Interferon in nasal secretions from infants with viral respiratory tract infections

Interferon levels in nasal secretions of infants under one year of age, and hospitalized with lower repiratory tract disease, were measured during two respiratory infection seasons. In the first year serial secretions from 50 infants with respiratory syncytial virus infection were examined. Undetectable or low levels of interferon were found in all samples, and mean levels did not fluctuate significantly in relation to disease and recovery. This was in contrast to anti-RSV IgA, which appeared and increased in concentration as virus shedding decreased and stopped. In the second year secretions were obtained from nine infants with influenza A virus infection as well as from 13 with RSV. All those with influenza developed measurable interferon in secretions (geometric mean titer 138 units/ml), which was acid and heat stable, and trypsin sensitive (type I interferon). RSV infection again stimulated very low levels (geometric mean 5 units/ml). The lack of correlation of interferon concentration with cessation of RSV shedding suggests either that it is not involved in recovery or that low levels are adequate. On the other hand, it appears that the young infant is fully capable of a brisk local interferon response, at least to infection by influenza A.     

Cystic fibrosis and malnutrition.

Cystic fibrosis as a specific disease entity has been known to be associated with malnutrition for almost half a century. The importance of the malnutrition in the disease process remains unknown, as does much information about specific nutritional deficiencies in CF. Supplements for children with CF should include extra energy as fat or carbohydrate, a form of linoleic acid that can be absorbed, hydrolyzed protein, fat-soluble vitamins with vitamins A and E in a water emulsion, vitamin B12, probably B vitamins and vitamin C, and trace minerals. Routine measurements of nutritional status, particularly in children with growth failure, should be made at regular intervals and should include a three-day diet record and a simultaneous 72-hour stool fat determination. If fat malabsorption is not controlled by pancreatic enzymes, the use of antacids or cimetidine should be considered. The true role of nutrition in patients with CF will not be known until the appropriate studies are completed.