[Takayasu's arteritis]. / Takayasus arteritt.

BACKGROUND: Takayasu's arteritis is a chronic, idiopathic, inflammatory disease that affects aorta and its main branches. The disease is rare; its etiology is unknown and shows race differences. The inflammation of the arteries may lead to stenosis, occlusions, dilatations or aneurysms. The clinical picture and angiographic findings are not previously reported in a Norwegian cohort. MATERIAL AND METHODS: We report a retrospective, hospital-based study describing the clinical picture, diagnostic findings, treatment and prognosis in a cohort of six patients in Central Norway with Takayasu's arteritis. The data was extracted through chart review. RESULTS: In the period 1988-2000, six patients with Takayasu's arteritis, five women and one man, were identified. All the patients were of Norwegian origin. Median age at diagnosis was 39 years, range 24-63 years, and median time from first symptoms to definite diagnosis was six months, range 1-36 months. The estimated minimum annual incidence was 0.8 per million. All patients had elevated erythrocyte sedimentation rate; five out of six patients had unilateral or bilateral subclavian stenosis; one patient had a thoracoabdominal aneurysm. All patients were treated with prednisolone. There were no deaths in the observation period of median 7.5 years, range 0-26 years. INTERPRETATION: Takayasu's arteritis is a rare disease in our region, with lower incidence than reported in the literature. The prognosis is excellent, but the morbidity was substantial. The clinical findings are similar to those reported in other studies. The location and appearance of the angiographic findings were characteristic for the disease.

African tick-bite fever imported into Norway: presentation of 8 cases.

We report on 8 Norwegian travellers to Southern Africa with African tick-bite fever (ATBF), a recently described spotted fever group rickettsiosis. All patients had acute flu-like symptoms and developed I or multiple inoculation eschars. The patients were treated with either doxycycline or ciprofloxacin, and all recovered. The diagnosis of ATBF was confirmed by the detection of specific IgM antibodies to Rickettsia africae by microimmunofluoroscence in convalescent-phase serum samples.

An epitope shared by enterobacterial and neisserial porin proteins.

A murine monoclonal antibody (MAb F9-16) raised against a porin protein epitope called Po I of an E. coli 055 strain showed broad cross-reactivity with bacteria within the Enterobacteriaceae, and also recognized neisseriae and moraxellae. In an immunodot assay, the antibody was bound by 32/33 strains of neisseriae and moraxellae after SDS treatment of the bacteria. Testing intact bacteria, 11/33 isolates showed definite MAb binding, including serogroup A and B meningococci. In Western blotting, the anti-Po I MAb targeted the gonococcal porin proteins PIA and PIB, and class 1, class 2, and class 3 porins of meningococci. The MAb showed no reactivity against decapeptides which corresponded to the whole length of a meningococcal class 1 porin protein of the subtype P1, 7, 16. These findings accord with the inference that enterobacterial, neisserial and moraxellae porin proteins share an epitope (Po I) which is determined by the three-dimensional rather than by the primary structure of the proteins and that this epitope is shielded in most isolates but surface-exposed in some isolates, including some strains of meningococci. Since Po I is broadly distributed among commensal and pathogenic bacteria and has demonstrated immunogenicity in humans, this epitope may play a role in elicitation of "normal" antibodies with immunoprotective activity.

[Spotted fever after travel to South Africa]. / Flekkfeber etter opphold i Søor-Afrika.

Three patients developed fever, malaise and a typical maculopapular rash a few days after returning to Norway from South Africa. In South Africa they had been bitten by ticks several times while hunting. Two patients, with lesions compatible with eschar, were hospitalized, and a diagnosis of rickettsial spotted fever was established based on the clinical presentation and positive Rickettsia conorii serology. Rickettsial diseases are extremely rare in Scandinavia, and a survey on rickettsioses is presented in this paper.

Immunogenicity expressed in patients with bacteraemia of an epitope shared by enterobacterial and neisserial porin proteins.

A monoclonal antibody (MAb) against an epitope (Po I) on an Escherichia coli O55 porin protein has shown broad cross-reactivity with other Enterobacteriaceae and with both pathogenic and non-pathogenic Neisseriaceae. In this study, we have measured antibody levels against the Po I site in patients with bacteraemia in order to examine the immunogenicity of the Po I domain in humans. A MAb-based competition ELISA (cELISA) was used. Only 20% of healthy controls had detectable levels of anti-Po I antibodies in serum. Of patients bacteraemic with enterobacteria (n = 45), 11% and 58% showed elevated antibody levels compared to healthy controls with the first and second serum specimens, respectively, and 73% of these patients showed > or = 10% increase in the antibody levels. Of patients bacteraemic with N. meningitidis (n = 20), only 30% showed > or = 10% increase in the antibody levels when paired serum specimens were tested. Levels of competing antibodies were similar in the cELISA with N. meningitidis (B: 15: P1, 7, 16) OM coat or E. coli O55 OM coat. The results demonstrated that the highly conserved porin protein domain Po I expressed immunogenicity in humans when present in bacteria which caused bacteraemia. This finding represents a challenge in further investigations on the immunobiological role of the cross-reacting antibodies.

[Severe gastroenteritis after domestic infection with Vibrio cholerae non-O1]. / Alvorlig gastroenteritt etter innenlands smitte med Vibrio cholerae non-O1.

Vibrio cholerae non-O1 has previously been isolated only occasionally in Norway from patients infected abroad. This report describes the clinical course in two patients who were domestically infected with V. cholerae non-O1. In one case, contaminated seafood, i.e. crab, was the probable source of infection. Both patients displayed a cholera-like type of illness, with severe diarrhoea and electrolyte disturbances. It is recommended that Norwegian laboratories be prepared to isolate vibrios also in domestically infected cases when watery diarrhoea is present.

Enhancement by a serum factor of the immunoaccessibility of an enterobacterial porin protein domain.

Monoclonal antibody (MAb) generated against the domain Po I on the outer membrane (OM) porin (Po) protein of an Escherichia coli 055 strain showed weak binding by the OM in ELISA. Human serum and sera from different animal species enhanced the MAb binding in ELISA when the antibody was incubated together with serum or the OM was pretreated with serum. Human serum also enhanced the MAb binding when coats were prepared by using OMs from various cross-reacting bacteria. The ability of human serum to amplify the MAb binding by OMs was similar to that of lysostaphin. Amplification by serum was not observed when MAbs against three other enterobacterial OM proteins were tested. The amplifying serum factor was destroyed by heating (100 degrees C) and by mercaptoethanol. It appeared in fractions which corresponded to an apparent molecular weight of 75,000-80,000 after gel permeation, and, after ion-exchange chromatography, in fractions which contained a protein of 60 kD when analysed by SDS-PAGE. These data support the notion that the serum-induced enhancement of the anti-Po I MAb binding was due to a previously described serum amidase (N-acetylmuramyl-L-alanine amidase) which has peptidoglycan-degrading activity. The effects of the amplifying serum factor may influence the antibody levels which are measured when OMs from Gram-negative bacteria are used as antigen in a serodiagnostic test.

A conserved domain on enterobacterial porin protein analysed by monoclonal antibody.

Broadly cross-reactive monoclonal antibodies (MAbs) against enterobacterial outer membrane (OM) porin (Po) protein were isolated after immunization of BALB/c mice with whole cells of E. coli 055:B5. MAbs (n = 6) of the IgG class but of four different isotypes were studied. Based on a competition ELISA, all of the MAbs were directed against one and the same Po protein domain (Po I). The MAbs cross-reacted with 72 of 74 strains from 10 different genera of the Enterobacteriaceae. One Morganella and one Salmonella strain showed no cross-reactivity. Also, nine strains of various Neisseria spp. cross-reacted while 21 strains of various other nonenteric Gram-negative bacteria showed no cross-reactivity. The Po I sites were inaccessible in intact homologous bacteria but partially accessible in the OM. Digestion of OM with lysozyme or lysostaphin affected the accessibility of the Po I sites in OMs of various enterobacteria. Lysostaphin strongly enhanced the immunoaccessibility, whereas lysozyme had lesser effects. The enzymes also affected the binding by Neisseria OMs of the anti-Po I MAb. The Po I site was immunogenic both in humans and rabbits. The data indicate that Po I is an important Po protein domain, and that the effects of peptidoglycan-degrading enzymes must be considered in studies of Po protein domains.

Antibody response to defined domains on enterobacterial outer membrane proteins in healthy persons and patients with bacteraemia.

Monoclonal antibody (MAb)-based competitive enzyme immunoassays (cELISAs) were elaborated to measure antibodies against MAb-defined domains on three different enterobacterial outer membrane (OM) proteins in sera from healthy individuals (n = 30) and in paired serum samples from patients (n = 45) with bacteraemia caused by enterobacteria or by various nonenteric bacteria (n = 15). The MAb-defined domains were Hm I and Hm II on the heat-modifiable (Hm) protein, PALp I and PALp II on the peptidoglycan-associated lipoprotein (PALp), and BLp I on Braun's lipoprotein (BLp). All MAbs have shown broad cross-reactivity with and specificity for enterobacteria. Sera from healthy individuals and from patients with infections caused by nonenteric bacteria contained low levels of MAb-blocking antibodies. Bacteraemia caused by enterobacteria resulted in generation of antibodies against the MAb-defined domains in many of the patients. Thus, 40% and 69% showed a positive BLp I cELISA with the first and second serum samples, respectively. Of the second serum samples, 20-38% showed positive Hm and PALp cELISAs. The BLp I cELISA showed higher diagnostic sensitivity than the previously described indirect ELISA for IgG antibodies against E. coli 055 OM protein antigens. Assays using the MAbs as competitors showed that the patients bacteraemic with enterobacteria, also generated antibodies against other domains on the OM proteins. The cELISAs may be useful in the diagnosis and management of patients with serious infections caused by enterobacteria. In this regard, the BLp I cELISA showed the most promising results.

Monoclonal antibodies against three different enterobacterial outer membrane proteins. Characterization, cross-reactivity, and binding to bacteria.

BALB/c mice were immunized with whole-cells of Escherichia coli 055:B5 or Proteus mirabilis NCTC 60 to produce broadly cross-reacting monoclonal antibodies (MAbs) against outer membrane (OM) proteins. A total of 10 anti-OM MAbs of the IgG class were selected. These included 5 MAbs against the heat-modifiable (Hm) protein, 3 against the peptidoglycan-associated lipoprotein (PALp), and 2 against Braun's lipoprotein (BLp). Based on competition ELISA, the MAbs defined 2 Hm protein binding sites (Hm I and Hm II), 2 PALp sites (PALp I and PALp II), and one BLp site (BLp I). The MAbs showed broad cross-reactivity against 74 strains of 10 different genera of the Enterobacteriaceae. Non-cross-reacting enteric bacilli occurred only among bacteria of the genera Salmonella, Proteus, and Providentia. The results revealed that Proteus and Providentia strains differed from other enteric bacilli with regard to BLp synthesis or specificity. A panel of 30 non-enteric Gram-negative bacteria did not cross-react. Testing of MAb binding to bacteria showed that a part of the BLp I, PALp I, and PALp II sites was immunoaccessible in intact homologous bacteria, and that the Hm I and Hm II epitopes were inaccessible. The MAbs should facilitate studies of structure and immunobiological function of enterobacterial OM proteins and should have a potential as immunodiagnostic reagents.

Serum antibodies to outer membrane proteins of Escherichia coli in healthy persons and patients with bacteremia.

Antibodies to Escherichia coli outer membrane proteins in sera from healthy persons and from patients bacteremic with various enteric or nonenteric bacteria were measured by an enzyme-linked immunosorbent assay (ELISA). Outer membranes were prepared from E. coli O55. Serum was absorbed with E. coli O55 lipopolysaccharide and diluted 1:100 for immunoglobulin A (IgA) or IgM and 1:1,000 for IgG antibodies. Paired serum specimens were obtained from the 56 patients included in the study (the first specimen on the day of positive blood culture and the second specimen 8 to 12 days later) and compared with sera from blood donors (n = 50) as controls. On an average, the patients bacteremic with enterobacteria (n = 40) showed increased levels of antibodies of all three immunoglobulin classes in the first serum specimens and significantly higher levels in the second specimens compared with the controls, although with considerable case-to-case variation. Increased levels of IgG antibodies showed the best combination of diagnostic specificity (100%) and sensitivity (53%) for bacteremia caused by enteric bacilli. Mostly, the antibody response was directed against the major E. coli O55 outer membrane proteins at 81,000, 38,500, 33,500, and 7,500 molecular weights as shown by Western blot (immunoblot) analysis. Some of the patients bacteremic with nonenteric bacteria showed increased levels of IgA antibodies, but not of IgG or IgM antibodies. Cross-reactivity of the nonenteric blood culture isolates with the E. coli outer membrane preparation was not demonstrated. The cross-reactivity of the E. coli O55 outer membrane proteins with those of enteric bacilli of other genera was examined by absorption experiments. Western blots with serum absorbed with live E. coli O55 provided evidence that the epitopes of the outer membrane protein at 7,500 molecular weight were available for antibody binding at the bacterial surface, and that at least some of the epitopes of the 38,500- and 33,500-molecular -weight proteins were accessible to antibodies. The results suggest that an ELISA for the measurement of antibodies against cross-reactive outer membrane proteins from enteric bacilli may be useful in the diagnosis of serious infections caused by members of the family Enterobacteriaceae, and that antibodies to the major outer membrane proteins may have an immunobiological function.

The porin protein of the outer membrane of Escherichia coli: reactivity in immunoblotting, antibody-binding by the native protein, and cross-reactivity with other enteric bacteria.

The experimental conditions for antibody-binding by the 38.5 kD porin protein of an E. coli 055 strain in immunoblotting were investigated. A non-ionic detergent in the buffer which contained the primary antibody was required for antibody-binding by electroblots of the SDS-denatured protein. Immunoblotting, using antiserum absorbed with bacteria or the outer membrane (OM) of the E. coli 055 strain, showed results concordant with inaccessibility to antibodies of the 38.5 kD porin protein in its native configuration in the bacterial cells, but immunoreactivity when contained in the OM. OM from strains of different genera of the Enterobacteriaceae and antisera against these strains when used in immunoblot analyses showed that the E. coli 055 porin protein harboured antigenic determinants which are common to the various genera of the enteric bacilli. Cross-reactivity with non-enteric Gram-negative bacteria was not observed.

Immunoadsorbent-purified antibodies in the study of antigenic relatedness of outer membrane proteins of enteric bacilli.

Immunoadsorbent chromatography was used for purification of antibodies to E. coli 055 outer membrane proteins. Antibodies to the 33.5 kD and 7.5 kD proteins were eluted when rabbit antisera were applied to an epoxy-activated Sepharose 6B column to which the outer membrane was coupled in the presence of dioxane. ELISA coats prepared with sonicated bacteria showed binding of the eluted antibodies with strains of all of seven different species of the enteric bacilli, but not with other Gram-negative bacilli or cocci, or with Gram-positive cocci; immunoblot analysis of transblots of SDS-PAGE-separated bacteria showed that antibodies to both of the 33.5 kD and 7.5 kD E. coli outer membrane proteins cross-reacted with the enteric bacilli of different species. Both of the anti-33.5 kD and -7.5 kD antibodies were bound by intact E. coli 055 cells, but more efficiently by sonically disrupted or heat-treated bacteria. The results show that affinity-purified anti-OM antibodies were useful for the study of the antigenic relatedness of E. coli OM proteins with proteins of other bacteria.