A Study of Tuberculosis Antibodies by Bentonite Flocculation

Bentonite particles sensitized with concentrated human Old Tuberculin were used for detection of circulating antibodies to M. tuberculosis in human sera.There was no sharp distinction between the titres of patients with active and inactive tuberculosis, but progressively higher antibody titres accompanied increased severity of infection. The sera of 95.3% of the patients studied had a titre of 1:8 or higher. This level was considered to be the minimal significant titre indicative of the presence of metabolically active bacilli in old and new lesions. Tuberculin-negative controls and syphilitic sera were negative. A common zone of incidence in the 1:8-1:32 range was found where differentiation between tuberculin-positive healthy people and patients with tuberculosis was not possible; however, titres of 1:64 or more were found only in tuberculous patients. The antibody under study is heat-labile.     

Evaluation of a serological test for tuberculosis.

The agglutination test of Nicholls was found to be ineffective in diagnosing active tuberculosis. A positive result (titre of 1/125 or more) was found in the serum of 74 (70%) out of 105 patients with newly diagnosed, smear-positive pulmonary tuberculosis; 61 (62%) out of 98 healthy family contacts; and 19 (63%) out of 30 patients with non-tuberculous conditions. These findings were not due to faulty technique since the results obtained at Hammersmith were similar to those obtained by Nicholls''s laboratory in the same serum samples. Twenty-seven of the tuberculous patients who had a negative result before treatment were retested two months after the start of chemotherapy but showed no evidence of a rising titre.     

Vaccinia virus persistence in a child against the background of immune deficiency

A young girl, vaccinated against smallpox 6 years before suffered from a persistent vaccinia virus infection and a congenital skin disease, i.e. epidermolysis bullosa. The virus was isolated from skin lesions at the vaccination site and remote sites and repeatedly from the blood; it was not isolated from bone-marrow specimen, saliva, pharynx or urine. The titre of virus-neutralizing antibodies was low (1:10), immunoglobulins A, M and G were within age-related limits; antibodies against measles and tetanus were at protective levels, skin tests were positive. Staphylococcal antitoxin titre was extremely high. The child's mother, not vaccinated against smallpox, possessed vaccinia--virus-neutralizing antibodies at high titre (over 1:320). Examination of the child did not show any quantitative immune deficiency. Immune deviations were found in the lymphocyte blast-transformation reaction on stimulation with PHA and specific antigen, as well as in the nonspecific-suppression test. The possible genesis of the virus persistence and the role of the virus in the clinical course of the disease are discussed.     

Haemagglutination-inhibiting and neutralizing antibodies to type 3 and 5 rhinoviruses in human sera and nasal washings.

Presence of antibodies to RV 3 and RV 5 was tested by HIT and NT in 60 human sera. Antibodies to RV 3 were detected in 23 sera by HIT in a titre range of 1:4--1:64 and in 19 sera by NT in a titre range of 1:4--1:256. Antibodies to RV 5 were detected in 31 sera by HIT in titres of 1:4--1:268 and 27 sera by NT in the same titre range. In a group of 22 persons with unequivocal serum antibodies nasal secretory antibodies were found in 11 subjects in titres of 1:4--1:32. In a group of 16 persons without detectable serum antibodies, presence of secretory antibodies (titre 1:4) was only found in four cases.     

Psittacosis in Manitoba

Paired blood specimens submitted to the Virus Laboratory, between January and September 1970, from 200 patients with a lower respiratory tract infection were examined for antibodies to the psittacosis-human pneumonitis group antigen. A high static titre of antibodies was found in four patients and a rising titre in three. The illness varied in the seven patients, tending to be severe, chronic and recurrent. All patients recovered following a course of antibiotic therapy which was repeated in four; treatment tended to be inadequate since the diagnosis of psittacosis was made retrospectively. The likely source of the infection in four of the patients was budgerigars, in one it was pigeons, in one it was a canary as well as a pigeon, and in one the source was not identified. Two additional patients had a fairly high static titre of antibodies to the psittacosis-human pneumonitis antigen but were excluded from this report since they showed a diagnostic increase in antibodies to a respiratory virus during the course of their illness; both patients had an avian contact and are being followed up.     

Use of the indirect hemagglutination reaction for detecting antibodies to Pseudomonas pyocyanea in acute suppurative destructive pneumonia]

No less than 4-fold increase in the antibody titres to Pseudomonas aeruginosa during the infectious process served as laboratory confirmation of its participation in the infectious process. In 49 of 91 patients hemagglutining titre exceeded the diagnostic one (1:640). In 9 patients (chiefly in infants) hemagglutinin titre remained low, but there was a rise of antibody level to Pseudomonas aeruginosa during the disease. High hemagglutinin titres were noted in 12 patients on admission to the clinic, with reduction of the antibody titres at the late periods of the disease. Antibody titres remained unchanged during the disease in 15 patients. In 3 cases the indirect hemagglutination test was assesed as negative. In the rest of the patients hemagglutinin titres varied within the range of the diagnostic titre. Thus, the indirect hemagglutination test with erythrocytic diagnostic agent permitting to determine antibodies to Pseudomonas aeruginosa could be used at the clinic in combination with bacteriological and other investigations for establishing etiology of the destructive process.     

Cytoplasmic islet-cell antibodies (ICA) and cytoplasmic complement- fixing antibodies (CF-ICA) in patients with newly detected and short-lasting diabetes mellitus type 1

The study aimed at assessing ICA and CF-ICA in the serum of patients with newly diagnosed and short-lasting diabetes mellitus type 1. Sixty patients with newly diagnosed diabetes type 1 (39 patients) and short-lasting diabetes of the same type (21 patients) aged between 2 and 34 years were classified. Anti-islet antibodies were detected with indirect immunoflourescence in specimens of fresh, frozen human pancreast in the tested group ICA were found in 53% of cases. At the time of diagnosis, ICA were found in 76% of children and in 14% of adult patients whereas respective data for diabetes mellitus lasting up to 2 years were 40% and 64%. Complement-fixing islet cytoplasmatic antibodies were found only in patients with ICA (47% of such cases). These antibodies were found in children with newly diagnosed diabetes mellitus (36%). In case of adults CF-ICA were detected in 7% of newly diagnosed diabetes mellitus cases and in 45% of cases with the disease lasting for 2 years. Titres of ICA ranged from 1:1 to 1:128 whereas titres CF-ICA from 1:1 to 1:8. No correlation between ICA titre and CF-ICA titre was noted.     

Studies on the production of anti-human-lymphocyte serum (ALS) in bulls]

The applicability of bulls as productive animals was considered for the preparation of anti-humans ALS. The course of immunologic response was studied by lymphoagglutination, lymphocytotoxicity, rosette inhibition, hemagglutination tests and by precipitin formation in two experimental groups immunized by different amounts of lymphocytes from peripheral blood of normal donors. The animals were found to respond well already after the second application of very small amounts of antigen (on day 0-4 times 10(7), on day 21-2 times 10(8) lymphocytes). They showed lymphoagglutination titre 1 : 512-2000, lymphocytotoxic titre being higher than 1 : 4000 and the rosette inhibition test gave a minimum titre of 1 : 65000. On the other hand, further application of a high amount of antigen (2 times 10(9), or 4 times 10(9) lymphocytes) did not lead to further increase in the titre; on the contrary - hyperimmunization resulted in a lower titre in the case of the rosette inhibition test, which is known to correlate best with the in vivo immunosuppressive activity. The hemagglutinin titre was also acceptable under the above conditions and the formation of undersirable precipitins against human serum proteins was negligible. Good response reached by a simple and economical immunization scheme speaks for the suitability of bulls for the production of ALS.     

Anti-cyclic citrullinated peptide antibodies in rheumatoid arthritis: relation with clinical features, cytokines and HLA-DRB1

The specificity and sensitivity of anti-cyclic citrullinated peptide antibodies (anti-CCP) was examined in Latin-American patients with rheumatoid arthritis (RA). The variables considered included: 1) relation with the activity of disease, 2) extra-articular manifestations (EAM), 3) synthesis of cytokines (IL-4, IL-10, IL-12, TNF-alpha, and IFN-gamma) and IgM and IgA rheumatoid factor (RF), and 4) the association with HLA-DRB1 polymorphism. Seventy-nine RA patients were assessed (69 with established RA, and 10 with recent-onset RA not receiving any treatment), 56 with ankylosing spondylitis (AS), 25 with systemic lupus erythematosus (SLE), 50 with primary Sj?gren's syndrome (pSS), and 10 healthy individuals. Of the 69 patients with established RA, 36 were reexamined 2 years later. The activity of the RA was measured by criteria adopted by the American College of Rheumatology. Anti-CCP2, RF and cytokines levels were determined by ELISA. HLA genotypes were established by first, PCR sequence amplification using sequence-specific primers and then, complete sequencing of the product. Anti-CCP antibodies were observed in 96% of patients with RA during the first evaluation and in 86% at the second evaluation (p = 0.12). No significant change in antibody titre was observed between the two evaluations (131 +/- 58.7 and 130.6 +/- 67.1 IU, respectively). The overall sensitivity and specificity was 94% and 92%, respectively; however, at titres > 60 IU, the values were 84% and 95%, respectively. The anti-CCP likelihood ratio positive test was 12 and the likelihood ratio negative test was 0.06. The positive predictive value was 87%, and the negative predictive value was 96%. Anti-CCP antibodies were observed in 12% of SLE and pSS patients, in 2% of AS patients, and in 10% of healthy controls. In RA patients, these antibodies were not associated with the activity of disease, EAM or HLA-DRB1 alleles; no significant correlation was observed between antibody titre and cytokines level. Although anti-CCP antibodies have potential as a diagnostic tool for RA, they are not useful for monitoring clinical activity or predicting the clinical course of disease. Antibody synthesis is HLA-DRB1 independent and not correlated with Th1/Th2 cytokines.     

Estudio comparativo de las reacciones serologicas cuantitativas con un antigeno metabolico de Aspergillus fumigatus

Summary The following quantitative serologic reactions: agar-gel immunodiffusion, complement-fixation, opposite electrophoresis and latex particle agglutination tests have been performed in 38 sera from mycologically proved pulmonary aspergillosis cases. A metabolic antigen from a strain ofAspergillus fumigatus according toAjello et al technic modified by us, has been employed. Sera from 120 subjects suffering from non-mycotic lung conditions, as well as 10 sera from histoplasmosis cases, 10 sera from S. A. blastomycosis and 2 sera from patients with lung aspergillosis produced byA. niger, gave negative results with the above mentioned seroligic reactions.One hundred per cent of positive results were obtained with the complement-fixation test (titre ranging from 1/20 to 1/1280), agar-gel immunodiffusion test (titre up to 1/64) and the opposite immunoelectrophoresis (titre ranging from 1/2 to 1/256). Twenty five per cent negative and 4 non-specific results were registered with the latex particle agglutination test.A correlation of the number of serum precipition bands obtained by the electrophoresis technic with the titre of the quantitative serologic reactions, as well as a correlation of the titre of the circulating antibodies with the severity of the clinical form of aspergillosis seems to be present.Electrophoretic motility of the specific antibody performed in 10 sera showed results like the IgM in 1 instance and an intermediate position between IgA and IgG in 9 samples.     

Neospora caninum infections in bovine foetuses and dairy cows with abortions in Argentina

Antibodies to Neospora caninum were measured in bovine foetuses, dairy cows and beef cows in Argentina using the IFAT, the N. caninum agglutination test, and the recombinant NCDG1 and NCDG2 ELISA. Serum antibodies (IFAT titre 1:80) were found in 20 of 82 (24.4%) dairy cow foetuses and one of 22 (4.5%) beef cow foetuses. Microscopic lesions suggestive of neosporosis were seen in brains of seven of eight foetuses with IFAT titres of 1:80. Antibodies (IFAT) were found in 122 of 189 (64.5%) dairy cows that aborted. Serum antibody titres (IFAT) of 189 dairy cows that aborted were: < 1:25 (67 cows), 1:25 (four cows), 1:50 (16 cows), 1:200 (seven cows), 1:> or = 800 (95 cows). Of the 87 sera with IFAT titres of < or = 1:50, 57 had no antibodies in 1:40 dilution and 30 had titres of 1:40 in the N. caninum agglutination test. Thus, sera from at least 56 dairy cows which had aborted were seronegative both in the N. caninum agglutination test and the IFAT. The distribution of positive and negative sera was similar when measured by ELISA, except that, depending on cut-off titre, the ELISA indicated a greater number of seropositive cows that were negative by the IFAT and N. caninum agglutination test. These results suggest that transplacental transmission of N. caninum in dairy cows in Argentina is frequent.     

Diagnosis of mycobacterial infection in acquired immunodeficiency syndrome (AIDS) patients and HIV carriers.

Differences in tuberculosis diagnosis between infected and non-infected HIV patients were described. In Barcelona, tuberculosis is present in 41.6% of 851 patients in whom AIDS was detected between 1981 and the first quarter of 1990. We reviewed the results of the methods used for tuberculosis diagnosis in 270 AIDS patients controlled in our hospital, in whom tuberculosis was detected (33.3%), and we compared these data with the results obtained in HIV carriers with tuberculosis and with tuberculous patients without HIV infection. Statistically significant differences were found between the three groups with respect to sex, age, results of Ziehl-Neelsen stain in pulmonary specimens and skin test reaction; between AIDS patients and the non-HIV infected population differences were observed in tuberculosis site. Positive skin test reaction diminished from tuberculous individuals non-HIV infected (95%), to HIV carriers with tuberculosis (71.8%) and AIDS patients with tuberculosis (21.8%). Acid-fast smears from pulmonary specimens were positive in 35.7%, 23.5% and 43.7% respectively. Statistically significant differences were found in tuberculosis localization between tuberculous patients non-HIV infected and tuberculous patients with AIDS, in the last group tuberculosis lymphadenitis was the most frequent localization (33.3%) of extrapulmonary tuberculosis, followed by abdominal tuberculosis (15.5%). The incidence of HIV infection among tuberculous patients was 4.6 in our study, but could be higher if patients between 19 and 30 years old were always checked for anti-HIV antibodies.     

The indirect hemagglutination reaction in the diagnosis of trichinosis

An indirect hemagglutination test (IHAT) for trichinosis using a Melcher's antigen was evaluated and compared with a precipitin test (PT) and a bentonite flocculation test (BFT). One hundred and forty eight serum samples from patients from the whole country confirmed or suspected to have trichinosis by clinical or epidemiological evidences were studied: 117 (79.1%) samples resulted positive by IHAT, 138 (93.2%) by PT and 65 (43.9%) by BFT. Sixty three serum samples from patients with strong clinical suspect of trichinosis presented the PT and the BFT positive and were compared with the IHAT for sensitivity study. IHAT was positive in 60 (95.2%) serum samples. In order to determine the specificity of IHAT 25 serum samples from healthy volunteers and 124 serum samples from individuals with other parasitoses, such as cysticercosis (48), hydatidosis (45) and fascioliasis (31) were studied. The specificity, using a titre > or = 1:16 as a possible diagnostic value was 96%. The use of IHAT with RP and BFT in the diagnosis of human trichinosis is discussed.     

Passive protection of mice with the 19 S and 7 S fractions of anti-pertussis sera in experiment.

Protective activity of anti-persussis rabbit and mouse sera and 19 S and 7 S fractions obtained from these sera was investigated in the test of passive protection of mice on a model of pertussis meningoencephalitis. The method of simultaneous intracerebral administration of the serum or fraction with live culture of a virulent B. pertussis strain was used. Hyperimmune rabbit serum containing mercaptoethanol-resistant agglutinins in a high titre was found to have the most pronounced protective effect. Serum of mice, collected 14 days after single immunization of the animals, did not show any protective properties. A small amount of protective activity was observed in the serum collected on the 30th day after a single administration of the vaccine. A sharp increase in the protective activity of the serum was observed after double immunization of mice. Correlation was found between the increase in the titre of agglutinins (in particular of 7 S antibodies) and the protective activity of the serum. Protective properties of 19 S and 7 S fractions isolated from immune rabbit and mouse sera by the method of gel filtration were investigated. Both fractions were found to possess protective properties, but fraction 7 S was more active than fraction 19 S.     

Preparation of a high titre Salmonella abortusovis H-antigen and antiserum and improvement of the microagglutination test.

Serological diagnosis of small ruminant abortions due to Salmonella abortusovis (S.a.o) was improved by using modified procedures to produce high titre H-antigens and anti-H serum. While the titres of the two standard antigens were 1:8 and 1:20, both modified antigens had a titre of 1:50. Similarly, the use of adjuvanted and non adjuvanted antigens for the production of anti-H hyperimmune serum resulted in a titre of 1:160,000 as compared to 1:20,000 when standard procedures were used. In addition, the slow micro-agglutination test has been modified and results can now be read within the same day.     

Seroprevalence of Chlamydophila pneumoniae in ischaemic heart disease

We investigated the presence of Chlamydophila pneumoniae antibodies in 125 patients with cardiovascular disease and in 128 controls. C. pneumoniae antibodies were measured by microimmunofluorescence assay. A significantly high prevalence of IgG C. pneumoniae antibodies at titre > or = 8 was found in patients (84%) in comparison to controls (47.6%). Considering as cut-off the IgG titre > or = 32, 52% of patients with coronaropathies and 18.75% of controls resulted positive (p < 0.0001). IgA C. pneumoniae antibodies were found in patients and controls without statistically significant differences. High C. pneumoniae antibodies (titre > or = 256) were found in 11% of patients with acute myocardial infarction (AMI) and in none of the controls. In patients, the percentage of IgG and IgA seropositivity increased with age and decreased in patients aged > 70 years. Only patients with AMI are at risk of having antibodies against C. pneumoniae (OR = 6.69). None of the known risk factors for cardiovascular disease was significantly associated with C. pneumoniae seropositivity IgG. This is the first report in our area on the possible association of C. pneumoniae IgG seropositivity and acute ischemic events.     

Detection of rainbow trout antibodies against viral haemorrhagic septicaemia virus (VHSV) by neutralisation test is highly dependent on the virus isolate used

Three serological tests, enzyme linked immunosorbent assay (ELISA), 50% plaque neutralisation test (50%PNT) and Western blotting (WB), were used to detect antibodies against viral haemorrhagic septicaemia virus (VHSV) in 50 rainbow trout broodstock from a rainbow trout farm endemically infected with VHS but with no clinical signs of infection. When the sera were examined by 50%PNT using the VHSV reference isolate DK-F1 or the heat attenuated DK-F25 mutant strain, no neutralizing antibodies were found. In contrast, when one of the virus isolates from the farm (homologous virus) was used in the 50%PNT, 90% of the fish were found to be positive. By examining a panel of different VHSV isolates in 50%PNT, it was demonstrated that the virus isolate used as test antigen could significantly affect the sensitivity and titre determination in 50%PNT for detection of rainbow trout antibodies against VHSV. When the sera were examined for the presence of VHSV antibodies by ELISA or WB, 61% were found to be positive. When conducting WB analysis, the viral glycoprotein was the protein most frequently recognized, followed by the viral nucleoprotein.     

Raising Antibodies to Staphylococcal Enterotoxins A and B

A method is described for raising specific antibodies to staphylococcal enterotoxins A (SEA) and B (SEB) by intravenous inoculation of rabbits with small doses of enterotoxin diluted in sterile physiological saline. A course of six injections over a period of two weeks was given on four occasions. After the third course, 3/5 rabbits given SEA had a titre ± 1/50 and 4/6 given SEB had a titre of 1/50. Titres were not appreciably enhanced by the fourth series of injections. Only minor non-specific reactions which would require no absorption were found at the end of the series. It is believed that the findings in this study would be reproducible and that the method is likely to be suitable for raising antisera to other enterotoxins. Reference is also made to preliminary experiments in which latex sensitized with SEA or SEB was inoculated intravenously into rabbits.     

The role of secretory antibodies in adenovirus infection

The protective role of secretory antibodies in the development of adenovirus infection has been established. More severe and prolonged course of adenovirus infection, accompanied by the involvement of the lower respiratory tract in the process, has been noted in patients with low titers of antibodies, or their absence, in secretions (O to 1:4). The presence of secretory antibodies in a titer of 1:8 considerably alleviated the course of the disease. The antibody titer 1:16 (according to the data of the passive hemagglutination test) has proved to be protective for children and adults in adenovirus infection. The results of the determination of antibodies in the secretions of the upper respiratory tract in the passive hemagglutination test may be used for the purposes of prognostication.     

Seroprevalence of Toxoplasma gondii antibodies in the rodent capybara (Hidrochoeris hidrochoeris) from Brazil

Capybaras (Hidrochoeris hidrochoeris) are 1 of the largest rodents used for meat in South and Central America. Prevalence of anti-Toxoplasma gondii antibodies in 149 feral H. hidrochoeris from the state of S?o Paulo, Brazil, was evaluated using the indirect immunofluorescent antibody test (IFAT) and the modified agglutination test (MAT). Using IFAT, antibodies (>1:16) were found in 104 (69.8%) and with the MAT, antibodies (>1:25) were found in 63 (42.3%) capybaras. This is the first report of prevalence of T. gondii antibodies in this host.