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Biomedical subjects

F K Pedersen

Publications and source records attributed to F K Pedersen.

At least 55 records · Page 3Linked to original sources
PubMed1985

Immune response to pneumococcal vaccine in mothers to infants with group B streptococcal septicemia: evidence for a divergent IgG/IgM ratio.

Eight women who had given birth to infants contracting neonatal septicemia with group B streptococci (GBS) were immunized with a 14-valent pneumococcal vaccine (Pneumovax). Type-specific IgM and IgG antibodies against 6 pneumococcal types were determined before and after vaccination. Ten healthy age-matched women were also vaccinated and served as controls. The study group showed significantly higher preimmune IgM levels against 3 of the 6 pneumococcal antigens, and lower IgG levels against 1 antigen. However, 6 weeks as well as 11/2 years after the immunization, no significant differences in IgG or IgM antibody levels could be demonstrated between the 2 groups. Before vaccination, significantly more study group women showed an arbitrary IgG/IgM ratio below 10 against pneumococcal types 1, 6A, 7F, 14 and 23F. 11/2 years after vaccination, the ratio was significantly lower for antibodies against 2 other types, 6A and 7F. We suggest, as a working hypothesis, that mothers of GBS-infected infants differ in their capacity to switch from IgM to IgG production.

Antibody Formation↗
PubMed1985

HLA-B27 in juvenile chronic arthritis.

The prevalence of HLA-B27 in 88 patients with juvenile chronic arthritis was 22/88 (25%) with little variation among the 3 commonly recognized onset types. This was significantly more frequent than the prevalence of 9.4% in a Danish reference population. A strong association was found between the HLA-B27 antigen and 3 subgroups of patients: (1) boys with pauciarticular and late onset disease; (2) girls with apophyseal joint fusion; (3) a group of patients in whom the clinical picture was compatible with reactive arthritis or incomplete Reiter's syndrome. When these 3 subgroups were excluded from the total patient population, only 8 of the remaining 63 patients carried the B27 antigen, i.e., 13%, which was not significantly different from the prevalence in the reference population. Thus, the 3 subgroups account completely for the increase of B27 in the entire group of patients.

Adolescent↗
PubMed1984

Pneumococcal antibodies and complement during and after periods of recurrent otitis.

Streptococcus pneumoniae frequently accounts for acute purulent otitis media (AOM) episodes. Recurrences are common and are most often caused by pneumococci of groups 6, 19 and 23. In 15 two-year-old children with recurrent AOM ( rAOM ) complement (C) components and antibodies against various pneumococcal capsular polysaccharides were analyzed during the acute phase of an AOM episode and 6 years later. Comparison was made with findings in non-otitis-prone children of comparable age. In contrast to non-otitis-prone children, 60% of children with rAOM had no detectable IgG antibodies against the pneumococcal capsular polysaccharides 6A or 19F. Analysis of C1 subcomponent complexes together with the finding of relatively low C1q concentrations gave evidence of disturbed C1 function in the acute phase of rAOM . At the 6-year follow-up antibodies against all the investigated pneumococcal capsular polysaccharides had increased in most of the children, but low IgG antibodies to type 6A polysaccharide were still more frequently found in the former rAOM children than in non-otitis-prone children. The C profiles had normalized at follow-up. These findings indicate a reduced ability in rAOM children to respond adequately with IgG antibodies to pneumococcal types encountered in rAOM . The combination of low antibody concentrations and the interference with the complement system and efficient opsonization through classical pathway activation could possibly contribute to the development of rAOM .

Antibodies, Bacterial↗
PubMed1984

Pneumococcal antibodies in families with recurrent otitis media.

In a recent study it was found that children with recurrent acute otitis media (rAOM), in contrast to healthy children, frequently lack detectable antipneumococcal IgG antibodies against capsular types 6A and 19F. In children with rAOM, the concentrations of antibodies against type 6A polysaccharide remained low even after the period of rAOM had ceased. Antibody levels against various pneumococcal capsular polysaccharides were determined in otitis-prone and healthy members of 19 families. 25 children with a history of rAOM (mean age 7.2 years) and their parents, one of whom in each family had had rAOM during childhood, were investigated. Compared to the parents, the rAOM children had lower concentrations of IgG antibodies against the pneumococcal types 6A, 14, 19F and 23F and of IgA antibodies against type 23F. Compared to their parents, the rAOM children had higher concentrations of IgM antibodies against types 3 and 23F. 'Healthy parents' did not differ from 'rAOM parents' in IgG antibody levels against any of the pneumococcal capsular polysaccharides investigated. The findings indicate that rAOM occurs in individuals with a delayed rather than with a persisting inability to mount an adequate antibody response against the offending pneumococci.

Antibodies, Bacterial↗
PubMed1984

Opsonic and antibody responses to pneumococcal polysaccharide types 6A, 19F and 23F after vaccination of immunocompromised patients.

Opsonic and antibody responses to pneumococcal polysaccharide types 6A, 19F and 23F were evaluated before and after vaccination with a 14-valent pneumococcal vaccine in 25 patients splenectomized due to trauma, non-malignant or malignant disease and in 8 non-splenectomized patients with malignant disease. In approximately 50% of the tests, a 2-fold or greater increase in antibody concentrations and a significantly enhanced opsonization of pneumococci was found. A close correlation between antibody increase an enhancement of opsonization was demonstrated. 93% of paired samples with postimmunization antibody increase above 150 ELISA units showed significantly enhanced opsonization. Increased postvaccination opsonic activity and antibody levels were infrequently accompanied by increased granulocyte chemotactic activity of the serum. No significant difference in antibody and opsonic response to vaccination was found between the groups of patients, except for patients with Hodgkin's disease receiving chemotherapy, who had a reduced immunization response. Prevaccination antibody concentration, type of antigen or age of the patients did not influence the outcome of vaccination.

Adult↗
PubMed1983

Antibody response to pneumococcal vaccination in patients with myelomatosis.

17 patients with myelomatosis were vaccinated with a 14-valent pneumococcal capsular polysaccharide vaccine. In comparison to 12 healthy controls, they had statistically significant lower combined geometric mean antibody concentrations (the geometric means of all 14 antigens), both before and 4 weeks after the immunization. Mean antibody increases, however, were remarkably similar in the 2 groups. After 18 months the geometric mean antibody concentrations of the patient group had returned to preimmunization levels or lower for 7 out of 14 antigens. 1 case of pneumococcal bacteraemia occurred in the patient group 8 1/2 months after vaccination in spite of a significant initial antibody response against the infecting serotype 23 F. Pneumococcal vaccination in patients with myelomatosis appears to yield subnormal antibody responses and therefore probably insufficient protection against pneumococcal infection.

Aged↗
PubMed1983

Postsplenectomy infections in Danish children splenectomized 1969-1978.

During the 10-year period 1969-1978 456 splenectomies in children 0-15 years old were registered in Denmark. The underlying disease in 56% was traumatic splenic rupture, in 20% hereditary spherocytosis, in 13% idiopathic thrombocytopenic purpura and in 11% various other diseases. Three hundred and eighty-four (84%) could be followed retrospectively for a mean period of 6.2 years after splenectomy. Twenty-one (5.5%) contracted bacteraemia or meningitis, in 15 (71%) caused by Streptococcus pneumoniae, and 6 (1.6%) died from the infection. The frequency of postsplenectomy infection (PSI) was lower in children with splenic rupture (2.5%) than in those with hereditary spherocytosis (4.9%), idiopathic thrombocytopenic purpura (11.5%) and Hodgkin's disease (13.8%). Sixteen percent of children splenectomized before the age of 4 years versus 4% above that age developed PSI. Ninety-five percent of the PSI cases occurred less than 6 years after splenectomy. The incidence of severe pneumococcal bacteraemia and pneumococcal meningitis in the splenectomized was 284 times that of non-splenectomized children.

Adolescent↗
PubMed1983

Pneumococcal meningitis and bacteraemia in Danish children 1969-1978. Serotypes, incidence and outcome.

The incidence of pneumococcal meningitis in Danish children during 1969-1978 was estimated to be 2.1/year/100,000 children from 0 to 14 years old. Fifty-five per cent of 146 children with pneumococcal meningitis and 61% of 61 with bacteraemia were below 2 years of age. Mortality from meningitis was 13% and from bacteraemia 7%. Of the children with meningitis, 14% had sequelae at the time of discharge from the hospital. Sequelae were not seen after bacteraemia. Among 277 pneumococcal isolates from spinal fluid and blood from Danish children during 1969-1978, serotypes 14, 18C, 6A + 6B, 23F, 7F and 19F, in that order of frequency, were the most common ones, accounting for 69% of all isolates. Serotypes included in current 14-valent pneumococcal polysaccharide vaccines made of 80% of all types, when types 6A and 6B are considered together (because it has been shown that they offer cross-protection).

Adolescent↗
PubMed1983

Comparison of enzyme-linked immunosorbent assay and radioimmunoassay for determination of anti-pneumococcal polysaccharide antibodies.

Antibodies against pneumococcal capsular polysaccharide types 1, 3, 6A, 7F, 8 and 9N were determined before and 4 weeks after pneumococcal vaccination by both enzyme-linked immunosorbent assay (ELISA) and radioimmunoassay (RIA) in 49 children, 42 of whom had been splenectomized. Using linear regression analysis a significant correlation between total antibody concentrations determined by ELISA and RIA was found for all 6 antigens (p less than 0.001 for each). The degree of correlation varied between types, antibodies against type 3 showing the best concordance, those against type 6A the poorest. In 84% of the samples assayed both the RIA and the ELISA determined antibody concentrations were either above (55%) or below (29%) the hypothetical protective antibody concentration.

Adolescent↗
PubMed1983

Immunoglobulin classes and persistence of anti-pneumococcal antibodies in splenectomized adults and adolescents after pneumococcal vaccination.

The IgG-, IgM- and IgA- anti-pneumococcal antibody response to pneumococcal vaccination in 29 splenectomized adults and adolescents with hereditary spherocytosis or previous traumatic splenic rupture was determined by an enzyme-linked immunosorbent assay. It was not significantly different from that of 12 healthy controls except for a lower IgM class antibody increase in the splenectomized against one of four antigens studied. The antibody response was predominantly of IgG class, but significant increases in IgM and IgA class antibodies against all four antigens (polysaccharide types 2, 6A, 12F and 14) studied were observed. In 1/29 splenectomized and 2/12 healthy individuals (7%) the IgG antibody class did not predominate. In 36 adults and adolescents splenectomized due to traumatic rupture or during surgery for gastric ulcer, 77% of the peak geometric mean total antibody concentration four weeks after vaccination was still present after 21 months (16-26 months).

Adolescent↗
PubMed1983

Antibody response to pneumococcal vaccine in splenectomized children.

The antibody response, measured as total immunoglobulin, of 66 splenectomized children to a 14-valent pneumococcal capsular polysaccharide vaccine was determined by an enzyme-linked immunosorbent assay. It did not differ significantly from that of 12 non-splenectomized children for 10 of the 14 polysaccharide antigens studied, but was lower for polysaccharide types 2, 3, 8 and 12F. Significant responses of both IgG and IgM antibody against all four antigens studied were found in 10 splenectomized and against all 14 antigens in five non-splenectomized children. In 2/10 splenectomized and 1/5 non-splenectomized children the arbitrary IgG/IgM ratio was below 1 in contrast to the pattern found in the other 12 patients. The increase in anti-pneumococcal antibody after vaccination in seven non-splenectomized children receiving corticosteroid therapy was only significantly lower than that of 12 untreated non-splenectomized children against two of the 14 antigens, and similar or higher against all antigens in five splenectomized children receiving steroid therapy compared to 66 splenectomized children not receiving such therapy. In 22 splenectomized children 70% of the peak geometric mean total antibody concentration four weeks after vaccination was still present after two years. Adverse reactions to the vaccine included local reactions at the vaccination site in 56% and fever in 9%. Side-effects were correlated to the geometric mean concentration of total antibody present at the time of vaccination. Immunogenicity of each of the 14 vaccine antigens varied considerably, as did the responses of different individuals.

Adolescent↗
PubMed1982

Concanavalin-A-activated suppressor cells in patients with juvenile rheumatoid arthritis.

Concanavalin-A-induced suppressor cell activity was investigated in 63 patients with a definite diagnosis of juvenile rheumatoid arthritis. Peripheral blood lymphoid cells from these patients did not have the same ability as cells from normal individuals to suppress the proliferative response of autologous cells, responding to phytohaemaglutinin, Candida albicans antigen, or allogeneic cells. No correlation was found between suppressor activity, disease activity, or number of joints involved. Nor was there any significant association between decreased suppressor cell activity and HLA-A, -B, -C, -D antigens, although there was a tendency towards association between decreased suppressor cell activity and HLA-B27.

Adolescent↗
PubMed1982

Antibody response to vaccination with pneumococcal capsular polysaccharides in splenectomized children.

In 67 splenectomized children vaccinated with a 14-valent pneumococcal capsular polysaccharide vaccine an antibody fold increase above 2 from pre- to postvaccination samples was found in 60% of all single type antibody determinations performed. The vaccine may only afford protection against 55% of those serotypes that cause serious infections in children, assuming a protective antibody level of 300 ng antibody N/ml. Our results indicate a somewhat reduced antibody response to pneumococcal vaccine in splenectomized children and suggest that pneumococcal vaccination may not be relied upon as the only kind of prophylaxis against pneumococcal infection in this patient group.

Adolescent↗