[Pelvic exam in gynecology and obstetrics: Guidelines for clinical practice]

OBJECTIVE

To provide guidelines for the pelvic clinical exam in gynecology and obstetrics.

MATERIAL AND METHODS

A multidisciplinary experts consensus committee of 45 experts was formed, including representatives of patients' associations and users of the health system. The entire guidelines process was conducted independently of any funding. The authors were advised to follow the rules of the Grading of Recommendations Assessment, Development and Evaluation (GRADE®) system to guide assessment of quality of evidence. The potential drawbacks of making strong recommendations in the presence of low-quality evidence were emphasized.

METHODS

The committee studied 40 questions within 4 fields for symptomatic or asymptomatic women (emergency conditions, gynecological consultation, gynecological diseases, obstetrics, and pregnancy). Each question was formulated in a PICO (Patients, Intervention, Comparison, Outcome) format and the evidence profiles were produced. The literature review and recommendations were made according to the GRADE® methodology.

RESULTS

The experts' synthesis work and the application of the GRADE method resulted in 27 recommendations. Among the formalized recommendations, 17 present a strong agreement, 7 a weak agreement and 3 an expert consensus agreement. Thirteen questions resulted in an absence of recommendation due to lack of evidence in the literature.

CONCLUSIONS

The need to perform clinical examination in gynecological and obstetrics patients was specified in 27 pre-defined situations based on scientific evidence. More research is required to investigate the benefit in other cases.

Culture phenotypes and molecular characterization of Mycobacterium avium subsp. paratuberculosis isolates from small ruminants

In this study the suitability of different solid media was investigated for the isolation of Mycobacterium avium subsp. paratuberculosis (Map) in order to identify the optimum single or combination of media to permit the isolation of all strain types from small ruminants. A subset of these Map strains was then further characterized by molecular typing methods to assess the genetic diversity of Map strains in the study area (Northern Greece). Map strains were isolated from tissues and faeces of infected goats (n=52) and sheep (n=8) and were analysed for polymorphisms in IS1311 to classify the strain type as Type C or S. The study found that M7H11 supplemented with mycobactin j, OADC and new born calf serum (M7H11+Mj) is the best single choice of medium for the primary isolation of Map of both Type C and S from small ruminants. The combination of M7H11+Mj and Herrolds egg yolk medium supplemented with mycobactin j and sodium pyruvate allowed the detection of all Map isolates in this study. Nineteen Map isolates were characterised by pulsed-field gel electrophoresis and the isolates demonstrated significant genetic diversity. Twelve different SnaBI and 16 distinct SpeI profiles were detected of which 25 have not been described previously and are new profiles. The combination of both enzyme profiles gave 13 different multiplex profiles. Ten different multiplex profiles were detected in goats and three in sheep. One ovine isolate gave the same multiplex profile as a caprine isolate and two different profiles were found within a single goat herd.

Lymphocyte recirculation in the sheep fetus

The numbers of circulating thymus-derived and surface Ig-bearing lymphocytes in the fetal lamb increase exponentially over the last third of gestation. Experiments in which [3H]thymidine was continuously infused into fetal lambs have established that these cells are long-lived in the fetus. The migration of 51Cr-labelled autologous lymphocytes from intestinal or prescapular lymph was compared in fetal lambs and adult sheep. A subpopulation of thymus-derived lymphocytes present in intestinal lymph of adults which migrated preferentially to the small intestine was not found in fetal intestinal lymph. There were marked differences in the migration of fetal and adult lymphocytes to the lungs and liver. In spite of the absence of circulating antibodies or immunoglobulins and of extrinsic antigen in the immunologically virgin sheep fetus, the circulation of lymphocytes through the spleen and lymph nodes of fetal lambs was more intense than in the adult, indicating that the pathways of recirculation and the capacity of cells to recirculate arise as a physiological process independently of antigenic stimulation.

Nucleophosmin is a novel Bax chaperone that regulates apoptotic cell death

The proapoptotic B-cell lymphoma-2 family protein Bax is a key regulatory point in the intrinsic apoptotic pathway. However, the factors controlling the process of Bax activation and translocation to mitochondria have yet to be fully identified and characterized. We performed affinity chromatography using peptides corresponding to the mitochondrial-targeting region of Bax, which is normally sequestered within the inactive structure. The molecular chaperone nucleophosmin was identified as a novel Bax-binding protein by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Reciprocal co-immunoprecipitation and proximity assays confirmed the Bax-nucleophosmin protein-protein interaction and verified that nucleophosmin only bound to activated conformationally altered Bax. Confocal microscopy in a cell-based apoptosis model, demonstrated that nucleophosmin translocation from nucleolus to cytosol preceded Bax movement. Specific knockdown of nucleophosmin expression using RNAi attenuated apoptosis as measured by mitochondrial cytochrome c release and activation of the caspase cascade. In a mouse model of ischaemic stroke, subcellular fractionation studies verified that nucleophosmin translocation occurred within 3 h, at a time before Bax translocation but after Bax conformational changes have occurred. Thus, we have elucidated a novel molecular mechanism whereby Bax becomes activated and translocates to the mitochondria to orchestrate mitochondrial dysfunction and apoptotic cell death, which opens new avenues for therapeutic intervention.

[Immunogenicity and safety of Di-Te-Ki-Pol vaccine "SSI" in Danish infants]

This study compared a tetravalent DTaP-IPV vaccine (Di-Te-Ki-Pol vaccine "SSI") with the vaccination regimen used in Denmark at that time, DT-IPV plus wholecell pertussis vaccine. Two hundred and seventy children were included at their five-week routine examination. The children were allocated to one of the two vaccination regimens. No hypotonic-hyporesponsive episodes or other vaccine-related serious adverse events were seen. Local reactions, febrile and crying episodes following the investigational vaccine were similar to the reactions seen after Di-Te-Pol vaccine. All children achieved protective antibody levels to polio, diphtheria and tetanus after completing the vaccination schedule. A significantly better response to pertussis toxin was seen after the investigational vaccine. We conclude that the Di-Te-Ki-Pol vaccine is safe and immunogenic when used according to the schedule tested.

Immunogenicity and safety of a tetravalent diphtheria-tetanus-acellular pertussis-inactivated poliovirus vaccine

The objective of this study was to investigate whether a tetravalent vaccine containing diphtheria, tetanus, monocomponent acellular pertussis and inactivated poliovirus (DTaP-IPV) was immunogenic and safe compared with the vaccination regime used in Denmark at the time of the study. The study was performed as an open controlled study in which 270 Danish children were enrolled at their 5 weeks' routine examination. The children were allocated to receive either (i) DTaP-IPV (12.5 Lf, 7 Lf, 40 microg, 40, 8, 32 DU) at 3, 5 and 12 months of age (n = 186) or (ii) DT-IPV (50 Lf, 12.5 Lf, 40, 8, 32 DU) at 5, 6 and 15 months of age plus whole-cell pertussis vaccine (> or = 4 IU) at 5 and 9 weeks and at 10 months of age (n = 84). No hypotonic hyporesponsive episodes or other vaccine-related serious adverse events were seen. Local reactions, febrile and crying episodes with the investigational vaccine (DTaP-IPV) were similar to the reactions seen with the existing DT-IPV vaccine. One month after completing the vaccination schedule, all children had antibodies above the defined protective antibody concentrations to polio, tetanus and diphtheria. For pertussis toxin, there was a significantly better response in the investigational vaccine group. We therefore conclude that, when used according to the schedule tested, the tetravalent DTaP-IPV vaccine is safe and immunogenic. In addition, the number of visits and the number of injections necessary are reduced with this vaccine and vaccination schedule.

Safety and immunogenicity of a new Neisseria meningitidis serogroup C-tetanus toxoid conjugate vaccine in healthy adults

We evaluated the safety and immunogenicity of a single dose of a new serogroup C O-deacetylated meningococcal polysaccharide-tetanus toxoid conjugate vaccine in 30 healthy adult volunteers. The vaccine was well tolerated with no serious adverse events and minimal local reactions and systemic symptoms. All subjects developed a fourfold or greater increase in serum bactericidal antibody (SBA) to serogroup C meningococcus. SBA geometric mean titre increased from 11 to 3649 (p<0.001). Serogroup C-specific IgG levels increased postvaccination from 0.65 to 17.02 microg/ml (p<0.001). Bactericidal titres pre- and postimmunisation showed significant correlation with serogroup C-specific IgG (r(2)=0.693). Antibody levels fell by 6 months postvaccination, however, meningococcal C IgG avidity increased indicating the successful induction of a T-cell-dependent antibody response.

CONCLUSION

meningococcal C-tetanus toxoid conjugate vaccine is immunogenic and well tolerated in healthy adults.

Bordetella pertussis and chronic cough in adults

To evaluate Bordetella pertussis as a cause of persistent cough in adults, we examined 201 patients who had a cough for 2-12 weeks and no pulmonary disease. We obtained the following at presentation: medical history, chest radiograph, respiratory function measurement, nasopharyngeal aspirate for polymerase chain reaction (PCR), nasopharyngeal swab specimen for culture, and a blood sample (acute serum). Four weeks later a second blood sample (convalescent serum) was obtained. Control sera were obtained from 164 age-matched healthy blood donors with no history of cough during the previous 12 weeks. Four patients were B. pertussis culture-positive; 11 (including the culture-positive patients) were B. pertussis PCR-positive; and 33, including 10 of the 11 PCR-positive patients, had serological evidence of recent B. pertussis infection. Pertussis-positive and -negative patients could not be discriminated by a history of cough. We conclude that B. pertussis infection is a common cause of persistent cough in adults. This is of concern, because these patients may be B. pertussis reservoirs from which transmission may occur to infants, in whom the disease can be devastating.

Mutual interactions between DTaP-IPV and Haemophilus influenzae type b (Hib)-conjugated vaccines in laboratory animal models

Potency and/or immunogenicity of three different Haemophilus influenzae type b-conjugated vaccines (Hib) and a DTaP-IPV vaccine alone, and their mutual interactions in DTaP-IPV-Hib combination was tested. In a mouse model, only combination of Act-Hib, in which tetanus toxoid (TT) was as active as non-conjugated TT, significantly increased the immunogenicity and potency of TT component of DTaP-IPV vaccine. Also, only combination of Hib-TITER, in which CRM197 was used as the carrier with DTaP-IPV, increased the potency of diphtheria toxoid (DT) component of DTaP-IPV vaccine significantly. It shows that the additive effect of tested Hib vaccines on immunogenicity and/or potency of TT and DT was mostly due to the existence of TT and CRM197, respectively, as the carrier in the mentioned Hib vaccines. No difference was shown in inoculation of DTaP-IPV and Hib conjugated vaccines in the same syringe or at separate sites. DTaP-IPV had dual effects on anti-Hib capsular polysaccharide (HibCP) responses to Hib vaccines in the mouse model. This duality was probably related to the carrier B-cell epitopes activity of Hib conjugated vaccines. The immunogenicity of TT component of Act-Hib and Amvax Hib-TT in the guinea pig model was shown and combination of mentioned Hib vaccines with DTaP-IPV, remarkably increased anti-TT antibody responses to the TT component of DTaP-IPV vaccine. These confirmed our results in the mouse model. Using two different protocols to evaluate the guinea pig model for induction of anti-HibCP immunity showed that a "long interval" protocol does not have any advantage over the "short interval" protocol. Also, combination of DTaP-IPV with Hib vaccines did not have any noticeable effect on anti-HibCP antibodies in the guinea pig model. Taken together, our observations in laboratory animal models may facilitate a better understanding of the mutual interactions between the different antigen components of a combined vaccine such as DTaP-IPV-Hib vaccine.

DTaP vaccines from north american vaccine (NAVA): composition and critical parameters

NAVA's acellular pertussis vaccine is based on highly purified pertussis toxin (PT) inactivated with H(2)O(2). PT was analysed using advanced biochemical methodology including mass spectroscopy (LC/MS), yielding mass and peptide mapping information on the subunits. Pertactin, adenylate cyclase, and Fim 1, 2 were below detection levels and only trace amounts of filamentous haemagglutinin (FHA) have been identified as a minor impurity. The vaccine does not induce anti-FHA antibodies during the course of a 3-dose primary immunization series in infants. B and T cell epitopes are preserved to a higher extent after H(2)O(2)detoxification when compared with chemical inactivation with formaldehyde, thus providing new information explaining why vaccines employing formaldehyde detoxified PT may need additional pertussis components added to induce high levels of protection. Anti-PT antibodies generated by NAVA diphtheria, tetanus, and acellular pertussis vaccine (DTaP) showed a positive correlation with protection against WHO-defined pertussis. The safety profiles for these vaccines showed low reactogenicity with no serious adverse events due to the vaccines.

Preclinical studies on a recombinant group B meningococcal porin as a carrier for a novel Haemophilus influenzae type b conjugate vaccine

In anticipation of future combination vaccines, a recombinant class 3 porin (rPorB) of group B meningococci was evaluated as an alternative carrier protein for a Haemophilus influenzae type b (Hib) polyribosylribotol phosphate (PRP) conjugate vaccine. The use of rPorB may avoid undesirable immunologic interactions among vaccine components, including epitopic suppression from conventional carriers (e.g. tetanus toxoid [TT]), as well as provide desirable immunomodulatory effects. Rats were found to be more reliable and consistent than mice or guinea pigs for studying antibody responses to the Hib conjugates. Different Hib conjugates, Hib-TT and Hib-rPorB, consisting of PRP conjugated by reductive amination to TT or rPorB, were compared in rats. Commercially available, licensed vaccines, HbOC (HibTITER) and PRP-T (OmniHib), were used as reference controls. Maximum geometric mean ELISA IgG titers were obtained in rats after only two doses, showing booster effects for all. However, Hib-rPorB immunization consistently resulted in responses that were 1-2 orders of magnitude greater than those for the other conjugates, including the licensed control vaccines. A maximum 4600-fold rise was observed for Hib-rPorB after two doses, and, unlike the other conjugates, a 100% response rate was always achieved without adjuvant. These results warrant further investigation of Hib-rPorB in combination with DTaP.

Multivalent pneumococcal capsular polysaccharide conjugate vaccines employing genetically detoxified pneumolysin as a carrier protein

A genetically detoxified pneumolysin, pneumolysoid (PLD), was investigated as a carrier protein for pneumococcal capsular polysaccharide (CPS). Such a CPS-PLD conjugate might provide additional protection against pneumococcal infections and resultant tissue damage. A single point mutant of pneumolysin was selected, which lacked measurable haemolytic activity, but exhibited the overall structural and immunological properties of the wild type. PLD conjugates were prepared from CPS serotypes 6B, 14, 19F, and 23F by reductive amination. The structural features of free PLD, as well as the corresponding CPS-PLD, as assessed by circular dichroism spectroscopy, were virtually indistinguishable from the wild type counterpart. Each of the CPS monovalent and tetravalent conjugate formulations were examined for immunogenicity in mice at both 0.5 and 2.0 micrograms CPS per dose. Tetanus toxoid (TT) conjugates were similarly created and used for comparison. The resultant conjugate vaccines elicited high levels of CPS-specific IgG that was opsonophagocytic for all serotypes tested. Opsonophagocytic titres, expressed as reciprocal dilutions resulting in 50% killing using HL-60 cells, ranged from 100 to 30,000, depending on the serotype and formulation. In general, the lower dose and tetravalent formulations yielded the best responses for all serotypes (i.e., either equivalent or better than the higher dose and monovalent formulations). The PLD conjugates were also generally equivalent to or better in CPS-specific responses than the TT conjugates. In particular, both the PLD conjugate and the tetravalent formulations induced responses for type 23F CPS that were approximately an order of magnitude greater than that of the corresponding TT conjugate and monovalent formulations. In addition, all the PLD conjugates elicited high levels of pneumolysin-specific IgG which were shown to neutralize pneumolysin-induced haemolytic activity in vitro. As a result of these findings, PLD appears to provide an advantageous alternative to conventional carrier proteins for pneumococcal multivalent CPS conjugate vaccines.

Intranasal vaccination: pharmaceutical evaluation of the vaccine delivery system and immunokinetic characteristics of the immune responses

The purpose of this study was to analyze the effect of some pharmaceutical excipients when used for mucosal vaccine formulations and to characterize the achieved immune response. After conducting various pharmaceutical evaluations of the formulations, immunokinetic studies were performed in mice, guinea pigs, and rabbits. The kinetics and the characteristics (antibody isotypes, etc.) of the immune response were studied, as well as the induced level of toxin neutralizing IgG antibodies, which are usually used as the only measures of the potency of vaccines. Results in mice show that intranasal vaccination results in a potent and rapid immune response, similar to that seen after subcutaneous immunization. In guinea pigs and rabbits, however, the subcutaneous immunization produced significantly stronger response than did intranasal vaccination. The most promising excipients were found to be either Polysorbate 20 or Cremophor EL in an aqueous mixture together with caprylic/capric glyceride. The results indicate that nontoxic and pharmaceutically acceptable excipients can be used for mucosal vaccination, providing an interesting alternative to parenteral vaccination.

The effect of conjugation on immunogenicity and potency of protein carriers of polyribosylribitol phosphate (PRP) conjugated vaccines in the mouse model

Immunogenicity and vaccine potency of carrier proteins of two different PRP-tetanus toxoid (PRP-T) conjugated vaccines, produced using different size PRP (Act-Hib & Amvax Hib-T), and one PRP-CRM197 (Hib-TITER) were studied. The immunogenicity and the vaccine potency of the carrier component of the tested PRP-conjugated vaccines, and their influences on the potency of the tetanus toxoid (T) and of the diphtheria toxoid (D) component of diphtheria toxoid-tetanus toxoid-acellular pertussis-inactivated polio vaccine (DTaP-IPV) were variable. The T component of Act-Hib (large size PRP) was as immunogenic and potent as the T component of the DTaP-IPV vaccine, and a combination of Act-Hib and DTaP-IPV resulted in a more than five-fold increase in the potency of the T However, Amvax Hib-T (small size PRP) did not show any anti-T response on its own, and a combination of Amvax Hib-T and DTaP-IPV did not affect the T potency of the DTaP-IPV vaccine. In immunogenicity studies with multiple shots, Hib-TITER (small size PRP) produced significantly less anti-D antibodies than non-conjugated D. Hib-TITER did not show any D potency on its own, while a combination of a Hib-TITER and DTaP-IPV increased the potency of the D component of DTaP-IPV vaccine significantly. Thus, in the case of a combination of T-and D-containing vaccines with a PRP-conjugated vaccine in which either T or CRMI 97 has been used as the carrier, the influence of these carriers on basic immunogenicity and vaccine potency of T and D, respectively, should be considered carefully. We propose the techniques employed in this study for the quality control of combined vaccines consisting of diphtheria, tetanus, and PRP-conjugated vaccines.

The Isopaque-Ficoll method re-evaluated: selective loss of autologous rosette-forming lymphocytes during isolation of mononuclear cells from human peripheral blood

A subpopulation of lymphocytes is defined, which--under conditions used for isolating mononuclear cells from peripheral blood by the Isopaque-Ficoll gradient--is lost to the erythrocyte pellet because of rosette formation with the autologous erythrocytes in the gradient. Reapplication of the resuspended erythrocyte pellet on a new gradient with higher density could, however, recover the subpopulation. Lymphocyte surface marker analysis on such cells showed that they were enriched in T cells (judged by rosette formation with sheep erythrocytes) and in autorosette-forming cells. The importance of these findings is discussed in relation to the wide use of the Isopaque-Ficoll method.

Improved ELISA for determination of anti-diphtheria and/or anti-tetanus antitoxin antibodies in sera

Double-antigen ELISAs for detection and quantification of anti-tetanus or anti-diphtheria antibodies in serum have been developed. The assays showed good correlations with established toxin neutralizing assays and were functionally specific for IgG antibodies. The double-antigen set-up allows specific antibodies to bind to antigen-coated microtitre wells with one arm and the free arm to bind to biotin-labelled antigen. The amount of antibodies able to bind labelled antigen was assessed by adding enzyme-conjugated streptavidin and colour substrate followed by measurement of the colour using an ELISA reader. The double-antigen principle makes it possible to compare samples of different species on the same plate, permitting the direct use of existing international references of animal or human origin. The double-antigen ELISAs showed a detection limit of 0.00002 IU/ml for both antibodies and were suitable for quantifying antibodies in blood samples collected on filter paper as well as in serum. The assays required no special equipment compared to traditional ELISA.

In vivo cell-mediated immunity and vaccination response following prolonged, intense exercise

Epidemiological and experimental studies have shown increased frequency and severity of infections after intense, long-term exercise. This study examines whether an in vivo impairment of the cell-mediated immunity and antibody production can be demonstrated after intense, long-term exercise. Twenty-two male triathletes performed one-half an ironman (group A). Vaccinations with tetanus and diphtheritis toxoid and purified pneumococcal polysaccharide were given after the exercise. Furthermore, a skin test with seven different antigens was applied on the forearm. Antibody titers were measured before and 2 wk after the exercise. The skin test was read 48 h after the application. Eleven non-exercising triathletes (group B) and 22 moderately trained men (group C) were used as control groups. Group A revealed a significantly lower skin test response to the tetanus antigen than both groups B and C. In group A, a smaller cumulative response (sum of the diameters of indurations and number of positive skin test spots) was found than in both groups B and C. No differences in antibody titers were found among the three groups. Thus, the in vivo cell-mediated immunity was impaired in the first days after prolonged, high intensity exercise, whereas there was no impairment of the in vivo antibody production measured 2 wk after vaccination.

Immunodominant domains present on the Bordetella pertussis vaccine component filamentous hemagglutinin

To identify immunologically important domains on filamentous hemagglutinin (FHA), a Bordetella pertussis protein included in new acellular pertussis vaccines (ACPVs), a series of monoclonal antibodies, sera from infants vaccinated with ACPVs or whole cell pertussis vaccine (WCPV), and sera from patients with pertussis were analyzed by immunoblots containing FHA fragments and recombinant FHA proteins. Immunodominant domains located at the COOH-terminus of FHA (type I domain) and near the NH2-terminus (type II domain) were defined by the reactivity with monoclonal antibodies. The sera from patients with pertussis and sera from infants vaccinated with WCPV or with 6 different investigational ACPVs specifically recognized well-defined regions within the type I and type II domains. Identification of these prominent immunologic epitopes on FHA should be useful for the construction of more well-defined pertussis vaccines and for the interpretation of human serologic responses, which may correlate with efficacy of pertussis vaccines.

Immunity to tetanus and diphtheria in rural Africa

To assess the effect of the Expanded Program on Immunization (EPI) in rural Africa, blood samples were collected in two Kenyan sublocations. Serum antibodies against tetanus toxoid were measured in 155 individuals 1-70 years of age. Titers greater than the protective level of 0.01 IU/ml were found in 47% of the population. Protection was significantly higher in children born after the launching of the EPI (68%) and in women who had been at childbearing age since then (69%). Significantly lower protection was demonstrated in other age and sex-groups. The level of protection in children was equal in the two populations, whereas protection in fertile women was significantly lower in the population living a long distance from a health center. Diphtheria anti-toxin was measured in the samples from one sublocation, and 70 of 84 individuals (83%) had antibody levels greater than the protective level. No age or sex difference could be found, and there was no correlation between response levels to diphtheria and tetanus. This implicates natural infections as an important source of diphtheria antibodies. Our findings demonstrate a need for better coverage of the adult population against tetanus. Furthermore, diphtheria transmission still appears to take place, underscoring the importance of diphtheria vaccination of travelers to rural Africa.

Intranasal booster vaccination against diphtheria and tetanus in man

The booster responses of three different formulations of intranasal (i.n.) diphtheria-tetanus (D-T) vaccines were determined in military recruits and compared with a conventional subcutaneous D-T vaccine. The vaccines for mucosal delivery were sprayed into one nostril and contained D and T toxoids in an enhancer mixture of polysorbate and caprylic/capric glycerides. All of the vaccines gave rise mainly to a systemic IgG response. Among 51 persons with anti-D antibody concentrations in serum below a protective level of 0.01 international units (IU ml-1) before vaccination, all except two attained protective antibody concentrations 4 weeks after vaccination. The median increase in anti-D antibody concentration was 113-fold with the most efficient i.n. formulation. The median increase in anti-T antibody level was 2.4-fold, however, the pre-vaccination levels for this antigen were very high. Within the examined levels, the booster response depended mainly on the dose of the antigen in the vaccine rather than on the concentration of the vehicle mixture. Compared with the parenteral D-T vaccine containing aluminium hydroxide as an adjuvant, all of the tested i.n. formulations showed somewhat lower immunogenicity in man as well as in pre-clinical guinea-pig studies. Among 215 persons immunized i.n., 61% preferred this route of administration rather than a parenteral injection, although the formulations were all associated with varying local symptoms, frequently stinging and pronounced, nasal secretion.

Fall-off in immunity following diphtheria revaccination--an 8 year follow-up study

Diphtheria may occur even among previously vaccinated persons and knowledge of the duration of immunity is of crucial importance when designing effective vaccination programmes. In a follow-up study of 42 representative probands revaccinated 8 years previously, a continuous fall-off in antitoxic immunity was demonstrated. 98% were still protected (antitoxin concentration > 0.01 IU/ml). From the distribution of titres in the group the individual risk of susceptibility 8 years after revaccination was calculated to be 0.8/1000 (0.2-2.9/1000, 95% confidence limits). Thus, repeated revaccinations are required to secure continuous protection. The fall-off pattern for diphtheria antitoxin was approximately the same as for tetanus antitoxin. Peak values following revaccination are decisive for the duration of immunity. As peak values following vaccination depend on naturally acquired immunity and consequently decrease as indigenous diphtheria in a population disappears, highly potent vaccines are required to secure long-term immunity following diphtheria revaccination. The effects of dose and adjuvant are discussed.

Booster vaccination against diphtheria and tetanus in man. Comparison of three different vaccine formulations--III

Adverse reactions and antibody levels were compared following a booster vaccination of 177 Danish military recruits with a plain, an aluminium hydroxide (0.5 mg Al per human dose, HD) and a calcium phosphate (0.25 mg Ca per HD) adsorbed diphtheria-tetanus (D-T) vaccine. The calcium phosphate adsorbed vaccine was given in a HD of 3 Lf of D and T toxoids and proved to be of equal efficacy as the aluminium hydroxide adsorbed vaccine which was injected in a dose containing twice the antigen amount. The calcium phosphate vaccine caused fewer adverse reactions than the one adsorbed to aluminium hydroxide. The plain vaccine (6 Lf per HD of D and T toxoid) had the highest efficacy with a similar low occurrence of adverse reactions as the calcium phosphate adsorbed vaccine. Potency assays in mice were in accordance with these immunogenicity results in man if a two dose immunization schedule was followed, but not if the vaccines were compared after a single immunization as requested by the procedure for potency testing according to current WHO and European Pharmacopoeia requirements. Both of the adsorbed vaccines primed mice for specific IgE antibody formation. This could be detected after a second immunization with either of the adsorbed vaccines or with the plain D-T vaccine. Also in humans, immunization with the plain vaccine boosted specific IgE formation to a detectable level. This may be ascribed to adjuvant priming during the primary vaccination series some 20 years previously.

Simultaneous quantitation of diphtheria and tetanus antibodies by double antigen, time-resolved fluorescence immunoassay

A dual, double antigen, time-resolved fluorescence immunoassay (DELFIA) for the simultaneous detection and quantitation of diphtheria (D) and tetanus (T) antibodies in sera has been developed. In the double antigen format one arm of the antibody binds to antigen coated microtitre wells and the other arm binds to labelled antigen to provide a fluorescent signal. This assay was found to be functionally specific for IgG antibodies and showed a good correlation with established toxin neutralization assays. Furthermore, the double antigen set-up was species independent, permitting the direct use of existing international references of animal origin to measure protective antibody levels in humans in international units (IU/ml). The detection limit corresponded to 0.0003 IU/ml with Eu(3+)-labelled toxoids and to 0.0035 IU/ml using Sm(3+)-labelled toxoids. The assay was fast with a high capacity making it a suitable method for serological surveillance studies.

Evaluation of local toxicity after repeated intranasal vaccination of guinea-pigs

In intranasal vaccination it is important that the adjuvant does not have any toxic effect on the sensitive nasal mucosa. In this study a histological and clinical evaluation of the effects of two different adjuvants in a vaccine containing detoxified diphtheria (DT) and tetanus toxoid (TT) in guinea pigs was done. The guinea pigs were divided in four groups and treated daily for 14 days with different formulations. Group I with saline, Groups 2 and 3 with the vaccines in a non-ionic surfactant formulation containing glycerides and Group 4 with tetraethyleneglycol formulation containing glycofurol. The guinea pigs in Groups 1, 2 and 4 were sacrificed on day 15 and Group 3, 1 week later and the tissues processed for histological examination. The animals remained healthy during the treatment and minor clinical signs, such as nose-blowing, decreased with time. The histological appearance, including the development of lymphoid tissue, was comparable in all groups. A specific toxic effect on the nasal mucosa by the different vaccine and adjuvant formulations was not observed.

Improved vaccination response during ranitidine treatment, and increased plasma histamine concentrations, in patients with B cell chronic lymphocytic leukemia

Patients with B cell chronic lymphocytic leukemia (B-CLL) have decreased capacity to mount relevant antibody responses upon immunization, and development of hypogammaglobulinemia is part of the natural history of the disease. We investigated the influence of histamine type-2 (H2) receptor blockade by ranitidine on the in vivo antibody production in B-CLL patients following vaccination. Anti-polysaccharide antibodies in B-CLL patients, vaccinated with a tetanus-toxoid conjugated vaccine against Haemophilus influenzae type-B (Hib), reached long-term protective levels in more than 90% of B-CLL patients randomized to ranitidine treatment, as compared to 43% of the untreated patients (P = 0.024). No difference in the response to vaccination against influenza virus types A and B protein could be detected between the two groups. Plasma histamine levels were 2-fold to 20-fold higher in 23 out of 31 B-CLL patients, compared to normal controls, and these levels showed a significant positive correlation to disease duration. These findings indicate the possibility of improving in vivo antibody production against a highly relevant pathogen in B-CLL patients by histamine type-2 receptor blockade, and the combined finding of an immune-stimulatory effect of ranitidine and increased plasma histamine levels, strongly suggests the involvement of histamine in the pathogenesis of B-CLL immunodeficiency.

Characterisation of ovine Bordetella parapertussis isolates by analysis of specific endotoxin (lipopolysaccharide) epitopes, filamentous haemagglutinin production, cellular fatty acid composition and antibiotic sensitivity

Isolates of Bordetella parapertussis, recovered from sheep or man, were characterised by reaction with specific anti-Bordetella lipopolysaccharide monoclonal antibodies, production of filamentous haemagglutinin, fatty acid patterns, and antibiotic sensitivity. Generally, the isolates lay within one of four groups, with separation of the ovine isolates into two groups. Reactions with specific monoclonal antibodies against lipopolysaccharide separated the ovine isolates into these two groupings. Analysis of the cellular fatty acid compositions by cluster analysis differentiated between the human and the ovine strains and also showed variation within the ovine isolates. When the production of filamentous haemagglutinin was analysed in an ELISA system, a similar pattern emerged. Varying concentrations of filamentous haemagglutinin (11-429 ng (mg total protein)-1) were extracted from the human isolates and the one group of ovine isolates with no significant protein detected in the other ovine group. These studies demonstrate variation between and within B. parapertussis isolates recovered from two mammalian sources.

Adjuvanticity of aluminium hydroxide and calcium phosphate in diphtheria-tetanus vaccines--I

The potencies of two diphtheria-tetanus vaccines (DT) adsorbed to either aluminium hydroxide or calcium phosphate were compared in mice and guinea pigs. The vaccines were made from the same batches of purified toxoids and contained the same amounts of antigens. Immunizations were done once or twice with different doses of vaccine injected undiluted, diluted in saline or diluted in the corresponding adjuvant. The various potency assays showed that the adjuvanticity of calcium phosphate was lower than or equal to aluminium hydroxide. Despite the range of potency assays done, none of the methods reflected the efficacy of these vaccines in revaccination of humans. A simplified potency assay is suggested for release of final vaccine formulations to reduce the number of animals in quality control.

Booster vaccination against diphtheria and tetanus in man. Comparison of calcium phosphate and aluminium hydroxide as adjuvants--II

Diphtheria and tetanus antibody levels were measured before and four weeks after booster vaccination of 313 Danish military recruits participating in a clinical trial to compare aluminium hydroxide and calcium phosphate as adjuvants in diphtheria-tetanus vaccines (DT). Twenty-eight percent of the men had a diphtheria pre-vaccination content below a protective level of 0.01 IU ml-1. The calcium phosphate adsorbed vaccine showed the highest efficacy for both antigens. Adverse reactions were rare but more frequent in the calcium group than in the aluminium group. No correlation was found between pre- or post-vaccination levels and adverse reactions and both vaccines gave rise to specific IgE formation. The results show that calcium phosphate is more effective but not a safer alternative to aluminium hydroxide when compared in vaccines containing 1.0 mg ml-1 of Ca or of Al.

Lymphocytic 2',5'-oligoadenylate synthetase activity increases prior to the appearance of neutralizing antibodies and immunoglobulin M and immunoglobulin G antibodies after primary and secondary immunization with yellow fever vaccine

Primary and secondary immunizations with live, attenuated yellow fever virus vaccine (17D strain) were performed in order to study the course of appearance of virus-neutralizing antibodies and immunoglobulin M (IgM) and IgG antibodies directed against the virus and the interferon-dependent enzyme 2',5'-oligoadenylate synthetase (2',5'AS) activity, determined in homogenates of peripheral B and T lymphocytes. From cellular ATP, this enzyme generates 2',5'-oligoadenylates which mediate degradation of viral mRNA by stimulation of a latent RNase. By day 4 after the first immunization, the earliest and highest 2',5'AS activity was present in the T-lymphocyte fraction. By day 7, the enzyme activity was highest in the B-lymphocyte fraction. Virus-neutralizing antibodies appeared on day 7, and IgM antibodies were present on day 12. After the second immunization, performed 2 years +/- 2 months later, the only significant increase in 2',5'AS activity was observed in the T-lymphocyte fraction. Virus-neutralizing antibodies were present from day 1, whereas no IgM antibodies were detected. By day 12, 80% of the vaccines were IgG positive. In the primary and secondary (memory) immune responses, 2',5'AS activity is expressed in the T-lymphocyte fraction prior to the appearance of antibodies directed against the virus and may serve as an early and sensitive marker of an ongoing virus infection which is otherwise difficult to detect. No change in conventional laboratory analysis parameters, such as in differential blood cell counts or total IgA, IgG, and IgM, disclosed the immune activity in either the primary or the secondary immunization.

Intranasal administration of diphtheria toxoid. Selecting antibody isotypes using formulations having various lipophilic characteristics

Non-ionic excipients, having different lipophilicity, were compared for their selection of immunological response in different organs and biological fluids. In order to express the lipophilicity of the formulation, the balance between the size and strength of the hydrophilic and lipophilic groups was used, called the hydrophile-lipophile balance (HLB) value. Mice were immunized and boosted intranasally with diphtheria toxoid, and samples were taken from the blood, spleen, nasal wash, lungs, saliva, stomach, duodenum, jejunum and the skin. In general, formulations which were highly hydrophilic and highly lipophilic were not able to augment the immunological response markedly (except for IgA). Formulations having intermediate HLB values, e.g. around 9.0, stimulated both IgG1 and IgG2a production, where the HLB = 5.5 formulation seemed to stimulate mainly IgG2b and IgG3 antibody production. On the other hand, comparing the IgA concentration in various samples with respective IgG level, increasing HLB value seems to augment the production of mainly IgA antibodies. The results indicate that the antibody isotypes may be controlled, using variations in the hydrophile-lipophile balance value.

Lymphocyte proliferative responses and the occurrence of dermatophilosis in cattle naturally infested with Amblyomma variegatum

The proliferative response of lymphocytes from tick-infested Zebu type, N'Dama and Friesian cattle and acaricide-treated Zebu types and Friesians in concanavalin A (Con A) stimulated cultures was monitored regularly for periods ranging from 11 to 27 months. The numbers of ticks on the animals and the presence of dermatophilosis were also noted. The Friesian cattle carried most and the N'Dama fewest Amblyomma variegatum ticks. The tick-infested Friesians all developed severe clinical dermatophilosis within 5 months of becoming tick-infested. Dermatophilosis lesions on the tick-infested Zebu type and N'Dama cattle were less common and less severe especially in the N'Damas. The proliferative response of lymphocytes from tick-infested Friesians in Con A stimulated cultures fell to almost half that of the acaricide-treated Friesians soon after the former became tick-infested. The tick-infested Zebu types also developed a depressed response compared with the tick-free Zebu group over a 27 month study period. However, the responses of the N'Damas was similar to that of the tick-free Zebu types. The addition of autologous serum to Con A stimulated cultures of lymphocytes derived from the tick-infested Zebu types and N'Damas suppressed their proliferative response compared with that of similar cultures for the tick-free Zebu types.

Immunoelectron microscopy of antigens of Bordetella pertussis using monoclonal antibodies to agglutinogens 2 and 3, filamentous haemagglutinin, pertussis toxin, pertactin and adenylate cyclase toxin

Immunogold electron microscopy and monoclonal antibodies (Mabs) were used to localize surface-related antigens of Bordetella pertussis. Unfixed organisms of B. pertussis strains which are included in the Danish whole-cell pertussis vaccine and fixed cells from a vial of vaccine were examined. Mabs to agglutinogens 2 and 3 labelled fimbria-like structures on both live and fixed cells in a serotype-specific manner. Mab against pertactin, a 69 kDa outer membrane protein, produced intense labelling of the surface of unfixed cells, whereas staining was reduced when fixed cells were examined. Mabs against filamentous haemagglutinin (FHA) stained aggregates of material between or adherent to both live and fixed cells. Negligible labelling of FHA on cell surfaces was observed. Mabs to pertussis toxin and adenylate cyclase toxin labelled loose-structured material which was adherent to or between cells, but neither of these toxin antigens was expressed on the surface of B. pertussis in Mab recognizable form. It is therefore suggested that these antigens are readily dispersed after exit from the outer membrane of B. pertussis.

Bordetella pertussis diagnosed by polymerase chain reaction

The object of this work was to test the polymerase chain reaction (PCR) for demonstration of Bordetella pertussis (BP) in nasopharyngeal secretions. The method was applied to patients with recently diagnosed pertussis, as verified by BP culture. In order to test the sensitivity and specificity of PCR for the diagnosis of BP, we used known concentrations of BP, Bordetella parapertussis and Bordetella bronchiseptica in aqueous solutions. PCR was furthermore carried out on species of bacteria that might be isolated from the nasopharynx. The applicability of PCR to patient specimens was tested in 25 patients in whose nasopharyngeal secretions BP had been demonstrated after 4-7 days of culture. The detection limit of PCR in aqueous solution was 1-2 BP bacteria per reaction tube. PCR was 100% specific for BP, showing no response with other Bordetella species or other bacteria known to colonize the nasopharynx. Of 25 patient specimens, 16 were PCR-positive 4-7 days after the positive primary culture had been established; only 5 out of 13 patient specimens were positive by repeated conventional nasopharyngeal culture at that time. We conclude that PCR is a possible alternative to culture for the demonstration of BP, as PCR is considerably faster than culture and might be more sensitive.

Reversible opening of the blood-brain barrier by anti-bacterial antibodies

The leukocyte adhesion molecule CR3 (CD11b/CD18, Mac-1) promotes leukocyte transmigration into tissues by engaging an unknown cognate ligand on the surface of vascular endothelial cells. Filamentous hemagglutinin (FHA), an adhesin of the bacterium Bordetella pertussis, binds to CR3. We hypothesized that FHA mimics the native ligand for the CR3 integrin on endothelial cells and predicted that anti-FHA antibodies should bind to endothelial cells, interfere with leukocyte recruitment, and induce endothelial permeability. Anti-FHA monoclonal antibodies bound to cerebral microvessels in sections from human brain and upon intravenous injection into rabbits. Antibody binding correlated with the ability to recognize two polypeptides in extracts of human cerebral vessels that were also bound by CD18. In vivo, antibody binding not only interfered with transmigration of leukocytes into cerebrospinal fluid but also induced a dose-dependent reversible increase in blood-brain barrier permeability sufficient to improve delivery of intravenously administered therapeutic agents to brain parenchyma.

Identification of B-cell epitopes on the S4 subunit of pertussis toxin

The main purpose of the present study was to identify B-cell epitopes on the S4 subunit of pertussis toxin (PT) by the synthetic peptide approach. Two strategies were followed: (i) screening of two series of overlapping peptides (12- and 25-residue peptides) covering the entire S4 sequence by a panel of murine monoclonal anti-PT antibodies and various polyclonal anti-PT antisera in an enzyme-linked immunosorbent assay (ELISA), and (ii) analysis of the S4 amino acid sequence by a predictive algorithm followed by synthesis and immunization of mice with the predicted peptides coupled to diphtheria toxoid. The anti-peptide conjugate antisera were tested in an ELISA for cross-reactivity with native PT, B oligomer, and S4. Screening of the free peptides in an ELISA by the PT antisera indicated the presence of six B-cell epitope-containing domains covered by residues 18 to 32, 33 to 46, 39 to 52, 51 to 65, 71 to 84, and 91 to 106. None of the peptides, however, were recognized by the monoclonal anti-PT antibodies in an ELISA. Immunization with six computer-predicted peptides (B1 to B6) and three potential T-cell epitopes (T1 to T3) gave rise to very high antibody responses towards the homologous conjugates. With the exception of the anti-T1/diphtheria toxoid antisera, all anti-peptide conjugate antisera cross-reacted with PT in an ELISA at different levels. None of these anti-peptide conjugate antisera, however, showed any PT-neutralizing effect as measured by the Chinese hamster ovary cell assay and the leukocytosis-promoting activity test. The results of the present study suggest that discontinuous epitopes are predominant in the S4 subunit of native PT.