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PubMed2002

Cellular, serological, and molecular polymorphism of the class I and class II loci of the canine Major Histocompatibility Complex.

This study was undertaken to determine the relationships between canine cellular and serological determinants and more recently described genes. Such relationships might reveal information about immunological reactivity or function of various proteins. To do this we studied the haplotypic associations of dog leukocyte antigen (DLA) class I and class II alleles determined from a panel of 14 DLA-D homozygous dogs. This panel of dogs was typed for the serological determinants DLA-A, DLA-B and DLA-C. Polymorphisms for DLA-DQA1, DLA-DQB1, DLA-DRB1 and DLA-88 were also determined. The number of alleles (one or two) for two microsatellite markers in the DLA region were also determined. Analyses of the nucleotide sequences and of the serological and cellular typing data revealed that phenotypic homozygosity, as defined by the DLA-D type in mixed leukocyte culture (MLC), tended to correlate with homozygosity at the DLA-DRB1 locus but not necessarily at the DLA-DQB1 locus. Furthermore, MLC specificity was determined by other loci besides DLA-DRB1 and DLA-DQB1. The amino acid at position 63 of the DR beta chain could contribute to the DLA-B serological specificity. DLA-88, the most polymorphic class I gene characterized to date, did not have an easily identifiable association with either the DLA-A or DLA-C class I serological specificities. Homozygosity or heterozygosity of each of two microsatellite markers, FH 2200 and FH 2202, located in the class I or class II region, respectively, did not correlate with homozygosity or heterozygosity of the most polymorphic known class I (DLA-88) or class II (DLA-DRB1) genes.

Animals↗
PubMed2001

The HLA Dictionary 2001: a summary of HLA-A, -B, -C, -DRB1/3/4/5 and -DQB1 alleles and their association with serologically defined HLA-A, -B, -C, -DR and -DQ antigens.

This report presents the serological equivalents of 123 HLA-A, 272 HLA-B and 155 HLA-DRB1 alleles. The equivalents cover over 64% of the presently identified HLA-A, -B and -DRB1 alleles. The dictionary is an update of the one published in 1999 (<1>Schreuder et al., 1999, Tissue Antigens, 54, 409) and also includes equivalents for HLA-C, DRB3, DRB4, DRB5 and DQB1 alleles. The data summarize information obtained by the WHO Nomenclature Committee for Factors of the HLA System, the International Cell Exchange (UCLA), the National Marrow Donor Program (NMDP) and individual laboratories. In addition, a listing is provided of alleles that are expressed as antigens with serological reaction patterns that differ from the well-established HLA specificities. The equivalents provided will be useful in guiding searches for unrelated hematopoietic stem cell donors in which patients and/or potential donors are typed by either serology or DNA-based methods. These equivalents will also serve typing and matching procedures for organ transplant programmes where HLA typings from donors and from recipients on waiting lists represent mixtures of serological and molecular typings. The tables with HLA equivalents and a questionnaire for submission of serological reaction patterns for poorly identified allelic products will also be available on the WMDA web page: www.worldmarrow.org

Alleles↗
PubMed2000

Can helicobacter pylori serology still be applied as a surrogate marker to identify peptic ulcer disease in dyspepsia?

BACKGROUND: Helicobacter pylori infection and associated peptic ulcer disease (PUD) has become less common in some countries. AIM: To determine if H. pylori serology alone or combined with a history of ingestion of non-steroidal anti-inflammatory drugs (NSAIDs) and an age threshold can be used as an indirect ulcer test. METHODS: Two hundred and fifty-two consecutive Australian patients (121 males, mean age 52 years) referred for endoscopy were enrolled. Blood was tested by a validated ELISA. At endoscopy, eight biopsies were taken for CLO-testing, culture and histology. NSAID use over the prior 3 months was recorded. RESULTS: One hundred and six (42%) patients were seropositive for H. pylori, 48 (19%) patients had PUD and 30 (12%) used NSAIDs. Serology alone had a sensitivity of 52% and a specificity of 60% for identifying PUD; the sensitivity and specificity were 60% and 55%, respectively, when combined with a history of NSAID use. Serology, regardless of NSAID use, would have saved 23% in endoscopy workload but would have missed 17% of PUD cases if an age threshold of < 45 years was chosen for omitting endoscopy. CONCLUSIONS: Serology was a poor ulcer test despite an excellent performance for detecting H. pylori. A strategy combining serology and an age threshold with a history of NSAID use to reduce endoscopy workloads may not always be appropriate.

Adult↗
PubMed2000

Serum thrombomodulin-a reliable marker of disease activity in systemic lupus erythematosus (SLE): advantage over established serological parameters to indicate disease activity.

To date no specific serological parameter is available to assess disease activity in SLE. Soluble serum thrombomodulin is a new marker of endothelial cell injury and vasculitis. The objective of this study was to compare in vivo soluble thrombomodulin as marker of disease activity in SLE with established and recent serological parameters. One hundred and twenty-four sera of 30 patients with proven SLE with different disease activities were tested for serum levels of thrombomodulin, intercellular adhesion molecule-1 (ICAM-1), E-selectin, vascular cell adhesion molecule-1 (VCAM-1), IL-2R, IL-6, IL-10, dsDNA by ELISA and dsDNA additionally by radioimmunoassay (RIA). C-reactive protein (CRP), complement component C3, IgG, creatinine, anti-nuclear antibodies (ANA) and intermediate filament antibodies were measured by standard laboratory tests. The clinical disease activity was evaluated by the Systemic Lupus Activity Measure (SLAM). Correlations of the different serological SLE disease activity parameters with the SLAM scores revealed the highest significance for serum thrombomodulin (correlation coefficient 0.82). This was further confirmed by the intra-individual analysis of follow-up sera. In addition, a moderate correlation could be found for IL-6, IL-10, ICAM-1, CRP and erythrocyte sedimentation rate (ESR). In summary, soluble thrombomodulin is the most important serological parameter of disease activity in SLE currently available, as shown by the in vivo studies. Soluble thrombomodulin might be a valuable serological parameter for therapeutical considerations.

Adolescent↗
PubMed2003

Celiac disease in children with Down syndrome: importance of follow-up and serologic screening.

BACKGROUND: Celiac disease, also known as gluten-sensitive enteropathy, is a chronic inflammation disease of the small intestinal mucosa. Detection of Ig-A antigliadin antibodies (AGA) and antiendomysial antibodies (EMA) in serum is important in the diagnosis and screening for celiac disease. Antiendomysial antibodies have greater sensitivity compared to antigliadin antibodies. It has been reported that the prevalence of celiac disease is higher in children with Down syndrome than the other autoimmune conditions. The aim of the present study was to investigate the incidence of celiac disease in children with Down syndrome, to assess the availability of Ig-A AGA and EMA for serologic screening, and to highlight the importance of follow-up for children with Down syndrome. METHODS: Forty-seven children with Down syndrome without known celiac disease were tested for total blood count, thyroid function tests, immunoglobulin values, Ig-A AGA and EMA. Duodenal biopsy was performed on eight patients who showed at least one serologically positive marker. RESULTS: The ages of the children with Down syndrome ranged from 2 to 18 years (30 boys/17 girls). The mean age was 6.55 +/- 3.88. Total blood count and immunoglobulin values were normal. Eleven of the 47 patients (23.40%) were found to be serologically positive, 10 (21.28%) having antigliadin antibody concentrations above normal; and six (12.77%) being positive for antiendomysial antibody. In five patients (10.64%), both Ig-A AGA and EMA concentrations were high and positive. Duodenal biopsies of three of eight cases (37.50%) revealed villous atrophy, lymphocyte infiltration and crypt hyperplasia. Three cases with abnormal biopsy results (100%) were below the 10th percentile for weight and height. Hypo-thyroidism was detected in one of 11 cases where at least one serologic marker was positive. CONCLUSION: Children with Down syndrome should be carefully examined in their follow up, and celiac disease should be considered in cases with growth retardation. Ig-A antigliadin antibodies and EMA are non-invasive, cheap and readily available serologic screening tests for celiac disease, and the positivity of both markers gives the most reliable result.

Adolescent↗
PubMed1991

Serologic distinction between human T-lymphotropic virus (HTLV) type I and HTLV type II.

In November 1988, the Food and Drug Administration approved reagents for serologic screening for human T-lymphotropic virus type I (HTLV-I) infection in blood donors and patients suspected of having HTLV-I-related illnesses. These reagents are able to detect HTLV type II (HTLV-II), a close relative of HTLV-I with no known pathologic effect. The distinction between the two forms of HTLV is important to the donor and to any recipient of blood containing HTLV. The application to sera from 38 seropositive blood donors and 2 recipients (37 "confirmed" positive and 3 indeterminate by Western blot) of two methods (Western blot and peptide enzyme immunoassay) for serologic distinction between HTLV-I and -II is described. These results were compared to those from polymerase chain reaction (PCR) analysis of HTLV proviral DNA obtained from donor peripheral blood mononuclear cells. The peptide enzyme immunoassay was found to be less sensitive than the Western blot, but completely concordant with PCR results when differential reactivity could be established. The Western blot pattern showed complete diagnostic concordance with the samples with confirmed-positive serologic tests, but was incorrect in two HTLV-II-infected donors with indeterminate serologic tests. Thirty-three (89%) of the 37 individuals from this predominantly Native American and Hispanic group of blood donors were found to have HTLV-II. These findings confirm and extend previous reports that HTLV-I infection may be less common, and HTLV-II infection more common, than previously believed. The peptide enzyme immunoassay can provide most individuals who have positive results with the HTLV-I/II screening test with serologic distinction between HTLV-I and HTLV-II.

Blood Donors↗
PubMed1996

Report on the Sixth International Society of Blood Transfusion Platelet Serology Workshop.

BACKGROUND: The Sixth International Society of Blood Transfusion Platelet Serology Workshop continued studies to identify methods to detect platelet-specific antigens and antibodies. STUDY DESIGN AND METHODS: The study was designed to meet three goals. The first was the establishment of antigen-typed platelet panels and determination of the correlation between serologic and DNA typing of platelet-specific antigens. The second goal was the determination of the proficiency of detecting platelet-specific antibodies by laboratory and by technique. The third goal was the identification of any platelet-specific antibodies present in uncharacterized (unknown) antisera. RESULTS: For platelet-antigen typing, concordance between serologic testing and DNA techniques was 93 percent for oligonucleotide typing and 92 percent for allele-specific restriction site analysis. Agreement between these two was 98 percent. Individual laboratories correctly identified the antibodies contained in coded sera 79 +/- 17 percent of the time. The expected results were obtained from the modified antigen-capture enzyme-linked immunosorbent assay in 75 +/- 46 percent of instances, from the monoclonal antibody-specific immobilization of platelet antigens assay in 72 +/- 24 percent of instances, from the mixed passive hemagglutination assay in 71 +/- 13 percent, from radioimmunoprecipitation procedures in 67 +/- 47 percent, and from Western blot 34 +/- 40 percent. Seven (54%) of 13 antisera of unknown specificity were determined to contain clearly identifiable platelet-specific alloantibodies. CONCLUSION: Concordant results were achieved by using either serologic or DNA techniques to identify platelet-specific antigens. Except for the significantly lower results found with Western blotting, all other platelet-specific antibody assays were comparable. Established serologic laboratories can identify and characterize plate-specific antibodies.

Antibody Specificity↗
PubMed2000

Comparative performances of an HTLV-I/II EIA and other serologic and PCR assays on samples from persons at risk for HTLV-II infection.

BACKGROUND: HTLV-I and HTLV-II are related exogenous pathogenic human retroviruses. Until recently, ELISAs based on HTLV-I antigens have been used to screen for the presence of HTLV-I or -II antibodies. The HTLV-I-based assays have not been as sensitive in detecting antibodies to HTLV-II as in detecting antibodies to HTLV-I. The Abbott HTLV-I/HTLV-II ELISA uses a combination of HTLV-I and HTLV-II antigens to detect antibodies to the whole HTLV group. The performance of this ELISA was compared to that of several HTLV-I-based serologic assays and an HTLV-II PCR assay in cohorts of South American Indians and New York City IV drug users (IVDUs) in whom HTLV-II is endemic. STUDY DESIGN AND METHODS: Sera from 429 South American Indians and New York City IVDUs were evaluated for HTLV antibodies by the use of three ELISAs (rgp21-enhanced HTLV-I/II, Cambridge Biotech; Vironostika HTLV-I/II, Organon Teknika; and HTLV-I/HTLV-II, Abbott), and a Western blot (WB) assay. Peripheral blood leukocyte DNA from each person was analyzed for HTLV-I and HTLV-II pol DNA via PCR. The HTLV-II PCR-positive samples were further subtyped via cloning and sequencing and/or oligomer restriction. RESULTS: Two hundred four samples (48%) were positive for HTLV-II by serologic and/or PCR assays. All of the positive samples from the Indians and approximately one-third of the positive samples from the IVDUs were of the HTLV-IIB subtype. Comparative analyses indicate that the sensitivity and specificity of the various assays were: PCR, 98 and 100 percent; Abbott HTLV-I/HTLV-II, 78 and 95 percent; Cambridge Biotech HTLV-I/II, 76 and 96 percent; Vironostika HTLV-I/II, 71 and 98 percent; and WB, 73 and 100 percent, respectively. CONCLUSION: There were no significant differences among the sensitivities and specificities of the HTLV-I/II ELISAs (p values, 0.056-0.438). The WB and PCR assays were much more specific than the other serologic assays (p</=0.03). However, the PCR assay is significantly (p<0.001) more sensitive than any of the serologic assays in the detection of HTLV-II infection. Thus, optimal detection of HTLV-II infection would seem to require both serologic and DNA PCR assays.

Enzyme-Linked Immunosorbent Assay↗
PubMed2000

Description of serologic features in autoimmune lymphoproliferative syndrome.

BACKGROUND: Autoimmune lymphoproliferative syndrome (ALPS) is a recently recognized and rare disorder associated with inherited defects in the FAS: gene or other regulators of lymphocyte apoptosis. It is characterized by massive lymphadenopathy; splenomegaly; autoimmunity including episodes of immune hemolytic anemia, thrombocytopenia, and neutropenia.(1) The serologic basis for immune cytopenias associated with ALPS has not been previously characterized. STUDY DESIGN AND METHODS: RBC, granulocyte, and platelet serologies for ALPS patients and hepatitis C patients were assessed. Medical records were reviewed for clinical, immunologic, serologic, and transfusion history. Testing included: DAT; serum screening for antibodies to RBCs, granulocytes, platelets, cardiolipin, penicillin-coated RBCs, and human leukocyte antigens; antibody identification and IgG subclass; RBC phenotype. RESULTS: In a cohort of 11 patients with apoptosis defects (eight with heterozygous FAS: gene mutations); many had histories of hemolytic anemia (7), thrombocytopenia (4), and/or leukopenia (11); nine received steroid therapy, seven underwent splenectomy; five had been remotely transfused. On the basis of serologic testing even when they were clinically stable, nine had positive DATs; two had alloantibodies; 6 had IgG and/or IgM antibodies to cardiolipin; seven had platelet-directed antibodies; three had granulocyte-directed antibodies; none had HLA antibodies. CONCLUSIONS: Nearly all ALPS patients have antibodies directed against one or more hematopoietic cell lineages. Serologic testing is critical in the evaluation of these individuals and when transfusion is indicated, red cells that are matched for clinically significant C, E, and K antigens should be considered.

Agglutination Tests↗
PubMed1997

Implications of Helicobacter pylori serological titer for the histological severity of antral gastritis.

BACKGROUND AND STUDY AIMS: We attempted to determine whether the serological titer of anti-Helicobacter pylori (HP) immunoglobulin (IgG) would be capable of predicting the presence of ulcer, or would correlate with the histological grading of gastritis in patients with dyspepsia. PATIENTS AND METHODS: One hundred eighty-three dyspeptic patients were prospectively included in the study after panendoscopy. Each patient underwent blood sampling for anti-HP IgG titer, and antral biopsy for both a rapid urease test (CLO) and histology. The severity of antral gastritis was semi-quantitated for acute and chronic inflammation scores (range 0-3). RESULTS: The HP findings were positive in 157 patients (85.5%), and their histological inflammation scores and serological titer were higher than those of HP-negative patients (P < 0.05). Based on the endoscopic findings, these 157 patients were classified into ulcer (n = 109) and non-ulcer dyspepsia (n = 48) subgroups. The mean chronic inflammation score in the ulcer subgroup was higher than that in the non-ulcer dyspepsia subgroup (1.77 vs. 1.28, P < 0.001). However, on the basis of only the titer itself, there was no cut-off value for serological titer to predict the presence or absence of ulcer in HP-infected patients. As the scores for either acute or chronic inflammation increased, the mean serological titer rose (acute inflammation score 0-3: 0.63, 0.78, 0.93, 1.39; chronic inflammation score 0-3: 0.18, 0.56, 0.88, 0.91). CONCLUSIONS: The titer of HP serology does not provide a method for predicting the presence of ulcer in patients with HP infection, but may indirectly offer evidence of the severity of histological changes.

Adult↗
PubMed1978

Serological characterization of B-tropic viruses of C57BL mice: possible origin by recombination of endogenous N-tropic and xenotropic viruses.

The serological properties of the gag gene products p15 and p12 of N- and B-tropic viruses of C57BL mice have been examined. Although these viruses were serologically identical by competition assays for proteins gp71 and p30, they were readily distinguishable in competition assays for proteins p15 and p12. Two isolates of N-tropic viruses had p12s serologically indistinguishable from AKR murine leukemia virus p12, while two B-tropic isolates had distinctly different p12s. The latter p12s were serologically indistinguishable from the p12 purified from the B-tropic radiation leukemia virus (RadLV)/VL-3. Moreover, this p12 was indistinguishable from the p12 of the endogenous C57BL/Ka xenotropic virus. Similarly, the p15s of the B-tropic viruses were serologically distinct from the AKR murine leukemia virus type of p15, as was the p15 of one C57BL N-tropic virus, whilc another N-tropic isolate had a p15 identical to the AKR murine leukemia virus p15. These results are interprered to suggest that the endogenous N-tropic virus of C57BL mice undergoes recombination with the endogenous, xenotropic virus and that this mechanism is involved in the generation of B-tropic viruses in C57BL mice.

Animals↗
PubMed2002

The serological gastric biopsy: a non-endoscopical diagnostic approach in management of the dyspeptic patient: significance for primary care based on a survey of the literature.

BACKGROUND: Measurement of the serum concentration of the secretory products of the gastric mucosa, pepsinogen A (PgA), pepsinogen C (PgC) and gastrin is called the serological gastric biopsy. Additional measurement of Helicobacter pylori antibodies and antibodies to parietal cells and intrinsic factor supports the non-invasive diagnostic value of the serum markers. In many clinical studies, the diagnostic potential of the serum markers in predicting the topography and severity of gastric mucosal disorders has been established. The aim was to assess the diagnostic value of the serological gastric biopsy for primary care. METHOD: Survey of the literature. RESULTS: The cell-physiological background of the serological gastric biopsy, the interpretation of the outcome of serum markers and the relation of these parameters to various gastric mucosal disorders are described. Measurement of PgA is a reliable way to discriminate between mucosal gastritis and functional dyspepsia. PgA is raised in duodenal, gastric and pyloric ulcer even though gastrin is normal. Both PgA and gastrin are raised in renal insufficiency and the Zollinger-Ellison syndrome. A low PgA is indicative of mucosal atrophy and a good indicator for gastric hypoacidity. An additional low PgA:C ratio is indicative of atrophic gastritis or extensive intestinal metaplasia of the stomach. A hypopepsinogenaemia can also be an alarm symptom for gastric cancer. A low PgA and a high gastrin is indicative of corpus atrophy. CONCLUSION: In primary care, the serological gastric biopsy might be a feasible and appropriate diagnostic method for management of the dyspeptic patient. Further research in general practice has to be done to validate the predictive value of the serological gastric biopsy and to define a diagnostic strategy.

Biomarkers↗
PubMed1982

Serology as an aid to diagnosis: uses and abuses.

The importance of correct interpretation of serological test results, common sources of error and problems associated with tests are discussed. In bovine brucellosis, a disease which is ideally suited to serological diagnosis, foetal contact with infection may cause the calf to be a serologically negative carrier. The immune tolerant animal resulting from foetal contact with virus is a major problem in the serological detection of border disease. In Johnes' disease and to a lesser extent in Brucella ovis and leptospiral infections, problems associated with sensitivity and specificity of the tests are stressed. Serovar specificity, cumbersome test procedures and negative tests in the incubation period cause difficulty in the interpretation of serological test results for leptospirosis. The importance of clinical examination, herd histories and alternative diagnostic procedures is important in all diseases. Wherever possible, flocks or herds should be maintained in specific disease-free state. Selection of stock from accredited herds or flocks is the most certain method of buying non-infected animals.

Journal Article↗
PubMed1998

Disparity between serological reactivity to Borrelia burgdorferi and evidence of past disease in a high-risk group.

A prevalence study of past Lyme borreliosis in persons with outdoor occupations was done. Consenting individuals (n = 302) were administered a questionnaire eliciting demographic and occupational data and a clinical history, and were asked to donate a serum specimen for detection of antibodies to Borrelia burgdorferi by enzyme-linked immunosorbent assay (ELISA), immunoblotting, and borrelia inhibition assays, and for detection of potentially cross-reactive antibodies. Of 302 individuals, 77 (25%) had reactive antibodies detected by ELISA. Of these 302 individuals, 44 (15%) met the criteria of the Centers for Disease Control and Prevention for serological reactivity as evidenced by immunoblotting, and 70 (23%) had inhibitory activity. Through the clinical criteria employed, only 11 individuals with serological reactivity had prior illness compatible with Lyme borreliosis. Higher ELISA absorbances were positively correlated with age and duration of outdoor occupation. The results from three serological assays and the lack of reactivity to potentially cross-reactive infectious agents indicate that serological reactivity was due to exposure to B. burgdorferi. The disparity between serological reactivity and the clinical evidence of Lyme borreliosis suggests cumulative exposure to a nonpathogenic form of B. burgdorferi.

Adult↗
PubMed1996

Diversity of antibody binding to V3 peptides representing consensus sequences of HIV type 1 genotypes A to E: an approach for HIV type 1 serological subtyping.

We investigated whether V3-binding assays might be useful to analyze human immunodeficiency virus type 1 (HIV-1) variants in different geographic regions. We showed that strong cross-reactivity between subtype-specific V3 peptides is almost inevitable in standard indirect enzyme-linked immunosorbent assays (EIA), impairing precise serological subtyping. We therefore developed a subtype-specific EIA (HIV-1 SSEIA) that uses the principle of blocking by an excess of peptide in the liquid phase. Using 231 serum samples collected from HIV-1-infected individuals in 10 different geographical areas from 4 continents, we showed that this approach detected the dominant subtype reactivity in more than 97% of the cases. Internal controls (0 and 100% blocking) were used for every sample such that comparative analysis was possible, independent of both the individual humoral response and the time of collection during the course of infection. This was validated by the excellent concordance of the serological profiles of couples and the temporal stability of the serological profile in individuals. The geographical distribution of the various subtypes in the SSEIA was in agreement with the present knowledge of the distribution of the various genotypes. Although the goal of this study was not an extensive seroepidemiological survey, our results showed that the various profiles in most of the regions were relatively homogeneous, but in central Africa there was a large diversity of serological profiles. Cluster analysis identified a limited number of V3 serogroups of serotypes within the HIV-1 group M. Five serogroups, some of them divided into subgroups, were identified and characterized by a mean serological profile. Our data confirmed that subtypes A and C, although being dissimilar genetic subtypes, present conserved antigenic properties in the V3 region, and that the D subtype is probably the most divergent within the group M (B Korber et al., J Virol 1994;68:6730). Cluster analysis showed a clear correlation between position within the dendrogram and geographical origin of the samples. This is further support for the reliability and thereof the usefulness of the SSEIA. This simple methodology may help facilitate the analysis of the distribution of various HIV-1 subtypes circulating in different populations and regions.

Amino Acid Sequence↗
PubMed1998

Helicobacter pylori serology in elderly people: a 21-year cohort comparison in 70-year-olds and a 20-year longitudinal population study in 70-90-year-olds.

AIMS: (i) to compare Helicobacter pylori serology in two 70-year-old cohorts in Gothenburg, Sweden, born 21 years apart, (ii) to study H. pylori serology in a 70-year-old cohort over 20 years. POPULATION AND METHOD: H. pylori serology at the age of 70 was investigated in 98 men and 132 women born in 1901/02 and in 77 men and 113 women born in 1922. In 21 men and 40 women Helicobacter serology was monitored longitudinally with examinations at 70, 81, and 90 years of age. The analyses were performed on frozen samples by use of an in-house enzyme immunoassay with a sensitivity of 0.99, specificity of 1.00 and positive and negative predictive values of 0.96 and 1.00, respectively. Absorbance values <0.500 were interpreted as negative; values of > or = 0.700 were interpreted as positive, and values in between as inconclusive. RESULTS: The 70-year-old cohort, born in 1922, showed a significantly lower proportion of subjects with positive H. pylori serology in both men (57.1% vs 80.6%) and women (48.7% vs 75.8%) compared with 70-year-olds born in 1901/02. There were no significant sex differences in either cohort. No longitudinal increase or decrease could be demonstrated in those who were examined at 70, 81 and 90 years of age. CONCLUSIONS: The difference in H. pylori prevalence between the two cohorts may reflect a rapid change in socio-economic conditions in Sweden during this 20-year period.

Age Factors↗
PubMed1996

Recall of original serologic response after challenge with homologous and heterologous Chlamydia trachomatis serovars.

Chlamydia trachomatis serovar-specific major outer membrane protein (MOMP) antigens are important targets of immune neutralization in vitro, and natural immunity to infection is associated with serovar specificity. Reinfection, often by different serovars, plays an essential role in chlamydial disease pathogenesis. By use of a murine model, the anamnestic serologic response was characterized following priming and challenge inoculations using 6 different serovars. The serologic response was evaluated using synthetic peptides representing MOMP variant segments (VS) 1,2,3, and 4 antigenic same serovar resulted in serologic responses to homologous VS1 peptides. After challenge with a different serovar, anti-VS1 serologic responses were often elicited with specificity to both the priming serovar and the challenge serovar. The recall of serologic response to the original serovar was typically dependent upon the antigenic relationship of the 2 serovars.

Amino Acid Sequence↗
PubMed1997

Serologic survey for control of hepatitis C in haemodialysis patients: third-generation assays and analysis of costs.

There is little information about the serologic survey for control of hepatitis C by using third-generation assays among chronic haemodialysis (HD) patients, and no analysis of costs has been made to this end. A serologic survey for control of hepatitis C was performed in 190 HD patients attending a single dialysis unit, using second- and third-generation assays. Costs of both serologic surveys were calculated. Anti-HCV prevalence tested by third-generation assays increased from 25% (48/190) to 28% (53/190) compared to second-generation testing; 56% (9/16) of patients showing uncertain findings by second-generation tests gave unequivocal results by third-generation assays; median duration of HD treatment and raised aminotransferase levels were positively associated (P = 0.004 and P = 0.012, respectively) with anti-HCV detected by third-generation assays. The serologic survey for control of hepatitis C in HD patients at our centre was slightly more expensive by third-generation assays compared to second-generation testing (US$18866 vs US$17200 per year). In summary, the use of third-generation tests largely clarified the uncertain results of second-generation tests; new additional positive patients were detected by third-generation assays compared to second-generation testing. Third-generation assays showed the association of duration of HD treatment and raised aminotransferase levels with anti-HCV antibody, as previously found by first- and second-generation assays. To date, third-generation screening and confirmatory assays seem extremely useful in the serologic survey for control of hepatitis C in HD centres without a considerable outlay.

Adult↗