Pneumococcal Antibody Concentrations Research Articles

Minimum protective serum concentrations of pneumococcal anti-capsular antibodies in infant rats.

Infant rats were passively immunized to determine the protective capacity of pneumococcal anticapsular antibodies. Animal-passaged strains of Streptococcus pneumoniae serotypes 1, 4, 5, 6b, 7f, 9v, 14, 18c, 19f, and 23f were used as challenge inocula (1-1500 cfu) in a model of pulmonary infection that resulted in bacteremia, meningitis, and death. From untreated control animals, histologic sections of lung demonstrated infiltrative pneumonia and lung homogenate cultures grew S. pneumoniae at concentrations of 10(3)-10(8) cfu per gram of lung tissue. A type-specific anti-capsular antibody serum concentration of 0.1-1.15 microg/mL resulted in a statistically significant reduction in mortality compared with the reduction in untreated controls, except for serotype 14, which required 2.32 microg/mL for a significant reduction in mortality. The serum antibody level that provided 50% reduction in mortality ranged from 0.1-3.5 microg/mL for all serotypes.

IgG subclass specific antibody response in recurrent bronchitis.

The IgG subclass specific immune response against pneumococcal type 3 polysaccharide antigen before and after immunisation in healthy children and children with recurrent bronchitis was studied. Recurrent bronchitis was defined as three or more episodes a year, during at least two consecutive years, of bronchopulmonary infection, productive cough with or without fever, and/or diffuse rales by physical examination. Twenty five patients and 15 healthy children were selected. The patient group had lower concentrations of IgG1 and IgG2 specific pneumococcal antibodies compared with healthy children, regardless of whether or not the total IgG2 concentration was low. The children with recurrent bronchitis showed a greater increase in IgG1 and IgG2 antibodies after immunisation than the controls. It is concluded that children with recurrent bronchitis show a decreased humoral immune response to pneumococcal type 3 polysaccharide antigen. This finding suggests that a defect in the humoral immune response against polysaccharide antigens is an important cause of recurrent bronchitis in childhood.

Antibody Response to Pneumococcal Vaccination in the Elderly

In order to evaluate the antibody response to primary pneumococcal vaccination in the elderly, 20 healthy persons aged 60 years or older, (mean age 62.8) were vaccinated with a 23-valent pneumococcal polysaccharide vaccine (Pneumovax 23). Blood samples were taken before and 4 weeks after vaccination and pneumococcal antibody concentrations were measured by ELISA and compared with those obtained after vaccination of younger persons (mean age 39 years). Significantly lower anti-type 2 antibody concentrations were found in the elderly after vaccination. Apart from this, no other significant differences were found neither in pre- and post-vaccination antibody concentrations nor in antibody fold increases between the two groups.

Pneumococcal Anticapsular Antibodies in Patients with Chronic Cardiovascular and Obstructive Lung Disease in the Netherlands

Differences in pneumococcal anticapsular antibody concentrations were assessed among patients with various chronic disorders and among young (25-35 years of age) and older adults (55-65 years). Antibody concentrations were determined by ELISA, using the whole 23-valent pneumococcal polysaccharide vaccine as antigen. No differences in mean or distribution of serum antibody concentrations were found among young adults (either healthy or asthmatic) or among older adults (healthy or with chronic obstructive pulmonary or chronic cardiovascular disease). Each group included individuals with low antibody levels. Therefore, the enhanced susceptibility to pneumococcal infections reported for some groups at risk, that is, elderly individuals and patients with chronic obstructive pulmonary or chronic cardiovascular disease, cannot be attributed solely to low anticapsular antibody concentrations.

Pneumococcal revaccination of splenectomized children

Forty-three Danish splenectomized children received a single subcutaneous dose of a 14-valent pneumococcal vaccine (Pneumovax 23; Merck). Blood samples were taken before, 4 weeks after and 5 years after vaccination. Total pneumococcal antibody concentrations as well as antibodies against each of the 14 pneumococcal capsular polysaccharide antigens were measured by the enzyme-linked immunosorbent assay method. Depending on the pneumococcal antibody status 5 years after primary vaccination, the children were either revaccinated with a new 23-valent pneumococcal vaccine or scheduled for reexamination later. The antibody concentrations found 5 years after vaccination showed a strong correlation with the prevaccination antibody concentrations. Revaccination of children with low antibody concentrations 5 years after primary vaccination is safe, is without significant side effects and leads to a satisfactory antibody response.

Antibody Persistence in Splenectomized Adults after Pneumococcal Vaccination

16 splenectomized adults, all vaccinated with a 14-valent pneumococcal vaccine (Pneumovax) 1978-79 had their pneumococcal antibody concentrations measured before and up to 10 years after vaccination. The antibody concentrations after vaccination declined to 71% in 2 years and remained at this level during the 10-year study period. Further studies are needed to see whether this applies to all vaccinated splenectomized adults.

Pneumococcal antibody concentrations in young Papua New Guinean Highland children with pneumonia.

The incidences and case-fatality rates from pneumonia in young children are much higher in Papua New Guinea than in developed countries. The most significant etiologic pathogens are Streptococcus pneumoniae and Haemophilus influenzae. The purpose of this study was to determine whether young PNG children have any abnormality of immune function which could predispose them to pneumonia. Pneumococcal antibody concentrations in pneumonia patients were compared with those in age-matched healthy Papua New Guinean and expatriate controls living in the same area

Pneumococcal serum antibody concentrations during the first three years of life: a study of otitis-prone and non-otitis-prone children

One hundred and thirteen children were followed prospectively from birth until the age of 3, serum being obtained from cord blood, and at the ages of 3, 6, 12, 18, 24, 30 and 36 months. Thirteen children developed recurrent acute otitis media (rAOM), 29 remained very healthy and the remaining children formed an intermediate group. Cord serum concentrations were determined of total IgG class, of IgG 1 and IgG 2 subclasses, as well as of specific IgG antibodies against the pneumococcal capsular types, 3, 6A and 19F. The specific pneumococcal IgG as well as IgA and IgM antibodies were also followed in the sequential serum samples up to the age of 3 in the rAOM and healthy children. Despite total IgG class and IgG 1 and IgG 2 subclass concentrations being of the same magnitude in cord serum of rAOM (median: 11.15, 7.48 and 2.16 g/l for IgG, IgG 1 and IgG 2, respectively) as in that of healthy children (median: 10.21, 8.16 and 2.16 g/l, respectively), both in cord serum and in most serum samples drawn during the first year of life, specific IgG antibodies against types 6A and 19F, but not against type 3, were significantly lower in the rAOM group than in the healthy children. In the intermediate group, cord serum concentrations of specific IgG antibodies to type 6A were of the same magnitude as in the healthy children. The only significant difference in specific IgM and IgA antibody concentrations against types 3, 6A and 19F between the two groups was noted for type 6A antibodies at 36 months of age where rAOM children exhibited lower values. The results indicate an association between pre-existing low specific IgG antibody levels against AOM-associated pneumococcal types and the development of rAOM.

Increased serum opsonic activity and antibody concentration in patients with sickle cell disease after pneumococcal polysaccharide immunization

Opsonic defects have been reported in unimmunized patients with sickle cell disease. We found significant increases (P less than 0.001) in serum opsonic activity, measured by a radiolabeled bacterial uptake assay, and in type 7 pneumococcal polysaccharide antibody concentration in 17 such patients 2 years of age or older after pneumococcal polysaccharide immunization. All 17 patients and six healthy controls achieved a type 7 antibody concentration of more than 300 ng antibody nitrogen per milliliter, believed to be the protective level of antibody in vivo. Six patients with sickle cell disease less than 2 years of age did not have a significant increase in type 7 antibody concentration after immunization. Only three of these six patients achieved a postimmunization type 7 antibody concentration exceeding 300 ng Ab N/ml. Overall, 16 of 23 patients with sickle cell disease (70%) had a twofold or greater increase in type 7 antibody concentration, and 13 of these (81%) had a corresponding increase in opsonic activity (P less than 0.001). Thus most patients who responded to pneumococcal polysaccharide immunization had a concurrent increase in opsonic activity in vitro.

Serum Antibody Response to Pneumococcal Vaccine in Children with Nephrotic Syndrome

Children with nephrotic syndrome are susceptible to serious pneumococcal disease and may be immunodeficient on the basis of abnormal humoral immune responses to natural antigens or immunoglobulin loss during relapse. As part of an ongoing study to evaluate pneumococcal anticapsular antibody concentration and immunologic competence, 27 steroid-responsive and six steroid-resistant patients with nephrotic syndrome, and 12 age-matched control subjects, were vaccinated with polyvalent pneumococcal vaccine. Antibody responders were defined as patients with at least a twofold increase in antibody after vaccination as well as an antibody concentration greater than 200 ng of anticapsular antibody nitrogen per milliliter (ngN/ml) after vaccination. Pneumococcal antibody concentrations before and after vaccination were significantly depressed in steroid-resistant patients when compared with control subjects (P less than .002) and with the steroid-responsive nephrotic syndrome group (P less then .001). Steroid-responsive nephrotic children who were not receiving corticosteroid therapy at the time of vaccination had significantly higher antibody concentrations to five pneumococcal types before vaccination and to seven types after vaccination compared with control subjects (P less than .05). Fewer steroid-responsive patients receiving corticosteroids achieved antibody concentrations greater than or equal to 200 ngN/ml against type 19F compared with patients not receiving steroids or with control subjects (P less than .05). These results suggest that pneumococcal vaccine is immunogenic in children with steroid-responsive nephrotic syndrome and may protect these patients from disease due to pneumococcal types contained in the vaccine.