Precipitating and non-precipitating complement consuming IgG subclass antibodies in pigeon breeders' disease

The sera of patients with pigeon breeder's disease usually contain precipitating serum factors as well as human complement consuming factors as shown by incubation of the serum with pigeon dropping antigens. Although a single serum factor, possibly an IgG antibody, might account for both phenomena, affinity chromatography experiments revealed that the sera of patients with pigeon breeders' disease contain non-recipitating, human complement consuming, serum factors besides precipitating serum factors which are also capable of complement consumption. The non-precipitating serum factors most likely belong to the IgG3 immunoglobulin subclass, whereas the precipitating antibodies belong to the subclasses IgG1 and IgG2.     

Detection of Precipitating and Complement Consuming Antibodies by Enzyme Linked Immune Sorbent Assay in Pigeon Breeders' Disease

The sera of patients with pigeon breeders' disease usually contain both precipitating andcomplement-fixing antibodies to antigens in pigeon droppings or pigeon serum. These antibodies are not equivalent. Both types of antibody could be detected by means of an ELISA technique, using either pigeon serum or pigeon dropping antigens in the solid phase. The good correlation between the ELISA results and the complement consumption assay indicates that the ELISA technique may represent a one-step assay for assessing both precipitating and complement-consuming IgG-class antibodies, thereby identifying both symptomatic patients and breeders potentially at risk. IgM antibodies appeared to be of minor significance in the serology of pigeon breeders' disease.     

Interference by rheumatoid factor activity in the detection of antiavian antibodies in pigeon breeder's disease

The assessment of antiavian antibodies is relevant for the study of pigeon breeder's disease; nevertheless, different factors may hamper their accurate detection. The objective of this study was to determine whether an endogenous interfering effect in pigeon breeder's disease might explain the simultaneous presence of IgM, IgG, and IgA antiavian antibodies in high titers as assessed by ELISA. Fifty-nine patients with pigeon breeder's disease, 80 healthy controls, and 47 asymptomatic breeders were studied. To assess possible interfering effects by endogenous immunoglobulins, serum IgG was separated through protein A-Sepharose CL-4B chromatography. Antiavian antibodies were measured in whole and separated samples by ELISA. Since a decline of IgM antiavian antibodies following IgG removal was consistent with a false-positive effect, the causes were studied. Hig values of IgM, IgG, and IgA antiavian antibodies were found in 17.4% of patients with pigeon breeder's disease. An IgM rheumatoid factor activity against IgG was found through ELISA in sera with false-positive IgM antiavian antibodies. Rheumatoid factor binding was confirmed by Western blot. Experimental addition of purified rheumatoid factor to sera with IgG antiavian antibodies replicated the interfering effect. A control group of rheumatoid arthritis with high rheumatoid factor values did not show positive antiavian antibodies tests. No IgG with anti-IgM or anti-IgA activity was found, and the detection of IgA against IgM and IgG was negative. In conclusion, the study of antiavian antibodies might be affected by different immunoassay conditions. An endogenous rheumatoid factor activity produced false-positive IgM results. Other similar interferences warrant a careful evaluation during the serological assessment of pigeon breeder's disease. Received: 3 December 2001 / Accepted: 22 April 2002     

Serum antibodies to pigeon antigens in smokers and nonsmokers

Antibodies to pigeon antigens were determined by double immunodiffusion and ELISA in 80 pigeon breeders without pigeon breeder's disease. Precipitating antibodies to pigeon serum and droppings were found in 5 and 8%, respectively, of 39 breeders who were smokers and in 46 and 51%, respectively, of 41 breeders who were nonsmokers (p less than 0.001). By ELISA, IgG antibodies to pigeon serum and droppings were detected in 44 and 54%, respectively, of smokers and in 81 and 85%, respectively, of nonsmokers (p less than 0.01). The antibody titres were generally higher in nonsmokers than in smokers. These findings may partly explain why allergic alveolitis occurs most often in nonsmokers.     

Antibodies against purified pigeon IgA in pigeon breeders' disease.

It is demonstrated that previously described PDF1-A antigens from pigeon dropping extract contain pigeon IgA. The sera of patients with pigeon breeders' disease contain precipitating antibodies against pigeon IgA, in contrast to the sera of pigeon breeders suffering from unrelated forms of pulmonary dysfunction. The degree of complement consumption by PDF1A antigens, pigeon serum, and pigeon IgA turned out to be correlated. No correlation was found between precipitating anti-pigeon IgA antibodies and complement consumption by pigeon IgA in patients' sera.     

Antigens in pigeon breeder's disease

Sera from patients with pigeon breeder's disease were analysed for precipitating antibodies by immunodiffusion and immunoelectrophoresis using whole pigeon dropping extract (PDE) and a purified fraction of PDE (PDE₁) as antigens. For comparison, sera from asymptomatic pigeon breeders and normal individuals were also tested for precipitating antibodies. Whereas whole PDE formed precipitin lines with normal serum as well as with serum from symptomatic and asymptomatic pigeon breeders. PDE, formed precipitin lines only with serum from individuals exposed to pigeons. This suggests that whole PDE forms non-specific (non-antigen-antibody reactions) as well as specific precipitin lines, while PDE₁ appears to form only specific lines. These data indicate that whole PDE has limited usefulness in studies of pigeon breeder's disease. It is also possible that PDE₁ will be useful in studies of this disease.     

Pigeon IgA: A Major Antigen in Pigeon Breeder's Disease

Pigeon IgA has been isolated from crop-milk and an antiserum was produced. Extracts of the dust in pigeon coops contained detectable amounts of pigeon IgA, but not IgG. The sera of patients with pigeon breeder's disease contained precipitating antibody against pigeon IgA.     

Cross reactions to antigens causing hypersensitivity pneumonitis

The sera of patients with asthma, aspergillosis, pigeon breeder's disease, farmer's lung, and a hypersensitivity pneumonitis in textile plant workers were screened by gel diffusion against a variety of fungal antigens and dust extracts. Patients with hypersensitivity pneumonitis were especially prone to develop precipitating antibody to numerous airborne antigens. From the results it was concluded that patients with hypersensitivity pneumonitis form precipitating antibodies to definite groups of antigens in their environment. Most of the patients had precipitins to house dust that formed lines of identity with fungi and thermophilic actinomycetes.     

A New Disease: a Nasal Form of Pigeon Breeder's Disease

In 47 allergic rhinitis patients regularly exposed to pigeons, nasal provocation tests with pigeon dropping extracts, in combination with other parameters, were performed. Twenty-five of the 47 patients developed a late nasal response (LNR) to pigeon droppings (53%), six of them an isolated response and 19 a dual response (immediate + late). The precipitating antibodies to pigeon droppings were positive in 20 (80%) and to pigeon serum in nine LNR patients (36%). Late skin responses to pigeon droppings occurred in 15 (60%) and to pigeon serum in seven LNR patients (28%). In 13 patients (52%) general malaise, in seven (28%) increased blood eosinophilia, in nine (36%) increased body temperature and in 11 (44%) haemorrhages in the nasal mucosa were observed during the LNR. The results of this study provide evidence for the existence of a new disease, a nasal form of pigeon breeder's disease.     

Serum antibodies to cross-reactive Neisseria outer membrane antigens in healthy persons and patients with meningococcal disease

Outer membranes (OMs) were prepared from the Neisseria meningitidis (Nm) strain 44/76, N. gonorrhoeae (Ng) NRL 8658, and N. lactamica (N1) ATCC 23970. Paired serum samples from 16 patients with serogroup B Nm disease and single samples from 30 blood donors were tested for IgG antibody levels against the three OMs in indirect ELISA, before and after absorption of the sera with N1 OM. Immunoblot analysis was used to identify OM target antigens for cross-reacting and strain-specific antibodies. Most of the Nm- and NG-antibodies in sera from healthy adults were directed against OM antigens shared by the three Neisseria strains. Nm disease induced antibody formation against common Neisseria antigens, identified as the H.8 antigen and LPS determinants, against LPS determinants shared only by the Nm and Ng strains and against a variety of Nm-specific OM antigens. Very low levels of Nm-specific antibodies characterized the Nm patients in the acute phase. Also, the results indicate that the OM ELISA which has been used for the diagnosis of Nm disease, would be more useful if antibodies against common Neisseria antigens were removed from the sera before testing.     

Cross-reaction between Yersinia outer membrane proteins and anti-Borrelia antibodies in sera of patients with Lyme disease

Diagnosis of Yersinia infections accompanied by reactive arthritis could be complicated by cross-reaction with other arthritogenic bacteria. The possible cross-reaction between Yersinia antigens and anti- Borrelia antibodies in blood sera of patients with Lyme disease was studied. The occurrence of specific IgA, IgG and IgM antibodies was analyzed in serum samples from 30 patients with Yersinia -triggered reactive arthritis, 30 patients with Lyme disease and five samples from healthy blood donors. For anti- Borrelia IgG antibodies, cross-reaction was detected with YopH, YopB, V-ag, YopD, YopN, YopP and YopE, and for IgA with YopD. For IgM, no cross-reaction was detected. Owing to cross-reactivity with Borrelia , the diagnosis of Yersinia -triggered reactive arthritis should be based on a combination of serological and clinical findings.     

人体包虫病主要特异性免疫球蛋白的水平及其临床意义

本文报道了应用酶联免疫吸附试验(ELISA)检测包虫病人血清中抗包虫特异性免疫球蛋白(IgG和IgM)的水平并对其临床意义进行了初步探讨。48例正常人血清特异性IgG和IgM的假阳性检出串均为0％;24例囊尾蚴病人血清特异性抗包虫IgG和IgM的假阳性检出效分别为:33.4％;4.16％;42例包虫病患者血清特异性IgG和IgM的阳性检出率分别为:80.95％,66.67％;两者之差经统计学处理具有显著意义(p<0.05)。肝包虫特异性IgG的阳性检出率较肺包虫高,肺包虫特异性IgM的阳性检出率较肝包虫高。这提示患者对包虫的免疫应答和其寄生的位置有关;诱导产生的特异性免疫球蛋白主要为IgG类,特异性IgM的水平与包虫囊壁的完整与否以及检测方法的灵敏性、特异性有关。     

Precipitating autoantibodies to mitochondrial proteins in progressive systemic sclerosis

Sera from 88 patients with progressive systemic sclerosis were examined for precipitating mitochondrial antibodies using sonicated rat liver mitochondrial fraction as an antigen source in immunodiffusion. Precipitin lines indicating the presence of anti-mitochondrial antibodies (AMA) in 22 patients were detected. Only six of 22 sera had, additionally, precipitating antibodies to nuclear antigens. Standardized reference sera containing antibodies to mitochondrial antigens (M-A, M-B and M-C systems) were used to further characterize the type of mitochondrial antibodies. M-B antibody was most commonly detected (72.7%) either alone (eight patients) or in combination (eight patients) with M-A and M-C antibodies. M-A antibody was found in 12 patients (54.5%) and M-C antibody was present in three. The antigen related to M-B is DNAase and trypsin sensitive, in contrast to the resistant M-A antigen. AMA were detected in 21 of 22 patients by indirect immunofluorescence. When solid phase ELISA was used to detect AMA using mitochondrial fraction as antigen, a significant difference (P less than 0.005) was noted between sera with and without precipitating mitochondrial antibody. The antibody was frequently present in patients with progressive systemic sclerosis detected 2 or more years earlier (P less than 0.01). Three patients were found to have primary biliary cirrhosis and others had pruritus, hepatomegaly or abnormal liver function tests. The implication of the findings is discussed.     

Antibodies against antigens of Candida albicans in patients with fungaemia and bacteraemia, studied by ELISA, precipitation, passive haemagglutination and immunofluorescence techniques

Antibodies against commercially available antigens of Candida albicans were assayed in 54 sera from 24 patients with fungaemia and in 66 sera from 33 patients with bacteraemia. In patients with persistent fungaemia, antibody was found during the week after the fungus was first cultured from the blood, but peak titres did not usually occur until the end of the second week. A significant rise in titre in C. albicans infection was observed in 50% of paired sera tested by passive haemagglutination (PHA), indirect immunofluorescence (IF) and Ouchterlony immunodiffusion (ID). The same percentage was obtained by counterimmunoelectrophoresis (CIE) against candida metabolic antigens, whereas it was increased to 88% when somatic antigens were used. Enzyme-linked immunosorbent assay (ELISA) demonstrated a rise of titre in 25, 75 and 50% of sera in IgM, IgG and IgA assays, respectively. Sera from patients with transient fungaemia demonstrated persistent antibody titres. In paired sera from patients with bacteraemia, ID and CIE titres were low (greater than or equal to 4). There was an increase of candida antibodies in 0-9% of patients by ELISA, ID or CIE and in 18-21% by PHA or IF. Clinically significant fungaemia was most reliably differentiated serologically from bacteraemia by CIE S-antigen and ELISA IgG assays.     

Demonstration of antibodies against Brucella melitensis 16M lipopolysaccharide and native hapten in human sera by enzyme-linked immunosorbent assay

An enzyme-linked immunosorbent assay (ELISA) for the detection and quantification of human immunoglobulin G (IgG), IgA, and IgM antibodies against Brucella melitensis 16M by using lipopolysaccharide (LPS) and native hapten (NH) as antigens is described. The results obtained with the LPS ELISA were compared with the results of the NH ELISA. A good statistically significant correlation was established between the antibody titers of the IgG class against both antigens. A total of 104 (99%) of the 105 serum samples of patients with brucellosis exhibited specific anti-NH antibodies by the ELISA technique. In 52 (50%) of these positive samples, antibodies against NH were detected by radial immunodiffusion (RID). In 100% of these RID-positive sera, the antibody titers of the IgG class with ELISA-determined anti-NH specificity were equal to or greater than 160. These results point to a higher sensitivity of the ELISA technique as compared with RID. Inhibition experiments revealed that the assay was specific for LPS and NH from B. melitensis 16M.     

Specificity of antibodies directed against the cytolethal distending toxin of Haemophilus ducreyi in patients with chancroid

Antibodies specific for the cytolethal-distending toxin of Haemophilus ducreyi (HdCDT) complex and for the CdtA, CdtB, and CdtC components were measured by ELISA in the sera of 50 patients with culture and/or PCR proven chancroid, 42 patients with periodontitis, 50 blood donors from Tanzania, 50 blood donors from Sweden. In addition, the biological activity e.g. neutralization capacity of the sera were tested. Our results demonstrate that majority of chancroid patients and healthy individuals had detectable levels of serum antibodies to HdCDT complex and to separate toxin components. However, high levels (> or =100 units) of antibodies to HdCDT complex were significantly more prevalent in the sera of patients with both chancroid and periodontitis than in the sera of the corresponding controls (P=0.001 and P=0.04, respectively). In the sera of the 50 patients with chancroid, antibodies to CdtA, CdtB, and CdtC were detected in 50, 35, and 34 individuals, respectively. Antibodies to CdtC, being less frequently detected than the antibodies to other components, show a good correlation with the neutralizing capacity of sera. High levels of neutralizing antibodies (> or =160) were detected in only 22 and 2% of the patients with chancroid and periodontitis, respectively. The data suggest that the low levels of anti-HdCDT antibodies, which include neutralizing antibodies, may contribute to limited protection in chancroid and since anti-HdCDT antibodies, may be detected in healthy individuals and in patients with certain disease conditions (e.g. periodontitis), they may not be specific markers for chancroid infection.     

Increasing the predictive value positive of the precipitin test for the diagnosis of deep-seated candidiasis.

Three hundred fifty human sera were tested by double immunodiffusion, crossed-line electrophoresis, and crossed immuno-affinoelectrophoresis with a concanavalin A intermediate gel for precipitating antibodies to antigens present in cytoplasmic extracts of Candida albicans. Sera from 48 of 287 hospitalized patients at risk of invasive candidiasis contained precipitating antibodies to Candida antigens. Of these 48 sera, 27 had precipitating antibodies only to cell-wall antigens present in the cytoplasmic extract, and 21 sera had precipitating antibodies to both cytoplasmic and cell-wall antigens. The latter sera came from patients who were 2.5 times as likely to have deep-seated candidiasis as those patients with precipitins exclusively to cell-wall antigens. Sera from seven of 22 patients with vaginal candidiasis and 10 of 41 patients with other fungal infections had precipitating antibodies to C. albicans cell-wall antigens; only two of these sera also contained precipitating antibodies to the cytoplasmic antigens. Crossed immunoaffinoelectrophoresis with concanavalin A reduced the number of false-positive results and increased the predictive value positive of the precipitin test for deep-seated candidiasis from 31% to 71%.     

Qualitative and quantitative evaluation of bird-specific IgG antibodies

BACKGROUND: Exposure to organic dust produced by birds often gives rise to an immune response, e.g. IgG antibodies, but intense exposure can lead to high concentrations of IgG antibodies and the development of allergic alveolitis, often known as "bird fancier's lung". The aim of this study was to establish the distribution of bird-specific IgG antibodies in exposed and nonexposed individuals and compare a nonquantitative and quantitative method in evaluating raised levels of IgG antibodies. METHODS: Sera were collected in Sweden and South Africa and levels of IgG antibodies specific to pigeon, budgerigar and parrot antigens were quantified using the UniCAP system. Results were compared to the precipitation in gel assay. The IgG antibody values of symptomatic patients without precipitating antibodies (non-PP group; n = 51) and patients with precipitating antibodies (PP group; n = 34) were analyzed and compared to nonexposed asymptomatic blood donors (BD group; n = 73) and environmentally exposed pigeon breeders (n = 11). RESULTS: The IgG antibody response of the analyzed groups in Sweden and South Africa did not vary significantly from each other. IgG antibody responses were the strongest to pigeon antigens with clear increased IgG antibody levels in the PP group [geometric mean (GM) 603 mg/l] compared to the non-PP (GM 6.9 mg/l) and BD group (GM 5.0 mg/l). Threshold values, calculated as the GM value from the BD group plus 3 standard deviations (99% confidence interval), were 9.8, 10.8 and 10.0 mg/l for pigeons, budgerigars and parrots, respectively. Comparison of the two methods resulted in a good concordance with a level of agreement of 94.1% (kappa statistic = 0.83). CONCLUSIONS: The UniCAP system for the detection of bird-specific IgG antibodies is a highly reproducible, generally available, quantitative method for routine diagnostic testing and monitoring of exposed subjects with a very high level of agreement to the precipitating gel assay.     

Antibodies to nRNP, Sm, Ro(SSA) and La(SSB) detected by ELISA: their specificity and inter-relations in connective tissue disease sera

The profile of autoantibodies to four soluble cellular ribonucleoproteins nRNP, Sm Ro(SSA) and La(SSB) was determined using ELISA with immuno-affinity-purified antigens in a connective tissue disease population. Compared with immunodiffusion, results using ELISA showed greater sensitivity but lower specificity and low titres of antibodies were frequently found in the sera of patients with connective tissue diseases other than systemic lupus erythematosus. This was true even for antibodies to Sm which have been considered highly specific for SLE. Antibodies to these antigens were predominantly of the IgG class and were capable of fixing complement irrespective of the clinical context. As previously demonstrated by immunodiffusion strong associations between anti-nRNP and anti-Sm and between anti-Ro(SSA) and anti-La(SSB) were detected by ELISA, while antibodies to nRNP and to Ro(SSA) identify distinctive serological groups. The observation that certain antibodies are closely linked suggests a relationship between the immune responses to particular antigens, and this might be explained by biological links between the antigens.     

High prevalence of human anti-bovine IgG antibodies as the major cause of false positive reactions in two-site immunoassays based on monoclonal antibodies

A sandwich ELISA for quantification of the endometrial protein PP14 revealed false positive reactions in 81% of male sera (n = 54). The PP14 ELISA was based on two monoclonal antibodies (Mabs) with different epitope specificities--a catcher and a biotinylated indicator. The monoclonal antibodies were purified by protein G affinity chromatography from culture supernatant containing 10% (v/v) fetal calf serum (FCS). Human anti-animal IgG (bovine, mouse, horse, and swine) antibodies and human anti-bovine serum albumin antibodies were measured using an ELISA design, with direct bridging of the solid phase and biotinylated antigens. The false positive reactions were abolished by addition of 1% (v/v) bovine serum to the dilution buffer (DB). Human anti-bovine IgG antibodies (HABIA) were detected in 99 out of 104 sera from blood donors (50 females; 54 males). HABIA levels in male sera (n = 54) were positively correlated to the false positive signals in the PP14 ELISA (r = 0.923; p < 0.0001). Antibodies to IgG from other mammalian species (mouse, horse, and swine) were also detected in the donor sera, but levels and frequencies were lower compared to that of HABIA. Furthermore, HABIA were positively correlated to human anti-bovine serum albumin antibodies in the donor sera (r = 0.639; p < 0.0001; n = 103). HABIA (prevalence 95%) cause false positive reactions due to crossbinding of contaminating bovine IgG and/or crossreaction with mouse IgG in two-site immunoassays. The apparent presence of human anti-mouse IgG antibodies (HAMA), described to create false positive results, may be due to a crossreacting fraction of the polyclonal circulating antibodies against bovine IgG.