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Biomedical subjects

Sven-Arne Silfverdal

Publications and source records attributed to Sven-Arne Silfverdal.

6 recordsLinked to original sources

Mycoplasma pneumoniae and Legionella pneumophila in community-acquired lower respiratory tract infections among hospitalized children: diagnosis by real time PCR.

Mycoplasma pneumoniae and Legionella pneumophila are increasingly recognized as important agents of community-acquired lower respiratory tract infections (LRTI). Mycoplasma pneumoniae has been also recognized as a cause of nosocomial infections. The aim of this study was to investigate the role of real time polymerase chain reaction (PCR) for the rapid diagnosis of these infections among hospitalized children with community-acquired LRTI. During 2001, 65 children were prospectively studied. Microbiological investigation consisted of capillary PCR with a LightCycler for M. pneumoniae and L. pneumophila in induced sputum or throat swab specimens, IgM enzyme immunoassay for M. pneumoniae and immunofluorescence for L. pneumophila in paired sera. Serology testing showed acute M. pneumoniae infection in 18 (27.5%) patients and L. pneumophila in 1 (1.5%). M. pneumoniae was also detected in sputum specimen by capillary PCR in 9 (50%) serologically diagnosed cases, including 4 (22%) with non-diagnostic IgM levels in the acute phase. Capillary PCR and IgM enzyme immunoassay diagnosed together 15 (83%) M. pneumoniae cases in the acute phase. It is concluded that M. pneumoniae is an important cause of LRTI necessitating hospitalization among children in Greece. Capillary PCR in sputum may diagnose M. pneumoniae LRTI in the acute setting and direct therapy and isolation of patients.

Adolescent↗

The transfer of immunity from mother to child.

The newborn's immune system grows fast from a small size at birth by exposure primarily to the intestinal microflora normally obtained from the mother at and after birth. While building up its immune system, the infant is supported by the transplacental IgG antibodies, which also contain anti-idiotypic antibodies, possibly also actively priming the offspring. The second mode of transfer of immunity occurs via the milk. Numerous major protective components, including secretory IgA (SIgA) antibodies and lactoferrin, are present. The breastfed infant is better protected against numerous common infections than the non-breastfed. Breastfeeding also seems to actively stimulate the infant's immune system by anti-idiotypes, uptake of milk lymphocytes, cytokines, etc. Therefore, the breastfed child continues to be better protected against various infections for some years. Vaccine responses are also often enhanced in breastfed infants. Long-lasting protection against certain immunological diseases such as allergies and celiac disease is also noted.

Female↗

Long term enhancement of the IgG2 antibody response to Haemophilus influenzae type b by breast-feeding.

SUBJECTS: Sets of sera were obtained from 30 children <6 years of age with invasive type b (Hib) infection and their mothers. Duration and mode of breast-feeding were monitored. Titers of IgG1, IgG2, IgA and IgM antibodies against Hib capsular polysaccharide were determined in sera taken during the acute illness and during early and late convalescence. RESULTS: Children 18 months or older with longer durations of exclusive breast-feeding (13 weeks or more; mean, 19.3 weeks) had higher Hib antibody concentrations of the IgG1, IgG2, IgA and IgM isotypes than those with a shorter duration of exclusive breast-feeding (<13 weeks; mean, 5.4 weeks). The difference was greatest for the IgG2 isotype. In regression analyses the association between the duration of exclusive breast-feeding and the anti-Hib IgG2 concentration was significant when breast-feeding, type of Hib infection, maternal Hib antibody titer and age were used as explanatory factors. In the group of 14 children <18 months of age no significant differences were noted. DISCUSSION: This study indicates the presence of a long lasting enhancing effect of breast-feeding on the antibody response to Hib in children, in particular on IgG2 Hib antibody production. This may result from the content in the milk of IFN-gamma and IFN-gamma-producing cells and possibly other factors, which can support IgG2 antibody production.

Age Factors↗

Breast-feeding, a complex support system for the offspring.

The newborn has an immune system, very limited in size at birth and its postnatal expansion and maturation takes time. In the meantime the transplacental IgG antibodies from the mother play an important role for the protection of the infant. However, these antibodies act in tissues and induce inflammation and are energy-consuming. In contrast, the milk secretory IgA antibodies stop microbes already on the mucosa preventing infection, tissue engagement and energy loss. In addition, the milk contains many protective factors such as lactoferrin and oligosacharides functioning as analogues for microbial receptors preventing mucosal attachment, the initial step of most infections. As a result, breast-feeding significantly reduces the risk of neonatal septicemia, respiratory tract infections, otitis media, diarrhea, urinary tract infections, infection-induced wheezing and necrotizing enterocolitis. Via several mechanisms it seems that human milk can actively stimulate the immune system of the breast-fed infant. This reduces the risk of infections like otitis media, respiratory tract infections, diarrhea and infection-induced wheezing for several years after the termination of breast-feeding. Furthermore, it seems that breast-feeding decreases the risk of attracting celiac disease and allergic diseases. The latter has been much debated, but a recent critical review of published reports gives good support for long-term protection of allergic diseases, especially in high-risk children.

Breast Feeding↗