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Studies in chronic allergic bronchopulmonary aspergillosis. 3. Immunological findings.

Precipitin tests by two different methods, double-diffusion (DD) and counterimmunoelectrophoresis (CIE), and measurements of total and specific IgE against Aspergillus fumigatus were made in 50 patients with chronic allergic bronchopulmonary aspergillosis and in three control groups--atopics with a positive immediate prick test to A. fumigatus but no evidence of allergic aspergillosis, atopics with a negative prick test to A. fumigatus, and non-atopics. Precipitins were found in 84% and 78% of the patients with aspergillosis by the DD and CIE methods respectively. Precipitins were also found in 6 out of 27 (22%) patients with a positive prick test to A. fumigatus but no evidence of aspergillosis and in 1 of 24 patients with a negative prick test to A. fumigatus. The means of specific and total IgE values were significantly higher in the group of patients with aspergillosis than in the three other groups of patients. The increase in specific but not total IgE showed a statistically significant correlation with positive precipitin tests in the patients with aspergillosis. Total IgE but not specific IgE values were significantly higher (0-02 less than P less than 0-05) in patients who had had a transient radiographic shadow in the previous three months. Positive precipitin tests were also significantly correlated with the number of transient shadows in the past and with the interval of time since the last transient shadow.

Aspergillosis↗

Incidence of serum antibodies to several Aspergillus species and to Candida albicans in cystic fibrosis.

The incidence of serum IgE antibodies to several species of aspergillus and the incidence of serum precipitins to these species and to Candida albicans were determined in 22 children with cystic fibrosis, 17 children with bronchial asthma, and 18 control subjects. IgE antibodies were found in 50 per cent of the patients with cystic fibrosis and in 29 per cent of the patients with bronchial asthma; none was found in the control subjects. Precipitins to aspergillus species were present in 59 per cent of the patients with cystic fibrosis, 35 per cent of the patients with bronchial asthma, and 11 per cent of the control subjects. Greater differences were noted when the total number of precipitin bands in each group was compared. There was a trend for the more severe cases of cystic fibrosis (based on the Shwachman-Kulczycki score) to have a greater incidence of precipitins and a lower frequency of IgE antibodies to aspergillus than the milder cases. Candida precipitins were found more frequently in patients with cystic fibrosis (45 per cent) than in patients with bronchial asthma (18 per cent); none was found in the control group. The potential role of fungal hypersensitivity in cystic fibrosis and the therapeutic implications are discussed in light of these findings.

Adolescent↗

Precipitating antibodies to nuclear antigens in systemic vasculitis.

We have examined sera from 61 patients with systemic vasculitis for precipitating antibodies to components of saline tissue extracts. Precipitins were rare in patients with polyarteritis nodosa (PAN) and their absence helped to distinguish PAN from vasculitis associated with other connective tissue diseases. Precipitins were detected in some patients with other vasculitides. Previously described precipitating antibodies (anti-Ro [SSA] and anti-La [SSB]) were restricted to a few patients with features of systemic lupus erythematosus (SLE). A different, as yet unidentified, precipitin which reacted with a component of rabbit thymus extract but not calf thymus or human spleen extracts was detected in many patients with rheumatoid disease. This precipitin was present in all patients with active rheumatoid vasculitis (RV) as well as 52% of patients with uncomplicated but active rheumatoid synovitis. Higher titres of precipitating antibody were present in patients with active RV than those with inactive RV or uncomplicated rheumatoid synovitis, and serial studies showed a good correlation between a fall in antibody titre and healing of vasculitis with treatment. These studies suggest that this unidentified precipitin may be an important marker of RV.

Antigens↗

Cultural and histopathologic confirmation of canine blastomycosis diagnosed by an agar-gel immunodiffusion test.

Sixteen sera from 17 dogs with blastomycosis produced a precipitin band identical with the diagnostically significant precipitin A band formed by a Blastomyces dermatitidis reference antiserum and a soluble B dermatitidis yeast-form antigen in the agar-gel immunodiffusion test (94% sensitivity). The other serum from a dog with histopathologic demonstration of B dermatitidis in pulmonic tissues produced an unrelated precipitin band. Sixteen of the 17 diagnoses made by the detection of precipitin A were confirmed by isolation and culture of B dermatitidis or by histopathologic demonstration of the pathogen. Three cases were confirmed by cultural isolation only, 10 by histopathologic demonstration only, and 3 by both. In three other dogs given amphotericin B, there were demonstrable changes in serum precipitin A reactions.

Animals↗

Allergic bronchopulmonary aspergillosis: reactivity of IgE and IgG antibodies with antigenic components of Aspergillus fumigatus (IgE/IgG antigen complexes).

Sera of patients with ABPA were tested by XRIE tests incorporating their own serum (self-XRIE) to detect the presence of IgG/IgE antigen complexes to a "reference" Aspergillus fumigatus preparation. Of the 32 sera studied, 29 (90%) had visible precipitin (IgG) peaks, and 27 of these 29 as well as the three apparently precipitin-negative sera, i.e., 30 (94%), showed binding of specific IgE by autoradiography. The two precipitin-positive sera that did not show IgE binding were also skin test negative and RAST negative to this A. fumigatus antigen. Specific IgG as determined in ELISA correlated well with the grading of the XIE precipitin peaks (p less than 0.05). There was also a highly significant correlation between specific IgE by RAST and grading the radioactive uptake seen in the autoradiograph (p less than 0.001) indicating, for each serum, the presence of IgG antibodies to most of the components to which there was specific IgE. In the self-XRIE tests there was considerable variation of reactivity from serum to serum, in numbers of antigen/antibody peaks observed, in relative peak heights, and in the intensity of the respective staining. By comparing each test to a "reference" pattern developed with the use of an ABPA serum pool, the antigenic components of A. fumigatus were found to be of two main types: (1) antigens that appeared to be poorly precipitating (possibly low-molecular-weight components) but showed strong IgE binding (these were apparently major allergenic components and with one exception proved to be the faster migrating components) and (2) antigens that produced the strongest precipitin reactions with only weak binding of specific IgE and therefore minor allergenic components.

Antibodies, Anti-Idiotypic↗

Identification of a tumor-associated antigen in cervical carcinoma by two dimensional (crossed) immunoelectrophoresis.

Two-dimensional immunoelectrophoresis was used to evaluate 8 cervical cancer speciments, 11 other gynecologic tumors, and 5 specimens of normal cervix. Antigens were water-soluble tissue extracts and antisera prepared in rabbits. When tested against antisera to cervical cancer, cancer antigens showed 14-17 precipitin lines whereas normal cervix showed 10-16. A single heavy heterogeneous precipitin line with an electrophoretic mobility of 0.58 relative to bovine albumin was observed in all cervical cancer specimens but not in normal cervical or other tumor specimens. Further evidence for the uniqueness of this antigen was sought by enhancement (addition of another antigen to the first phase of electrophoresis which increased the size of common peaks) and suppression (addition of another antiserum to the second phase, whereby the peak size of components to which both sera have antibody was decreased). The specific precipitin line was neither suppressed by the addition of antisera to normal tissue nor enhanced when normal tissue antigen was added to the tumor antigen preparation. More conclusively, adsorption of the tumor antiserum with normal tissue had no effect on the unique tumor-associated precipitin line, whereas all other precipitin lines were removed. This antigen was common to other cervical tumors because enhancement was demonstrated with three other cervical tumor specimens. The identification of a distinct and separate antigen associated with cervical carcinoma will permit further characterization and possible development of immunodiagnostic methods.

Antigen-Antibody Reactions↗

Basic amino acids predominate in the sequential autoantigenic determinants of the small nuclear 70K ribonucleoprotein.

Autoantibodies binding the 70K nRNP polypeptide are commonly found in the serum of patients with systemic lupus erythematosus. IgG antibodies binding overlapping octapeptides of 70K nRNP have been evaluated in 10 patients with anti-nRNP precipitins, seven patients with other autoimmune serology, and four normal human sera. Neither normal controls nor patients without an anti-nRNP precipitin significantly bind any of the 70K nRNP octapeptides. Sera containing an anti-nRNP precipitin strongly bind various combinations of eleven different regions of the 70K nRNP protein. One antigenic region is consistently the most reactive in nine of ten nRNP precipitin positive sera tested. This sequence, KDKDRDRKRRSSRSR, is highly charged and has a similar pattern of alternating basic amino acids also present in seven of the other purported humoral autoimmune epitopes of the 70K nRNP polypeptide. The closely related DRKR and ERKR are important components of two of these epitopes. All regions of the 70K peptide bound by human anti-nRNP precipitin positive sera are very rich in the basic amino acids, especially lysine (chi-square = 23.03, odds ratio = 13.3, P < 0.000001).

Amino Acid Sequence↗

[Type specific protein antigen of group B streptococci [II]. Diversity of the c alpha protein antigen].

The c protein antigen of group B streptococci has been reported to consist of at least two acid extractable antigens, c alpha and c beta. We previously reported that strain FZ301 contain the c alpha and novel protein antigen, named as S antigen by Denka Seiken, and the c alpha antigen of this strain exhibit a more complicated structure. In this report described the analysis of the diversity of the c alpha antigen by immunoelectrophoresis and immunodiffusion. Hot acid extract from strain A909 produced a single precipitin band against the anti-121424c alpha serum but the 121424 extract produced double precipitin bands by immunoelectrophoresis. These c alpha antigens showed anodic migration, but the 121424c alpha antigens tended to migrate slower than the A909c alpha antigen. Moreover, the anti-A909c alpha serum produced a single precipitin band when tested after electrophoresis of the 121424 extract. When examined by immunodiffusion, the anti-121424c alpha serum produced two distinct precipitin bands with the 121424 and FZ301 extract, and these were reactions of identity. However, the A909 extract produced only one band which joined one of the two bands produced with the 121424 extract. These results shown that the strain 121424 contain c alpha and S antigen as well as strain FZ301. The precipitin band of the c alpha antigen in the A909 extract against the anti-A909 serum formed the spur with the reaction of the c alpha antigen in the 121424 or FZ301 extract on immunodiffusion. Moreover, the c alpha antibody in the anti-A909 serum failed to removed completely by repeated adsorption with strain 121424.(ABSTRACT TRUNCATED AT 250 WORDS)

Antigens, Bacterial↗

Serological studies of Actinomyces israelii by crossed immunoelectrophoresis: taxonomic and diagnostic applications.

Crossed immunoelectrophoresis (CIE) with intermediate gel was applied to the serological analysis of Actinomyces israelii to develop a test with high efficiency in the laboratory diagnosis of human actinomycosis and classification of A. israelii. Recently developed standard antigen-antibody systems for A. israelii by CIE were used as reference. The reference systems were based on standard preparations of cytoplasmic and whole cell-associated antigens of A. israelii and a standard immunoglobulin G pool purified from rabbit antisera to formalin-treated whole cells and cell lysates of A. israelii. The specificity of the standard antigens for A. israelii was evaluated in CIE studies by screening for antibodies to components of the antigens in rabbit antisera raised against related bacteria. The standard system for A. israelii based on cytoplasmic antigens formed species-specific precipitins whereas antisera raised against A. naeslundii and/or Propionibacterium acnes precipitated components of the other standard antigens. As a result of these analyses, the standard system for A. israelii based on 10 cytoplasmic antigens was used as reference for CIE studies to detect humoral antibodies to A. israelii in sera from nine patients with actinomycosis. All the sera from the patients formed at the time of diagnosis one or more precipitins in terms of the 10 reference precipitins. Up to five precipitins were found in single sera. Follow-up studies covering a period of one-half year after treatment showed a gradually decreased precipitin response in the course of time. In control sera from patients with newly diagnosed tuberculosis, nocardiosis, deep Candida infection, and aspergillosis, and in sera from healthy blood donors, no antibodies were detected with specificity for the reference antigens.

Actinomyces↗

Agar-Gel Precipitating Antibody in Pseudomonas aeruginosa Infections.

The human immune response to Pseudomonas aeruginosa infection was studied by using the double diffusion in agar-gel technique. Antigens from Fisher-Devlin-Gnabasik immunotypes were prepared by both trichloroacetic acid extraction and ultrasonic disruption. Serum from 72 of 168 patients (43%) from whom P. aeruginosa was isolated formed from one to eight precipitin bands. Precipitins were demonstrated in the sera of 60 of 66 (91%) patients recovering from bacteremia and deep infections; however, they were usually absent when Pseudomonas infection was fatal or when there was no clinical evidence of significant infection. Precipitating antibody was detectable at serum dilutions as high as 1:32, and appearance of single bands correlated with hemagglutinating antibody titers of >/=1:128. Antigen from sonically disrupted organisms usually resulted in stronger precipitin bands than trichloroacetic acid extracts, and antigen from the homologous infecting strain occasionally increased test sensitivity. None of 50 normal controls had Pseudomonas precipitins as was the case in patients convalescing from Escherichia coli (15 patients), Klebsiella-Enterobacter-Serratia (18), and Proteus (14) bacteremias. Measurement of agar-gel precipitins was useful and specific in evaluating the circulating antibody response to P. aeruginosa infections.

Journal Article↗

Immunogenicity of Mycoplasma pneumoniae.

The immunogenicity of Mycoplasma pneumoniae for New Zealand white female rabbits was studied by using an immunization scheme which employed initial intramuscular immunization with vaccine in incomplete Freund adjuvant followed 3 weeks later by a series of five intravenous injections of fluid vaccine. Small doses of immunogen (15 to 150 mug of mycoplasmic protein per rabbit) gave rise to sera which contained antilipid complement-fixing antibody, produced one to three precipitin lines, but gave poor growth-inhibition on agar. Larger doses of immunogen (1.5 to 15 mg per rabbit) gave rise to sera which gave higher antilipid complement-fixing titers, four to eight precipitin lines, and good growth-inhibition. Doses smaller than 15 mug per rabbit failed to give rise to detectable antibody. Growth-inhibiting antibody was produced later than the other antibodies. The number of precipitin lines was controlled more critically by the quality of the antisera, as determined by the amount of immunogen, than by the quantity of serological test antigen. All sera which gave any precipitin lines produced a common precipitin line which stained for lipid.

Journal Article↗

Homogeneity and heterogeneity of toxins produced by Clostridium botulinum type C and D strains.

Five Clostridium botulinum strains were used in the present work, two of type C, C-Stockholm (C-ST) and C-CB19, and three of type D, D-South African (D-SA), D-1873, and D-CB16. The toxins, except for those of C-CB19 and D-CB16, were purified, and antisera were prepared in rabbits. To clarify the antigenicity of the toxins, neutralization and agar gel double-diffusion tests were performed. Anti-C-ST toxin serum neutralized two kinds of type C(1) toxin to a similar extent. Antisera against D-SA and D-1873 toxins, however, showed different neutralizing activity toward three type D toxins. Precipitin lines formed between D-SA and D-1873 toxins, and their antisera spurred to each other. From anti-D-SA toxin serum, two neutralizing fractions, one which neutralized D-SA, D-1873, and D-CB16 and one which neutralized only D-SA, were obtained. These results indicate that the antigenicities of D-SA and D-1873 toxins are not identical. Anti-C-ST toxin serum produced cross-neutralization on type D toxins, although the neutralization titer differed depending on the kind of toxin used. A precipitin line was formed with D-SA toxin, but not with D-1873; the developed line spurred to the C-ST toxin precipitin line. Two anti-D toxin sera also caused cross-neutralization on type C(1) toxins. However, the neutralizing activity of each serum to the same type C(1) toxin was different, and only anti-D-SA toxin serum developed a precipitin line with C-ST toxin which spurred to the D-SA toxin precipitin line. From anti-D-SA toxin serum, two different fractions capable of neutralizing C(1) and D toxins were obtained; one neutralized C-ST, C-CB19, and D-SA toxins, but not D-1873 and D-CB16, and the other neutralized all five toxins. There may be at least two common parts among C-ST, C-CB16, and D-SA toxin molecules.

Antigens, Bacterial↗

Evaluation of a rapid enzyme-linked immunosorbent assay for IgG antibodies to Aspergillus fumigatus in the serological diagnosis of allergic aspergillosis.

A range of 6 somatic and culture filtrate antigens of Aspergillus fumigatus were evaluated in a rapid ELISA procedure for anti-A. fumigatus IgG where the component incubation times had been reduced to 10 min. Sera from patients with allergic aspergillosis, patients with suspected allergic aspergillosis, and asthmatic patients with or without A. fumigatus precipitins were tested. For all antigens, levels of anti-A. fumigatus IgG were higher in patients with allergic aspergillosis than in the other 3 groups. Low levels of specific IgG were, however, detected in asthmatic patients who had no precipitins against A. fumigatus. None of the antigen preparations enabled all patients with proven or suspected allergic aspergillosis to be separated from the other 2 groups of asthmatic patients. Positive-negative discrimination in ELISA was achieved by the inclusion of 10 pools of precipitin test-negative sera from the 50 asthmatics without A. fumigatus precipitins. The number of sera that were classed as positive in ELISA ranged from 9 to 15 in the allergic aspergillosis group, depending on the antigen used; in the suspected aspergillosis group, the number of positive reactions ranged from 1 to 8, while in the asthmatics with precipitins, the number ranged from 0 to 2.

Antibodies, Fungal↗

Screening for autoantibodies to SS-A/RO by indirect immunofluorescence using HEp-2000 cells.

We evaluated indirect immunofluorescence (IF) using HEp-2000 slides, which are transfected with SS-A cDNA, for screening for anti-SS-A antibodies, by comparing it with counterimmunoelectrophoresis (CIE). A total of 2427 specimens were screened for IF reactivity and for SS-A precipitins, of which 1033 (43%) were negative on both IF and CIE. There were 1271 SS-A precipitin-negative specimens (52%) which were IF-positive but lacked the distinctive SS-A staining pattern. One precipitin-negative serum was IF-positive with the distinctive SS-A pattern in the HEp-2000 system. One hundred and twenty-two specimens (5%) were positive for anti-SS-A precipitins on CIE, 107 showed the distinctive SS-A fluorescence staining pattern, whereas 15 of these precipitin-positive samples (12%) were IF-positive but did not display the distinctive SS-A pattern on the transfected cells. Fourteen of the 15 samples in which the distinctive SS-A pattern was not observed displayed other significant antinuclear antibody (titre equal or >1:320) patterns. In conclusion, the presence of the typical 'distinctive' SS-A pattern on IF using the HEp-2000 slides is highly specific for the presence of autoantibodies to SS-A and has a sensitivity of 88% for detecting these antibodies.

Antibodies, Antinuclear↗

[Serological studies on rabbits inoculated with Toxoplasma gondii]

Serological studies on toxoplasmosis were conducted with rabbits sera that were immunized with RH strain or infected with Beverley strain of Toxoplasma gondii. Complement fixation tests, agar-gel double diffusion tests and agar-gel immunoelectrophoresis were performed. Toxoplasma crude antigen was prepared from the organisms in mice peritoneal fluids, which were infected with RH strain of Toxoplasma gondii. The organisms were suspended in saline volume originally exudated and counted in hemocytometer for purity of the organisms over 99%. These suspended organisms were prepared by sonication, and the solution was centrifuged for 30 min. at 10,000 rpm in 4 degrees C. These supernatant fluids were used as crude antigen. On the other hand, purified antigens were fractionated on Sephadex G-200 gel filtration. A Sephadex G-200 column, 80 by 4 cm, equilibrated with Tris-HCl-(0.1M)-NaCl (1.0M) buffer, pH 8.0 was used. The eluate fractions were collected in 3 ml per hour and the absorbance at 280 nm was measured with a Beckman Du-2 spectrophotometer. Each tube is pooled into 6 fractions by protein density graph. For immunization of rabbits, crude antigen of RH strain was emulsified with an equal amount of incomplete Freund's adjuvant and l ml of mixture was injected subcutaneously into them once a week for 5 successive weeks. Antisera were obtained at an interval of a week, beginning the first week after the last immunization, while several rabbits were infected with Beverley strain of Toxoplasma gondii by inoculating about 200 cysts and antisera were obtained from them serially at a week interval. The results were as follows: 1. The sera from the rabbits immunized with the RH strain or infected with Beverley strain of Toxoplasma gondii againist the crude antigen showed the first positive reactions in 2 or 3 weeks after the administration or immunization in complement fixation tests. Maximum titers appeared in 4 or 5 weeks after immunization with RH strain and in 7 or 9 weeks after infection with Beverley strain respectively. 2. Complement fixation tests showed the positive reactions in the rabbits sera immunized with RH strain against the purified antigens II, III, IV, V and VI: moreover, antigen IV fraction showed the highest titer. On the other hand in the rabbits sera infected with Beverley strain against the purifed antigens II, III and IV fractions showed the positive reaction; especially, antigen fraction IV showed the highest titer. 3. In immuno-diffusion tests, the sera from the rabbits immunized with RH strain and infected with Beverley strain, against the crude antigen appeared the precipitin bands 2 weeks after the immunization or infection. And the former showed the 2 or 5 precipitin bands after 5-8 weeks and the latter showed the l or 2 precipitin bands after 6 weeks. 4. The sera from the rabbits immunized with RH strain against the purified antigens II, III, IV,V and VI showed the precipitin bands, and the sera from the rabbits infected with Beverley strain against the purified antigens II, III and IV showed the precipitin bands in the immuno-diffusion tests. Especially antigen IV was the strongest reaction against the sera from RH strain and Beverley strain. 5. In agar-gel immunoelectrophoresis, the immunized sera against the crude antigen showed 8 arcs. But the infected sera against the crude antigen showed 4 or 5 arcs. 6. The immunized sera against the fractionated antigens II, III, IV, V, VI showed arcs, but against the fractionated antigen IV showed 6 arcs and in the antigens II, III, V, VI showed l or 2 arcs only. On the other hand, the infected sera against the fractionated antigens IV showed 4 arcs, II and III showed the l arcs, which was the most weak of all.

Journal Article↗

The immune response of brown trout (Salmo trutta L.) to injection with soluble antigens.

The immune response of brown trout (Salmo trutta) to horse serum and keyhole limpet haemocyanin was studied. Intraperitoneal and intramuscular injections were used, with and without adjuvant, in 209 fish. Complement-fixing antibodies (CFA) and precipitins were produced to both antigens. CFA were detected after 8 days to haemocyanin and after 13 days to horse serum. Maximum CFA titres to a single intraperitoneal injection of horse serum or haemocyanin were reached at 44 and 43-46 days respectively. Precipitins to a single injection of haemocyanin given intraperitoneally were detected after 19 days using gel diffusion. Similarly using the intramuscular route they were detected after 22 days. However, using counter-current electrophoresis, precipitins were detected after 8 days by the intraperitoneal route and after 9 days by the intramuscular. Precipitins to horse serum given intraperitoneally were demonstrated after 22 days by both gel diffusion and counter-current electrophoresis. Fish given 2 intraperitoneal injections of haemocyanin in adjuvant reached maximum CFA titres after 55 days; a 3rd injection on day 56 did not produce a marked increase in titre. Fish given intramuscular injections of haemocyanin in adjuvant showed maximum CFA titres at day 43. After a 3rd injection on day 56, maximum CFA titres were reached between days 92 and 106. Intramuscular injections gave significantly higher titres than those given by the intraperitoneal route. Some fish which showed no precipitins by gel diffusion were positive by counter-current electrophoresis. Precipitating antibodies to haemocyanin migrating in the beta2-gamma1 region were detected by immuno-electrophoresis.

Animals↗

Diagnosis of systemic candidosis by immunodiffusion test with locally prepared antigen.

Locally-made C. albicans, C. tropicalis, C. krusei antigens and antisera were made and compared with reference C. albicans and C. krusei antigens and antisera from the Center for Disease Control (CDC), Atlanta, Georgia, U.S.A., and the Provincial Laboratory of Public Health, University of Alberta, Edmonton, Alberta, Canada, respectively. The local antigens and antisera showed 3 precipitin bands when reacted with locally-made and reference antisera. When tested with human sera from 171 normal persons (aged 17-24 years), 30 Candida vaginitis, 30 Candida balanitis, 30 mucocutaneous candidosis, 30 pityriasis versicolor and 10 aspergillosis patients revealed no precipitin band. When tested with cryptococcosis, 2 out of 6 sera showed a precipitin band but only at 1:1 dilution. Four candidosis sera offered by CDC showed precipitin bands at dilutions up to 1:4. Three Thai candidosis sera also showed precipitin bands at dilutions up to 1:2. Therefore, we judged the baseline titer for Thai population to be 1:2.

Adolescent↗

Pseudomonas aeruginosa infection in cystic fibrosis. Bactericidal effect of serum from normal individuals and patients with cystic fibrosis on P. aeruginosa strains from patients with cystic fibrosis or other diseases.

P. aeruginosa strains originating from the respiratory tract of patients with cystic fibrosis (CF) and patients with other diseases (non-CF) were analysed with regard to their sensitivity to the bactericidal activity of human serum. P. aeruginosa strains isolated from CF patients were more sensitive than strains from non-CF patients to the bactericidal activity of normal human serum. The bactericidal activity was heatlabile. As regards the sensitivity to normal human serum, mucoid and non-mucoid variants were not found to differ. Strains originating from chronically infected CF patients with many precipitins against these bacteria did not differ with respect to serum sensitivity from strains originating from intermittently colonized CF patients without P. aeruginosa precipitins. Compared with normal sera, CF sera showed similar or higher bactericidal activity against a panel of P. aeruginosa strains. In this respect, any difference between CF sera with precipitins and CF sera without precipitins against P. aeurginosa was not found. Sera from three CF patients chronically infected with P. aeruginosa, and with many precipitins against these bacteria, showed a selective inability in bactericidal activity against the patients' own P. aeruginosa isolate possibly reflecting the presence of "bactericidal blocking" antibodies.

Adolescent↗