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PubMed1998

The leukocyte adhesiveness/aggregation test as an inflammation-related, plasma-dependent agglutination phenomenon.

The leukocyte adhesiveness/aggregation test (LAAT) is a non-specific marker of inflammation. In the present study, we examined the expression of the CD11b/CD18 as well as the CD62L antigens on the surface of peripheral blood leukocytes in 84 patients with various inflammatory conditions and 60 controls by using whole blood flow cytometry. We also conducted several in vitro experiments in order to explain the mechanism of the leukocyte adhesiveness/aggregation. A significant (r= -0.36, p<0.001) negative correlation was found between the expression of CD62L on the surface of peripheral blood polymorphonuclears and the state of LAA. There was no correlation between the availability of the CD11b/CD18 antigen and the adhesive state of these cells. In a series of in vitro experiments, we could show that it is possible to significantly reduce the number of aggregated leukocytes in the peripheral blood by using dilutions with buffer but not with plasma. There is no change in the degree of aggregation following incubation at low temperature in the presence of an aerobic metabolism blocker or following incubation with a divalent ion chelator. Additionally, white blood cells could be seen to adhere to protein-rich areas in the peripheral slides. We assume that the state of LAA in the peripheral blood as revealed by the LAA test is more a plasma factor-dependent agglutination than a firm aggregation phenomenon. Factors other than the leukocyte integrins or selectins should be sought as being responsible for this LAA phenomenon.

Adult↗
PubMed1988

Quantitation of human chorionic gonadotrophin by the planimetry of latex agglutination-inhibition results on microtiter plates.

A new type of heavy latex particle (LP) coated with the conjugates of human chorionic gonadotrophin (hCG) and bovine serum albumin (BSA) was used as indicator for the microtiter agglutination-inhibition assay of hCG using a monoclonal antibody (McAb) to hCG. The precipitation patterns of LP were measured by an automatic planimetry system. The detection limit of this method was 4 to 8 IU/l. Human luteinizing hormone (hLH) and follicle-stimulating hormone (FSH) caused hardly any cross-reaction in the presence of 3,350 IU/l and 1,500 IU/l, respectively. This planimetric immunoassay (PMIA) method provides a potentially useful method for hormone assay.

Agglutination Tests↗
PubMed2003

Screening for methicillin resistance in Staphylococcus aureus and coagulase-negative staphylococci: an evaluation of three selective media and Mastalex-MRSA latex agglutination.

Laboratory confirmation of MRSA is important for the implementation of infection control; conventional screening culture methods take up to five days for confirmation. The purpose of this study is to ascertain the efficiency of three selective media for growth of methicillin-resistant Staphylococcus aureus (MRSA) before and after enrichment in salt broth, and to evaluate the Mastalex-MRSA latex agglutination kit for detection of methicillin resistance. Screening swabs were collected from 63 patients, yielding 125 S. aureus isolates and 40 coagulase-negative staphylococcus (CNS) isolates. Selective media used were mannitol salt agar (MSA), Baird-Parker agar with ciprofloxacin (BPC) and bromocresol purple (BCPA). Polymerase chain reaction (PCR) for mecA gene detection was used as the reference standard for evaluation of the Mastalex-MRSA assay, which was also evaluated on colonies of S. aureus from the selective media. No significant difference was found in efficiency of MRSA isolation among the selective media. Pre-enrichment in the salt broth did not enhance isolation of MRSA. Methicillin-sensitive S. aureus and CNS were significantly inhibited in all selective media (P<0.05). Only BPC significantly selected out methicillin-resistant CNS (P<0.01). Mastalex-MRSA was 97% specific and sensitive for the detection of MRSA. It was 65% sensitive and 100% specific in detecting methicillin resistance in CNS. In conclusion, all selective media performed equally well (MRSA isolation rate of approximately 80%). Mastalex-MRSA provided rapid and reliable detection of MRSA from selective media, reducing the time required for confirmation of this organism.

Agglutination Tests↗
PubMed2001

The correlation of agglutination titer with positive blood cultures in brucellosis: A comparison of two study periods.

Brucellosis is an endemic zoonosis in Saudi Arabia. Correlation of Brucella agglutination antibody titer with positive blood culture was performed over 2 time periods (1986 and 1998). At the King Fahad National Guard Hospital we generally consider a titer value of 1:320 or greater as being diagnostic of Brucella. Using this cut-off, the positive predictive value of 39.3% (95% CI=31.5 to 47.6) in the 1986 study increased to 55.7% (95% CI=42.4 to 68.5) in the recent study (P=0.03). This improvement is probably due to parallel improvement in both methodologies.

Agglutination Tests↗
PubMed1975

Gametic differentiation in Chlamydomonas reinhardtii. II. Flagellar membranes and the agglutination reaction.

A structural and biochemical study is presented concerning the agglutination of gametic flagella, the initial step in the mating reaction of Chlamydomonas reinhardtii. An alteration in the distribution of the intramembranous particles revealed by freeze-fracturing of flagella membranes is shown to accompany gametic differentiation in both mating types. The isolation and electrophoretic analysis of flagellar membranes and mastigonemes are reported; no electrophoretic differences can be detected when the membrane or mastigoneme glycoproteins from vegative and gametic cells are compared, nor when glycoproteins from the two mating types are compared, and no novel polypeptides are present in gametic preparations. The membrane vesicles, after they are freed of mastigonemes by sedimentation through a discontinuous sucrose gradient, are extremely active as an isoagglutinin, indicating a direct involvement of the membrane in the mating reaction.

Agglutination↗
PubMed1982

Comparison of slide agglutination test (Phadebact) with counterimmunoelectrophoresis for detection of streptococcal group antigens.

Sera from mice infected with group B streptococci and culture supernatants of group B, A, and C streptococci were examined for the presence of group-specific antigens by the Phadebact slide agglutination (PSA) test and counterimmunoelectrophoresis (CIE). The results were correlated with the number of organisms present in the blood or in vitro cultures. The PSA test was slightly more sensitive than CIE.

Agglutination Tests↗
PubMed1984

Evaluation of the Directigen and Phadebact agglutination tests.

Comparison testing of the Directigen latex agglutination (LA) kit, the Phadebact coagglutination (COA) kit, and counter-immunoelectrophoresis (CIE) demonstrated that the commercial LA reagents were slightly more sensitive than the COA reagents for the detection of pneumococcal polysaccharide types 2, 4, 8, 9, 12, 19, 23, 25, 51, and 56, and meningococcal polysaccharide from Group C. The COA reagents were slightly more sensitive than the LA reagents for the detection of pneumococcal polysaccharide type 6A. The sensitivity of LA and COA reagents for the detection of Hemophilus influenzae type b capsular polysaccharide, pneumococcal polysaccharide types 1, 3, 14, and meningococcal Group A were equivalent. Purified meningococcal polysaccharides of Groups B, C, and W135 were detected uniformly by CIE but not with the COA reagent. The COA reagent reacted with antigen of Groups B, C, and W135 from broth culture but with less sensitivity than CIE. In general, CIE was the least sensitive method for detecting bacterial antigens. In addition, the commercial CIE antisera for H. influenzae type b, or meningococcal polysaccharides were susceptible to false-negative results due to antigen excess.

Agglutination Tests↗
PubMed1983

Enzyme-linked immunosorbent assay (ELISA) with bacterial sonicate antigen for IgM, IgA, and IgG antibodies to Francisella tularensis: comparison with bacterial agglutination test and ELISA with lipopolysaccharide antigen.

An enzyme-linked immunosorbent assay (ELISA) with bacterial sonicate (S) as antigen developed for determining the presence of IgM, IgA, and IgG antibodies to Francisella tularensis was compared with the bacterial agglutination (BA) test and a corresponding ELISA using lipopolysaccharide (LPS) antigen. Of the organisms tested, F tularensis was the only one to cause significant inhibition, indicating the specificity of the S-ELISA. BA test titers correlated significantly with antibody levels in all three immunoglobulin classes and most closely with IgM antibodies (r = 0.83). With some minor exceptions, the S-ELISA and the LPS-ELISA gave identical results, and the correlations between the tests were very close (r = 0.94-0.99). The S-ELISA confirmed the tularemia diagnosis with the first serum specimens from 43% of patients with tularemia vs 17% of the BA test. In addition, no seroconversion was observed by the BA test in 4% of the patients, although large increases were observed in S-ELISA titers.

Adolescent↗
PubMed1987

The antibody from an infertile woman that induces sperm agglutination interacts with rat testicular cells and sperm.

The serum obtained from an infertile woman induced a specific head-to-head agglutination of human and rat sperm. The immunoglobulin G (IgG) fraction of the serum was obtained and found to interact with the proteins of rat sperm in testis and epididymis. Using an indirect immunofluorescent method with rat sperm from vas deferens, we determined that the antibody recognized the protein on the convex and concave regions of the acrosome and over the entire tail. However, with testicular spermatozoa, the antibody recognized only the distal end of the tails. In paraffin sections of adult rat testis, sperm tails located at the luminal region of the seminiferous tubules stained intensely. Weak but significant staining also occurred on late spermatids. In the epididymal sections, staining was restricted to spermatozoa in the lumen. On the other hand, sections of testes from 25-day-old rats containing spermatogonia and early spermatocytes had a completely negative reaction. Testicular somatic cells, including Sertoli cells, peritubular myoid cells and interstitial cells, did not stain. To identify the testicular protein interacting with the antibody, adult rat testis proteins were prepared and analyzed by a sodium dodecyl sulfate-polyacrylamide gel electrophoretic (SDS-PAGE) immunoblot technique. The antibody interacted with a protein with an estimated molecular weight of 82,000 in the testicular homogenate and particulate fraction, whereas the reaction was considerably weaker with the testicular cytosol fraction.

Animals↗
PubMed1985

Agglutinate formation in serum samples mixed with intravenous fat emulsions.

The degree of fat agglutination (the so-called "creaming phenomenon") was measured in sera from 51 critically ill patients, 200 ambulatory patients and 24 healthy volunteers. A 400-microliter serum sample was mixed with 10 microliter of a fat emulsion (Intralipid), incubated at 37 degrees C, and examined after 2, 6, and 24 h. Almost all samples from critically ill patients exhibited creaming, as did 31% of the samples from ambulatory patients. Serum samples from healthy volunteers were incubated with purified C-reactive protein (CRP). At a CRP concentration of 40 mg/L, creaming was always observed. Creaming also occurred at normal serum levels of CRP, but at increased concentrations of other serum proteins. Finally, the creaming test was performed with 12 different fat emulsions, mixed with sera from critically ill and healthy subjects. Healthy sera produced no creaming and sera from critically ill patients invariably showed creaming with every emulsion.

Agglutination↗
PubMed1976

Antileukocyte antibody in postpartum and renal transplant subjects. A comparison of capillary agglutination and lymphocytotoxicity reactions.

Sera were obtained from 48 gravida II prenatal and 211 multiparous nonpregnant females and examined for leukocyte antibodies comparing a standard lymphocytotoxicity (CY) test with capillary agglutination (CA). Antibody was detected in 41% of the samples in both groups but only CA tests were positive with approximately one-half of the prenatal and three-fourths of the multiparous specimens. Although, CA reactions, when accompanied by positive CY responses, usually correlated with HLA, no correlation with HLA, 5b, or the neutrophil antigens was determined for 35 of the 48 sera reacting only by CA. As a model to test the specificity of CA positive-CY negative antisera, four extensively studied sera were further analyzed in 16 families. Independent segregation from the HLA complex and ABO and Rh antigens was confirmed and two of the sera appeared to detect separate clusters of reactions in conjunction with some of the other reagents. Pre- and postgraft samples obtained from 23 living related and 75 cadaveric renal transplanted patients were investigated and compared for graft function and prospective tissue typing. Although direct crossmatches were negative prior to surgery, 17.9% of the pretransplant samples from living related and 28.0% from cadaveric recipients contained detectable antibody when tested against a cell panel. Similar to the prenatal and multiparous groups, the majority of these responses were detected by CA. Following engraftment, antibody first became evident in 11 of 19 (58%) living related and in 23 of 53 (48.2%) cadaveric hosts. There was a striking association between the development of CA and CY antibody and failure, as contrasted to 100% 9-month or greater survival in 10 of 10 living related and 15 of 15 cadaveric transplants in whom only CA antibodies arose postoperatively. In total, these studies indicate that CA reacts with HLA antigens in common with CY tests. In addition, CA may detect HLA when CY is negative but many other reactions appear to be directed at non-HLA specificities. The relevance of CA-only responses to clinical transplantation remains uncertain, but we may speculate that they have an enhancing effect on the course of renal transplantation and are associated with important histocompatibility determinants.

Agglutination Tests↗
PubMed2002

Evaluation of serological markers to differentiate between ulcerative colitis and Crohn's disease: pANCA, ASCA and agglutinating antibodies to anaerobic coccoid rods.

BACKGROUND: Accurate diagnosis of inflammatory bowel disease, in particular the differentiation between ulcerative colitis and Crohn's disease, is important for treatment and prognosis. Several serological markers have been used as non-invasive diagnostic tools in inflammatory bowel disease patients both to differentiate ulcerative colitis from Crohn's disease and to define patient subgroups. AIM: To evaluate the diagnostic accuracy of three serological tests in differentiating ulcerative colitis from Crohn's disease by single or combined use. METHODS: Sera from 51 patients with clinically well-defined ulcerative colitis and 50 patients with clinically well-defined Crohn's disease were analysed. Detection assays for the presence of perinuclear anti-neutrophil cytoplasmatic antibodies (pANCA), antibodies against (ASCA) and serum agglutinating antibodies to anaerobic coccoid rods were studied. Sensitivity, specificity, predictive values and likelihood ratios of each of these serological tests were determined. RESULTS: In supporting the diagnosis of ulcerative colitis, the sensitivity and specificity of the pANCA test were 63% and 86%, respectively. The ASCA test (immunoglobulin A or immunoglobulin G positive) for diagnosing Crohn's disease had a sensitivity of 72% and a specificity of 82%. The sensitivity of antibodies to anaerobic coccoid rods in diagnosing Crohn's disease was 52%, whereas specificity was 90%. A combination of pANCA-positive and ASCA-negative results in the case of ulcerative colitis showed a sensitivity and specificity of 51% and 94%, respectively. However, for ASCA-positive and pANCA-negative results in the case of Crohn's disease, sensitivity was 64% and specificity was 94%. The combination of all three tests increased positive predictive value and specificity to 100% for both ulcerative colitis and Crohn's disease. In Crohn's disease patients, positive pANCA was correlated with colonic involvement. No correlation was found between the presence of any of these antibodies and disease activity, duration and behaviour or medical treatment. CONCLUSIONS: The value of these serological tests in differentiating ulcerative colitis from Crohn's disease is limited when used separately but, by combining two or more tests, the positive predictive value and specificity can be improved substantially. These tests might be of help in studying disease heterogeneity, and may contribute to defining various subgroups of patients with different pathogeneses.

Adolescent↗
PubMed1980

Evaluation of the phenol-induced flagellar agglutination test for the identification of the cholera group of vibrios.

Applied routinely to 1081 recently isolated cultures, the phenol-induced slide-agglutination test (standard procedure) with flagellar antiserum corrently identified 98.9% of Vibrio cholerae strains of O type-I and NAG serotypes; 1.0% of cultures were unstable in phenol-saline. The incidence of instability and other types of defect was higher (7.3%) in older stock cultures. The majority of such strains were successfully tested by one of the three modified procedures. No cross-reactions were observed in 47 cultures of other species including the halophilic vibrios. Only one out of the 1205 cultures of V. cholerae tested by all procedures reacted negatively; this strain was found to lack functional flagella. These results establish the significance of flagellar specificity as a classificatory determinant in V. cholerae, and the fidelity and utility of the phenol test in routine bacteriology.

Agglutination Tests↗
PubMed1989

The use of an IgM immunosorbent agglutination assay to diagnose congenital toxoplasmosis.

An IgM immunosorbent agglutination assay (ISAGA) was compared with a standard ELISA IgM test for the diagnosis of congenital toxoplasmosis. It was more sensitive, detecting all of five mothers of infected babies whereas the IgM ELISA was positive in two of three mothers tested at delivery and neither of two mothers referred 10-12 months after delivery. Five women infected in a previous pregnancy had IgM detectable by ISAGA in a subsequent pregnancy. The assays were comparable when sera from patients with past infection were tested or following toxoplasma-associated miscarriage or abortion. Four cord sera from congenitally-infected babies were positive by the ISAGA but only three of these were positive by ELISA for IgM. The ISAGA also detected IgM in another four sera from congenitally-infected babies referred late (10-18 months old); none were IgM positive by ELISA. The increased sensitivity of the ISAGA is an improvement in the diagnosis of congenital toxoplasmosis.

Agglutination Tests↗
PubMed1991

A rapid micro-agglutination technique for the detection of antibody to Legionella pneumophila serogroup 5.

A rapid micro-agglutination test (RMAT) for the detection of antibody to Legionella pneumophila serogroup 5 is described. It was found to be both sensitive and specific when compared with the indirect immunofluorescence test. Evaluation of 89 paired sera from patients with respiratory symptoms showed that the incidence of L. pneumophila serogroup 5 respiratory infection in East Anglia is low: only one case was found in this study. The RMAT would be easy to perform as a screening test in a routine serological laboratory.

Agglutination Tests↗
PubMed1993

Co-agglutination (Co-A) test for circulating antigen in hydatid disease.

A co-agglutination (Co-A) test with Staphylococcus aureus (Cowan's strain I) bearing protein A coated with specific hydatid antibodies, was used to demonstrate circulating hydatid antigen in serum for the diagnosis of hydatid disease. The test had a sensitivity of 95% and specificity of 89% in detecting hydatid antigen in serum. A false positive reaction was observed with 18.5% of control sera from patients with various parasitic diseases. However, these all gave negative results when tested after further dilution. The test is reliable and rapid; the result could be obtained within 30-45 min of receipt of a serum sample. Since the test is simple and the reagents are inexpensive and easily available, it can be used in less well equipped laboratories in developing countries.

Agglutination Tests↗
PubMed1996

Reactivity of various leishmanial antigens in a direct agglutination test and their value in differentiating post-kala azar dermal leishmaniasis from leprosy and other skin conditions.

A direct agglutination test (DAT) for the detection of post-kala azar dermal leishmaniasis (PKDL) was evaluated in conditions that simulate the disease clinically or immunologically. A reference strain of Leishmania donovani (LEM 1399), and antigen preparations from Leishmania isolates from Bangladeshi patients with post-kala azar dermal leishmaniasis or visceral leishmaniasis were used. A titre of at least 51,200 was obtained in tests of patients with PKDL with all three antigens, whereas a maximum titre of 1600 was recorded in patients with cutaneous leishmaniasis, mucocutaneous leishmaniasis or leprosy. Antigens from dermal isolates of L. tropica (LV 140) and L. braziliensis (LV 65) yielded titres of 1600-6400 in patients with PKDL. The lowest titre recorded in 70 patients tested with the homologous PKDL antigen was 409,600. In patients with leprosy, cutaneous leishmaniasis, syphilis, onchocerciasis, tuberculosis, blastomycosis or vitiligo, titres ranged from 100 to 1600. Tha DAT is better than current parasitological and histopathological methods for the diagnosis of PKDL in areas in which leprosy is co-endemic.

Agglutination Tests↗
PubMed1998

Evaluation of clinical usefulness of the microplate agglutination test for serological diagnosis of legionella pneumonia.

Recently, a microplate agglutination test (MPAT) was established for the serological diagnosis of legionella pneumonia. To evaluate its usefulness, this study examined antibody titres in 121 serum samples serially obtained from 40 patients with pneumonia, including 17 cases of confirmed legionella pneumonia. Six of the 17 proven cases became serologically positive within 4 weeks of the onset of pneumonia as assayed by MPAT (cut-off value: four-fold rise to > or = 128 in paired sera or > or = 256 in a single serum specimen), whereas the remaining 11 cases were serologically negative despite serial examination. Four proven cases who were treated with corticosteroids in the acute phase had antibody titres <8 during the first 4 weeks of infection, after which one case showed an elevation in antibody titre for the first time, 13 weeks after the onset of disease. In contrast, all non-proven cases had antibody titres of < or = 64, and only one case developed a four-fold or greater rise in titre. These results indicate that MPAT is a useful method for the laboratory diagnosis of suspected legionella pneumonia, although several false-negative cases were observed. This suggests that the previously established MPAT criteria may require modification, possibly to slightly lower values. These data also indicate that serial examination over the first month of infection may be necessary for serodiagnosis of legionella pneumonia, especially in patients treated with corticosteroids.

Agglutination Tests↗