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PubMed1990

Isolation of tube precipitin antibody-reactive fractions of Coccidioides immitis.

Patients presenting with primary coccidioidal infection have been shown by earlier investigators to produce immunoglobulin M (IgM) precipitin antibodies to lysates of mycelial and spherule phases of Coccidioides immitis. This humoral response has been detected by tube precipitin (TP) and immunodiffusion (ID)-TP assays of patient sera, which are valuable aids in early diagnosis of coccidioidomycosis. Several reports of antigenic fractions which show reactivity with patient TP antibody have been published. However, confusion persists with respect to the nature of the specific serologically reactive macromolecule(s). In this study we isolated two TP antibody-reactive antigens (TP-Ags) from an alkali-soluble, water-soluble fraction of the inner conidial wall and a culture filtrate plus toluene lysate of the mycelial phase of C. immitis. The crude antigens were first separated by concanavalin A (ConA) chromatography. The TP-Ags were identified in ID-TP assays as 120- and 110-kilodalton (kDa) fractions which were electroeluted from reducing sodium dodecyl sulfate-polyacrylamide gel electrophoresis separations of the ConA-bound conidial wall extract and ConA-bound culture filtrate plus lysate preparation, respectively. Following electroelution, the 120-kDa fraction was subjected to gel filtration chromatography which yielded a major 240-kDa and minor 120-kDa component. The apparent dimer may be a product of disulfide bond formation resulting from reassociation of the reduced, monomeric components (120 kDa). The latter was suggested by the presence of cysteine in the isolated fraction. The electroeluted 110-kDa fraction was subjected to ion-exchange chromatography. The DEAE-isolated, TP antibody-reactive fraction was identified as antigen 2 in the coccidioidin-anti-coccidioidin reference system. Homogeneity of the TP-Ags was demonstrated in silver-stained sodium dodecyl sulfate-polyacrylamide gels of the respective chromatographically isolated fractions. The two purified TP-Ags showed reactivity in the TP and ID-TP assays and were capable of binding patient IgM but comparatively little IgG antibody, as determined by an enzyme-linked immunosorbent assay. It appears that the diagnostic TP reaction between sera from patients with coccidioidomycosis and the ID reference antigens examined in this study is a composite of IgM binding to both a 120-kDa and a 110-kDa antigen.

Antibodies, Fungal↗
PubMed1981

Sensitivity, specificity, and predictive value of anti-candida serum precipitin and agglutinin quantification: comparison of counterimmunoelectrophoresis and latex agglutination.

Many serological techniques have been developed to aid in the discrimination of significant candidiasis from other clinical states. Serum anti-candida precipitin and agglutinin quantification by counterimmunoelectrophoresis and latex agglutination were statistically evaluated as to their respective ability to accomplish this discrimination. Forty-five serum specimens from 16 patients with documented disease and 2 with presumptive disease and 81 specimens from 70 control patients were studied. The control population consisted of patients with candida colonization, transient candidemia, bacteremia, other systemic mycoses, and healthy medical personnel. The two techniques were compared as to sensitivity, specificity, and predictive value of a positive and a negative test. Using a precipitin or agglutinin titer of greater than or equal to 1:8 as the criterion for a positive test, we obtained the following results: counterimmunoelectrophoresis, 78, 97, 88, and 94%, respectively; latex agglutination, 94, 50, 33, and 97%, respectively.

Agglutinins↗
PubMed1978

Capillary precipitin typing of Streptococcus pneumoniae.

The Neufeld test is presently the method of choice for typing Streptococcus pneumoniae. Although the test is reliable and relatively easy to perform, a simpler test, not requiring microscopic examination, would facilitate large-scale testing. A capillary precipitine test has been designed and tested for its usefulness in typing pneumococci. The type-specific carbohydrate antigens were obtained from broth culture supernatants. The antigens were reacted with type-specific antisera in glass capillary pipettes. Results from 82 reference antigens and 166 antigens from diagnostic pneumococcal strains showed that the reactions ere specific, and the results agreed with Neufeld test results. These results indicate that the precipitin test is as specific as the Neufeld test. The test is easy to perform, requires small amounts of antiserum, and can be completed in a short period of time.

Humans↗
PubMed2006

Diagnostic value of serum precipitins to mould antigens in active hypersensitivity pneumonitis.

Serum precipitins have a controversial diagnostic value in hypersensitivity pneumonitis (HP). The present authors' objective was to assess their diagnostic value by developing scores from a panel of specific antigens tested by two techniques (electrosyneresis and double diffusion) to discriminate active HP from other interstitial lung diseases. Consecutive patients presenting with a condition for which HP was considered in the differential diagnosis were included in the study. All patients underwent the same standardised diagnostic procedure, including precipitin tests performed in routine conditions. Clinical manifestations, bronchoalveolar lavage and high-resolution computed tomography defined the presence or absence of HP. Receiver-operating characteristic curves and logistic regression were used to develop the serological scores. A total of 122 patients (including 31 cases of HP) were included in the study. Five antigens from the panel were selected for the serological scores (Absidia corymbifera, Eurotium amstelodami, Wallemia sebi, Saccharopolyspora rectivirgula and mesophilic Streptomyces sp.). Electrosyneresis was more discriminative than the double-diffusion technique. Predictive negative values varied 81-88% and predictive positive values varied 71-75% for prevalence of HP 20-35%. In conclusion, serological scores using a panel of relevant antigens may guide both biological and clinical practice in areas of high prevalence of hypersensitivity pneumonitis.

Adult↗
PubMed1993

Agar gel precipitin line patterns and pathogenicity of infectious bursal disease viruses.

Twenty-nine strains of infectious bursal disease virus could be classified into three groups by the agar gel precipitin line patterns using two representative base antigens of F539 and G691 strains. The precipitin line of the first group (16 strains including F539) did not fuse with that of G691 base antigen and spur was seen. The line of the second group (2 strains) did not fuse with those of both base antigens. The line of the third group (11 strains including G691) did not fuse with that of F539 base antigen. Every strain of the first group was highly pathogenic for chickens showing a mortality of 40% or more.

Animals↗
PubMed2001

Comparison between precipitin and ELISA tests in the bloodmeal detection of Aedes aegypti (Linnaeus) and Aedes fluviatilis (Lutz) mosquitoes experimentally fed on feline, canine and human hosts.

The identification of arthropod bloodmeals is important in many epidemiological studies, as, the understanding of the life cycle of vectors and the pathogens they transmit, as well as helping to define arthropods' control strategies. The precipitin test has been used for decades, but ELISA is slowly becoming more popular. To compare the two tests for sensitivity, specificity and accuracy to detect small insect bloodmeals, Aedes aegypti or Ae. fluviatilis mosquitoes were fed either on feline, canine or human hosts. Mosquitoes were frozen at 6, 12, 24, 48 or 72 h after feeding. Precipitin test showed better specificity and accuracy and ELISA test showed higher sensitivity. Better results with both tests were achieved when mosquitoes were frozen within 48 h from feeding.

Aedes↗
PubMed1976

Semi-micro quantitative gel precipitin reaction.

Quantitative gel precipitin reactions were made on a semi-micro-scale. This required overall reduction of the dimensions of the necessary apparatus. Resulting from this was the ability to use agarose gel at low concentration not possible with the conventional macro quantitative gel precipitin technique. Further advantages were the reduction of time for the completion of the experiments and also that of the volume of the reactants. Diffusion coefficients of antigens determined by the semi-micro technique agreed with those obtained with the more accurate optical methods.

Precipitin Tests↗
PubMed1980

Schistosomiasis japonica in Barrio San Antonio, Basey, Samar in the Philippines. IV. "Atypical" precipitates in the circumoval precipitin test--a reaction of recent infection.

Morphologically distinct circumoval precipitin reactions, not having the usual "segmented" appearance, are characteristic of recently acquired infection of man with Schistosoma japonicum. In contrast to the precipitins seen in plasma of those with chronic infections, reactions of recent infection (RRI) are commonly, large, vacuolated blebs or, if elongate, are smooth and vacuolated in structure. Recognition of these RRI provides a practical, simple method to study incidence of infection and the techniques used are readily accepted by children in primary school grades.

Child↗
PubMed1976

Precipitins in Liberian sera reacting with goat and sheep sera.

Precipitins in nine sera from normal Liberian adults were shown to react with an alpha-globulin in goat and sheep sera. No cross-reaction was demonstrated with bovine sera. Hence these precipitins are different to others previously described. At present their significance, if any, is unknown. They are important as a possible cause of unexplained reactions in serological tests using sheep or goat serum as a source of antigen or antibody.

Adult↗
PubMed1978

Schistosomiasis japonica in Barrio San Antonio, Basey, Samar in the Philippines: II. Quantitative fecal examination and circumoval precipitin tests.

An improved quantitative stool examination technique (MFCT) and two variations in the performance of the circumoval precipitin test, one using whole serum (SCOPT) and the other employing the eluate from finger prick blood dried on filter paper (FPCOPT), were evaluated in a field study to detect infection with S. japonicum among residents of an endemic barrio in Samar. The sensitivity of SCOPT was above 90%, that of MFCT was between 80 to 90%, while that of FPCOPT was only about 50%. Intensity of infection as judged by fecal egg excretion and duration of infection as indicated by age were shown to be determinants of serum reactivity (and hence sensitivity of the two serodiagnostic tests). The relative insensitivity of FPCOPT observed in this work, also evident in some published data of previous workers, puts to doubt the wisdom of using this technique as the procedure of choice in epidemiologic surveys in the Philippines as currently favored in that country. Atypical positive reactions in circumoval precipitin tests using whole serum were detected which may make the differentiation of relatively recent from old infections possible.

Adolescent↗
PubMed1975

The effect of antilymphocyte globulin (ALG) on precipitin formation to human serum albumin in rabbits.

The effects of pig anti-rabbit ALG on precipitin formation to human serum albumin were studied in rabbits with an aim to contribute to an elucidation of the effects of ALG on the humoral antibody response. Antibody levels were assayed quantitatively after the first, second and third local injection of antigen with adjuvant. ALG was found to suppress distinctly, though not completely precipitin formation throughout the immunization cycle in the experimental group compared to the control groups injected with pig IgG or saline at the same time intervals. The immunosuppressive effect was particularly pronounced after the third injection of antigen which did not further increase antibody levels in experimental animals as compared to the controls. The system appears to be effective in partial suppression of the humoral antibody response when a good preparation with appropriate dosage and timing is used.

Animals↗
PubMed1975

The circumoval precipitin test in early experimental schistosomiasis japonica.

The time of the appearance of circumoval precipitins by testing weekly blood samples of rabbits infected with light, moderate and heavy doses of cercariae of Schistosoma japonicum as well as their titers were determined. In heavy infections, circumoval precupitins appeared as early as the end of the 4th week or 28th day after cercarial penetration while the appearance of detectable levels in light infections was delayed only up to the 7th week after infection. In view of these observations, the circumoval precipitin test should be used for detection of early schistosomal infection before eggs are demonstrable in the faeces.

Animals↗
PubMed1976

Precipitin response of cattle to commercial wart vaccine.

Fifty young bulls were given commercial wart vaccine upon their arrival at a bull stud establishment. The bulls were given 2 additional vaccinations 2 and 24 weeks later. The precipitin antibody response of these bulls to bovine papilloma virus was monitored. Antibody levels increased significantly, particularly after the 3rd vaccination was given at 24 weeks, but decreased markedly within 20 weeks after the last vaccination was given. These results demonstrated that formalin-inactivated bovine papilloma virus was capable of inducing precipitin antibody similar to infective bovine papilloma virus. Multiple, repeated vaccination provided the best serologic response.

Animals↗
PubMed1978

Low molecular weight C1q-precipitins in hypocomplementemic vasculitis-urticaria syndrome: partial purification and characterization as immunoglobulin.

A lupus-like syndrome involving chronic urticaria with cutaneous vasculitis, systemic symptoms, hypocomplementemia with preferential depletion of C1q, and low m.w. (7S) C1q-precipitins has recently been defined. The C1q-precipitin activity (C1q-p) seems to represent a diagnostic marker of the disease, but its chemical nature is not yet clear. We have partially purified and characterized C1q-p from the serum of two patients with this syndrome and compared its activity with the C1q-precipitating activity of aggregated human gamma-globulin (AHGG) anti-C1q antibodies, and several polynucleotides including DNA and polyinosinic acid. C1q-p was found to partition with IgG during precipitation by ammonium sulfate and low ionic strength buffer as well as during column chromatography on DEAE-cellulose and G-200 Sephadex. Like AHGG, but in complete contrast to the polynucleotides, the C1q-precipitating activity of C1q-p was sensitive to pepsin, trypsin, and acidic conditions, but unaffected by DNAse or RNAse; the C1q-precipitating activity of anti-C1q antibody was not diminished by any of these procedures. Thus, C1q-p consists of gamma-migrating protein of low m.w., and its C1q-precipitating activity is indistinguishable from that of AHGG. These results are consistent with the concept that C1q-p is comprised, at least in part, of IgG that binds C1q via the Fc portion of the molecule.

Binding, Competitive↗
PubMedDate not supplied

A trivalent antigen for the detection of type I avian adenovirus precipitin.

A double immunodiffusion antigen prepared from cell-culture-propagated CELO virus was not capable of detecting precipitin directed against all of the type I avian adenovirus (fowl adenoviruses) isolates tested. However, an antigen pool containing CELO-4, B-3, and IBH-2 (Tipton) fowl adenovirus isolates detected precipitin directed against representative isolates of 10 type I serotypes. Additionally, this antigen pool markedly improved detection of adenovirus field exposure.

Adenoviridae↗
PubMed1979

A theoretical approach to precipitin reactions: insight from computer simulation.

The theoretical consequences of different hypotheses of the mechanism of precipitin reactions have been evaluated by means of computer simulation. It has been found that the formation of compositionally different complexes in different antigen/antibody mixtures provides a valid explanation of the zoning phenomenon, but this concept fails to explain the absence of free antigen and of antigen in soluble complexes at the point of maximum percipitation. It is found that the following hypothesis provides an improved qualitative and quantitative explanation of percipitin reactions. In the first stage of the total reaction a series of compositionally different complexes is formed. As the second stage of the total reaction two kinds of processes are proposed. Inherently insoluble complexes precipitate causing the remaining soluble complexes to participate in mutual rearrangements to re-establish a new state of equilibrium in the supernatant. The inherently insoluble complexes, moreover, create a hydrophobic phase, distinct from the supernatant and cause the remaining otherwise soluble complexes to distribute themselves between the two phases according to a partition coefficient. A mathematical apparatus to study the consequences of this hypothesis is presented, and it is demonstrated that the features of precipitin curves can be explained nearly completely this way.

Antigen-Antibody Complex↗
PubMed1979

Measurements of precipitin reactions by difference turbidimetry: a new method.

A new method for the measurement of precipitin and flocculation reactions between antibodies and antigens has been developed. The technique, called difference turbidimetry, involves the use of tandem cuvettes providing the opportunity of using separated and unmixed antigen and antibody as blank solutions for spectrophotometric readings in the ultraviolet wavelength range. By use of this technique genuine difference turbidity spectra have been recorded for the reaction between human serum albumin and rabbit-anti-human serum albumin IgG. It was found that difference turbidimetry at low wavelengths (e.g. 280 nm) allows the construction of precipitin curves with a very clearly expressed zoning phenomenon at a sensitivity which in terms of antigen and antibody concentrations is more than twice the sensitivity of conventional procedures. It is of special interest that the zone of equivalence differs when the same reaction between an antigen and its antibody is measured by difference turbidimetry, by absorbance of washed and redissolved precipitate, and by amount of precipitated antigen.

Antigen-Antibody Reactions↗
PubMed1979

Milk precipitins in selective IgA deficiency.

Precipitating antibody to cow milk's antigens (commonly bovine IgM) is found in 40-50% of selective IgA deficient patients. These precipitins may obscure the diagnosis of selective IgA deficiency by formation of anti-antiserum precipitin rings in radial immunodiffusion. Abnormal immunoregulatory function along with excess absorption of milk antigens in the absence of secretory IgA may be predisposing factors. Elimination of dietary cow's milk results in disappearance of these antibodies.

Animals↗