sensitivity of the tests were as follows: DAT (FD), 96% (95% CI 91-98); DAT (AQ), 97% (95% CI 93-99); rK39 strip test, 99% (95% CI 95-100). The specificity of DAT (FD), DAT (AQ) and rK39 strip tests were 85% (95% CI 81-88), 87% (95% CI 83-91) and 89% (95% CI 86-92), respectively. A significant correlation (high degree of agreement) was observed between all tests (kappa>0.80). We conclude that the sensitivity of FD antigen is comparable to that of AQ antigen. Similarly, the rK39 strip test is as sensitive as the DAT, but the strip test's greater convenience of use makes it a better tool for diagnosis of VL in peripheral areas of endemic regions.

Agglutination Tests↗
PubMed2004

Evaluation of the card agglutination test (CATT/T. evansi) for detection of Trypanosoma evansi infection in water buffaloes (Bubalus bubalis) in Egypt.

A card agglutination test (CATT/T. evansi) was evaluated for detection of antibodies against Trypanosoma evansi (T. evansi) in experimentally and naturally infected buffaloes. Four calves were inoculated with a strain of T. evansi isolated from a dromedary camel. Parasitological examination of the calves revealed trypanosomes in the blood from days 4 to 9 post-inoculation (PI). General emaciation appeared from day 26 PI and aggravated until the end of the experiment (day 88 PI). Antibodies against T. evansi were detectable from day 8 PI till the end of the experiment. Parasitological examination of 200 water buffalo blood samples obtained from slaughterhouses revealed negative results. Serological examination of these animals showed that 48 (24%) water buffaloes had anti-T. evansi antibodies.

Agglutination Tests↗
PubMed2004

Determination of an optimized cut-off value for the Neospora agglutination test for serodiagnosis in cattle.

A definitive diagnosis of neosporosis in cattle implies the examination of the aborted fetus. However, in many instances fetal material is not available. Therefore, most diagnosis are based on serological tests. At the moment, there are no consensuses about the cut-off for serodiagnosis of neosporosis in cattle, for any test. The objective of the present study was to estimate the best cut-off for the Neospora agglutination test (NAT) for serodiagnosis in cattle. For that purpose, 246 serum samples from 4 groups of dairy cows (aborted Neospora positive; not aborted healthy; aborted other diseases and herds endemic neosporosis) were collected and antibodies anti-N. caninum were determined by NAT. Additionally, immunoblot (IB) was performed with sera from all cows of the endemic neosporosis group and the patterns of seroreactivity were contrasted with the NAT titers for this group of cows. Evaluation of the optimized sensitivity and specificity was calculated using Youden's J-statistics. The best Youden's J-statistic was obtained at 1:40 titer, presenting 100% of sensitivity and 90.4% of specificity with negative and positive predictive values of 100 and 75.0%, respectively. The comparison between NAT titers and the IB banding pattern support the results of the statistical analysis, i.e. titers of 1:40 and higher showed a complex pattern of bands, while titers lower than 1:40 did not precipitate any bands. These results indicate that 1:40 was an optimized NAT cut-off for serodiagnosis in cattle.

Aborted Fetus↗
PubMed2005

Comparison of a commercial ELISA with the modified agglutination test for detection of Toxoplasma infection in the domestic pig.

The modified agglutination test (MAT) and a commercially available enzyme-linked immunosorbent assay (ELISA) were compared for detection of antibodies to Toxoplasma gondii in naturally-infected market-aged pigs. Infected pigs were obtained from commercial slaughter facilities and from farms where infection had previously been detected. Infection was confirmed by bioassay in cats. For 70 bioassay positive pigs, 60 were positive by MAT (85.7% sensitivity) and 62 were positive by ELISA (88.6% sensitivity). Of 204 bioassay negative samples 193 were negative by MAT (94.6% specificity) and 200 were negative by ELISA (98.0% specificity). Good correlation was seen between MAT and ELISA results. The results suggest that the ELISA may be a good tool for epidemiological studies of Toxoplasma infection on pig farms.

Agglutination Tests↗
PubMed1997

Experimental cutaneous leishmaniasis. IV. The humoral response of Cebus apella (Primates: Cebidae) to infections of Leishmania (Leishmania) amazonensis, L. (Viannia) lainsoni and L. (V.) braziliensis using the direct agglutination test.

The direct agglutination test (DAT) was used to evaluate the serological response of 150 serum samples taken from 15 captive-bred capuchin monkeys Cebus apella. These animals had been experimentally infected with either L. (Leishmania) amazonensis, L. (Viannia) lainsoni or L. (V.) braziliensis. Monkeys infected with L. (L.) amazonensis or L. (V.) lainsoni were challenged with the homologous parasite one month after their spontaneous cure. DAT antigens were prepared from L. (L.) donovani, L. (L.) amazonensis and L. (V.) braziliensis. Antigens were difficult to standardise and it was impossible to produce an L. (V.) lainsoni antigen as parasites remained aggregated even after trypsinization. The DAT detected significant humoral responses in all the infected monkeys. Titres were higher when homologous antigens were used, especially in secondary responses. This suggests that homologous antigen should be used to detect antibodies in human cutaneous leishmaniasis.

Agglutination Tests↗
PubMed1986

Detection of autoimmunity to sperm: mixed antiglobulin reaction (MAR) test or sperm agglutination? A study on 537 men from infertile couples.

Two different ways of testing for antisperm antibodies were compared: the mixed antiglobulin reaction (MAR) test for demonstration of antibodies of the IgG and IgA classes bound in vivo to the sperm membrane antigens and the gelatin agglutination test for detection of nonbound antisperm antibodies in serum and seminal plasma. Samples from 537 men from infertile couples were investigated. Antibodies bound to the sperm membrane were detected in 49 men (9.1%), IgG in 44 (8.2%), and IgA in 38 cases (7.1%). Sperm agglutinins were recorded in seminal plasma from 30 men (5.6%) and in serum (titer greater than or equal to 16) from 43 men (8.0%). The investigation revealed a very close correlation between the results of MAR testing and the occurrence of sperm agglutinins in serum and seminal plasma. However, if one focuses on antisperm antibodies of the IgA class, which seem to play the major role in male immune infertility, the MAR test offered the advantage that a minor group of patients with pure IgG responses could be distinguished, and rare cases with mainly or exclusively locally produced IgA antibodies could be detected.

Autoantibodies↗
PubMed1994

Comparison of flow cytometric measurement of seminal antisperm antibodies with the mixed antiglobulin reaction and the serum tray agglutination test.

OBJECTIVE: To compare the mixed antiglobulin reaction (MAR) and the serum tray agglutination test (TAT) with the flow cytometric (FCM) measurement of sperm antibodies. To evaluate by FCM the correlation in sperm antibody parameters between paired semen ejaculates obtained 2 to 4 weeks apart and the effect of washing on sperm antibody levels. SETTING: University-based infertility clinic. PATIENTS: The TAT and FCM were done on 81 patients with a positive immunoglobulin (Ig)G-MAR test. The correlation of sperm antibody parameters between paired semen samples was done in 16 men. A few samples were used to study the effect of washing on sperm antibody parameters. MAIN OUTCOME MEASURES: The proportion of spermatozoa positive for IgG and IgA antibodies as well as the number of antibody molecules per spermatozoa measured by FCM. RESULTS: In general, the degree of MAR positivity but not that of the TAT correlated with the sperm antibody load. With reference to FCM the MAR test had an 1% false positive rate, whereas the serum TAT had a 25% false negative rate. Correlation between FCM measurements of paired semen samples was good. Washing the spermatozoa once removed the loosely bound antibodies; further washes were not useful. CONCLUSION: Flow cytometry is a reliable technique that correlates with the MAR test. In patients with a strongly positive MAR, FCM is useful to identify patients with a low sperm antibody load. It is speculated that patients with a low sperm antibody load may respond better to IVF treatment.

Agglutination Tests↗