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Biomedical subjects

R W Peeling

Publications and source records attributed to R W Peeling.

At least 55 records · Page 3Linked to original sources
PubMed1997

The presence of serum antibody to the chlamydial heat shock protein (CHSP60) as a diagnostic test for tubal factor infertility.

OBJECTIVE: To study the utility of testing for heat shock protein 60 (CHSP60) antibodies in the diagnosis of tubal factor infertility. DESIGN: Prospective case control. SETTING: Canadian university hospital infertility clinic. PATIENT(S): Women presenting for infertility investigation. INTERVENTION(S): Sera were collected from 77 patients. MAIN OUTCOME MEASURE(S): The relationship between tubal factor infertility and the presence of antibodies to Chlamydia trachomatis and CHSP60 was assessed. RESULT(S): There were no significant differences between antibodies to C. trachomatis in women with tubal factor infertility (63%) and other causes of infertility (46%). However, more women with tubal factor infertility (44%) had anti-CHSP60 antibodies compared with other causes of infertility (8%). Antibody testing for C. trachomatis has only a 63% sensitivity and a 54% specificity for detecting tubal factor infertility. In contrast, the CHSP60 antibody test has a 44% sensitivity and a 92% specificity for detecting tubal factor infertility. There is a good positive likelihood ratio of 5.5 for CHSP60 antibody testing detecting the presence of tubal factor infertility. Combining CHSP60 antibody with antibody testing for C. trachomatis has an excellent positive likelihood ratio of 10 for the detection of C. trachomatis-associated tubal factor infertility. CONCLUSION(S): CHSP60 antibody testing is a more accurate test than antibody testing for C. trachomatis for predicting chlamydia-associated tubal factor infertility. These tests, when used in combination at initial infertility evaluation, would provide a rapid noninterventive means of diagnosing tubal factor infertility.

Adult↗
PubMed1997

Antibody to chlamydial hsp60 predicts an increased risk for chlamydial pelvic inflammatory disease.

To determine whether serum antibody to Chlamydia trachomatis antigens alters the risk of C. trachomatis pelvic inflammatory disease (PID), 280 female sex workers were prospectively evaluated over a 33-month period for incident C. trachomatis and Neisseria gonorrhoeae cervical infection and for clinical PID. At enrollment, women were tested for antibody to C. trachomatis elementary bodies by an indirect microimmunofluorescence assay and to recombinant chlamydial hsp60 (Chsp60) by an ELISA format. At each follow-up visit, women were tested for cervical chlamydial and gonococcal infection and were identified as having clinical PID if they complained of lower abdominal pain and were found to have uterine and adnexal tenderness on pelvic examination. The data demonstrate that antibody to Chsp60 predicts a 2- to 3-fold increased risk for C. trachomatis PID.

Adolescent↗
PubMed1997

Prevalence and correlates of antibody to chlamydial heat shock protein in women attending sexually transmitted disease clinics and women with confirmed pelvic inflammatory disease.

A cross-sectional study of 306 women was done to correlate antibody to the chlamydial hsp60 (Chsp60) with epidemiologic, serologic, and laparoscopic findings of women with and without pelvic inflammatory disease (PID). Of the 306 women, 150 had confirmed PID by laparoscopic (n = 69) or histologic (n = 81) criteria, and 156 sexually transmitted disease clinic attendees without clinical PID did (n = 94) or did not (n = 62) have chlamydia. In multivariate analyses, Chsp60 antibody was independently associated with confirmed PID, age > 20 years, nonwhite race, > 10 lifetime sex partners, current oral contraceptive use, and IgG antibody titers; it was not associated with a positive Chlamydia trachomatis culture. Among the 69 women with laparoscopic evidence of PID, the highest level of Chsp60 antibody (optical density > 1.0) was found in 8 (80%) of 10 women with occluded tubes, compared with 11 (19%) of 58 with patent tubes (P < .001). We conclude that antibody to Chsp60 was significantly correlated with risk factors for PID, confirmed PID, and occluded fallopian tubes but not with acute C. trachomatis infection without PID.

Acute Disease↗
PubMed1996

Ambulatory patients with community-acquired pneumonia: the frequency of atypical agents and clinical course.

OBJECTIVES: To determine the etiology of community-acquired pneumonia in patients treated in an ambulatory setting, using serological methods, and to compare presenting symptoms, radiographic manifestations, and clinical outcomes of patients with pneumonia of "atypical" and undetermined etiology. PATIENTS AND METHODS: This prospective cohort study was conducted in emergency room and outpatient facilities of Victoria General Hospital, Halifax, Nova Scotia, and in offices of participating family doctors based in Halifax. One hundred forty-nine adults with acute onset of one or more symptoms or signs suggestive of pneumonia and radiographic evidence of pneumonia who provided informed consent were enrolled. Patients known to be HIV positive or who had been discharged from a hospital within the previous 10 days were ineligible for enrollment. Demographic features and clinical data were collected by direct patient interview and chart review by trained research nurses. Outcome measures included quantitative evaluation of pneumonia-specific symptoms, and responses to the Short Form 36 Health Survey at presentation and at 30 days after presentation. Information was also collected on each patient's health prior to pneumonia, as well as the time until each patient's self-reported return to work and to usual activities. The etiology of pneumonia was determined by testing acute and convalescent serum samples for antibodies to Legionella pneumophila serogroup 1, Mycoplasma pneumoniae, Chlamydia pneumoniae, Chlamydia psittaci, Coxiella burnetii, adenovirus, respiratory syncytia virus, influenza viruses A and B, and parainfluenza viruses 1, 2, 3. RESULTS: The study population consisted of 149 patients, 54 (36%) of whom were men, with a mean age (+/- SD) of 41 +/- 15 years. An etiological diagnosis was made in 74 (49.7%) patients using serological methods. Etiological agents included M pneumoniae 34 (22.8%); C pneumoniae 16 (10.7%); M pneumoniae and C pneumoniae 5 (3.4%); C burnetii 4 (2.7%); influenza A virus 4 (2.7%); and other agents 6% (7.4%). Three patients (2%) had a conventional bacterial etiology, and 72 patients (48.3%) had pneumonia of undetermined etiology. Patients with pneumonia of known (atypical) and undetermined etiology were similar in terms of age, gender, race, education, employment, and comorbidity. Despite a higher proportion of patients with pneumonia of known etiology reporting sweats, chills, and headache at presentation, the two groups were similar for symptom severity and bother. The patients with pneumonia of undetermined etiology were more likely to have multilobar pneumonia (P < 0.02). Both patients with atypical pneumonia and those with pneumonia of undetermined etiology suffered severe deterioration of physical functioning with a marked but incomplete recovery at 30 days. Those with atypical pneumonia had higher physical functioning and general mental health scores at 30 days. CONCLUSIONS: Nearly half the cases of ambulatory community-acquired pneumonia are due to "atypical" agents. It is not possible to reliably distinguish patients with atypical pneumonia from those with pneumonia of undetermined etiology by clinical features at baseline. The outcomes in terms of resolution of symptoms, functional status, return to work, and return to usual activities are essentially similar in the two groups.

Adult↗
PubMed1996

Does serologic evidence of remote Chlamydia trachomatis infection and its heat shock protein (CHSP 60) affect in vitro fertilization-embryo transfer outcome?

OBJECTIVE: To examine IVF-ET outcome in patients with and without serologic evidence of Chlamydia trachomatis infection and chlamydia heat shock protein 60 (CHSP 60) antibodies. DESIGN: Retrospective case control. SETTING: University-affiliated IVF-ET program. MAIN OUTCOME MEASURES: A total of 195 IVF-ET patients with tubal factor infertility underwent oocyte pick-up, 166 of these women had ET resulting in a total of 37 pregnancies. Serum antibody testing for evidence of remote C. trachomatis and CHSP 60, as well as pregnancy outcome, were determined for all patients. RESULTS: There were no differences in pregnancy rates or outcomes between C. trachomatis seropositive versus seronegative groups: 27/118 (23%) C. trachomatis seropositive versus 10/77 (13%) C. trachomatis seronegative patients achieved pregnancy per oocyte pick-up. Pregnancy rates per ET were 27/105 (26%) in C. trachomatis seropositive versus 10/61 (16%) C. trachomatis seronegative patients. In the C. trachomatis positive subgroup, significantly higher pregnancy rates were found in the CHSP 60 antibody positive patients: 24/67 (36%) CHSP 60 positive versus 3/51 (6.0%) CHSP 60 negative patients were pregnant after oocyte pick-up (OR = 8.9, 95% CI = 2.3 to 27.5). Pregnancy rates per ET were 24/57 (42%) in CHSP 60 positive versus 3/48 (7%) CHSP 60 negative patients (OR = 10.9, 95% CI = 2.8 to 33.6). There were no significant differences in any group when examining the following pregnancy outcomes: spontaneous abortion, ectopic pregnancy, preterm and multiple pregnancy rates. CONCLUSIONS: [1] There are no differences in pregnancy rates or outcomes in patients with and without serologic evidence of previous C. trachomatis infections. [2] In women seropositive for C. trachomatis, significantly higher pregnancy rates are found in women who are CHSP 60 antibody positive versus negative. [3] Pregnancy outcomes do not appear to be different between these groups.

Antibodies, Bacterial↗
PubMed1996

Serological study of responses to selected pathogens causing respiratory tract infection in the institutionalized elderly.

In a prospective 2-year study, serological responses to selected pathogens were analyzed in 224 episodes of fever attributable to respiratory tract infection (51.8%) or of unknown source (48.2%) in 131 residents of two long-term-care facilities. A serological response was identified in 45 episodes (20.1%): Chlamydia pneumoniae (14 episodes), Haemophilus influenzae type b (1), influenza virus type A (14), respiratory syncytial virus (RSV;2), parainfluenza virus type 3 (7), C. pneumoniae and H. influenzae (3), C. pneumoniae and influenza virus type A (2), C. pneumoniae and RSV (1), and C. pneumoniae and parainfluenza virus type 3 (1). No serological responses to Chlamydia psittaci, Chlamydia trachomatis, parainfluenza virus types 1 and 2, influenza virus type B, or Mycoplasma pneumoniae were seen. Vaccination did not affect the duration of fever in those residents with serologically confirmed influenza A. Serologically confirmed C. pneumoniae infection was detected in 9.4% of all febrile episodes. Serological responses to a second agent were detected in 33% of the patients with C. pneumoniae infections, and these dual infections were associated with an underlying malignancy (P = .02). C. pneumoniae should be recognized as a potential pathogen when choosing empirical antimicrobial therapy for respiratory tract infection in residents of long-term-care facilities.

Aged↗
PubMed1996

Risk factors for Chlamydia trachomatis pelvic inflammatory disease among sex workers in Nairobi, Kenya.

Among 302 female sex workers in Nairobi, Kenya, who were followed for 17.6 +/- 11.1 months, 146 had one or more infections with Chlamydia trachomatis; 102 had uncomplicated cervical infection only, 23 had C. trachomatis pelvic inflammatory disease (PID), and 21 had combined C. trachomatis and Neisseria gonorrhoeae PID. As determined by multivariate logistic regression analysis, risk factors for C. trachomatis PID included repeated C. trachomatis infection (odds ratio [OR], 1.8; 95% confidence interval [CI], 1.3-2.4; P = .0004), antibody to C. trachomatis heat-shock protein 60 (OR, 3.9; CI, 1.04-14.5; P = .04), oral contraceptive use (OR, 0.28; 95% CI, 0.08-0.99; P = .048), and number of episodes of nongonococcal nonchlamydial PID (OR, 1.7; 95% CI, 1.1-2.7; P = .02). Among human immunodeficiency virus (HIV)-seropositive women, a CD4 lymphocyte count of <400/mm3 was an additional independent risk factor for C. trachomatis PID (OR, 21.7; 95% CI, 1.2-383; P = .036); among HLA-typed women, HLA-A31 was independently associated with C. trachomatis PID (OR, 5.6; 95% CI, 1.1-29.4; P = .043). The results suggest an immune-mediated pathogenesis for C. trachomatis PID.

Adult↗
PubMed1996

HLA class I and II polymorphisms and trachomatous scarring in a Chlamydia trachomatis-endemic population.

Immune responses to Chlamydia trachomatis contribute to protection from infection and to immunopathologic disease. To test whether subjects' HLA class I (A, B, and Cw) or class II (DRbeta1 and DQbeta1) types influence risk of trachomatous scarring from chronic infection with C trachomatis, 153 cases and pair-matched controls in Gambia were studied. No HLA type was associated with protection from scarring, indicating that protective immune responses are not limited to only one or a few HLA-restricted epitopes in C. trachomatis antigens. One class I antigen, HLA-A28, was significantly more common among cases than controls (25.8% vs. 15.9%, respectively; McNemar's odds ratio [OR], 1.88; 95% confidence interval [CI] = 1.01-3.49; P = .046). In DNA subtyping of the A28 specificity, the A*6801 allele was equally common among cases and controls, but the A*6802 allele was significantly overrepresented among cases (McNemar's OR, 3.14; 95% CI = 1.32-7.44; P = .009). This association may be due to an immunopathologic HLA-A*6802-restricted cytotoxic T lymphocyte response.

Adolescent↗
PubMed1996

Acceptability and usefulness of vaginal washes in premenarcheal girls as a diagnostic procedure for sexually transmitted diseases. The Child Protection Centre at the Winnipeg Children's Hospital.

OBJECTIVE: To assess the suitability of vaginal washes as specimens for sexually transmitted disease diagnosis and determine the usefulness of PCR technology for Chlamydia trachomatis diagnosis in prepubertal girls. STUDY DESIGN: Paired sets of vaginal secretions were collected with swabs and by vaginal wash from 138 prepubertal girls for evaluation because of alleged sexual abuse. Detection by culture of Neisseria gonorrhoeae and C. trachomatis was compared between the two sampling techniques. PCR techniques were also used to test 29 vaginal wash specimens for C. trachomatis. RESULTS: In the prepubertal girls N. gonorrhoeae was detected in two wash specimens but in only one swab specimen; C. trachomatis was detected by culture in both paired specimens from two children and by PCR in vaginal washes from both of the two children positive by culture; PCR identified two other infected children. CONCLUSIONS: A vaginal wash technique coupled with newer molecular amplification technology may be useful in the assessment of sexually abused children.

Adolescent↗
PubMed1996

Diagnosis of Chlamydia trachomatis infections in asymptomatic men and women by PCR assay.

A PCR assay was evaluated for its ability to detect genital chlamydial infection in asymptomatic men and women. Urethral swab specimens were collected from 472 men for culture and PCR assay, and first-void urine (FVU) specimens were collected from 379 of these men for enzyme immunoassay (EIA) and PCR assay. Cervical swab specimens were collected from 242 women for culture, EIA, and PCR assay. Patients were considered infected if they were culture positive or positive by PCR with both plasmid- and major outer membrane protein-based primers. By using this extended "gold standard," the prevalence of infection in this population was 7.6% for men and 7.9% for women. For men, the sensitivities of urethral swab specimen culture and PCR and FVU specimen EIA and PCR were 61, 72, 55, and 91%, respectively. All assays had specificities of > or = 99.8%. The positive and negative predictive values for PCR testing of FVU specimens were 100 and 99.4%, respectively, compared with values of 96.3 and 97.8%, respectively, for PCR of urethral swab specimens. The sensitivities of cervical swab specimen culture and PCR testing were 42 and 90%, respectively, with corresponding specificities of 100 and 99.3%. All cervical swabs were negative by EIA. Molecular techniques such as PCR assays are valuable tools for the detection of symptomatic genital chlamydial infection. In particular, PCR assays of FVU specimens from men offer a highly sensitive, noninvasive screening tool that will likely improve patient compliance for diagnostic testing.

Adult↗
PubMed1995

Serologic evidence of Chlamydia trachomatis infection and risk of preterm birth.

OBJECTIVE: To determine whether serologic evidence of Chlamydia trachomatis during pregnancy is a risk factor for preterm delivery (before 37 weeks' gestation). DESIGN: Chart review. SETTING: Antenatal clinics associated with a teaching hospital. PATIENTS: A group of 103 unselected consecutive patients presenting for routine prenatal care. OUTCOME MEASURES: Pregnancy outcome and C. trachomatis serologic status. RESULTS: A total of 21 women (20%) were found to be seropositive for IgG antibodies to C. trachomatis. They were similar to the seronegative women with respect to maternal age, parity, history of preterm birth, obstetric or medical problems, smoking status, history of drug abuse, educational status and psychosocial stressors. The seropositive women were significantly more likely than the seronegative women to have a preterm birth (24% [5/21] v. 7% [6/82]i p = 0.029, odds ratio 3.96, 95% confidence interval 1.08 to 14.57), an infant with a lower mean gestational age at birth (262 [standard deviation (SD) 19] days v. 273 [SD 15] days; p = 0.0052) and an infant with a lower mean birth weight (3125 [SD 692] g v. 3473 [SD 696] g; p = 0.0434). The positive predictive value of a seropositive result for preterm birth was 31% (5/16); the negative predictive value of a seronegative result for preterm birth was 8% (6/76). CONCLUSION: Women with serologic evidence of C. trachomatis may be at risk for preterm birth. Further study is required to determine whether serologic testing for C. trachomatis should be a routine part of prenatal care.

Adult↗
PubMed1994

Molecular techniques for the laboratory identification of Chlamydia trachomatis.

Chlamydia trachomatis detection has been substantially advanced by molecular amplification methods. As diagnostic or screening tests, the methods have shown performance characteristics equivalent to culture, but are more rapid and have no special requirements for specimen transport. The challenge for this generation of diagnostic tests is to prevent laboratory and specimen cross contamination.

Chlamydia trachomatis↗
PubMed1994

Chlamydia trachomatis antigens: role in immunity and pathogenesis.

As an intracellular bacteria, Chlamydia trachomatis is an extraordinarily successful pathogen. Chlamydial infections are among the most common of all human infections. Chlamydial disease is less common than infection and is attributed to immune responses to specific antigens of the organism. A major variant surface protein, major outer membrane protein (MOMP), is the principal target of neutralizing antibodies and may be the target of protective immunity. The detailed genetic and immunochemical knowledge of MOMP has stimulated multiple attempts to design an oligopeptide vaccine. Success has been limited in part because of the antigenic variation that the protein exhibits and in part because of the absence of knowledge regarding the three-dimensional structure of the protein. Individuals with severe forms of chlamydial disease often display immune responses to a common chlamydial heat shock protein 60 (hsp60) antigen. Because the protein shares nearly 50% sequence identity with the human homolog, it is speculated that molecular mimacy may result in autoimmune inflammatory damage that in turn causes chlamydial disease sequelae. Because hsp60 immune responses are genetically determined, susceptibility genes for chlamydial disease may also exist. A detailed understanding of the immunobiology of C. trachomatis infection may result from molecular study of chlamydial antigens and the precise nature of immune responses they elicit. Nevertheless, even with the rapid progress that has been made in uncovering the major chlamydial antigens, more remains hidden than revealed. As demonstrated by their successful ecology, chlamydiae remain several stops ahead of even their most ardent pursuers.

Animals↗
PubMed1993

A novel approach to the laboratory diagnosis of Chlamydia trachomatis infections using monoclonal anti-idiotypic antibodies.

We have developed a novel enzyme immunoassay (EIA) for the specific detection of Chlamydia trachomatis utilizing a monoclonal anti-idiotypic antibody to an antibody directed against a chlamydia specific epitope on 60 kDa heat-shock protein (HSP60). The basis of the assay is the inhibition of the binding of idiotype to anti-idiotype by antigen present in test samples. Two configurations of the assay were developed: a blocking EIA and a competition EIA. Greater sensitivity was observed using the competition EIA, with the assay detecting purified recombinant HSP60 and purified chlamydia in a concentration-dependent manner from 0.01 to 10 micrograms protein and from 0.5 to 12 micrograms total protein, respectively. The assay is highly specific and offers several potential advantages over currently available EIAs for the detection of this pathogen.

Animals↗
PubMed1992

The role of the laboratory in a Chlamydia control programme in a developing country.

The laboratory components of a Chlamydia trachomatis disease control programme for a developing country are reviewed. Early diagnosis of chlamydial infections is the most cost effective means of preventing the long term sequelae of trachoma, pelvic inflammatory disease, ectopic pregnancy and infertility, which are now a major public health burden to the health care system in developing countries. Public health strategies are required to establish both a co-ordinated limited system of laboratory services, and to promote the diagnosis and treatment of disease syndromes in the absence of laboratory support. Laboratory tests for the specific diagnoses of chlamydial infections requiring different levels of expertise and equipment can be instituted within settings appropriate to the resources and technical expertise available. Emphasis is given to appropriate cost effective utilization of laboratory testing.

Chlamydia Infections↗
PubMed1991

Chlamydial infections and the quinolones.

Some of the newer fluoroquinolones may be suitable agents for the treatment of Chlamydia trachomatis infections and non-gonococcal urethritis. To date, small studies with both ofloxacin and fleroxacin appear to achieve cure rates of 85-100% for urethritis and cervicitis due to Chlamydia trachomatis. However, large well-designed clinical trials are required to determine the efficacy and acceptance of these and other fluoroquinolones in the treatment of patients with genital or respiratory syndromes due to chlamydiae or other bacterial pathogens causing infections with similar manifestations.

4-Quinolones↗
PubMed1991

Neutralization of Chlamydia trachomatis: kinetics and stoichiometry.

Monoclonal antibodies to the major outer membrane protein of Chlamydia trachomatis were used to neutralize C. trachomatis infectivity in HeLa 229 cells and to determine the kinetics and stoichiometry of the reaction. In vitro neutralization of C. trachomatis infectivity proceeded as a first-order reaction and required an activation energy of approximately 20 kcal/mol (ca. 84 kJ/mol). The rate of neutralization was linear with respect to antibody concentration and reaction temperature. The efficiency of neutralization decreased exponentially as the ratio of noninfective to infective chlamydiae increased in the antigen preparation. The neutralization assay was also significantly affected by reaction parameters such as the reaction volume and the duration of incubation. Stoichiometric calculations showed that an average ratio of 10(3) and 10(4) immunoglobulin molecules per chlamydial particle was required to yield 50% neutralization by monoclonal antibodies specifying serovar-specific and species-specific epitopes, respectively. The implications of these findings for vaccine design and for the role of the major outer membrane protein in the pathogenesis of chlamydial infections are discussed.

Antibodies, Monoclonal↗