Search PubMed⌕ Search

Biomedical subjects

O Meurman

Publications and source records attributed to O Meurman.

At least 73 records · Page 4Linked to original sources

Comparison of a simple latex agglutination test with hemolysis-in-gel, hemagglutination inhibition, and radioimmunoassay for detection of rubella virus antibodies.

Rubella virus antibodies were measured in 300 sera from pregnant women visiting a maternity center by using a new, simple latex test, Rubalex. The results were compared with those obtained by using hemolysis in gel, hemagglutination inhibition, and radioimmunoassay. The sensitivity of the latex test was 100, 98.0, and 99.6% when compared with hemolysis in gel, hemagglutination inhibition, and radioimmunoassay, respectively. Its comparative specificity was 96.2, 95.7, and 90.7%, and the predictive value of a positive result was 99.2, 99.2, and 98%, respectively. When assayed with the British standard anti-rubella serum its sensitivity was 11 IU/ml. The latex test gave a positive result within 2 min, and 87% of the positive samples had already reacted after 1 min. The negative results remained as such for at least 8 min. No prozone effect was observed for sera with hemagglutination inhibition titers from 256 to 2,048. We concluded that the latex test, Rubalex, was readily applicable for measuring rubella immunity with a reaction time of 2 min in undiluted samples.

Antibodies, Viral↗

Detection of specific immunoglobulin M antibody to rubella virus by use of an enzyme-labeled antigen.

A direct antibody capture enzyme immunoassay (EIA) for the detection of rubella-specific immunoglobulin M (IgM) antibody was developed. Polystyrene microtiter strips coated with rabbit anti-human IgM were used as solid phase, and a semipurified rubella antigen labeled with horseradish peroxidase was used as indicator. By testing a panel of 238 serum specimens (not including sera from newborns with congenital rubella), the direct EIA was compared with the indirect EIA used routinely in our diagnostic unit and with a commercial IgM capture EIA (RubEnz M II) that employs a horseradish peroxidase-labeled anti-rubella monoclonal antibody as indicator. Overall agreement of direct EIA with indirect EIA and RubEnz M II was 95%, whereas agreement between direct and indirect EIA was 96.2%, and agreement between direct EIA and RubEnz M II was 97.8%. Sensitivity of the direct assay was higher than that of the indirect EIA and similar to that of the RubEnz M II assay. Specific IgM antibody could always be detected in serum specimens taken from patients with primary acute rubella infection between days 4 and 56 after the onset of rash. The assay was highly specific, and it was not affected either by rheumatoid factor or by high levels of specific IgG in sera. Another important advantage that the direct EIA has over the indirect EIA is that it requires 10 to 20 times less antigen per serum specimen tested.

Antibodies, Viral↗

Sensitive enzyme immunoassay for detecting immunoglobulin M antibodies to Sindbis virus and further evidence that Pogosta disease is caused by a western equine encephalitis complex virus.

An antibody capture enzyme immunoassay (EIA) was adapted for the detection of immunoglobulin M (IgM) antibody to Sindbis (SIN) virus. Sera from humans with a febrile illness characterized by rash and arthralgia in eastern Finland (Pogosta [POG] disease) and Sweden (Ockelbo disease) and from humans with western equine encephalitis (WEE) virus infection in the United States were tested for IgM antibodies by EIA. Seroconversions were documented in patients with POG disease and with WEE virus infections by using SIN virus as antigen and rabbit anti-SIN virus immunoglobulin; this confirms previous observations that POG disease is caused by a virus closely related to SIN virus and that IgM antibodies to WEE complex alphaviruses are not type specific. This IgM EIA provided a sensitive diagnostic and research tool applicable to epidemiologic problems posed by POG disease.

Antibodies, Viral↗

Antibody response to respiratory syncytial virus structural proteins in children with acute respiratory syncytial virus infection.

The purified respiratory syncytial virus (RSV), Randall strain contained 10 polypeptides (72,000 molecular weight [72K], 66K, 48K, 42K, 40K, 36K, 30K, 23K, 18K, and 15K), 8 of which proved to be virus specific, and polypeptides 48K and 23K were glycosylated. In addition, a high-molecular-weight (150K), virus-specific glycopolypeptide was immunoprecipitated from RSV-infected cell lysate. The antibody response in human sera serially collected from children with primary RSV infection was mainly directed against the polypeptides 30K, 48K, and 72K. The immune response against the other viral proteins was also already detectable in the acute-phase sera. These results indicate that the immune response in RSV infection differs significantly from those for other diseases caused by paramyxoviruses.

Acute Disease↗

Adenoviral diseases in children: a study of 105 hospital cases.

The clinical findings for 105 children hospitalized with adenoviral infection were studied prospectively. In 82 children, the diagnosis was based on the detection of adenovirus antigen in the nasopharyngeal specimens and in 17 children in the feces. In the remaining six patients, findings from nasopharyngeal specimens were negative but a significant increase in CF (complement fixation) titers was detected. The clinical picture of adenoviral infection was characterized by high-grade (mean 39.4 degrees C) and prolonged fever (mean duration 5.4 days). Tonsillitis, otitis, and gastroenteritis were the most common illnesses. In 17% of the patients, no identifiable focus of infection could be demonstrated; nine children with no identifiable focus of infection had febrile convulsions. The WBC count and ESR varied from normal values to values seen in bacterial infections; thus it was difficult to distinguish adenoviral disease from a bacterial disease. Forty-five children were referred to the hospital due to infection unresponsive to antimicrobial therapy. The rapid detection of adenovirus antigen in nasopharyngeal specimens or feces proved to have a great clinical value in the diagnosis of adenoviral infections.

Adenoviridae Infections↗

Altered hemolysis in single radial hemolysis from a single serum sample as an indicator of recent primary rubella virus infection.

The quality of hemolysis in the single radial hemolysis (SRH) test was observed to be altered in a small proportion (5.7%) of sera (N = 9628) studied for rubella rubella antibodies. Three different types of altered hemolysis were identified. Two of these types, the "soft margin" (SM) or the "soft zone" (SZ), occurred singly or in combination in 97% of paired sera (N = 321) taken 3-30 days after primary rubella infection (diagnostic seroconversion). For comparison, diagnostic increases of rubella antibodies (N = 77), including both primary and reinfections, contained these types of altered hemolysis in 80% of the cases. Of the remaining 20% of the samples (N = 15), rubella antibodies of IgM class were looked for in seven cases but not found. After primary rubella, SZ was always present in the first serum sample and disappeared rapidly within 20 days while SM persisted longer. The predictive value of the different types of hemolysis was estimated from 96 primary sera, which had altered hemolysis. In this material, SZ was followed by a diagnostic increase of antibodies in 87% of the cases; the prognostic value of the SM was significant but lower. These data show that the appearance of SM or SZ in a single serum sample is a useful marker of recent primary rubella. On the other hand, a normal hemolysis in SRH can be used to exclude recent primary rubella, but not reinfection, with a high degree of probability.

Antibodies, Viral↗

Diagnosis of respiratory syncytial virus infection in children: comparison of viral antigen detection and serology.

Direct detection of viral antigen in nasopharyngeal secretion by radioimmunoassay was compared with serology by IgG antibody enzyme immunoassay for diagnostic efficacy in 77 children with clinically suspected respiratory syncytial virus (RSV) infections. Antigen detection gave a positive diagnosis in 26 of 33 (79%) children in whom RSV infection was diagnosed by any of the two methods. The diagnostic efficacy of antigen detection was dependent upon the interval after onset at which specimens were collected; 88% of specimens taken during the first 5 days and 50% of specimens taken 6-10 days after onset of illness were positive. It was also dependent on the age of the patients, the diagnostic efficacy being 88 and 76% in children under and over 6 months of age, respectively.

Antigens, Viral↗

Immunoglobulin class-specific antibody response in respiratory syncytial virus infection measured by enzyme immunoassay.

Immunoglobulin class-specific enzyme immunoassay (EIA) was used for determination of antibody responses in sera collected from 26 children with acute primary respiratory syncytial virus (RSV) infections. All 26 patients had IgG antibody responses with a significant titer increase in 24 (92%); an IgM antibody response was detected in 19 of the 26 (73%). From patients aged 6 months or less only 5 of 8 produced detectable IgM antibodies, whereas all patients aged 1-2 years did so. IgM antibodies appeared within 1 week after onset of illness and persisted from 20 days to 2-3 months. An IgA antibody response was observed in 20 of 26 (77%) patients with a significant titer increase detected in 17 of 26 (65%) patients. In some patients the persistence of IgA antibodies followed that of the IgM antibodies, but in others the IgA antibody titers remained stable up to the end of the follow-up. The most sensitive assay system for serological diagnosis of acute RSV infection in children was the determination of titer increases by IgG antibody.

Adult↗

Vaccination with a live RA 27/3 strain rubella vaccine (Rudivax), a follow-up study.

Thirteen-year-old Helsinki schoolgirls were screened for rubella antibodies using fingertip blood specimens and the single radial haemolysis (SRH) test. The seronegative individuals (326/1234; 26.4%) were immunized with the RA 27/3 strain of rubella vaccine (Rudivax). All 326 produced SRH and haemagglutinin inhibition (HAI) antibodies and 129 IgM antibodies (39.4%) detected by enzyme immunoassay in the two-month follow-up serum samples. The incidence and nature of side effects was low. In the twenty-four month follow-up serum samples all individuals had substantial levels of rubella antibodies and no clinical reinfections had occurred during the observation period.

Adolescent↗

Rapid diagnosis of adenoviral tonsillitis: a prospective clinical study.

Adenovirus antigen was detected by radioimmunoassay in the nasopharyngeal specimens of 30 of 74 children with febrile exudative tonsillitis. In the other 44 children, the cause of tonsillitis was identified in 16 (beta-hemolytic streptococci or Epstein-Barr, parainfluenza, or herpes simplex viruses). The clinical picture of adenoviral tonsillitis was difficult to differentiate from that of streptococcal disease; 20 of the patients had originally been given antibiotics. In 68% of patients without complications, the serum concentration of C-reactive protein was less than 20 mg/L, suggesting a viral disease. No other hematologic test was found helpful in identifying the adenoviral tonsillitis. The rapid detection of adenovirus antigen permitted withdrawal of unnecessary and ineffective antibiotic treatment in most patients.

Adenoviridae Infections↗

B-cell function in vitro during rubella infection.

B-cell function in vitro was studied in patients with natural rubella virus infection. Lymphocyte responses to mitogens in a blast transformation test were decreased at the onset of the rash. Spontaneous immunoglobulin production by peripheral blood lymphocytes was increased during the acute phase of illness. In regulatory T-cell subpopulations, increased proportions of cells with suppressor/cytotoxic phenotypes and decreased proportions of cells with helper/inducer phenotypes were detected simultaneously with the increased spontaneous immunoglobulin production. All parameters studied were recovered during the convalescent phase.

Adolescent↗

Circulating immune complexes in patients with acute measles and rubella virus infections.

A solid-phase C1q radioimmunoassay was used to test for immune complexes (ICs) in sera obtained longitudinally from patients recovering from acute, uncomplicated measles and rubella virus infections. ICs were detected in 12 (18.5%) of 65 sera from 14 measles patients who did not have prolonged IC formation. Of 12 IC-positive measles sera, 9 were collected 4 weeks or more after rash onset. Transient appearance of detectable circulating ICs occurred sooner in 22 rubella patients who did not have prolonged IC formation. Of 109 rubella sera, 14 (12.8%) were IC-positive, and, of these, 10 were collected within 3 weeks of rash onset. Prolonged IC formation was found for an additional four measles and two rubella virus patients. Fractionation of sera from these six patients revealed that levels of large-sized ICs were highest in the initial 10 days after rash onset. Levels of large-sized ICs then declined to those for medium- and small (approximately immunoglobulin G)-sized ICs. IC-associated virus-specific antigens were detected in some of the sera from the six patients having prolonged IC formation. These results suggest two things: first, measles and rubella virus patients differ in the timing of virus clearance or in the reestablishment of normal immunity after infection; second, virus clearance is prolonged in some measles and rubella virus patients who have seemingly normal recoveries from their infections.

Acute Disease↗

Immunoassay diagnosis of adenovirus infections in children.

Direct detection of viral antigen in nasopharyngeal secretions and stool specimens by radioimmunoassay and the determination of serum antibody responses by complement fixation and immunoglobulin class-specific enzyme immunoassay against the hexon antigen were compared for diagnostic efficacy in 52 children with acute adenovirus infections. The highest diagnosis rate (85% of the cases) was obtained by antigen detection in nasopharyngeal secretions. Adenovirus antigen was also detected in stools of 72% of the 18 patients tested. The immunoglobulin G (IgG) antibody enzyme immunoassay detected 77% of the cases, being more sensitive than the complement fixation test with a 67% detection rate. The IgM antibody response was variable with no clear correlation with the age of the patient or severity of the clinical symptoms. IgM antibody response was detected in 48% of the patients and had the normal transient course, with a persistence of the IgM antibodies of approximately 2 months. Determination of IgA antibodies gave a diagnostic increase in titer in 37% of the cases and was found less suitable for serological diagnosis. Because of the clinical importance of rapid laboratory diagnosis, the direct detection of viral antigen in nasopharyngeal secretions or stool or both should be used as the primary diagnostic test in adenovirus infections.

Adenoviridae↗