National outbreak of Salmonella senftenberg associated with infant food

Eight cases of Salmonella senftenberg infection in infants were identified in the first half of 1995 in England, five were indistinguishable S. senftenberg strains. A case-control study showed an association between illness and consumption of one brand of baby cereal (P = 0.03). The cereal manufacturer reported isolating S. senftenberg in June 1994 from an undistributed cereal batch. Outbreak strains and the cereal strain were all plasmid-free in contrast to other human isolates of S. senftenberg in the same period. Changes in the production process were implemented to prevent further contamination. Surveillance centres should strengthen the detection and investigation of outbreaks of gastrointestinal infection in susceptible groups, especially young children. In this outbreak, the study of only five cases led to identification of the vehicle of infection. Even when few cases are reported, epidemiological investigation in conjunction with molecular typing may lead to public health action which prevents continuing or future outbreaks.

Restricted TCR V alpha repertoire in the T cell response to a tolerogenic determinant of type II collagen

Tolerization of B10.RIII mice (H-2r) with i.v.-injected type II collagen (CII) renders the animals resistant to induction of collagen-induced arthritis (CIA). The B10.RIII mouse is of particular interest, in that the T cell determinants that induce tolerance are different from those that induce arthritis. To characterize T cells that react with the tolerogenic determinant and play a role in regulation of arthritis, we have developed a panel of T cell hybridomas reactive with the tolerogenic T cell epitope, CII 607-621. None of the hybrids cross-reacted with either the arthritogenic CII 445-453 or murine CII. As determined by PCR and immunofluorescence, the T cell response to the tolerogenic determinant was oligoclonal, with evident preferential usage of V alpha. Through the analysis of a large panel of T cell hybridomas, preferential usage of V alpha2, J alpha44, J beta2.7, and D beta2.1 was observed. Characterization of T cells reactive with the immunodominant determinant, CII 607-621, responsible for the induction of tolerance should prove important in developing novel therapeutic approaches for the treatment of autoimmune diseases.

Restricted TCR V alpha repertoire in the T cell response to a tolerogenic determinant of type II collagen

Tolerization of B10.RIII mice (H-2r) with i.v.-injected type II collagen (CII) renders the animals resistant to induction of collagen-induced arthritis (CIA). The B10.RIII mouse is of particular interest, in that the T cell determinants that induce tolerance are different from those that induce arthritis. To characterize T cells that react with the tolerogenic determinant and play a role in regulation of arthritis, we have developed a panel of T cell hybridomas reactive with the tolerogenic T cell epitope, CII 607-621. None of the hybrids cross-reacted with either the arthritogenic CII 445-453 or murine CII. As determined by PCR and immunofluorescence, the T cell response to the tolerogenic determinant was oligoclonal, with evident preferential usage of V alpha. Through the analysis of a large panel of T cell hybridomas, preferential usage of V alpha2, J alpha44, J beta2.7, and D beta2.1 was observed. Characterization of T cells reactive with the immunodominant determinant, CII 607-621, responsible for the induction of tolerance should prove important in developing novel therapeutic approaches for the treatment of autoimmune diseases.

Community immunization programme in response to an outbreak of invasive Neisseria meningitidis serogroup C infection in the Trent region of England 1995-1996

Between 8 December 1995 and 16 January 1996 seven laboratory confirmed cases of septicaemia owing to infection with Neisseria meningitidis serogroup C strains and one highly probable case of meningococcal septicaemia occurred in three electoral wards in south Rotherham and the Retford area of north Nottinghamshire. All cases occurred among children aged 1-17 years. One patient died. The public health response to this outbreak was the largest community prophylactic antibiotic and immunization programme against meningococcal infection, to date, in the United Kingdom. The target group for each Health Authority was 8900 for Rotherham Health Authorities and 8000 for North Nottinghamshire Health. Local logistical factors led to differences in the implementation of the programme by each Health Authority. At the completion of each programme, 8320 doses of vaccine had been administered (92.5 per cent coverage) during the Rotherham Health Authorities programme and 7660 (95.7 per cent coverage) during the North Nottinghamshire Health programme. The additional financial cost of the exercise amounted to approximately Pounds 125000 for each Health Authority. This paper describes the evolution of the outbreak, the decision-making process resulting in the immunization programme in each Health Authority, the implementation of each programme, problems identified and lessons learned.

Application of molecular methods to a nosocomial outbreak of Salmonella enteritidis phage type 4

A nosocomial outbreak of Salmonella enteritidis phage type 4 occurred in July 1995. Seven definite cases were identified over 13 days affecting four wards in a London hospital. The outbreak strain was characterized by plasmid profile typing and pulsed-field gel electrophoresis (PFGE), and was unusual in that it did not possess a 38 MDa plasmid common to most isolates of S. enteritidis PT 4 made from humans and food animals in England and Wales. Seven asymptomatic excreters were identified on screening. No additional cases occurred on wards after standard isolation procedures were implemented. No common or continuing food or dietary source was identified. Results of epidemiological, microbiological and environmental investigations suggested that the outbreak was due to person-to-person transmission within the hospital. The source of the outbreak was not established but was probably due to admission of a patient with an unrecognized infection of S. enteritidis PT 4. The study highlights the importance of close collaboration between hospital staff, epidemiologists and microbiologists, and demonstrates the value of molecular techniques for strain subdivision in outbreak investigations.

An HLA-DR1 transgene confers susceptibility to collagen-induced arthritis elicited with human type II collagen

Rheumatoid arthritis (RA) is an autoimmune disease that is strongly associated with the expression of several HLA-DR haplotypes, including DR1 (DRB1*0101). Although the antigen that initiates RA remains elusive, it has been shown that many patients have autoimmunity directed to type II collagen (CII). To test the hypothesis that HLA-DR1 is capable of mediating an immune response to CII, we have generated transgenic mice expressing chimeric (human/mouse) HLA-DR1. When the DR1 transgenic mice were immunized with human CII (hCII), they developed a severe autoimmune arthritis, evidenced by severe swelling and erythema of the limbs and marked inflammation and erosion of articular joints. The development of the autoimmune arthritis was accompanied by strong DR1-restricted T and B cell responses to hCII. The T cell response was focused on a dominant determinant contained within CII(259-273) from which an eight amino acid core was defined. The B cell response was characterized by high titers of antibody specific for hCII, and a high degree of cross-reactivity with murine type II collagen. These data demonstrate that HLA-DR1 is capable of presenting peptides derived from hCII, and suggest that this DR1 transgenic model will be useful in the development of DR1-specific therapies for RA.

Suppression of murine collagen-induced arthritis by nasal administration of collagen

DBA/1 mice were administered type II collagen (CII) or collagen peptides intranasally before systemic immunization to determine whether tolerance could be induced and autoimmune arthritis suppressed. Although prior experiments have demonstrated that collagen given intravenously or orally is effective, the respiratory mucosal route offers several theoretical advantages for dosing peptides, in addition to ease of use. Intact CII, CB11 and a synthetic peptide containing the immunodominant T-cell epitope recognized by H-2q mice were all effective in reducing the incidence and severity of arthritis and the immune response to CII. Since previous studies have demonstrated the importance of IgG2 antibody subclasses to the induction of collagen-induced arthritis, total immunoglobulin G (IgG), IgG1, and IgG2a and IgG2b were measured. IgG2 antibody subclasses were significantly downregulated by the treatment regimen, whereas a slight decrease in IgG1 antibodies was noted that was not significant. In an effort to determine the mechanism by which arthritis was attenuated, cervical lymph node and spleen cells from treated mice were cultured separately with CII and supernatants tested for the presence of T-cell lymphokines. The cells provided a T-helper 2 (Th2)-like response to CII, with T cells from lymph nodes secreting interleukin-4 (IL-4) and splenocytes secreting both IL-4 and IL-10, whereas a Th1-like response was detected in immunized mice not tolerized with CII. These findings indicate that the downregulation of arthritis that occurs with intranasal administration of CII is associated with Th2-type lymphokine profile and a decrease in complement-fixing antibody subclass.

Management of clusters of meningococcal disease. PHIS Meningococcus Working Group and Public Health Medicine Environmental Group

Guidance on the management of clustered cases of meningococcal disease has been revised following a review of the clusters that occurred in England and Wales between 1 April 1995 and 31 March 1996. Public health action is indicated for confirmed and probable cases but not in response to possible cases. The importance of microbiological confirmation is re-emphasised. Intervention is recommended for defined target groups when two or more confirmed or probable cases occur in a preschool group or school within a four week period. We present a framework to assist in the management of clusters of invasive serogroup C infections in larger and less defined communities.

Marshmallows cause an outbreak of infection with Salmonella enteritidis phage type 4

Thirty-six cases of Salmonella enteritidis phage type (PT) 4 infection, mainly in children, were notified in one local authority in the two weeks beginning on 23 October 1995. Twenty-four cases and 42 controls nominated by cases were included in a case control study, which showed a significant association between illness and the consumption of marshmallow confectionery from a bakery. S. enteritidis PT4 was isolated from samples of the marshmallow, and all isolates had the same plasmid and pulsed field gel electrophoresis profiles. The marshmallow had been made using raw egg white, which shows that not all caterers follow the Department of Health's advice.

Autoantibodies to murine type II collagen in collagen-induced arthritis: a comparison of susceptible and nonsusceptible strains

Collagen-induced arthritis (CIA) is an experimental autoimmune disease elicited in genetically susceptible strains of mice by immunization with heterologous type II collagen. This experimental disease is mediated by the immune response of both T cells and B cells, and susceptibility is restricted by the class II molecules of the MHC. In this study we identify specific epitopes bound by autoantibodies elicited through immunization of several haplotypes of C57BL/10 mice with chick alpha1 (II)-CB11. ELISA analysis using a panel of 15-mer murine type II collagen peptides revealed a pattern of autoantibody epitope specificity that was remarkably similar among CIA-susceptible and nonsusceptible congenic strains, regardless of class II haplotype. However, one epitope was identified that was bound only by autoantibodies from CIA-susceptible strains bearing I-A(q) (B10.Q and B10.QbetaBR). In addition, this epitope was also present within affinity-purified Ab obtained from the CIA-susceptible strain DBA/1 (I-A(q)). Analyses of immune serum from B10.Q and B10.QbetaBR mice revealed that a subset of the antibodies binding this epitope were of the IgG2 subclass, and therefore efficient at fixing complement, a requirement for pathogenicity of the Abs in CIA.

Autoantibodies to murine type II collagen in collagen-induced arthritis: a comparison of susceptible and nonsusceptible strains

Collagen-induced arthritis (CIA) is an experimental autoimmune disease elicited in genetically susceptible strains of mice by immunization with heterologous type II collagen. This experimental disease is mediated by the immune response of both T cells and B cells, and susceptibility is restricted by the class II molecules of the MHC. In this study we identify specific epitopes bound by autoantibodies elicited through immunization of several haplotypes of C57BL/10 mice with chick alpha1 (II)-CB11. ELISA analysis using a panel of 15-mer murine type II collagen peptides revealed a pattern of autoantibody epitope specificity that was remarkably similar among CIA-susceptible and nonsusceptible congenic strains, regardless of class II haplotype. However, one epitope was identified that was bound only by autoantibodies from CIA-susceptible strains bearing I-A(q) (B10.Q and B10.QbetaBR). In addition, this epitope was also present within affinity-purified Ab obtained from the CIA-susceptible strain DBA/1 (I-A(q)). Analyses of immune serum from B10.Q and B10.QbetaBR mice revealed that a subset of the antibodies binding this epitope were of the IgG2 subclass, and therefore efficient at fixing complement, a requirement for pathogenicity of the Abs in CIA.

International epidemiological and microbiological study of outbreak of Salmonella agona infection from a ready to eat savoury snack--I: England and Wales and the United States

OBJECTIVES

To identify the source of an international outbreak of food poisoning due to Salmonella agona phage type 15 and to measure how long the underlying cause persisted.

DESIGN

Case-control study of 16 primary household cases and 32 controls of similar age and dietary habit. Packets of the implicated foodstuff manufactured on a range of days were examined for salmonella. All isolates of the epidemic phage type were further characterised by pulsed field gel electrophoresis.

RESULTS

27 cases were identified, of which 26 were in children. The case-control study showed a strong association between infection with S agona phage type 15 and consumption of a peanut flavoured ready to eat kosher savoury snack imported from Israel. S agona phage type 15 was isolated from samples of this snack. The combined food sampling results from the United Kingdom, Canada, the United States, and Israel showed that contaminated snacks were manufactured on at least seven separate dates during a four month period between October 1994 and February 1995. Voluntary recalls of the product successfully interrupted transmission.

CONCLUSIONS

Rapid international exchanges of information led to the identification of the source of a major outbreak of S agona in Israel and of associated cases in North America. The outbreak showed the value of the Salm-Net surveillance system and its links outside Europe, both for increasing case ascertainment and for improving the information on the duration of the fault at the manufacturing plant.

Identification of MHC class II and TCR binding residues in the type II collagen immunodominant determinant mediating collagen-induced arthritis

Collagen-induced arthritis (CIA), an autoimmune arthritis model, is elicited by the immunization of genetically susceptible strains of mice with type II collagen (CII). We have analyzed the molecular interactions that occur during the presentation of the immunodominant determinant within CII(257-270) by the murine class II susceptibility allele, I.Aq. Utilizing a soluble I-A binding assay and clonally distinct CII-specific T cells, we have identified the residues that control the ability of the CII(257-270) peptide to bind to I-Aq and those that interact with the TCR. In competitive binding assays with a panel of analog peptides, only two residues within CII(257-270) were found to participate in the binding of this peptide to I-Aq, residues 260 (Ile) and 263 (Phe). When these substitutions were combined into a single peptide, no binding of the peptide to I-Aq could be detected. Although no other substitutions decreased the binding affinity of the peptides, substitution of several amino acid residues lying outside of the determinant core increased the peptide's affinity for I-Aq and in some instances greatly enhanced the potency of the peptide in stimulating T cells. In antigen presentation assays, clonotypic variation in the recognition of several analog peptides indicated that residues 261, 262, 264, 266, and 267 are likely TCR contact sites. Since residue 266 interacts with the TCR and is the only residue in this determinant that differs between chick/bovine CII and mouse CII, these data indicate that immunity to the autoantigen may play a role in this model.

Antibiotic prescribing during an outbreak of meningococcal disease

During a prolonged outbreak of meningococcal disease caused by serogroup B serotype 15 sulphonamide-resistant strains in one British health district, there was considerable variation in attack rates by town. General practitioner (GP) antibiotic prescribing rates were compared in high and low incidence towns. The only significant difference found was that erythromycin prescribing was more frequent in the high incidence towns (rate ratio 4.0, 95% CI 3.2-4.8, in March 1987 and 3.0, 95% CI 2.4-3.7, in November 1987). This was probably due to increased GP consultation rates for upper respiratory tract infection (URTI), but higher erythromycin usage may have increased meningococcal acquisition rates or susceptibility to meningococcal disease. Antibiotic prescribing rates should be further investigated in defined areas of high and low incidence of meningococcal disease.

Respiratory syncytial virus infection and meningococcal disease

Although viral respiratory tract infections may predispose to meningococcal disease, strong evidence that they do so exists only for influenza. Data on laboratory reported cases of respiratory syncytial virus (RSV) infections and meningococcal disease in England and Wales from mid-1989 to mid-1994 were analysed. Although the rise in RSV cases preceded the rise in meningococcal disease cases each winter, the interval between the rise and fall of the two diseases was inconsistent, no association was found between time series after removal of the seasonal component, and there was no evidence that more cases of meningococcal disease occurred in winters with more RSV disease. RSV may have less effect on the two most likely mechanisms whereby influenza predisposes to meningococcal disease, namely lowered immunity and impaired pharyngeal defences.

Vaccination with a recombinant V alpha domain of a TCR prevents the development of collagen-induced arthritis

A recombinant TCR domain, derived from a T cell hybridoma that recognizes an immunodominant type II collagen epitope, was used to vaccinate against collagen-induced arthritis in DBA/1 (H-2q) mice. The recombinant TCR domain comprises VA11.1-JA17 gene segments and is representative of the V alpha domains expressed by oligoclonal T cells in this disease model. Vaccination of mice 28 days before type II collagen (CII) immunization with this V alpha 11.1 domain resulted in a significantly decreased incidence of arthritis in DBA/1 mice, in contrast to vaccination with a V alpha 4-J alpha 40 domain derived from an encephalitogenic T cell hybridoma specific for MBP. Disease blockade is accompanied by a reduction in T and B cell responses to both the immunogen bovine CII and the autoantigen murine CII. V alpha 4 and V alpha 11.1 domains were found to be highly immunogenic in DBA/1 mice, inducing both T cell proliferation and the production of V alpha specific Abs, indicating that the vaccination effect of V alpha 11.1 is specific. This is the first report of V alpha-directed immunotherapy in an autoimmune disease model and demonstrates the potential use of recombinant TCR vaccines in the treatment of autoimmune diseases that involve oligoclonal autoreactive T cells.

Vaccination with a recombinant V alpha domain of a TCR prevents the development of collagen-induced arthritis

A recombinant TCR domain, derived from a T cell hybridoma that recognizes an immunodominant type II collagen epitope, was used to vaccinate against collagen-induced arthritis in DBA/1 (H-2q) mice. The recombinant TCR domain comprises VA11.1-JA17 gene segments and is representative of the V alpha domains expressed by oligoclonal T cells in this disease model. Vaccination of mice 28 days before type II collagen (CII) immunization with this V alpha 11.1 domain resulted in a significantly decreased incidence of arthritis in DBA/1 mice, in contrast to vaccination with a V alpha 4-J alpha 40 domain derived from an encephalitogenic T cell hybridoma specific for MBP. Disease blockade is accompanied by a reduction in T and B cell responses to both the immunogen bovine CII and the autoantigen murine CII. V alpha 4 and V alpha 11.1 domains were found to be highly immunogenic in DBA/1 mice, inducing both T cell proliferation and the production of V alpha specific Abs, indicating that the vaccination effect of V alpha 11.1 is specific. This is the first report of V alpha-directed immunotherapy in an autoimmune disease model and demonstrates the potential use of recombinant TCR vaccines in the treatment of autoimmune diseases that involve oligoclonal autoreactive T cells.

Identification and characterization of a major tolerogenic T-cell epitope of type II collagen that suppresses arthritis in B10.RIII mice

Tolerization of B10.RIII mice (H-2r) with intravenously injected type II collagen (CII) renders the animals resistant to induction of collagen-induced arthritis (CIA). In order to clarify H-2r-restricted T-cell responses that modulate CIA, we have analysed the T-cell proliferative response of B10.RIII mice against cyanogen bromide (CB) peptides of CII, and detected the strongest response to alpha 1(II)-CB10 (CII 552-897). A panel of chemically synthesized overlapping peptide homologues was used to deduce the minimum structure of this determinant which was found to be CII 610-618. A 15-residue synthetic peptide flanking this region, CII 607-621, was found to effectively suppress arthritis when administered as a tolerogen. Collectively, these data identify the structural component within alpha 1(II)-CB10 which is capable of inducing tolerance in B10.RIII mice. A similar approach to the treatment of autoimmune arthritis, involving the institution of self-tolerance, has potential applicability to human rheumatoid arthritis.

Collagen-induced arthritis in B10.RIII mice (H-2r): identification of an arthritogenic T-cell determinant

Susceptibility to collagen-induced arthritis (CIA), a murine model of autoimmune arthritis, is strongly linked to only two major histocompatibility complex (MHC) haplotypes, H-2q and H-2r. In order to identify the determinants of type II collagen (CII) required to induce arthritis in H-2r-bearing mice, B10.RIII mice were immunized with bovine, chick or human CII. Only bovine CII induced significant arthritis and autoantibodies. When the major CNBr peptides of bovine collagen were isolated and used for immunization, only mice immunized with CB8, representing CII 403-551, developed arthritis. To identify immunogenic epitope(s) within CB8, a panel of synthetic peptides representing overlapping sequences of the bovine peptide was generated. When each peptide was cultured with T cells from B10.RIII mice immunized with CII, one peptide, representing CII 430-466, contained a major T-cell epitope. By using an in vitro lymphokine production assay, the T-cell epitope was further narrowed to CII 442-456. These findings suggest that a T-cell determinant important for the initiation of arthritis in B10.RIII (H-2r) mice is located within a 15 amino acid sequence, residues 442-456 of bovine CII.

Identification and characterization of a tolerogenic T cell determinant within residues 181-209 of chick type II collagen

The murine model of collagen-induced arthritis is characterized by the development of an immune response against joint cartilage. Arthritis can be significantly suppressed by the administration of type II collagen (CII) or one of the CNBr peptides, CB11 (CII 124-402) as a tolerogen prior to immunization. We have previously shown that two synthetic peptides, representing sequences CII 260-270 and CII 181-209, are effective tolerogens. In this paper, we now characterize the T cell determinant with CII 181-209. A series of synthetic peptides overlapping CII 181-209 and analogs of chick CII 181-209 containing site-directed amino acid substitutions was developed and cultured with T cells from DBA/1 mice immunized with CII. Supernatants were collected and analyzed for the presence of the T cell lymphokine IFN-gamma. These data indicate the critical T cell determinant to be located within CII 190-200. This conclusion is further supported by the observation that an unodecapeptide representing CII 190-200 was just as effective as CII 181-209 in suppressing arthritis and anti-CII antibody response when tested as a tolerogen. Analogs containing single amino acid substitutions at residues 191, 194, 197, 198, or 200 were significantly less effective in inducing T cell responses. Each of these peptide analogs was then given as neonatal tolerogens to DBA/1 mice. Mice were subsequently immunized and observed for the development of arthritis. These studies identified residues 194, 197, 198, and 200, and probably residue 191, as critical for tolerance and the suppression of arthritis. Elucidation of the fine structures of T cell determinants which are critical for suppression of arthritis should allow these techniques to be used for developing specific immunotherapeutic approaches to autoimmune arthritis.

Smoking, the environment and meningococcal disease: a case control study

This case control study investigated environmental factors in 74 confirmed cases of meningococcal disease (MD). In children aged under 5, passive smoking in the home (30 or more cigarettes daily) was associated with an odds ratio (OR) of 7.5 (95% confidence interval (CI) 1.46-38.66). ORs increased both with the numbers of cigarettes smoked and with the number of smokers in the household, suggesting a dose-response relationship. MD in this age group was also significantly associated with household overcrowding (more than 1.5 persons per room) (OR 6.0, 95% CI 1.10-32.8), with kisses on the mouth with 4 or more contacts in the previous 2 weeks (OR 2.46, 95% CI 1.09-5.56), with exposure to dust from plaster, brick or stone in the previous 2 weeks (OR 2.24, 95% CI 1.07-4.65); and with changes in residence (OR 3.0, 95% CI 1.0-8.99), marital arguments (OR 3.0, 95% CI 1.26-7.17) and legal disputes in the previous 6 months (OR 3.10, 95% CI 1.24-7.78). These associations were independent of social class. Public health measures to lower the prevalence of cigarette smoking by parents of young children may reduce the incidence of MD. The influence of building dust and stressful life events merits further investigation.

Characterization of the T cell determinants in the induction of autoimmune arthritis by bovine alpha 1(II)-CB11 in H-2q mice

Collagen-induced arthritis (CIA) is an experimental autoimmune disease elicited in genetically susceptible strains of mice by immunization with heterologous type II collagen. This experimental disease is mediated by the immune response of both T and B cells, and susceptibility is restricted by the class II molecules of the MHC. To study the T cell determinants of bovine type II collagen (CII) that mediate the autoimmune response in H-2q mice, we have identified a cyanogen bromide fragment of bovine CII, CII(124-402), that induces arthritis in DBA/1 mice. Using an overlapping set of peptides to map the T cell response to CII(124-402), we have determined that the I-Aq-restricted T cell response to this collagen fragment is mediated by a single immunodominant antigenic determinant. Consequently, this determinant plays a central role in promoting the production of the collagen-specific Abs and the induction of CIA in H-2q mice. Characterization of this immunodominant determinant revealed that the core residues required for T cell stimulation consists of only eight amino acids and is located at amino acids 260 through 267 of bovine CII. The systematic analysis of the contribution of each of these amino acids, in conjunction with sequences of other peptides known to bind to I-Aq, have allowed us to propose a peptide binding motif for the collagen arthritis susceptibility allele, I-Aq.

Characterization of the T cell determinants in the induction of autoimmune arthritis by bovine alpha 1(II)-CB11 in H-2q mice

Collagen-induced arthritis (CIA) is an experimental autoimmune disease elicited in genetically susceptible strains of mice by immunization with heterologous type II collagen. This experimental disease is mediated by the immune response of both T and B cells, and susceptibility is restricted by the class II molecules of the MHC. To study the T cell determinants of bovine type II collagen (CII) that mediate the autoimmune response in H-2q mice, we have identified a cyanogen bromide fragment of bovine CII, CII(124-402), that induces arthritis in DBA/1 mice. Using an overlapping set of peptides to map the T cell response to CII(124-402), we have determined that the I-Aq-restricted T cell response to this collagen fragment is mediated by a single immunodominant antigenic determinant. Consequently, this determinant plays a central role in promoting the production of the collagen-specific Abs and the induction of CIA in H-2q mice. Characterization of this immunodominant determinant revealed that the core residues required for T cell stimulation consists of only eight amino acids and is located at amino acids 260 through 267 of bovine CII. The systematic analysis of the contribution of each of these amino acids, in conjunction with sequences of other peptides known to bind to I-Aq, have allowed us to propose a peptide binding motif for the collagen arthritis susceptibility allele, I-Aq.

T cell epitopes of type II collagen that regulate murine collagen-induced arthritis

Chick type II collagen (CII), a protein commonly found in joint cartilage, induces an autoimmune arthritis when administered to susceptible strains of mice. A cyanogen bromide fragment of CII, CB11, contains the requisite epitopes critical for inducing collagen-induced arthritis. If administered as a tolerogen, however, before immunization, CB11 prevents the onset of disease. Therefore, delineation of structural elements of CB11 that can regulate autoreactive T cells became the goal of this study. To delineate the structural elements of CB11 antigenic to T cells, 14 peptides containing overlapping sequences of CB11 were generated. Mononuclear cells from CII-immunized DBA/1 mice were cultured with these peptides and the resulting supernatants examined for the production of IFN-gamma. Two peptides, CII 181-209 and CII 245-270, generated the greatest responses. The ability of these two peptides to regulate arthritis was tested by administering them to neonatal DBA/1 mice as tolerogens before immunization with CII. Both peptides suppressed the incidence of arthritis whereas no other peptide used as a tolerogen significantly altered the course of the disease. T cells from four arthritis-resistant murine strains did not recognize either peptide when immunized with CII, whereas cells from the disease-susceptible B10.Q mice responded well to both. Thus, the coincidence of T cell responses to CII 181-209 and CII 245-270 in CIA-susceptible mice and the lack of response in disease-resistant strains or CII-tolerized mice identify these two peptides as containing important T cell epitopes that regulate CIA.

T cell epitopes of type II collagen that regulate murine collagen-induced arthritis

Chick type II collagen (CII), a protein commonly found in joint cartilage, induces an autoimmune arthritis when administered to susceptible strains of mice. A cyanogen bromide fragment of CII, CB11, contains the requisite epitopes critical for inducing collagen-induced arthritis. If administered as a tolerogen, however, before immunization, CB11 prevents the onset of disease. Therefore, delineation of structural elements of CB11 that can regulate autoreactive T cells became the goal of this study. To delineate the structural elements of CB11 antigenic to T cells, 14 peptides containing overlapping sequences of CB11 were generated. Mononuclear cells from CII-immunized DBA/1 mice were cultured with these peptides and the resulting supernatants examined for the production of IFN-gamma. Two peptides, CII 181-209 and CII 245-270, generated the greatest responses. The ability of these two peptides to regulate arthritis was tested by administering them to neonatal DBA/1 mice as tolerogens before immunization with CII. Both peptides suppressed the incidence of arthritis whereas no other peptide used as a tolerogen significantly altered the course of the disease. T cells from four arthritis-resistant murine strains did not recognize either peptide when immunized with CII, whereas cells from the disease-susceptible B10.Q mice responded well to both. Thus, the coincidence of T cell responses to CII 181-209 and CII 245-270 in CIA-susceptible mice and the lack of response in disease-resistant strains or CII-tolerized mice identify these two peptides as containing important T cell epitopes that regulate CIA.

A synthetic peptide analogue of a determinant of type II collagen prevents the onset of collagen-induced arthritis

The immunization of genetically susceptible strains of mice with type II collagen (CII) elicits a collagen-induced arthritis that resembles rheumatoid arthritis. Our laboratory previously identified a region of CII, CII-245-270, that contains a T cell epitope that is prominent in the immune response to CII. Residues critical to the I-Aq-restricted presentation of this determinant have been characterized. To produce synthetic peptides with the potential of disrupting I-Aq-restricted Ag presentation, synthetic analogue peptides were developed that contain site-directed substitutions in critical positions. One analogue peptide was found to be an efficient competitor for binding to I-Aq and to be capable of inhibiting T cell responses in vitro. When DBA/1 mice were coimmunized with CII and the analogue peptide, the incidence and severity of arthritis were greatly reduced, concordant with the humoral immune responses to CII.

A synthetic peptide analogue of a determinant of type II collagen prevents the onset of collagen-induced arthritis

The immunization of genetically susceptible strains of mice with type II collagen (CII) elicits a collagen-induced arthritis that resembles rheumatoid arthritis. Our laboratory previously identified a region of CII, CII-245-270, that contains a T cell epitope that is prominent in the immune response to CII. Residues critical to the I-Aq-restricted presentation of this determinant have been characterized. To produce synthetic peptides with the potential of disrupting I-Aq-restricted Ag presentation, synthetic analogue peptides were developed that contain site-directed substitutions in critical positions. One analogue peptide was found to be an efficient competitor for binding to I-Aq and to be capable of inhibiting T cell responses in vitro. When DBA/1 mice were coimmunized with CII and the analogue peptide, the incidence and severity of arthritis were greatly reduced, concordant with the humoral immune responses to CII.

Audit of near patient cholesterol testing in occupational health clinics

An audit of near patient cholesterol testing was carried out in occupational health clinics. The aims were to examine the statistical agreement between Reflotron and laboratory measurements of blood cholesterol and to formulate a policy for the use of Reflotrons in cholesterol testing. Three hundred and fifty-two staff members attending occupational health clinics over a period of 10 months had blood taken for both Reflotron and laboratory measurements. The correlation between the two methods was 0.95. The Reflotron had a negative bias compared to the laboratory, with the mean difference between the two methods of measurement being -0.21 mmol/l (95 per cent confidence interval -0.18 to -0.25 mmol/l). Despite the high correlation coefficient and small mean difference, the scatter of Reflotron-laboratory differences was broad, with 95 per cent of the differences lying in the range of 0.95 mmol/l below to 0.52 mmol/l above the laboratory result. For Reflotron results of 5.50 mmol/l and greater, the sensitivity and specificity of the Reflotron in detecting subjects with laboratory cholesterol levels greater than 6.5 mmol/l were 100 per cent and 70 per cent respectively. The laboratory participated in two external quality assessment schemes for cholesterol testing during the course of the audit and all the results of these fell within the acceptable limits. The audit demonstrated that the Reflotron was too imprecise to be used to give accurate measurements of blood cholesterol. However, providing a suitable Reflotron result above which patients were sent for confirmatory laboratory testing was selected, it was an acceptable screening device in the detection of hypercholesterolaemia. Other Reflotron users should consider carrying out similar audits.

Characterization of a tolerogenic T cell epitope of type II collagen and its relevance to collagen-induced arthritis

A synthetic peptide representing sequences of type II collagen, (CII 245-270), has previously been used to induce tolerance and suppress arthritis in DBA/1 mice. To determine important residues, a series of peptides, each containing one or two site-directed substitutions, was generated. Mononuclear cells from DBA/1 mice immunized with CII were cultured in the presence of each peptide and the T cell response determined by measuring IFN-gamma in culture supernatant fluids. Substitutions within the region CII 260-270 led to significant decreases in IFN-gamma responses, identifying this sequence as a T cell epitope. To determine the effects of substitutions within this epitope on arthritis, substituted peptides were administered to neonatal mice as tolerogens. Five site-directed substitutions, four of which included the insertion of a residue found in type I collagen to replace its type II counterpart, abrogated the ability of the peptides to induce tolerance and suppress arthritis. These substitutions were located at residues 260, 261, 263, 264, and 266. Two patterns of T cell reactivity were observed. Peptides containing individual substitutions at positions 261, 264, or 266 were capable of generating a significant T lymphokine response, although those containing substitutions at residues 260 or 263 were ineffective Ag. Systematic analysis of the fine structures of T cell determinants important for autoimmune arthritis can lead to strategies for therapeutic intervention.

Characterization of a tolerogenic T cell epitope of type II collagen and its relevance to collagen-induced arthritis

A synthetic peptide representing sequences of type II collagen, (CII 245-270), has previously been used to induce tolerance and suppress arthritis in DBA/1 mice. To determine important residues, a series of peptides, each containing one or two site-directed substitutions, was generated. Mononuclear cells from DBA/1 mice immunized with CII were cultured in the presence of each peptide and the T cell response determined by measuring IFN-gamma in culture supernatant fluids. Substitutions within the region CII 260-270 led to significant decreases in IFN-gamma responses, identifying this sequence as a T cell epitope. To determine the effects of substitutions within this epitope on arthritis, substituted peptides were administered to neonatal mice as tolerogens. Five site-directed substitutions, four of which included the insertion of a residue found in type I collagen to replace its type II counterpart, abrogated the ability of the peptides to induce tolerance and suppress arthritis. These substitutions were located at residues 260, 261, 263, 264, and 266. Two patterns of T cell reactivity were observed. Peptides containing individual substitutions at positions 261, 264, or 266 were capable of generating a significant T lymphokine response, although those containing substitutions at residues 260 or 263 were ineffective Ag. Systematic analysis of the fine structures of T cell determinants important for autoimmune arthritis can lead to strategies for therapeutic intervention.

An outbreak of hepatitis A in Gloucester, UK

During an outbreak of hepatitis A that occurred in Gloucester, UK between September 1989 and January 1991, 162 clinical cases were identified through notifications and laboratory reports, a monthly attack rate of 1.05 per 10,000 residents. The highest attack rate was seen in 5-14-year-olds. There were significant correlations between hepatitis A attack rates in the electoral wards of Gloucester and with the Jarman UPA 8 scores for the wards and with overcrowding, unemployment, under 5-year-olds and ethnic minority. The use of human normal immune globulin prophylaxis (HNIG) for household contacts was unsuccessful in ending the outbreak, partly because only one third of cases reported a household contact with recent hepatitis A. Our experience does not support the use of HNIG in stopping community-wide outbreaks of hepatitis A. Two public health campaigns were mounted during the outbreak; both were followed by a fall in the number of cases. Greater priority should be given to the implementation and evaluation of public health campaigns in future community-wide outbreaks of hepatitis A.

Salivary antibody testing in a school outbreak of hepatitis A

During a community-wide outbreak of hepatitis A in Gloucester, UK there was a high attack rate in children attending two city primary schools and a pre-school centre sharing the same site. In September 1990, saliva specimens were collected from 478 (85%) of the 562 children. The prevalence of antibody to hepatitis A virus (anti-HAV), as determined by saliva testing, was 29.6%; highest prevalences were seen in 5-6-year-olds and in children from that area of the city at the centre of the community-wide outbreak. The proportion of immune children with a history of clinical hepatitis varied with age from 1 in 42.7 of under-5-year-olds to 1 in 4.7 of 8-10-year-olds. Six children who received prophylaxis with human normal immune globulin (HNIG) because they were household contacts of cases subsequently became infected. Since there was evidence of transmission outside the school environment it is unlikely that a policy of universal prophylaxis within the schools would have stopped the outbreak. Mass prophylaxis in school outbreaks is only likely to be effective if most transmission is occurring at school and if the target population can be clearly defined. Salivary antibody testing is a simple, practical and acceptable procedure in young children. Salivary antibody surveys in conjunction with vaccination against hepatitis A should provide a cost-effective method for control of future outbreaks.

Induction of arthritis with monoclonal antibodies to collagen

mAb were developed from DBA/1 mice immunized with chick type II collagen. A total of 69 IgG antibodies was isolated and characterized. The majority (36%) reacted with a CNBr-derived peptide CB11 previously identified as containing a major immunogenic and arthritogenic epitope(s). Seven of the antibodies reactive with CB11 crossreacted strongly with mouse type II collagen. These were administered to DBA/1 mice in an attempt to induce arthritis. Individual antibodies were able to induce mild lesions consisting of minimal synovial proliferation but not overt arthritis. However, a combination of antibodies induced severe arthritis with marked destruction of articular cartilage. The minimal effective combination consisted of three antibodies. Arthritis developed within 48 to 72 h after injection of the antibodies and persisted for the duration of the observation period of 3 wk. Antibody levels were measured at intervals and persisted for the 3 wk observation period although at diminishing levels. Competitive binding assays demonstrated that each of the effective antibodies bound independently suggesting that some spatial or quantitative relationship was important possibly related to their ability to activate complement.

Induction of arthritis with monoclonal antibodies to collagen

mAb were developed from DBA/1 mice immunized with chick type II collagen. A total of 69 IgG antibodies was isolated and characterized. The majority (36%) reacted with a CNBr-derived peptide CB11 previously identified as containing a major immunogenic and arthritogenic epitope(s). Seven of the antibodies reactive with CB11 crossreacted strongly with mouse type II collagen. These were administered to DBA/1 mice in an attempt to induce arthritis. Individual antibodies were able to induce mild lesions consisting of minimal synovial proliferation but not overt arthritis. However, a combination of antibodies induced severe arthritis with marked destruction of articular cartilage. The minimal effective combination consisted of three antibodies. Arthritis developed within 48 to 72 h after injection of the antibodies and persisted for the duration of the observation period of 3 wk. Antibody levels were measured at intervals and persisted for the 3 wk observation period although at diminishing levels. Competitive binding assays demonstrated that each of the effective antibodies bound independently suggesting that some spatial or quantitative relationship was important possibly related to their ability to activate complement.

Influenza A and meningococcal disease

There are several anecdotal accounts of the association between outbreaks of influenza and meningococcal disease. The exceptional increase in the number of cases of meningococcal infection 2 weeks after an influenza A outbreak in England and Wales during November and December, 1989, provided an opportunity to investigate the relation between the two events. Patients with meningococcal disease in December, 1989, were more likely than age-matched controls to show serological evidence of recent influenza A infection (odds ratio 3.9, 95% Cl 1.2-13.9). The most likely explanation for the association is immune suppression induced by influenza A, though a lowering of mucosal resistance to meningococcal invasion may also be a factor. Public health authorities should be aware of the association and should be prepared to alert medical practitioners and the public to the increased risk of meningococcal disease when influenza A outbreaks occur.

The role of C5 and T-cell receptor Vb genes in susceptibility to collagen-induced arthritis

Collagen-induced arthritis (CIA) is a rodent arthritis model in which immunization with heterologous type II collagen induces an inflammatory polyarthritis. Susceptibility to the disease is mediated by major histocompatibility complex (MHC) genes as well as genes at other loci. Previous studies of the SWR/J mouse strain, which is resistant to CIA despite bearing the susceptible H-2q haplotype, have suggested that this resistance is the result of a deletion of T-cell receptor (Tcr) Vb gene segments which is carried by this strain. Other studies have implicated a deficiency in complement component C5 as the cause for the resistance. In order to assess the relative importance of these two genes in susceptibility to CIA, and to provide an estimate of the number of independent genes involved in the disease, we analyzed 196 F2 progeny of a (DBA/1 x SWR/J) cross for arthritis susceptibility, and expression of both C5 and Tcr genes. Thirty of the F2 progeny developed arthritis. All of the arthritic mice had at least one copy of the wild-type C5 allele, while the Tcr-Vb haplotypes were distributed in Mendelian fashion. These results demonstrate that C5 sufficiency is an absolute requirement for CIA, but that Tcr-Vb genes located within the SWR deletion have little influence. Genetic analysis of the incidence rate suggests that there is polygenic control of susceptibility to CIA and that in addition to H-2, 5-6 other independent loci (including C5) may be involved.

SWR mice are resistant to collagen-induced arthritis but produce potentially arthritogenic antibodies

SWR mice are resistant to collagen-induced arthritis but produce antibodies to type II collagen. To determine if these antibodies have arthritogenic potential, serum from collagen-immunized mice was concentrated and passively transferred to DBA/1 mice. The recipients developed severe arthritis within 72 hours. To evaluate the role of complement, SWR mice were bred with congenic inbred B10.D2/oSn (complement deficient) and B10.D2/nSn (complement normal) mice. Collagen-immunized (SWR x B10.D2/nSn)F1 mice had high levels of C5 and were susceptible to arthritis, while (SWR x B10.D2/oSn)F1 mice were deficient in C5 and were resistant to arthritis.

Meningococcal carriage in close contacts of cases

Between 1 October 1986 and 31 March 1987, 55 cases of meningococcal disease were identified in the South-West of England, an attack rate of 1.54 per 100,000 during the study period. Antibiotics used in the treatment of the disease successfully eliminated nasopharyngeal carriage of meningococci in 13 out of 14 cases without use of rifampicin. The overall meningococcal carriage rate in 384 close contacts was 18.2% and the carriage rate of strains indistinguishable from the associated case strain was 11.1%. The carriage rate of indistinguishable strains in household contacts (16.0%) was higher than the carriage rate in contacts living at other addresses (7.0%, P less than 0.05). A 2-day course of rifampicin successfully eradicated meningococci from 46 (98%) of 47 colonized contacts. In one third of cases groupable meningococci were isolated from at least one household contact; 92% of these isolates were of the same serogroup as the associated case strain. When a meningococcus is not isolated from a deep site in a clinical case of meningococcal disease, culture of serogroup A or C strains from nasopharyngeal swabs of the case or of household contacts is an indication that the close contact group should be offered meningococcal A + C vaccine in addition to chemoprophylaxis. The failure in this and other studies to isolate meningococci from any household contact in the majority of cases may be due either to the relative insensitivity of nasopharyngeal swabbing in detecting meningococcal carriage or to the acquisition of meningococci by most index cases from sources outside the household.

Fibroid and myometrial steroid receptors in women treated with gonadotropin-releasing hormone agonist leuprolide acetate

The reduction in uterine and fibroid volume associated with the chronic administration of a gonadotropin-releasing hormone agonist (GnRH-a) is thought to be secondary to the analogue induced hypoestrogenic state. Our hypothesis was that the concentration of bioactive estrogen receptors (ER) and progesterone receptors (PR) may be important in the regulation of fibroid growth. The purpose of this study was to determine ER and PR content in fibroids and myometria from women pretreated with GnRH-a compared with controls. Tissue was obtained from 20 premenopausal women with uterine fibroids who were randomized to receive either leuprolide acetate depot, 3.75 mg intramuscularly every 28 days for four injections (n = 10) or placebo (n = 10) before myomectomy. The mean fibroid ER and PR content was significantly greater than the mean myometrial ER and PR content. The mean fibroid ER content for GnRH-a-treated patients was significantly greater than in placebo-treated patients (143.3 +/- 22.8 versus 36.1 +/- 14.3 fmol/mg). The mean fibroid PR and the mean myometrial ER and PR content were not significantly different between treatment groups. Clinically, the significant increase in fibroid ER may be an explanation for the rapid regrowth of fibroids observed after the cessation of GnRH-a therapy.

The role of stromelysin in the cartilage destruction that accompanies inflammatory arthritis

Articular cartilage from arthritic joints of rats immunized with type II collagen is severely depleted of proteoglycans. Depletion begins within 48 hours after the onset of inflammation, prior to extensive pannus formation, and may represent a critical first step in cartilage destruction. We have immunolocalized stromelysin, an enzyme that is believed to play a major role in the pathologic degradation of proteoglycans, in the joints of rats with collagen-induced arthritis. Immunoperoxidase staining of frozen tissue sections demonstrated the presence of stromelysin in both the synovium and chondrocytes. In contrast, collagenase was localized primarily to the pannus-cartilage junction. Neither enzyme was detectable in joints from normal animals. To test the hypothesis that chondrocytes respond directly to inflammatory mediators by increasing the production of stromelysin, isolated chrondrocytes were incubated with various concentrations of interleukin-1. The culture media were also assayed for the presence of stromelysin by immunoreactivity on Western blots and by analysis of enzymatic activity on casein substrate gels. A 3-fold increase in a doublet of proteins synthesized in response to 10 units/ml of interleukin-1 was observed. These proteins also immunoreacted with the stromelysin antibody and degraded casein. Northern blotting results established that the increased levels of stromelysin were accompanied by increases in stromelysin-specific messenger RNA levels. These results suggest that stromelysin is responsible for proteoglycan degradation in early inflammatory arthritis, and that chondrocytes may play a direct role in the earliest stages of the degradation of their own matrices.

A CD4 cell is capable of transferring suppression of collagen-induced arthritis

Collagen-induced arthritis can be suppressed by i.v. injection of intact type II collagen (CII) but not type I collagen before immunization. To identify the mechanism mediating this suppression, splenocytes were obtained from mice injected with CII or OVA and administered to recipients that were subsequently immunized with CII. Mice receiving cells from donors injected with CII had a lower incidence of arthritis and lower antibody titers than those receiving cells from OVA-injected donors. Treatment of cells with 3000 rad of gamma-irradiation abrogated the suppression. To determine the phenotype of these donor cells, spleen cells were fractionated by adherence to plates coated with mouse anti-IgG to enrich for Thy-1+ phenotype. Thy-1+ cells injected into naive mice could significantly suppress arthritis. Further depletion of T cell subsets by panning revealed that depletion of CD4+ cells prevented the transfer of suppression whereas removal of CD8+ cells had no effect. Isolated CD4+ cells transferred into naive mice were also suppressive. Recently the Pgp-1 (Ly-24) Ag has been described to identify a unique memory subset of CD4+ cells when present on the cell surface. In CII-tolerized spleen populations, removal of the Pgp-1+ (Ly-24) subset of T cells abrogated suppression and transfer of isolated Pgp-1+ cells suppressed arthritis. These findings indicate that the Pgp-1+ subset of CD4+ cells can suppress collagen-induced arthritis and suggest that a CD4+ memory cell down-regulates autoimmunity. In addition, treatment of donor animals with cyclosporin, which inhibits the development of CD4+ cells, abrogated suppression.

A CD4 cell is capable of transferring suppression of collagen-induced arthritis

Collagen-induced arthritis can be suppressed by i.v. injection of intact type II collagen (CII) but not type I collagen before immunization. To identify the mechanism mediating this suppression, splenocytes were obtained from mice injected with CII or OVA and administered to recipients that were subsequently immunized with CII. Mice receiving cells from donors injected with CII had a lower incidence of arthritis and lower antibody titers than those receiving cells from OVA-injected donors. Treatment of cells with 3000 rad of gamma-irradiation abrogated the suppression. To determine the phenotype of these donor cells, spleen cells were fractionated by adherence to plates coated with mouse anti-IgG to enrich for Thy-1+ phenotype. Thy-1+ cells injected into naive mice could significantly suppress arthritis. Further depletion of T cell subsets by panning revealed that depletion of CD4+ cells prevented the transfer of suppression whereas removal of CD8+ cells had no effect. Isolated CD4+ cells transferred into naive mice were also suppressive. Recently the Pgp-1 (Ly-24) Ag has been described to identify a unique memory subset of CD4+ cells when present on the cell surface. In CII-tolerized spleen populations, removal of the Pgp-1+ (Ly-24) subset of T cells abrogated suppression and transfer of isolated Pgp-1+ cells suppressed arthritis. These findings indicate that the Pgp-1+ subset of CD4+ cells can suppress collagen-induced arthritis and suggest that a CD4+ memory cell down-regulates autoimmunity. In addition, treatment of donor animals with cyclosporin, which inhibits the development of CD4+ cells, abrogated suppression.

Identification of an immunosuppressive epitope of type II collagen that confers protection against collagen-induced arthritis

We have previously reported that collagen-induced arthritis can be suppressed by intravenous injection of native type II (CII) but not type I collagen. We have now identified denatured fragments of CII capable of suppressing collagen-induced arthritis and inducing tolerance. Purified CII was cleaved with cyanogen bromide (CB), and the major resulting peptides were isolated. Female DBA/1 mice were administered OVA, native CII, or one of the CB peptides, intravenously, before immunization with native CII, 6 wk after immunization, mice tolerized with CII and CB11 had a markedly lower incidence of arthritis compared with controls. There was a correlation between the overall antibody response and the incidence of arthritis. In addition, animals tolerized with either CII or CB11 had a decreased antibody response not only to CII, but also to each of the other CB peptides tested. To identify the epitope involved in suppression of arthritis, five synthetic peptides, 21-26 amino acids in length, corresponding to selected regions of CB11, were generated. Each of the peptides was injected intravenously into mice before immunization. Only one of these, CB11 122-147, was capable of suppressing arthritis. In addition, mice given the synthetic peptide CB11 122-147 neonatally were suppressed for arthritis and antibody responsiveness when immunized with CII at 8 wk of age. Thus, we have identified CB11 122-147 as an epitope of CII important in induction of tolerance and suppression of disease. Further experiments narrowing down the pivotal amino acids for the immunogenicity of this epitope and the role this epitope plays in induction and regulation of disease will enhance our understanding of how the immune response to collagen affects autoimmune arthritis.

Effect of smoking on meningococcal carriage

A case-control study was done to examine whether certain environmental or medical factors were associated with meningococcal carriage. Questionnaires were posted to 138 meningococcal carriers and their controls, and to 52 carriers of Neisseria lactamica and their controls. Carriers were matched to controls by age, sex, and area of residence. The overall response rate was 89%. There were no differences in environmental or medical factors between N lactamica carriers and their controls, nor in household crowding, housing conditions, frequency of physical exercise, or upper respiratory disorders between meningococcal carriers and their controls. Active smoking and the presence of other smokers in the household were independently associated with meningococcal carriage; the risk of carriage increased significantly with heavier smoking.

Systemic administration of TIMP in the treatment of collagen-induced arthritis in mice

The type II collagen induced arthritis model was used to evaluate the efficacy of tissue inhibitor of metalloproteases (TIMP) in suppressing the disease in DBA/1 mice. Treatment began following the first clinical manifestations of the disease state. Clinical observations, histological and radiographic findings show a decreased incidence of joint erosion in the treated population relative to the controls. It is concluded that systemic administration of recombinant human TIMP suppresses the pathology of type II collagen induced arthritis.

The Stonehouse study: secretor status and carriage of Neisseria species

The genetically determined inability to secrete the water-soluble glycoprotein form of the ABO blood group antigens into saliva and other body fluids is a recognized risk factor for meningococcal disease. During a community-wide investigation of a prolonged outbreak of disease due to a B15:P1.16 sulphonamide-resistant strain of Neisseria meningitidis in Stonehouse, Gloucestershire (the Stonehouse survey), the ABO blood group and secretor status of almost 5000 residents was determined. The proportion of non-secretors in the Stonehouse population was significantly higher than the proportion of non-secretors among blood donors in the South West Region and in England generally. Seven of 13 Stonehouse residents with meningococcal disease who were tested were found to be non-secretors, a high proportion. The outbreak in Stonehouse cannot be explained solely in terms of the increased proportion of non-secretors. There was no clear correlation between the proportions of non-secretors in different areas within the town and the incidence of cases of meningococcal disease. Carriers of meningococci, whether outbreak or other strains, were not more likely to be non-secretors. The reasons why non-secretors are more susceptible to meningococcal disease remain to be determined, but they do not appear to be related to carriage of meningococci.