iPSC-derived cortical neurons to study sporadic Alzheimer disease: A transcriptome comparison with post-mortem brain samples.

Alzheimer's disease (AD) is the most common cause of dementia, characterized by the progressive impairment of cognition and memory loss. Sporadic AD (sAD) represents approximately 95 % of the AD cases and is induced by a complex interplay between genetic and environmental factors called "Alzheimerogens". Heavy metals (e.g. copper) and pesticides (e.g. fipronil) can affect many AD-related processes, including neuroinflammation (considered as AD-inducing factor). Research would benefit from in vitro models to investigate effects of Alzheimerogens. We compared transcriptomics changes in sAD induced pluripotent stem cell (iPSC) derived cortical neurons to differentially expressed genes (DEGs) identified in post-mortem AD brain tissue. These analyses showed that many AD-related processes could be identified in the sAD iPSC-derived neurons, and furthermore, could even identify more DEGs functioning in these processes than post-mortem AD-brain tissue. Thereafter, we exposed the iPSCs to AD-inducing factors (copper(II)chloride, fipronil sulfone and an inflammatory cytokine cocktail). Cytokine exposure induced expression of immune related genes while copper-exposure affected genes involved in lipid and cholesterol metabolism, which are known AD-related processes. Fipronil-exposure did not result in significant transcriptomic changes, although prolonged exposures or higher doses may be necessary. Overall, we show that iPSC-derived cortical neurons can be beneficial in vitro models to identify Alzheimerogens and AD-related molecular mechanisms.

In vitro RHE skin sensitisation assays: Applicability to challenging substances.

In the last 20 years, alternative approaches to the identification of skin sensitisation hazards have been at the forefront of the 3Rs and have helped refine the validation and acceptance processes. However, experience with the local lymph node assay showed that, post-validation, challenges still occurred, particularly when a wider diversity of chemical substances was addressed, a situation which will arise with validated in vitro alternatives. In the present work, a range of substances potentially challenging to assess in current nonanimal OECD test guidelines were evaluated in several of the emerging in vitro alternatives. Twelve such substances (of which just over half were known skin sensitisers) were assessed in 4 assays, all based on reconstructed human epidermis (RHE) models. For hazard identification, the overall predictive accuracy ranged around 70% for three assays, although for one (SensCeeTox), it fell below 50% when human data was used as the benchmark. In most cases, sensitivity was high, such that sensitisation was overpredicted. As the substances were challenging to assess in other nonanimal methods, the results indicate that the 3D RHE models may be a useful tool for assessing skin sensitisation potentials without needing to revert to animal use.

Preliminary performance data of the RHE/IL-18 assay performed on SkinEthic™ RHE for the identification of contact sensitizers.

OBJECTIVE: The purpose of this study was to evaluate the performances of the RHE/IL-18 assay using the SkinEthic™ RHE model for the identification of contact sensitizers. METHODS: A set of 18 substances and mixtures was tested on this epidermal model, following the RHE/IL-18 protocol. The final results of the assay were obtained following 5 interpretation schemes, to determine the optimal prediction model for this assay with this specific test system. The data were analysed with a special focus on the basal level of IL-18 release and on the performance obtained with respect to three different gold standards: LLNA, HRIPT and an integrated reference, constructed from all available results. RESULTS: No important differences were found in the performance levels depending on the three gold standards. The performances obtained with the SkinEthic™ RHE model support that this model may be considered as an alternative to different reconstructed epidermis models (EpiDERM™ , EpiCS™ and VUMC-EE) for the performance of RHE/IL-18 assays. CONCLUSION: The prediction model to be used was refined, and more substances have to be tested in order to gather enough data for this evaluation and to determine the right criteria applicable for this assay using the SkinEthic™ RHE test system.

IgE versus IgG4 epitopes of the peanut allergen Ara h 1 in patients with severe allergy.

BACKGROUND: Development and maintenance of tolerance to food allergens appears to be associated with alterations in antigen specific IgE and IgG4 responses. Previous studies have focused only on comparing IgE and IgG4 linear epitope recognition patterns but take no account of conformational epitopes. OBJECTIVE: The aim of this study was to compare Ara h 1-specific IgE and IgG4 epitope recognition patterns in patients with severe peanut allergy, applying a method allowing for identification of both linear and conformational epitopes. METHODS: Polyclonal sera from three individual patients, suffering from severe allergic reaction to peanuts, including anaphylaxis, were used to analyse the IgE and IgG4 epitope recognition patterns of the major peanut allergen Ara h 1. Epitope identification was conducted by competitive immuno-screening of a phage-displayed random heptamer peptide library. Resulting epitope-mimicking sequences were aligned for identification of consensus sequences and localised on the surface of the Ara h 1 molecule by a computer-based algorithm. RESULTS: All epitope-mimicking sequences identified were found to correspond to conformational epitopes. Each individual patient had his/her own distinct IgE as well as IgG4 epitope recognition profile, though some important IgE epitopes were common to all patients. In general the IgG4 epitope pattern was more heterogeneous than the IgE pattern, did not coincide with IgE epitopes and had a lower affinity than IgE. CONCLUSIONS: This study demonstrated the usefulness of the phage-display technology in distinguishing between the epitope pattern of IgE and IgG4, giving detailed information on fine specificity and affinity. Competitive immuno-screening of phage-display random peptide libraries could be a future valuable tool to study the balance and dynamics of the IgE and IgG4 epitope recognition repertoire and provide a diagnostic tool giving information on the associated allergic phenotype.

IgE epitopes of intact and digested Ara h 1: a comparative study in humans and rats.

BACKGROUND: Allergen epitope characterization provides valuable information useful for the understanding of proteins as food allergens. It is believed that IgE epitopes in general are conformational, nevertheless, for food allergens known to sensitize through the gastrointestinal tract linear epitopes have been suggested to be of great importance. OBJECTIVE: The aim of this study was to identify IgE specific epitopes of intact and digested Ara h 1, and to compare epitope patterns between humans and rats. METHODS: Sera from five peanut allergic patients and five Brown Norway rats were used to identify intact and digested Ara h 1-specific IgE epitopes by competitive immunoscreening of a phage-displayed random hepta-mer peptide library using polyclonal IgE from the individual sera. The resulting peptide sequences were mapped on the surface of a three-dimensional structure of the Ara h 1 molecule to mimic epitopes using a computer-based algorithm. RESULTS: Patients as well as rats were shown to have individual IgE epitope patterns. All epitope mimics were conformational and found to cluster into three different areas of the Ara h 1 molecule. Five epitope motifs were identified by patient IgE, which by far accounted for most of the eluted peptide sequences. Epitope patterns were rather similar for both intact and digested Ara h 1 as well as for humans and rats. CONCLUSIONS: Individual patient specific epitope patterns have been identified for the major allergen Ara h 1. IgE binding epitopes have been suggested as biomarkers for persistency and severity of food allergy, wherefore recognition of particular epitope patterns or motifs could be a valuable tool for prevention, diagnosis, and treatment of food allergy.

Vaccination for birch pollen allergy: comparison of the affinities of specific immunoglobulins E, G1 and G4 measured by surface plasmon resonance.

BACKGROUND: Allergen-specific immunotherapy (SIT) is associated with increased levels of allergen-specific IgG in serum. However, it is not clear to what extent qualitative changes in the allergen binding capacity of IgG may be induced as well. OBJECTIVE: The purpose of this study was to investigate the influences of SIT on antibody affinity. METHODS: The binding affinity of purified serum IgG1, IgG4 and IgE to the major allergen in birch (Betula verrucosa) pollen, Bet v 1, was analysed by surface plasmon resonance. The antibodies were obtained from 10 birch pollen-allergic patients receiving SIT and from 10 patients with no SIT. RESULTS: The patients having received SIT have a significant higher titre of anti-Bet v 1 antibodies in their blood, but the affinity to Bet v 1 of allergen-specific IgE, IgG1 and IgG4 does not differ between the two groups. For IgG1 and IgG4, correlations between less allergic symptoms and affinity of the antibodies were observed both in the SIT group and to a smaller extent in the non-SIT group. CONCLUSION: SIT has no effect on antibody affinity of allergen-specific IgE, IgG1 or IgG4. Allergic patients with high-affinity IgG1 and IgG4 antibodies report less symptoms than patients with low-affinity antibodies.

Individuals with occupational allergy to detergent enzymes display a differential transcriptional regulation and cellular immune response.

BACKGROUND: In spite of significant safety measures, allergy to industrial enzymes remains a major concern. The increasing prevalence of occupational allergy emphasizes the need to investigate the functional properties of enzyme-exposed dendritic cells (DCs), as DCs possess a potent ability to activate allergen-specific T cells. OBJECTIVE: This study aims at elucidating the molecular mechanisms underlying allergic immune responses to lipase, an industrial enzyme. For this purpose, we studied the effect of both hypoallergenic and wild-type lipase on the transcriptional regulation in DCs and their stimulatory effect on memory CD4+ T cells. METHODS: Five individuals with documented lipase allergy were tested for specific serum IgE. DCs from these individuals, stimulated with lipases, were assayed for their ability to affect proliferation and polarization of memory T cells. The effect of lipases on transcriptional activity in DCs was evaluated using global expression analysis. RESULTS: Lipase-specific IgE levels varied considerably between donors, with donor 4 exhibiting highest levels, and a potent specific CD4+ T cell recall response was demonstrated only for donor 4. No difference was detected in cytokine profile when T cells from donor 4 were co-cultured with DCs pulsed with either hypoallergenic or wild-type lipase, as demonstrated by high IL-4 and IL-13, and low IFN-gamma production. However, the lipases induced different genetic signatures in DCs from donor 4, as compared with the non-responders. CONCLUSIONS: DCs from individuals with clinically diagnosed allergy to lipase displayed a differential response to stimulation with hypoallergenic and wild-type lipase in vitro. Only allergen-pulsed DCs from donor 4 were able to induce CD4+ T cell proliferation. The lipase-specific T cells displayed a T-helper type 2 phenotype, which was not altered by hypoallergenic lipase-pulsed DCs. Furthermore, DCs derived from donor 4 and stimulated with either of the lipases displayed different transcriptional profiles, as compared with the other donors. These signatures represent genes of potential importance for an immunoregulatory role of DC in an ongoing allergic response.

STDS in women attending family planning clinics: a case study in Addis Ababa.

For cultural reasons modern contraception has been slow to gain acceptance in Ethiopia. Knowledge about contraception and abortion is still limited in many family and community settings in which it is socially disapproved. By 1990 only 4% of Ethiopian females aged 15-49 used contraception. Little is known of sexually transmitted disease (STD) prevalence in family planning (FP) attenders in Africa in general and Ethiopia in particular, even though attenders of family planning clinics (FPCs) are appropriate target groups for epidemiological studies and control programmes. A study of 2111 women of whom 542 (25.7%) attended FPCs in Addis Ababa showed utilisation rates to be highest in women who were: Tigre (33%) or Amhara (31%), aged 20-34 years (30%), age 16 or older at first marriage/coitus (28%:38% in those first married after 25 years); who had a monthly family income of 10 Ethiopian Birr (EB) or more (33%:36% for those with income 100-500 EB), three or more children (37%), more than five lifetime husbands/sexual partners (39%); or were bargirls (73%) or prostitutes (43%). The seroprevalence rates for all STDs, higher in FPC attenders compared with other women, were syphilis (TPHA) 39%, Neisseria gonorrhoeae 66%, genital chlamydia 64%, HSV-2 41%, HBV 40% and Haemophilus ducreyi 20%. Only 4% of FPC attenders had no serological evidence of STD: 64% were seropositive for 3 or more different STD. Clinical evidence of pelvic inflammatory disease (PID) was also more common in the FPC attenders (54%), 37% having evidence of salpingitis. The FPC provides a favourable setting for screening women likely to have high seroprevalence of STD, who for lack of symptoms will not attend either an STD clinic nor a hospital for routine check up. We recommend that measures be taken to adequately screen, treat and educate FPC attenders, their partners, and as appropriate and when possible their clients, in an attempt to control STDs and ultimately HIV in the community. Social, economic and cultural factors in the occurrence of STDs, prostitution, family planning and modern contraception coverage in Ethiopia are identified and deficiencies of current programmes briefly discussed with the objective of targeting services more effectively.

In vitro stimulation of peripheral blood mononuclear cells (PBMC) from HIV- and HIV+ chancroid patients by Haemophilus ducreyi antigens.

The cellular immune responses to fractionated Haemophilus ducreyi antigens, coated on latex beads, were assessed in patients with chancroid and in controls, using an in vitro lymphocyte proliferation assay. Several fractions of H. ducreyi antigen revealed stimulating activity. However, only the molecular size ranges 91-78 kD, 59-29 kD, and 25-21 kD induced proliferation that may be specifically related to H. ducreyi infection. Lymphocytes from four HIV- patients, successfully treated for chancroid, were not stimulated by H. ducreyi antigen. In general, lymphocytes from HIV+ chancroid patients were less responsive to H. ducreyi antigen compared with those from HIV- chancroid patients. However, two HIV-infected patients showed exceptionally strong responses to high molecular weight fractions. To our knowledge this is the first report demonstrating that H. ducreyi contains specific T cell-stimulating antigens. Based on this work, further identification and purification of the T cell antigens is feasible.

Monoclonal antibodies against Haemophilus ducreyi lipooligosaccharide and their diagnostic usefulness.

Monoclonal antibodies against the lipooligosaccharide of Haemophilus ducreyi were produced. Two of them, MAHD6 and MAHD7, were found to be relatively, although not absolutely, specific and reacted with nearly all strains of Haemophilus ducreyi tested: 59 of 60 and 60 of 60, respectively. The diagnostic usefulness of MAHD7 was assessed. Clinical specimens collected in Zambia from patients with genital ulcers were tested using indirect immunofluorescence (IF), enzyme immunoassay (EIA), the polymerase chain reaction (PCR) and bacterial culture. Compared with culture, IF had a sensitivity of 100%; compared with PCR, sensitivity was 89%. The corresponding figures for the EIA were 83% and 74%, respectively. The sensitivity of culture compared with PCR was 63%. The results suggest that IF on genital smears using MAHD7 might be an excellent tool for the diagnosis of chancroid in high-prevalence populations. However, further evaluation of the specificity of this test is needed.

Localisation and immunological properties of a 24-kDa surface protein of Haemophilus ducreyi.

The cell wall and outer structures of Haemophilus ducreyi bacteria were investigated. The 24-kDa outer protein from two strains was purified with an SDS-PAGE preparative continuous-elution electrophoresis cell. The protein was further characterised by SDS-PAGE and immunoblotting, and the immunological properties were investigated by ELISA. Localisation on the bacterial surface was investigated by immuno-electron-microscopy with a polyclonal antiserum raised against the purified protein. A triple-laminar cell wall typical of gram-negative bacteria, close cellular contact between bacterial cells and outer blebs were seen on thin sections. An additional high mol. wt band of c. 165 kDa was seen when not treated by heating to 100 degrees C. A high density fibrilla-like material was detected on the bacterial cell and in the environment by negative staining and immuno-electron-microscopy with antisera specific for the 24-kDa protein. The surface localisation of the 24-kDa protein was confirmed by an ELISA technique with the specific antiserum and whole bacterial cells as antigen. The presence of antibodies to the 24-kDa protein was demonstrated in antisera to 13 strains of H. ducreyi, indicating antigenic identity or within-species cross-reactivity. Low titres of antibodies to this protein were also detected in 19 antisera raised against different strains of gram-negative bacteria, indicating cross-reactivity with other species. Antibody response to the 24-kDa protein in rabbits immunised subcutaneously with live bacteria resulted in a secondary IgG response. Of 28 sera from patients with culture-verified chancroid, 26 manifested high titres of IgG antibodies to the 24-kDa protein, thus indicating the involvement of this antigen in the disease process in man.

Monoclonal antibodies against Haemophilus lipopolysaccharides: clone DP8 specific for Haemophilus ducreyi and clone DH24 binding to lacto-N-neotetraose.

Mouse monoclonal antibodies (MAbs) DP8 [immunoglobulin G1(kappa)] and DH24 [immunoglobulin M(kappa)], which are specific for Haemophilus ducreyi lipopolysaccharide (LPS), were generated by fusing mouse myeloma NS0 cells with spleen cells of BALB/c mice immunized with a total membrane preparation of H. ducreyi. MAb DP8 reacted in whole-cell enzyme immunoassay (EIA) and colony dot immunoblotting with all 50 strains of H. ducreyi but not with any other bacteria tested, which suggests an exposed and species-specific epitope on the H. ducreyi cell surface. This conclusion was supported by the finding that DP8 bound to all six H. ducreyi LPSs tested but not to any of the Haemophilus influenzae or enterobacterial LPSs or synthetic glycoconjugates. The MAb DH24 bound to 43 of 50 strains of H. ducreyi and to few strains of H. influenzae, Neisseria gonorrhoeae, and Neisseria meningitidis, as evaluated by whole-cell EIA and colony dot immunoblotting. The MAb DH24 reacted with five of the six H. ducreyi LPSs tested and with the lacto-N-neotetraose (Gal beta 1-->4GlcNAc beta 1-->3Gal beta 1-->4Glc) series of synthetic glycoconjugates, as determined by EIA. By using polysaccharides obtained after both mild acidic hydrolysis and strong alkali treatment and dephosphorylated samples as inhibitors of the MAbs binding to H. ducreyi LPS antigens, it could be shown that phosphate groups were essential for the binding of DP8 to LPS but that they did not affect antigenic recognition by DH24. None of the MAbs bound to isolated lipid A, but aggregation caused by the fatty acids of lipid A was essential for epitope recognition.

Seroprevalence and incidence of sexually transmitted diseases in a rural Ugandan population.

The aim of the study was to determine in a rural population the age- and sex-specific prevalence and incidence rates of serological reactivity of 5 common sexually transmitted diseases (STDs) and their association with HIV-1 antibody status. Of the adult population of two villages (529 adults aged 15 years or more) 294 provided an adequate blood specimen both on enrollment and at 12 months. The sera were tested at 3 collaborating laboratories for antibodies against HIV-1, Treponema pallidum, Haemophilus ducreyi, Chlamydia trachomatis and herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2). A sample of 45 children were tested for HSV-1 and HSV-2. Seroprevalence rates in adults on enrollment were 7.8% for HIV-1, 10.8% for active syphilis, 10.4% for H. ducreyi, 66.0% for C. trachomatis, 91.2% for HSV-1 and 67.9% for HSV-2. Males were significantly more likely than females to be seropositive for H. ducreyi (15.6% versus 6.6%), but less likely to be HSV-2 antibody positive (57.0% versus 74.4%). Reactivity to H. ducreyi, C. trachomatis and HSV-2 rose with increasing age. In contrast, active syphilis showed no age trend. All STDs tended to be more common in those HIV-1 seropositive. Incidence rates over the 12 months were nil for HIV-1, 0.5% for syphilis, 1.2% for H. ducreyi, 11.3% for C. trachomatis, and 16.7% for HSV-2. The results of this exploratory study indicate that all STDs included are common in this rural population. The high HSV-2 prevalence rate among adolescents suggests that HSV-2 may be an important risk factor for HIV-1 infection.(ABSTRACT TRUNCATED AT 250 WORDS)

PIP: A seroprevalence survey conducted in rural Uganda revealed a high potential for interaction between sexually transmitted diseases (STDs) such as herpes simplex virus type 2 (HSV-2) and human immunodeficiency virus (HIV). Venous blood samples were collected at baseline and one year later from 294 randomly selected adults aged 15 years or over from two neighboring villages. At baseline, 23 (7.8%) adults were HIV-positive; no seroconversion occurred during the one-year study period. STD prevalence rates were 10.8% for syphilis, 10.4% for Hemophilus ducreyi, 66.0% for Chlamydia trachomatis, and 91.2% for HSV-1 and 67.9% for HSV-2. More females (74.4%) than males (57.0%) were HSV-2 antibody-positive. Reactivity to H. ducreyi, C. trachomatis, and HSV-2 rose with increasing age, but there was no such trend for syphilis. HIV prevalence rates were 0.0% among those with no serologic evidence of previous STDs, 2.6% among those with one or two prior STDs, and 20.0% among those with three or four STD markers. Of particular concern was the high rate of HSV-2 prevalence among adolescents (85% among females aged 20-24 years and 82% in males aged 25-29 years). It is suggested that age-specific HSV-2 seroprevalence can provide an accurate marker of premarital sexual activity among Ugandan adolescents since it lacks the potential for bias associated with self-reporting in this population.

Teenage obstetric and gynaecological problems in an African city.

OBJECTIVE: To measure the prevalence of sexually transmitted diseases (STD), pelvic inflammatory disease (PID), cervical cancer, pregnancy and use of contraception in teenagers, and to determine socioeconomic factors associated with these conditions to aid planners of medical services and promotion of sexual health. SUBJECTS: 181 Ethiopian teenagers and 1,845 women aged 20 to 45 years for comparison. SETTING: Gynaecological outpatient department, antenatal, postnatal and family planning clinics, in two teaching hospitals and a mother and child heath centre in Addis Ababa, Ethiopia. METHODS: Results of serologic tests for STD, clinical evidence of PID, and cervical cytology were analysed against socio-economic factors. RESULTS: In teenagers early age at first marriage/coitus, more common in those of rural origin, was associated with poverty, a greater number of lifetime sexual partners, and prostitution: 40 pc were first sexually active before the menarche. Prevalence of seropositivity to specific STD pathogens was; Treponema pallidum (TPHA) 21 pc, Neisseria gonorrhoeae (gonococcal antibody test: GAT) 40 pc, genital chlamydiae 51 pc, hepatitis B virus 36 pc, herpes simplex virus (HSV-2) 32 pc, and Haemophilus ducreyi 16 pc: 92 pc of teenagers were seropositive to one or more STD's. STD seroprevalence was higher in those with more than one sexual partner, those sexually active by age 15 (very high in those sexually active by age 12), those involved in prostitution and those attending the family planning clinic. Forty three pc had clinical evidence of PID; one married at age 10 had invasive cervical cancer by age 18; 40 pc of teenagers were pregnant compared with 25 pc of those aged 20 to 45; 21 pc attended for family planning; of regular FPC attenders 81 pc were GAT seropositive. CONCLUSION: Despite legislation early age of sexual debut is common, STD and PID are widely prevalent, the pregnancy rate in adolescents is high and contributes to the national population growth rate. Action is required at family, medical and governmental level to encourage cultural acceptance that marriage and sexual activity should not occur before the age of 16 years, with education appropriate to culture to prevent STD. Similar studies are recommended in other countries to establish a baseline for informed strategy regarding prevention of STD and health education.

PIP: A survey of 181 Ethiopian females ages 14-19 years recruited from health facilities in Addis Ababa revealed a high incidence of obstetric and gynecologic problems. All subjects completed a questionnaire administered by a female health worker and underwent a gynecologic examination and serologic tests. 49% of subjects were married and 18% were divorced; 11% were prostitutes. Age at first intercourse was under 12 years in 18%, 13-15 years in 38%, and 16 years or above in 44%; 40% were sexually active before menarche. 92% of adolescents had at least one sexually transmitted disease (STD), predominantly gonorrhea (40%), genital chlamydia (51%), hepatitis B (36%), herpes simplex virus (32%), and syphilis (21%), and 43% had clinical signs of pelvic inflammatory disease (PID). 53% had had at least one pregnancy. The earlier the age at first intercourse, the more likely it was that the adolescent would have multiple sexual partners and several STDs; adolescents in this category were also more likely to be from poor families from rural areas. Only 21% were attending a family planning clinic for annual check-ups; 14% of these females were using contraception. Although only 8% were infertile at the time of assessment, 23% had clinical evidence of salpingitis--a risk factor for future infertility. Given the long-term health risks (e.g., infertility, cervical cancer, and gonorrhea-related infant morbidity) associated with the patterns observed among these adolescents, it is recommended that STD education receive higher priority and that the Ethiopian Government consider greater enforcement of the law prohibiting sexual intercourse and marriage before the age of 16 years.

Seroepidemiological studies of Haemophilus ducreyi infection in Ethiopian women.

BACKGROUND AND OBJECTIVES: To measure prevalence of anti-Haemophilus ducreyi antibodies in sera from Ethiopian female attendees, and to determine significant socioeconomic associations. STUDY DESIGN: A modified ELISA immunoassay was used to test sera of 1,831 Ethiopian women attending gynecological, obstetric, and family planning clinics in Addis Ababa. RESULTS: Overall seropositivity was 19.4%. Prevalence rates for seropositivity for antibodies to H. ducreyi were significantly associated with ethnic group and religion, older age (> or = 50 years: 28%), early age at first coitus (< 13 years: 28%) and first coitus before the menarche (25%), being divorced (27%) or a prostitute (24%), longer duration of marriage (> 20 years: 27%) and sexual life (> 20 years: 24%), number of lifetime sexual partners (2 to 5 partners: 27%) and self-reported history of both syphilis and gonorrhea (31%). Of these factors, the two most significant were first coitus before the menarche (P < 0.0001) and not being still married to the first husband/sexual partner (P < 0.001). Differences in seropositivity according to ethnic group and religion may be explained by the number of women within each group who had only one lifetime sexual partner. Women with serological evidence of exposure to another sexually transmitted disease (STD) had a greater risk of exposure to H. ducreyi. The odds ratio for H. ducreyi seropositivity in women with syphilis or gonorrhea was 3.6, for women with genital chlamydial infection, 2.3, and for those with HBV or HSV-2, 1.4 and 1.3 respectively. CONCLUSIONS: This study illustrates the usefulness of the modified ELISA immunoassay for measuring exposure to H. ducreyi, and the usefulness of H. ducreyi as a marker for cumulative sexual exposure. Further studies on the association of HIV transmission and H. ducreyi in Ethiopia are now indicated.

PIP: Genital ulcerated disease (GUD), which includes chancroid, has been identified as a risk factor for HIV transmission. This study reports the prevalence of anti-Hemophilus ducreyi (chancroid) antibodies in 1831 Ethiopian women and looks at the behavioral and social factors which might affect the incidence and potential spread of chancroid. Patient data regarding ethnic and socioeconomic aspects were collected from detailed questionnaires. Blood collection was performed under medical surveillance. Complete gynecological examinations were performed. Papanicolaou stained smears were used as the basis of the cytological data. Serological studies utilized an enzyme immunoassay (EIA) test for STD detection. Statistical tests used included the Chi-square test, the multivariate analysis technique, and the Cochran-Mantel-Haenszel General Association Statistic Test. Antibodies to H. ducreyi were found in 335 women (19.4%). Prevalence of H. ducreyi was significantly associated with Amhara or Tigre ethnic heritage; older age; first coitus before beginning menstruation; history of STDs; divorced status; being a prostitute; longer duration of married and sexual life; and younger age at first coitus. Logistic regression demonstrated that 3 factors were significant when associated with H. ducreyi seropositivity. First coitus before beginning menstruation was highly significant (OR 1.95; 95% CI, 1.49-2.57; P 0.0001). Not being still married to the first husband was also significant (OR 1.68; 95% CI, 1.23-2.30; P 0.001). Being of the Ethiopian Orthodox religion was significant (OR 2.11; 95% CI, 1.21-3.68; P 0.005). Prevalence in women with 2-5 lifetime husbands was higher than in women with only 1 husband.

A socioeconomic, clinical and serological study in an African city of prostitutes and women still married to their first husband.

The aim of this paper was to compare women involved in prostitution with a group of women still married to their first husband and reporting having had only one sexual partner, in order to ascertain what factors if any contributed to women going into prostitution or staying still married to their first husband, their only sexual partner, and thereafter to compare clinical and serological aspects of the gynaecological conditions of the women in these two groups. The role of prostitutes in transmission of sexually transmitted diseases (STD) is widely recognised. Socioeconomic factors determining whether a woman will drift into prostitution or have a stable first marriage are largely unknown as are prevalence rates of STD, pelvic inflammatory disease (PID) and cervical cancer in these women. A socioeconomic, clinical and serologic study is reported for 2111 Ethiopian women attending teaching hospitals and maternal and child health clinics in Addis Ababa, analysing basic demographic data of three groups of women: (i) 278 engaged in prostitution, (ii) 730 still married to their one and only sexual partner, and (iii) 1103 single, widowed, divorced or married to their second or subsequent partner. Thereafter groups (i) and (ii) were compared and contrasted with regard to further socioeconomic, clinical and serological associations. The most significant socioeconomic associations for women in prostitution were low income (95% had < 50 Ethiopian birr [< U.S. $25] per month), ethnic group, and the timing of first coitus in relation to the menarche (81% were first married by age 15), in that order. Women still married to their first sexual partner had higher income, higher age at first marriage and longer duration of marriage. Sero-prevalence rates of STD in prostitutes were high: gonorrhoea 88%, genital chlamydiae 78%, syphilis (TPHA) 62%, HSV2 and HBV 46%, and chancroid 19%: 67% had PID and 2.9% cervical cancer. In comparison, rates for women married to their first and only sexual partner were: gonorrhoea 40%, genital chlamydiae 54%, syphilis (TPHA) 19%, HSV2 33%, HBV 35%, chancroid 13%, PID 47% and cervical cancer 1%. While the very high prevalence of STD in women involved in prostitution is not so unexpected, the high rate of STD in women still married to their first and only sexual partner is indicative of male promiscuity. Control of prostitution and diseases spread by it, together with education of both men and women is a national priority.

Human T cell lymphotropic virus type I infection among female sex workers in Peru.

Four hundred female sex workers attending a sexually transmitted disease clinic in Lima, Peru, were interviewed for demographic information and medical, contraceptive, and sexual practice histories. Cervical cultures were done for Neisseria gonorrhoeae and Chlamydia trachomatis, and serum was tested for antibodies to human immunodeficiency virus, human T cell lymphotropic virus type I (HTLV-I), Treponema pallidum, C. trachomatis, herpes simplex virus type 2 (HSV-2), and Haemophilus ducreyi. The prevalence of HTLV-I increased with duration of prostitution from 3.6% (< 3 years) to 9.3% (3-6 years) to 15.9% (> 6 years; P < .01). After adjustment for duration of prostitution, reduced risk of HTLV-I was significantly correlated with condom use for more than half of all sexual exposures for > 3 years (odds ratio [OR], 0.34; 95% confidence interval [CI], 0.13-0.89). Further adjusting for condom use, HTLV-I seropositivity was associated with C. trachomatis (OR, 3.7; 95% CI, 1.4-13.2) and with antibody to HSV-2 (OR, 3.7; 95% CI, 0.5-29.6). Thus, duration of prostitution, lack of consistent condom use, and past infection with C. trachomatis were significantly associated with HTLV-I seropositivity.

Enzyme immunoassays (EIAs) for the detection of anti-Haemophilus ducreyi serum IgA, IgG, and IgM antibodies.

BACKGROUND AND OBJECTIVES: Chancroid is a risk factor for heterosexually acquiring HIV. Controlling its spread may reduce HIV transmission. GOAL OF THE STUDY: To develop EIAs for assessing antibody levels and for seroepidemiologic studies. STUDY DESIGN: Anti-Haemophilus ducreyi IgA, IgG and IgM EIAs were standardized using a crude cocktail antigen. Evaluation was on sera from Kenya, Rwanda, Thailand and The Gambia. The two-tailed student's t test was used to compare results. RESULTS: The specificity of IgA was 97% (95% confidence interval (CI): 95-99%), of IgG was 92% (95% CI: 89-95%), and of IgM was 99% (95% CI: 98-100%). The sensitivity of IgA was 88% (95% CI: 83-93%), of IgG was 93% (95% CI:89-97%), and of IgM was 78% (95% CI:71-85%) in patients having an ulceration for more than eight days. Thus, 95% (95% CI:92-98%) of the chancroid patients were seropositive for at least one antibody type. The IgG and IgA EIAs were more sensitive in patients older than 24 years of age. Higher IgG rates were found in HIV infected chancroid patients. CONCLUSION: The EIAs should be useful for studying the kinetics of antibody levels and the epidemiology of H. ducreyi infection.

PIP: In Belgium, the Department of Infection and Immunity of the Institute of Tropical Medicine in Antwerp modified an experimental enzyme immunoassay (EIA) for the detection of serum IgG to Hemophilus ducreyi to develop EIAs for detection of anti-H. ducreyi IgA and IgM antibodies. They tested the modified EIA on sera from people in Nairobi, Kenya; Kigali, Rwanda; Banjul, The Gambia; and Bangkok, Thailand, who had a sexually transmitted disease. The EIA was able to identify correctly those who did not have anti-H ducreyi IgA, IgG, and IgM antibodies in 97%, 92%, and 99% of cases, respectively. Among people with a genital ulceration for more than 8 days, it was able to identify correctly those who had IgA, IgG, and IgM antibodies in 88%, 93%, and 78% of cases, respectively. 95% of all culture-proven chancroid patients tested seropositive for at least 1 antibody type. The sensitivity of IgG and IgA EIAs was significantly enhanced in patients with culture-proven chancroid who were older than 24 years old (p .01). HIV seropositive people from Kigali who had culture-proven chancroid had higher anti-H. ducreyi IgG seropositivity rates (but not IgA and IgM seropositivity rates), than did HIV seronegative chancroid people from Kigali (p .05). The increased IgG seropositivity rate was not related to higher antibody titers, however, suggesting that HIV infection modifies the response to H. ducreyi. These results show that the 3 EIAs hold promise as a means to study the kinetics of antibodies and the epidemiology of chancroid.

Antigen detection and immunological typing of Haemophilus ducreyi with a specific rabbit polyclonal serum.

A rabbit polyclonal serum was raised against the 29-kDa species-specific marker, as well as the 30- to 34-kDa immunotype-specific markers of Haemophilus ducreyi described elsewhere (E. Roggen, S. De Breucker, E. Van Dyck, and P. Piot, Infect. Immun. 60:590-595, 1992). These antigens were purified from a cocktail of H. ducreyi isolates by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The immune serum reacted in enzyme-linked immunosorbent assay (ELISA) preferentially with H. ducreyi, at a titer as high as 50,000. To make it specific to H. ducreyi, nonspecific antibodies were removed by adsorption on a mixture of Haemophilus spp., Escherichia coli, Candida albicans, and Corynebacterium spp. In the 29- to 34-kDa region of immunoblot profiles from H. ducreyi isolates (n = 450), the adsorbed serum revealed essentially the same antigens as did a pool of well-characterized human sera. Yet, eight different immunotypes were observed. With this rabbit polyclonal serum, an ELISA-based antigen detection test was developed. The adsorbed serum reacted specifically with all H. ducreyi isolates tested (n = 450), but not with other bacterial species (n = 15). This test was evaluated with a limited number of clinical specimens from African patients with culture-proven chancroid and no evidence for any other ulcerating etiology (n = 10) and a number of chancroid-negative control patients from Belgium (n = 20). Within this context, the test yielded a sensitivity and specificity of 100%.