Immune response capacity after human splenic autotransplantation: restoration of response to individual pneumococcal vaccine subtypes.
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OBJECTIVE: To evaluate features of general immune function, in particular the restoration of the humoral immune response to pneumococcal capsular polysaccharides, in humans undergoing a spleen autotransplantation after splenectomy because of trauma. SUMMARY BACKGROUND DATA: After splenectomy, patients have an increased risk of overwhelming infection or sepsis involving encapsulated bacteria such as pneumococci. The value of human spleen autotransplantation after splenectomy because of trauma has long been questioned. Mononuclear phagocyte system function appeared to be similar to that in splenectomized persons. The presence of specific antipneumococcal antibodies would allow other parts of the mononuclear phagocyte system, such as those in the liver, to phagocytose opsonized bacteria. METHODS: Ten consecutive patients undergoing splenectomy followed by autotransplantation were compared with the next 14 consecutive patients undergoing splenectomy alone. After a minimum of 6 months, the patients were vaccinated with 23-valent pneumococcal vaccine. Blood samples were taken at the time of vaccination and after 3 and 6 weeks for antipneumococcal capsular polysaccharides IgM and IgG enzyme-linked immunosorbent assay against types 3, 4, 6, 9, 14, and 23. Splenic regrowth was evaluated by scintigraphy. RESULTS: Surprisingly, several of the nonautotransplanted patients showed scintigraphic activity, indicating the presence of either accessory spleens or traumatic seeding (splenosis). Significant antibody titer increases (more than twofold) were found for both IgM and IgG in the autotransplanted patients. Splenectomized-only patients showed no significant increase in Ig levels in patients without splenic regrowth and partial improvement in patients with splenosis/accessory spleens. CONCLUSIONS: Considering this significant antipneumococcal antibody increase, spleen autotransplants can be expected to permit an adequate humoral response to pneumococcal infections and presumably also to other TI-2 antigens, and to protect against overwhelming postsplenectomy infection or sepsis. (+info)
Paediatric, invasive pneumococcal disease in Switzerland, 1985-1994. Swiss Pneumococcal Study Group.
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BACKGROUND: Cost effective use of new vaccines against pneumococcal disease in children requires detailed information about the local epidemiology of pneumococcal infections. METHODS: Data on 393 culture-confirmed cases of invasive pneumococcal infection in children (<17 years) hospitalized in Swiss paediatric clinics were collected retrospectively for the years 1985-1994. RESULTS: Meningitis (42%) was most frequent, followed by pneumonia (28%) and bacteraemia (26%). The overall annual incidence was 2.7 cases per 100000 children <17 years old and 11 cases per 100000 children <2 years old. Annual incidence rates were stable over the study period. Lethality was high for meningitis (8.6%) and bacteraemia (8.9%). A history of basal skull fracture was reported in 3.3% of children with pneumococcal meningitis. Residence in a rural region was associated with an increased risk of pneumococcal infection (relative risk = 1.45, 95% confidence interval: 1.01-2.00). CONCLUSIONS: Paediatric, invasive pneumococcal disease seems to be less frequent in Switzerland than in other European and non-European countries. This may be due to differences in diagnostic strategies and lower frequency of risk factors such as the use of day care. Children with a history of basal skull fracture are at increased risk for pneumococcal meningitis. Further investigation of the association of invasive pneumococcal infection with rural residence and the use of antibiotics for upper respiratory tract infections might give new insight into the dynamics of Streptococcus pneumoniae infection and the development of antibiotic resistance. (+info)
Repertoire of human antibodies against the polysaccharide capsule of Streptococcus pneumoniae serotype 6B.
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We examined the repertoire of antibodies to Streptococcus pneumoniae 6B capsular polysaccharide induced with the conventional polysaccharide vaccine in adults at the molecular level two ways. In the first, we purified from the sera of seven vaccinees antipneumococcal antibodies and determined their amino acid sequences. Their VH regions are mainly the products of VH3 family genes (candidate genes, 3-23, 3-07, 3-66, and 3-74), but the product of a VH1 family gene (candidate gene, 1-03) is occasionally used. All seven individuals have small amounts of polyclonal kappa+ antibodies (Vkappa1 to Vkappa4 families), although kappa+ antibodies are occasionally dominated by antibodies formed with the product of the A27 Vkappa gene. In contrast, lambda+ anti-6B antibodies are dominated by the antibodies derived from one of 3 very similar Vlambda2 family genes (candidate genes, 2c, 2e, and 2a2) and Clambda1 gene product. The Vlambda2(+) antibodies express the 8.12 idiotype, which is expressed on anti-double-stranded-DNA antibodies. In one case, Vlambda is derived from a rarely expressed Vlambda gene, 10a. In the second approach, we studied a human hybridoma (Dob1) producing anti-6B antibody. Its VH region sequence is closely related to those of the 3-15 VH gene (88% nucleotide homology) and JH4 (92% homology). Its VL region is homologous to the 2a2 Vlambda2 gene (91%) and Jlambda1/Clambda1. Taken together, the V region of human anti-6B antibodies is commonly formed by a VH3 and a Vlambda2 family gene product. (+info)
Previous respiratory tract infections and antibiotic consumption in children with long- and short-term carriage of penicillin-resistant Streptococcus pneumoniae.
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Previous respiratory tract infections (RTI) and antibiotics consumption as possible risk factors for extended duration of PRP carriage were investigated in 24 children (cases) with previous carriage of penicillin-resistant pneumococci (PRP) for a duration exceeding 120 days (median 168 days) and a control group of 53 children with a duration of PRP carriage less than 90 days (median 21 days). The cases had experienced 0.99 episodes of acute otitis media (AOM) per life-year compared to 0.79 episodes in the controls (P = 0.32). For antibiotic-treated RTI other than AOM, the corresponding numbers were 0.49 and 0.29 episodes per life-year, respectively (P = 0.01). No differences in antibiotic consumption in the 3 months preceding the carriage, nor during the carriage period were noted. Other factors than impaired host defence to respiratory tract pathogens or antibiotics consumption seem to be more important in determining the duration of PRP carriage. (+info)
Pneumococcal psoas abscess.
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A 47-year-old woman was admitted to our hospital because of severe low back pain. A computed tomography (CT) scan revealed a left sided psoas muscle abscess. On the first hospital day, US-guided drainage was performed. Streptococcus pneumoniae was isolated from the pus. Thereafter, the open drainage of the abscess and antibiotic treatment were given with subsequent clinical improvement. Only 10 cases of pneumococcal psoas abscess have been previously reported in the world literature. (+info)
Increased activity of 16-membered lactone ring macrolides against erythromycin-resistant Streptococcus pyogenes and Streptococcus pneumoniae: characterization of South African isolates.
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The susceptibility of 40 erythromycin-resistant isolates of Streptococcus pyogenes and 40 multiply-resistant isolates of Streptococcus pneumoniae to six macrolide antibiotics, representing 14-, 15- and 16-membered lactone ring structures, was tested. The genetic basis for macrolide resistance in the strains was also determined. Both erm and mef determinants were encountered in the 36 S. pneumoniae isolates tested, but only mef in the five S. pyogenes isolates tested. All isolates showed cross-resistance among the 14-membered macrolides erythromycin, clarithromycin and roxithromycin and the 15-membered macrolide, azithromycin. However, the erythromycin-resistant S. pyogenes isolates retained full susceptibility to spiramycin and josamycin (16-membered agents). These latter two antibiotics were also more active than the other macrolides against erythromycin-resistant S. pneumoniae isolates, especially josamycin which was 8-64 times more active than erythromycin; spiramycin was only two to eight times more active than erythromycin. (+info)
Moxifloxacin: a comparison with other antimicrobial agents of in-vitro activity against Streptococcus pneumoniae.
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Two hundred representative isolates, including 26 strains of Streptococcus pneumoniae with intermediate resistance to penicillin, were selected from a collection obtained from blood cultures of patients with bacteraemic pneumococcal pneumonia. The MICs of moxifloxacin (BAY 12-8039), grepafloxacin, sparfloxacin, levofloxacin, ofloxacin, ciprofloxacin, erythromycin, tetracycline and penicillin G were determined by a standard agar dilution technique. Moxifloxacin had the highest in-vitro activity against S. pneumoniae (MIC90 = 0.25 mg/L; MIC range 0.06-0.25 mg/L). The MIC90 values were one dilution lower than those obtained with sparfloxacin and grepafloxacin, three dilutions lower than those obtained with levofloxacin, and four dilutions lower than those of ofloxacin and ciprofloxacin. (+info)
Maternal immunization.
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Maternal immunization can enhance passive immunity of infants to pathogens that cause life-threatening illnesses. In most instances, immunization during pregnancy will provide important protection for the woman as well as for her offspring. The tetanus toxoid and influenza vaccines are examples of vaccines that provide a double benefit. Other vaccines under evaluation include those for respiratory syncytial virus, pneumococci, group B streptococci, and Haemophilus influenzae type b. Although most IgG antibody crosses the placenta in the third trimester, the process is time-dependent, dictating that immunization should be accomplished ideally at least 6 weeks prior to delivery. IgG1 antibodies are transferred preferentially. Maternal immunization has not interfered with active immunization of the infant. Inactivated vaccines administered in the third trimester of pregnancy pose no known risk to the woman or to her fetus. (+info)