Rubella Hemagglutination Inhibition Research Articles

VIRUS ANTIBODY LEVELS IN RHEUMATOID ARTHRITIS AND SYSTEMIC LUPUS ERYTHEMATOSUS

Abstract Sera from 30 patients with rheumatoid arthritis (RA), 10 with systemic lupus erythematosus (SLE) and 99 healthy control subjects have been studied for several viral antibodies by haemagglutination inhibition (HI) and complement fixation (CF). Measles HI antibodies were significantly increased in both RA and SLE. The geometric mean of the measles antibody titres, expressed as log2 of the reciprocal mean antibody titre, where 1.00 equals a titre of 1: 10, was 1.17 in the controls, 2.45 in patients with RA (p<0.01), and even higher, and 3.80 (p<0.01), in patients with SLE. The measles CF antibody titres of SLE patients, but not of RA patients, also differed significantly from those of controls. In addition, the mean rubella HI titre was slightly increased in SLE (p<0.02). The significantly elevated measles antibody levels in RA and SLE may be due to altered immuno‐logical reactivity in these diseases, but a viral aetiology cannot be excluded.

Use of Trypsin-Modified Human Erythrocytes in Rubella Hemagglutination-Inhibition Testing

A method of treating human erythrocytes with trypsin has been modified and found to be an efficient and practical indicator system for the rubella hemagglutination-inhibition test. Both the trypsin-treated human cells and the widely used, newborn chicken erythrocytes were used in comparative testing of 464 selected diagnostic rubella serums. Results with each cell system were essentially the same. The trypsin treatment procedure has been found to be relatively simple, and with our limited testing has not presented any problems with reproducibility. Other advantages include the ready availability of human cells, greater intralaboratory standardization of the test by using the same donors over a long period of time, and elimination of adsorption of test sera with red blood cells.

Improved Dextran Sulfate-Calcium Chloride Method for the Removal of Nonspecific Inhibitors with Modifications for Nonspecific Agglutinin Removal in the Rubella Hemagglutination Inhibition Test

The dextran sulfate precipitation method for removal of nonspecific inhibitors from sera to be tested in the rubella hemagglutination-inhibition test was modified by shortening the dextran sulfate-serum mixture incubation period from 2 hr to 30 min. A comparative study using both treatment times showed no significant difference in rubella antibody titers. Reducing the treatment time even further also gave comparable results, indicating the select 30-min incubation period is not marginal for undertreatment. It was shown that 41.5% of the 159 serums tested had nonspecific agglutinins at levels from 1:8 to as high as 1:64. In each specimen, all demonstrable nonspecific agglutinin was removed by adsorption with 10%, 0- to 2-day-old chick red blood cells rather than the usually recommended 50% adult chicken erythrocytes.

REINFECTION WITH RUBELLA IN PREGNANT WOMEN

Abstract Three women with pre-existing levels of rubella haemagglutination-inhibition antibody developed significant rises in titre after exposure to rubella during early pregnancy. The titration of antibody in serum fractions obtained after sucrose density-gradient ultracentrifugation showed that the rise in titre was only in the IgG fraction—a response characteristic of a secondary immune response. At birth the three infants were normal and had no clinical or serological evidence of congenital rubella. When a significant increase in antibody titre is observed, it is important to identify the type of antibody response before deciding to perform a therapeutic abortion.

Loss of rubella hemagglutination inhibition antibody in congenital rubella. Failure of seronegative children with congenital rubella to respond to HPV-77 rubella vaccine.

Serial determinations of rubella hemagglutination inhibition (HI) antibody levels were performed on serum specimens obtained from 223 women who had rubella during pregnancy and their 223 children with congenital rubella. The decline in HI antibody following congenital infection was more rapid than following postnatal infection. By the end of five years, 27 of these children no longer had detectable HI antibody, although all mothers still had antibody. Among 270 children with congenital rubella who had reached their fifth birthday, 50 (18.5%) were seronegative. When 19 such seronegative children were given rubella vaccine [HPV]-77 (high-passage virus strain), only two (10%) of them seroconverted. In contrast, 134 of 135 (99%) normal children of the same age seroconverted.

Measles and rubella hemagglutination-inhibition antibody patterns in Mexican and Paraguayan children.

Serum specimens, collected in the county of Huixquilucan, State of México, México, and nationwide in Paraguay, were studied for hemagglutination-inhibition antibody to measles and rubella. The Mexican sample population comprised 667 children up to 17 years of age, and the Paraguayan sample was composed of 408 children of comparable ages. Tests revealed that preschool children in both study populations acquired antibody to measles virus fairly rapidly; 70.9% and 65.4% of the Mexican and Paraguayan children, respectively, had antibody to measles virus at the age of 7 years. In comparison to the Mexican children, however, Paraguayans of school age had a consistently higher prevalence of measles antibody; and in cohorts older than 8 years antibody prevalence ranged from 91.2% to 100%. Measlesantibody prevalence in similar cohorts in México ranged from 75% to 88.2%. Seroconversion to rubella virus among Paraguayan children studied was drastically slower than that seen among Mexican children. By the age of 7 years, only 17.1% of Paraguayans had rubella antibody in contrast to 75.8% seroconversion in México. Even more striking was the finding that there were no rubella-seronegative children among cohorts 13 years of age, or older, in Huixquilucan. Possible mechanisms for the unusually high prevalence of antibody to rubella are discussed.

Single-sample diagnosis of recent rubella by fractionation of antibody on Sephadex G-200 column.

To facilitate the diagnosis of recent rubella infection, rubella haemagglutination inhibiting antibody has been determined in four fractions obtained by Sephadex G-200 gel filtration of samples of serum. All the 21 samples collected at the convalescent stage of the disease had varying proportions of haemagglutination inhibiting antibody in fraction 1, representing the major portion of IgM antibody whereas all but three out of 22 sera from persons with no history of recent rubella had negative titres in this fraction. The haemagglutination inhibiting titres in the three positive sera in the second group was very low as compared to the other fractions. Fractionation of sera on a Sephadex G-200 column coupled with the rubella haemagglutination inhibition test can, therefore, be used to diagnose recent rubella infection.

Rubella vaccine responses and other viral antibodies in Syracuse children.

Rubella vaccine was administered to 289 preschool children in the winter and spring of 1969-1970. Among children with seronegative reactions, 94% acquired rubella hemagglutination-inhibition (HI) antibodies; 10 of the 13 who had remained negative responded with low titers to second doses of the same vaccine. Immunization histories were verified in over 85% of the children. Rubeola HI antibodies were present in 90% and those to mumps and vaccinia in 35% and 62%, respectively. Almost half had A2/HK/3/68 and A2/Jap/305/57 influenza antibodies. Poliovirus neutralizing antibodies were not detected to type 1 in 45% and to type 3 in 37%. The importance of maintaining continuing serological surveillance is emphasized by these data.

Rubella booster immunization. Serologic response to a second dose of vaccine.

To determine the persisting effect on base-line antibody levels of a booster dose of rubella vaccine, blood specimens were obtained eight to ten weeks following revaccination from 92 study children immunized initially in July 1968. Only six of 92 (6.5%) revaccinees demonstrated a fourfold or greater rise in rubella hemagglutination-inhibiting (HI) antibody titer. The HI titers before administration of the booster dose were low in all six (1:32 or less); however, similar low titers were noted in 33 revaccinees who demonstrated no increase in antibody. These data suggest that a second dose of rubella vaccine given approximately two years following primary immunization does not significantly increase antibody levels and, therefore, may be ineffective in enhancing resistance to reinfection.

Rubella Booster Immunization

To determine the persisting effect on base-line antibody levels of a booster dose of rubella vaccine, blood specimens were obtained eight to ten weeks following revaccination from 92 study children immunized initially in July 1968. Only six of 92 (6.5%) revaccinees demonstrated a fourfold or greater rise in rubella hemagglutination-inhibiting (HI) antibody titer. The HI titers before administration of the booster dose were low in all six (1:32 or less); however, similar low titers were noted in 33 revaccinees who demonstrated no increase in antibody. These data suggest that a second dose of rubella vaccine given approximately two years following primary immunization does not significantly increase antibody levels and, therefore, may be ineffective in enhancing resistance to reinfection.

Use of a New Buffer System with Formalinized Sheep Erythrocytes in the Rubella Hemagglutination-Inhibition Test

The increased sensitivity and improved agglutination and settling patterns of formalinized sheep erythrocytes in a new buffer, HEPES ( N -2-hydroxyethylpiperazine N ′-2′-ethanesulfonic acid), make this system more suitable for use in the rubella hemagglutination-inhibition test.

Antibody response to rubella virion (V) and soluble (S) antigens in rubella infection and following vaccination with live attenuated rubella virus.

The antibody response to rubella virion antigen and rubella S antigen was studied in natural rubella infection and after vaccination with live attenuated rubella virus by the complement fixation (CF), platelet aggregation (PA), and hemagglutination inhibition (HI) techniques. In natural rubella infection CP and HI antibodies to rubella virion appeared early and rapidly reached high titers. The CP and PA antibody responses to rubella S antigen were more delayed and great individual variation was seen. Generally CF-S titers were several times lower than CF-V titers. The CF antibody response to rubella S antigen is thus different from the immune response to nucleoprotein S antigens of paramyxoviruses, supporting the concept that rubella S antigen is a subunit of virus envelope. Use of virus-free rubella S antigen preparations in routine CF test is recommended for detecting later rises of antibody titer. After rubella vaccination a 95% seroconversion rate was recorded in both HI and CF-V tests, but the titers were lower than after natural infection. The CF-S and PA antibody responses were weaker and measurable antibodies developed in only 50% and 25% of the cases respectively. Rubella-specific IgM antibodies could be detected in rubella infection by both sucrose gradient fractionation (followed by HI titration) and fluorescent antibody (FA) techniques. The former was a little more sensitive. In the seronegative vaccinees IgM antibodies became demonstrable in 50% of the cases between the 20th and 55th day after vaccination.

Failure to Transmit Rubella Virus Vaccine

Attenuated rubella viruses retain the property of pharyngeal shedding and might cause unrestricted secondary infections in susceptible contacts of vaccinees. To test this possibility, Cendehill rubella vaccine was administered to 15 susceptible women whose husbands were without detectable rubella hemagglutination-inhibition (HI) antibody. All women developed antibody after immunization. No male spouses had HI antibody eight weeks after administration of the vaccine to the women, or approximately five weeks after the expected period of pharyngeal virus shedding. Lack of spread of rubella vaccine virus among young married couples with close physical contact is further evidence for the low transmissibility of these viruses.

Use of a New Buffer System with Formalinized Sheep Erythrocytes in the Rubella Hemagglutination-Inhibition Test

The increased sensitivity and improved agglutination and settling patterns of formalinized sheep erythrocytes in a new buffer, HEPES (N-2-hydroxyethylpiperazine N'-2'-ethanesulfonic acid), make this system more suitable for use in the rubella hemagglutination-inhibition test.

Congenital rubella presenting as retarded language development.

A preschool communication screening program was conducted in Montgomery County, Maryland. Advertisements through news media, local nursery schools and day care centers, and local physicians urged parents to bring children suspected of having speech, hearing, or visual disorders of any etiology for examination. Blood specimens were obtained from most of the children examined and rubella hemagglutination inhibition (HI) antibody determinations were performed on the sera. From the 52 children born in 1964, the year of the last rubella epidemic, 41 sera were obtained. Rubella HI antibody was found in five, and four of these children were found upon further examination to have clinical signs consistent with the congenital rubella syndrome. Congenital rubella had not been previously diagnosed in three of these four children.

A Two-Year Follow-up of Rubella Antibodies in a Female Population with Special Reference to Reinfections

AbstractThe sera of 122 women were tested for rubella antibodies at the beginning and end of a two-year period. Four of the 17 initially seronegative women were positive by the end of the period. Four of the initially positive women had 4-fold or greater increases in hemagglutination inhibition (HI) titers, but no increase in complement fixation (CF) or platelet aggregation (PA) titers. In most cases the rubella HI titers had not changed within 2 years, and in no case had they declined below detectable level. The number of CF positives decreased from 51% to 27%, and the PA positives from 70% to 65%. The possibility that minor localized virus infections maintain rubella immunity is discussed.

Rubella Vaccine Comparative Study

In this placebo controlled trial of rubella vaccines administered randomly to first-grade children in Memphis, 100% of 206 susceptible HPV-77 DK 12 recipients, 92% of 214 susceptible HPV-77 DE 5 recipients, and 87% of 213 susceptible HPV-80 recipients developed rubella hemagglutination-inhibition (HI) titers of ≥ 1:10 within seven weeks after vaccination (September 1968). The geometric mean titers (GMT) of respondents to HPV-77 DK 12, HPV-77 DE 5, and HPV-80 were 1:183, 1:108, and 1:124, respectively. There had been no significant decrease in GMT by the 39th week after vaccination (April 1969). Between September and April, a period in which rubella was occurring in Memphis, significantly fewer ( P

Intrauterine Rubella Infection Following Immunization With Rubella Vaccine

A woman with no detectable rubella hemagglutination-inhibiting (HI) antibody received rubella vaccine at three weeks of gestation. The pregnancy was terminated at eight weeks and rubella virus was recovered from decidua. The virus isolate stimulated high amounts of interferon and inhibited DNA synthesis in phytohemagglutinin (PHA) stimulated lymphocytes far less (53%) than did wild-type Ellis strain rubella virus (95%). Histologic changes seen in decidua were similar to those seen in gestational rubella.

Measurement of Rubella Antibody by Hemagglutination Inhibition

Abstract The variables which affect the qualitative and quantitative aspects of the interaction between fowl erythrocytes and rubella virus were defined and evaluated. The sensitivity of the hemagglutination reaction is at least tenfold greater at pH 6.0 to 6.5 than it is at pH 7.2, the pH of dextrose-gelatin-Veronal which is widely used as diluent for rubella hemagglutination (HA) and hemagglutination inhibition (HAI) tests. In the presence of 0.001 M Ca++ ion the reaction is two to eight times more sensitive than it is in the absence of Ca++ ion. The development of agglutinated and non-agglutinated RBC patterns that are stable and clearly distinguishable from one another is critically dependent upon the concentrations of gelatin and/or albumin in the diluent. The diluents employed in previously published HAI test procedures differ widely with respect to pH, Ca++, gelatin and/or albumin concentration. The lack of comparability of HAI test results among laboratories may in part reflect these differences in diluent composition. In an effort to correct such difficulties, optimal conditions for the agglutination of fowl RBC by rubella virus were defined. A 0.14 M NaCl solution buffered with N-2-hydroxyethylpiperazine-N'-2'-ethanesulfonic acid (HEPES) at pH 6.05 to 6.15, containing 0.001 M CaCl2, 1.0% bovine serum albumin and 0.00025% gelatin was shown to provide conditions for a maximally sensitive, stable and clear test. Under these conditions the outcome of the hemagglutination test is solely a function of the concentration of hemagglutinin in the test specimen.

Variables of the rubella hemagglutination-inhibition test system and their effect on antigen and antibody titers.

A systematic study was made of certain variables of the rubella hemagglutination-inhibition (HI) test system and their effect on antigen and antibody titers. Erythrocytes from pigeons and 1-day-old chicks gave similar antigen and antibody titers, but goose erythrocytes gave lower titers. Indicator erythrocytes could be stored in Alsever's solution at 4 C for as long as 2 weeks without losing sensitivity in hemagglutination (HA) and HI tests. Antigen titers varied by eightfold or more in different diluent systems; titers were generally higher at pH 6.2 than at pH 7.2. A diluent without Ca(2+) gave antigen titers as high as those obtained in diluents with added Ca(2+) ions. Antibody titers also varied in different diluent systems. HEPES diluents at pH 6.2 gave higher antibody titers than those obtained in other diluents, but occasional "false-positive" inhibition reactions were seen. Kaolin suspended in borate saline at pH 9.0 effectively removed inhibitor from sera without absorbing specific antibody, but at pH 7.3 it removed various amounts of specific antibody. Antibody titers of sera treated with kaolin at pH 9.0 were similar to those of sera treated with heparin-MnCl(2); treatment with dextran sulfate-CaCl(2) gave lower antibody titers. Antigens varied widely in sensitivity for detecting HI antibody and in the ability to detect diagnostically significant increases in antibody. Sensitivity in detecting antibody was not related to the HA titer of the antigens. Tween-ether-treated antigens gave lower antibody titers but were more reliable than corresponding untreated antigens for serological diagnosis of infection.