No abstract

The effects of partially purified human leucocyte interferon (PIF) and of a preparation purified by passage twice through a monoclonal antibody affinity chromatography column (NK2EF) were compared with those of a control solution in healthy volunteers. After intramuscular injections both interferon preparations caused rises in pulse rate and body temperature, changes in circulating white cell counts, and various unpleasant symptoms, the most common of which were headache, malaise, and fever. Slightly lower doses of NK21F were given, and this was reflected in lower peak serum concentrations. Mean symptom scores, however, were not lower after NK2IF than after PIF. Local inflammatory reactions eight hours after intradermal inoculations of these interferons were similar.Purification of interferon using a monoclonal antibody does not reduce the facets of its activity considered in this study. They are therefore inherent in the leucocyte interferon type selected by the antibody.

An enzyme-linked immunosorbent assay (ELISA) was developed for diagnosing human coronavirus (HCV) infections in children. One hundred and seventy seven nose swabs, throat swabs, and nasopharyngeal aspirates were collected from 30 children suffering from acute respiratory infections. These samples were tested for HCV antigens by ELISA and 28.2% of the samples were shown to be HCV positive. These results indicate that our ELISA should prove useful in the diagnosis of HCV infections in children. Further studies are in progress to extend the ELISA to detect HCVs in experimentally and naturally acquired infections in adults.

Specimens from a total of 162 patients were studied prospectively using a rapid nucleic acid synthesis inhibition assay and a plaque-reduction assay to detect interferon levels in serum and cerebrospinal fluid. The specificity, consistency, and diagnostic applications of the rapid assay were evaluated by intensively investigating each patient for possible viral illness. Forty-one percent of patients with proven acute virus infections (excluding those with acute hepatitis and infectious mononucleosis) had unequivocal detectable interferon in serum or cerebrospinal fluid, compared with only two patients with bacterial infections (7%) who had equivocal interferon in the serum. Retrospective analysis showed the test to have high specificity for virus infections, but in patients with clinical syndromes of uncertain aetiology the test was not a particularly sensitive indicator of the presence of subsequently detected virus. The presence of interferon was not related to the time during the illness at which the sample was taken, nor to the numbers of lymphocytes in the cerebrospinal fluid, nor to the patients' general symptoms.