Anti-gamma-globulin factors in human allograft recipients.
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Agglutination Tests↗
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Rapid diagnosis of typhoid fever by detection of Barber protein and Vi antigen of Salmonella serotype typhi.
Co-agglutination (coagg) and latex agglutination (LA) tests were used for the detection of Salmonella serotype Typhi Vi and Barber protein (BP) antigens in sera from five groups of individuals (A-E). Group A consisted of 30 blood culture-positive cases of typhoid fever and group B consisted of 30 suspected cases of typhoid fever who had sterile blood cultures but positive Widal tests. Thirty cases of pyrexia of unknown origin (PUO) were placed in group C, while group D consisted of 15 cases of septicaemia caused by organisms other than Salmonella serotype Typhi. Group E comprised 50 normal healthy individuals with no history of typhoid fever or TAB vaccination in the previous 5 years. The Vi-LA test performed best with 96.7% of group A sera and 90% of group B sera giving positive results. No false positive results and only 2.58% false negative results were obtained with this test. Considering patients with positive blood culture results or positive Widal tests as true positives, the sensitivities of the Vi-LA, BP-LA, Vi-coagg and BP-coagg tests were 93.3, 91.7, 83.3 and 86.7%, respectively. The specificities of these tests were 100, 98.5, 98.5 and 98.5%, respectively. It is suggested that the Vi-LA test can be used for the rapid and early diagnosis of typhoid fever.
Agglutination Tests↗
Binding of extracellular matrix proteins to the surface of anaerobic bacteria.
The binding of fibronectin, vitronectin, collagen and sialoprotein to 65 anaerobic strains was investigated by means of latex agglutination tests. The binding of fibronectin, collagen and lactoferrin to the same strains was also tested by means of 125I-labelled proteins. The strains were isolated from abdominal infections (55%), from the faeces of healthy subjects (29%) or from the depths of tonsils removed at tonsillectomy (16%). The binding of fibronectin and collagen to Bacteroides fragilis strains, tested by the latex agglutination assay, was stronger than their binding to other species. The vitronectin binding of the strains was less common, but was always accompanied by fibronectin binding. Binding to fibronectin-coated beads was inhibited by pre-incubation of the bacterial cells with soluble fibronectin and by heat or protease treatment of the bacterial suspension. No inhibition of the binding was observed with carbohydrates. None of the 65 strains exhibited any binding to fetuin or asialofetuin; 8% of the strains had a binding site for mucin. The binding to mucin-coated beads was inhibited by pre-incubation of the cells with mucin. The radiolabelling method indicated a low binding to 125I-fibronectin. The binding of 125I-collagen-I and 125I-lactoferrin was higher for the anaerobic strains tested.
Bacteria, Anaerobic↗
Detection of verocytotoxin from stool and serological testing of patients with diarrhea caused by Escherichia coli O157 : H7.
The detection of verocytotoxin (VT) in stool and measurement of antibodies against VT and three antigens (unheated-antigen, LPS, and flagellin) of Escherichia coli O157 : H7 in the serum of patients with diarrhea were examined. Five of 14 inpatients during an outbreak had fecal VT2 in stool taken within 5 days of onset to hospitalization. Among these 5, 3 of them also had fecal VT-producing E. coli (VTEC) serotype O157 : H7, whereas the other 2 did not. In the passive hemagglutination (PHA) test with formalinized sheep red blood cells sensitized with three VTEC O157 : H7 antigens, 49 (74.2%) of 66 outbreak patients and 3 of 3 sporadic cases had antibodies against both or one of unheated-antigen and LPS of E. coli O157, but none had antibody against flagellin. In addition, anti-VT2 antibody was demonstrated in serum samples from 15 (94%) of 16 inpatients and 2 (4%) of 50 outpatients in an outbreak by a VT-enzyme-linked immunosorbent assay (VT-ELISA). These results showed that serological assay particularly for antibodies against VT and unheated-antigen or LPS of VTEC O157 may provide a useful tool for diagnosis of infection with VTEC O157.
Adult↗
Capsular typing of klebsiellae by coagglutination and latex agglutination.
A simple method for capsular serotype determination of Klebsiella is described, using staphylococci or latex particles coated by specific antibodies and the supernatant of a bacterial suspension in saline as antigen. These methods may be at least as reliable as other methods and easier to perform and less expensive than other methods.
Agglutination Tests↗
Rapid presumptive identification of Cryptococcus neoformans by staphylococcal coagglutination.
A coagglutination reagent was prepared by sensitizing the Cowan I strain of Staphylococcus aureus with rabbit immune globulin directed against Cryptococcus neofromans A15 and absorbed with C. laurentii. This reagent was evaluated for its usefulness in differentiating C. neoformans from other yeast colonies rapidly. Antigen-containing extracts were prepared form Sabouraud dextrose agar cultures of 48 C. neoformans, 33 other Cryptococcus species, 21 Candida, 4 Torulopsis, 3 Saccharomyces, and 2 Rhodotorula strains. This was done by suspending a 0.001-ml loopful of colony growth in 0.5 ml of phenolized saline, mixing for 30 s, and then centrifuging. Equal volumes (50 microliters) of coagglutination reagent and yeast extract were mixed within marked circles on a glass slide and then mechanically rotated at 180 rpm for 8 min. Forty-five of the 48 strains of C. neoformans produced strong (3+ to 4+) agglutination, and 3 strains of serotype C produced weak (1+ to 2+) agglutination with the reagent. Other Cryptococcus species which reacted positively were 4 C. albidus subsp. diffluens, 7 C. albidus subsp. albidus, and 2 C. terreus strains; however, false-positive errors in identification were circumvented by performing a supplemental rapid test for nitrate utilization which differentiated these yeasts from C. neoformans. None of the other yeasts tested (including 14 C. laurentii, 2 C. luteolus, and 2 C. uniguttulatus strains) produced any degree of agglutination with the reagent. A commercial cryptococcal latex agglutination reagent (Crypto-Test, Microbiological Associates, Walkersville, Md.) proved less reliable for identifying C. neoformans yeast colonies because of cross-reactions which occurred with all other species of Cryptococcus tested.
Agglutination Tests↗
Detection of cytomegalovirus antibody with latex agglutination.
Transfusion-acquired cytomegalovirus (CMV) infections should be prevented in seronegative immunocompromised patients by providing blood products from donors who are also seronegative. Latex agglutination was investigated as a simple and rapid method for detecting antibody against CMV. Latex beads were coated with CMV antigen, incubated for 8 min at room temperature with 25 microliter of sera, and examined for agglutination. The sensitivity and specificity of latex agglutination was compared with that of indirect hemagglutination (IHA, Cetus Corp., Emeryville, Calif.) and enzyme immunoassay (EIA) with sera from 604 random blood donors or patients. Of 327 serum samples shown to be seronegative by EIA and IHA, 327 had a latex agglutination titer of less than 1:4 (specificity, 100%). Of 236 serum samples with detectable antibody by EIA and IHA, 228 had a latex agglutination titer of 1:4 or greater (sensitivity, 97%). Plasma collected with EDTA, heparin, or citrate was satisfactory for latex agglutination. Latex agglutination results correlated quantitatively with those of EIA, and the test also detected fourfold or greater rises in antibody with paired sera from six patients with posttransfusion CMV infections. Latex agglutination is a sensitive and specific assay that is rapid and simple to perform and should be effective in selecting seronegative blood donors to prevent posttransfusion CMV infections in seronegative recipients.
Antibodies, Viral↗
Differences in antibody responses with rapid agglutination tests for the detection of rubella antibodies.
Rapid agglutination tests (Rubaquick, Rubascan, and Rubacell) were used to screen sera (374 from immune and 124 from susceptible patients) for rubella immunity. Compared with enzyme immunoassay (Rubazyme) the erythrocyte agglutination assays (Rubaquick and Rubacell) were greater than 98% sensitive and 92 to 96% specific. The latex test (Rubascan) was sensitive (97.8%) and specific (96.8%) on undiluted serum but only 68.7% sensitive on serum diluted 1:10. Although the three rapid assays detected a substantial number of positive sera within 3 months of rubella immunization, a large number of variable responses were seen after infection with rubella. Analysis of discordant results suggests that these tests may be effectively used for immunity screening. The different individual assay results observed on low-titered sera or blood collected shortly after infection or immunization may not be comparable, because each assay has a different antigenic component on the agglutinin.
Antibodies, Viral↗
Latex agglutination test for rubella antibodies: report based on data from the College of American Pathologists surveys, 1983 to 1985.
In the College of American Pathologists (CAP) rubella survey program, 45% of laboratories rely on the latex agglutination (LA) card assay for detecting rubella immunoglobulin G (IgG) antibodies. By using CAP survey data over a 3-year period, we compared LA results with hemagglutination inhibition (HI) and enzyme immunoassay (EIA) results. EIA indices were used to classify results into three categories: nonimmune, EIA index of 0.300 or less; borderline, EIA index of 0.300 to 0.619; and immune, EIA index of 1.700 or greater. There was 91% or more agreement between LA, HI, and EIA for categories i and iii. In category ii, the response from LA users varied, depending on the level of antibody present in the survey samples; at an EIA index of 0.346, 81% reported nonimmune status, whereas at an EIA index of 0.619, 48% reported nonimmune status. Less than 10% indicated borderline status. In testing of samples in the same category, approximately 40%, using the HI method, reported titers of less than 1:8 (nonimmune status). Among EIA users, 97 to 99% regarded the specimens as nonimmune. On analysis of specimens in the borderline category, the LA test showed a pattern of sensitivity and specificity comparable to that reported with the HI technique, whereas the EIA method showed a greater degree of precision. The LA card assay provides a rapid screening test in which LA is read macroscopically, and the procedure differs considerably from the fully quantitative HI and EIA methods.(ABSTRACT TRUNCATED AT 250 WORDS)
Antibodies, Viral↗
Serum immunoglobulins in juvenile rheumatoid arthritis.
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Adolescent↗
Effect of dextran on the reaction between rheumatoid factor and human gamma globulin.
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Agglutination↗
Evaluation of Bactigen latex agglutination and Phadebact coagglutination for detection of bacterial antigens in cerebrospinal fluid.
The Bactigen latex agglutination and Phadebact coagglutination tests were evaluated for their ability to detect bacterial antigens of Haemophilus influenzae type b, Streptococcus pneumoniae (83 serotypes) and Neisseria meningitidis groups A, B, C, and Y in 214 samples of cerebrospinal fluid (CSF). Bactigen latex agglutination was more sensitive than Phadebact coagglutination: it detected 87% (59/68) of culture positive CSF specimens, whereas Phadebact detected 72% (52/72). Bactigen detected all cases of meningitis caused by S pneumoniae and H influenzae. Of the 19 specimens that were positive for N meningitidis, 74% were detected by Phadebact and only 53% by Bactigen. Gram stain results were positive for 85% of all specimens positive on culture. Bactigen was slightly more specific (97%) than Phadebact (96%). Bactigen, however, showed less specificity (81%) than Phadebact (94%) on 31 CSF specimens that were culture positive for organisms other than the test organisms. These included two CSF specimens from patients with tuberculous meningitis which gave false positive results for S pneumoniae with the Bactigen reagents. No false positive results were obtained on 104 culture negative CSF samples. Bactigen latex agglutination was superior to Phadebact coagglutination and Gram stain for the detection of S pneumoniae and H influenzae in CSF specimens from patients with bacteriologically proved meningitis.
Agglutination Tests↗
Diagnosis of cytomegalovirus infection in heart transplant recipients.
In a prospective study eight (47%) heart transplant recipients had recurrent cytomegalovirus (CMV) infection. Of these, five had received hearts from seropositive donors. Neither serology nor virus isolation from urine was reliably associated with clinical CMV infection, but a high CMV IgM index correlated with CMV infection.
Antibodies, Viral↗
[A comparison of two tests for rheumatoid factor: latex test and l-agglutination (author's transl)].
Positive and negative reactions of latex test (LX) and streptococcal L-agglutination (LA) were correlated significantly with one another. However, in approximately 70% of the sera tested only one test was positive, LX at a much higher rate than LA. Postive rheumatoid factor tests were found in 117 patients with rheumatoid arthritis and in 595 patients with other diseases, exclusive of connective tissue diseases. Among the seropositive patients with rheumatoid arthritis, a positive reaction was seen in 85% and 71% by LX or LA respectively. Patients with nonrheumatic diseases showed positive reactions at a rate of 3,1%, with 2,3% and 1,7% in LX or La respectively. This shows that LA is less sensitive, but more specific as compared with LX. With increasing age of the patients, the rate of "nonspecific positive" reactors in patients with nonrheumatic diseases increases, more strongly for LX than for LA. The distribution of positive tests (LX positive, LA positive, or both positive) was analyzed in various groups of patients. The rate of positive reactions in both tests is significantly higher than patients with rheumatoid arthritis; it further increases with the severity of the disease. In cases with positive CRP, the rate of sera positive in both tests is higher, equally in patients with and without rheumatoid arthritis. In patients with nonrheumatic diseases an elevated serum gamma-globulin is associated with positive reactions in both tests and with positive LX. In all other grouping of patients, the rheumatoid factor tests did not yield significant deviations from chance distribution, as determined by chi2 analysis.
Age Factors↗
[The characteristics of a Russian-made kit for the serological identification of streptococci groups A, B and C].
The first Soviet kits for the serological identification of streptococci, groups A, B, and C, on the basis of the coagglutination test were developed. Each kit was intended for 35-40 determinations. The optimum concentration of streptococci during their identification by means of the reagents making up the kit was about 1.6 x 10(9) cells/ml. The specificity of the reagents in comparison with the results of the identification of streptococci by reference methods was 97.3 +/- 0.9%. The reagents making up the kits can be presumably used for solving a number of practical problems in the epidemiological surveillance of streptococcal infection.
Agglutination Tests↗
Serodiagnosis of ovine toxoplasmosis: an assessment of the latex agglutination test and the value of IgM specific titres after experimental oocyst-induced infections.
The antibody response of 20 pregnant ewes to oocyst infection with Toxoplasma gondii was determined by the latex agglutination test (LAT) and compared with the indirect fluorescent antibody test (IFAT) and a commercially available indirect haemagglutination test (IHAT). The LAT and IFAT showed a similar rapid response with antibody first appearing by two to three weeks after infection and titres that correlated closely (r = 0.81, P less than 0.001). The IHAT response was slower and less consistent up to seven weeks after infection. The LAT response was biphasic in seven of the sheep. Sera were fractionated using a minicolumn gel filtration technique and specific IgM and IgG titres determined by LAT. IgM titres peaked three weeks after infection and IgG titres exceeded IgM titres at a mean time of 4.7 weeks after infection (range 3 to 7). Eleven sheep exhibited fetopathy with abortion/parturition 12 to 53 days after infection; in nine of them IgG titres exceeded IgM at that time. A non-specific anti-toxoplasma reaction associated with IgM antibody occurred at low titre in one sheep. The results indicate that used from a dilution of 1/64 the LAT is a sensitive, reliable and rapidly responsive serological test for toxoplasma infection in ewes and it may be utilised with sample fractionation techniques to determine IgM titres. It is suggested that the best time to examine ewe sera to assist diagnosis of toxoplasma abortion is one week after abortion. While the determination of specific IgM titres in ewe sera may assist epidemiological studies and, sometimes, diagnosis, in the majority of aborting ewe sera it is unlikely to aid diagnosis.
Abortion, Veterinary↗
[The quantitative determination of the IgM rheumatoid factor using a solid-phase radioimmunoassay. Comparison with the agglutination test and the radioimmuno-polyethyleneglycol precipitation test].
A solid-phase radioimmunoassay capable of detecting nanogram quantities of human IgM rheumatoid factor using a monoclonal anti-mu-chain antibody is described. Human IgG did not interfere with the detection of IgM RF by this method. The small nonspecific binding of nonRF IgM to the human IgG coated tubes utilized in the assay must be corrected for by assaying samples in parallel bovine serum albumin coated control tubes only in cases of deviation of IgM from normal range. 69 coded and randomly arranged sera from patients with rheumatoid arthritis (RA), nonrheumatic joint diseases and healthy adult control subjects were investigated by this method, agglutination techniques as well as RIPEGA. A good correlation between solid-phase radioimmunoassay and agglutination techniques was found. Patients with seropositive RA had significantly higher concentrations of IgM RF than seronegative RA patients or control subjects (mean +/- 1 SD = 133,3 +/- 187,2 micrograms/ml versus 4,7 +/- 6,5 micrograms/ml and 2,2 +/- 4,0 micrograms/ml; resp.).
Agglutination Tests↗
[Laboratory diagnosis in rheumatology].
The laboratory diagnostics essentially contributed to the pathogenetic clarification of rheumatological problems and gives multifarious support to the rheumatologist in differential and activity diagnostics and thus also decisively contributes to early diagnostics and therapy. When the acute-phase-reactions serve for the differentiation of inflammatory-rheumatic diseases and degenerative diseases and for the establishment of the degree of activity, so the ASR further the diagnostic ascertainment of a rheumatic fever, the agglutination tests for proving the rheumatoid factor further the differential diagnosis of the rheumatoid arthritis, the LE-phenomenon and the ANF further the differential diagnosis of the LEV, the proof of cardiac auto-antibodies essentially furthers the diagnostics of carditis, the increase of uric acid the early recognition of gout, the synovial diagnostics at length became necessary for the clarification of clinically unclear mon- or oligoarthritides and the determination of the local activity for the observation and judgment of the course. Notwithstanding the primate of the clinic without an effective laboratory diagnostics a modern rheumatology can no more be performed nowadays.
Antibodies, Antinuclear↗