Facilitators and barriers for RhD-immunized women to become and remain anti-D donors.

BACKGROUND: The successful introduction of prophylaxis with anti-RhD immunoglobulin has resulted in a significant decline of pregnancy-related RhD immunizations but also has decreased the availability of naturally immunized women as (new) anti-D donors. An influx of new donors is necessary to maintain a sufficient pool of anti-D donors. We investigated motivators, barriers, and predictors for anti-D donorship in RhD-immunized women. STUDY DESIGN AND METHODS: A mixed-methods design was applied, including focus group discussions and questionnaires. Two focus groups (including 11 women) served as input for the questionnaire. RESULTS: In total, 47.6% of 750 anti-D donors and potential donors completed the questionnaire (50.4% donors; 38% nondonors; 11.6% former donors). Almost 70% of the nondonors would have become donors if they had known about the possibility. Travel time investment was reported as a disadvantage; one-half of donors mentioned no disadvantages. Motivators for anti-D donorship were "doing something in return" (31.2%) and "preventing others having a sick child or losing a child" (33.9%). In multivariable analysis, living single (odds ratio, 5.8; p = 0.02) and living partnered without resident children (odds ratio, 7.9; p = 0.03), compared with living partnered with children, were predictors for anti-D donorship. Not being registered as an organ donor (odds ratio, 0.25; p < 0.001) predicted that the individual would not be an anti-D donor. CONCLUSION: The main barrier for anti-D donorship was a lack of knowledge. Positive predictors of anti-D donorship were living without resident children, altruism, and being registered as an organ donor. A blood bank should develop targeted recruitment strategies with a focus on spreading knowledge about anti-D donorship among RhD-immunized women.

Pathogen safety of intravenous Rh immunoglobulin liquid and other immune globulin products: enhanced nanofiltration and manufacturing process overview.

Plasma products for therapeutic use pose specific challenges in manufacturing to ensure products maintain biologic activity and are safe with respect to contamination and transmission of disease-causing agents. Various processes have demonstrated effectiveness in eliminating, reducing, or inactivating viral contaminants. Recently, the possibility of transmitting variant Creutzfeld-Jakob disease (vCJD) or transmissible spongiform encephalopathies (TSE) through blood-based products has become a concern. The present study involves the validation of a hyperimmune immunoglobulin manufacturing process incorporating a nanofiltration step with a nominal pore size of 20 nm for removal of viral contaminants and other adventitious agents. Processing intermediates during the manufacture of IV Rh IgG (WinRho SDF/WinRho SDF Liquid, Cangene Corporation, Manitoba, Canada) were spiked with model viruses and processed in scaled-down procedures to validate the viral reduction capacity of each step. Anion-exchange chromatography and solvent/detergent steps are known to contribute to virus removal and inactivation. The Planova 20 N nanofiltration step was effective in reducing model viruses representing a wide range of viral morphologies with varying degrees of resistance to physicochemical inactivation. All in-process and final batch testing met current standards for production of IV Rh IgG manufactured with the previously licensed filter, which had a larger nominal pore size of 35 nm. The manufacturing process, employing a Planova 35 N filtration step, has been proactively improved by the change to a smaller-pore 20 N filter. Replacement of the 35 N filter with the 20 N filter produces a similar product while enhancing the capability for removal of smaller viruses and prions.

Characterisation of a chromatographically produced anti-D immunoglobulin product.

A chromatographic fractionation method has been developed for the production of a liquid-stable anti-D immunoglobulin product for intravenous and intramuscular use. An immunoglobulin fraction, highly enriched with anti-D immunoglobulins, was isolated by cation-exchange column chromatography and further polished, first by anion-exchange chromatography, followed by an aluminium hydroxide gel treatment. The process includes two specific steps for virus inactivation and removal, namely S/D treatment and nanofiltration. The overall anti-D process yield is about 56%. The final product is stabilised with human albumin and glycine and placed in ready-to-use syringes. The anti-D product was shown to be stable in liquid state for at least 30 months at 4 degrees C.

[Rhesus prophylaxis--history and current status]. / Die Rhesusprophylaxe--Geschichte und aktueller Stand.

The varying symptoms of rhesus incompatibility were recognized and described approximately sixty years ago. Jörg Schneider, then at the Freiburg University Hospital in Germany, had been the very first investigator to perform rhesus prophylaxis in pregnant women. The exact date of this achievement is August 9, 1963. One year later, Schneider could report on nine women, who-following delivery of a rhesus-positive child-did not develop rhesus antibodies during a subsequent pregnancy with a rhesus-positive fetus. Since the late sixties, rhesus prophylaxis has been an integral part of prenatal care in Germany. In the meantime, the role of ante-partum prophylaxis has also been established. Since the introduction of post-partum rhesus prophylaxis, fetal morbidity and mortality has been reduced by 90 percent.

Human monoclonal antibodies against the rhesus D antigen from women with severe Rh immunization submitted to high-dose intravenous immunoglobulin treatment.

The pre- and postpartum maternal serum anti-D concentrations of 28 women with severe Rh(D) immunization who received high-dose intravenous immunoglobulin treatment has been determined. In all cases, including 1 in which the newborn was D negative, a sharp increment in the anti-D titer was observed after delivery. The specific immunoglobulin concentration rose to levels ranging from 4.7 to 204.0 micrograms/ml and, in 20% of the patients, increments of fifty times or greater were observed. Human monoclonal antibodies (hmAb) have been produced from Epstein-Barr virus-transformed lymphoblastoid B cell lines derived from 1 of these naturally hyperimmunized patients whose serum contained an anti-D-category DVI antibody. Four anti-D-secreting cell lines (97.E3.39.214, 44.E4.R1.257, E7.R1.126.83.115 and E11V.117.63; hereafter referred to as 214, 257, 115 and 63) have been established and maintained in continuous culture for periods ranging from several months to 3 years, without loss of antibody production capacity. Antibodies 115 and 214 recognize all Du samples tested at the same level as the polyclonal positive control. Antibodies 63 and 257 show a significantly lower reaction strength with some of the Du samples. Studies with D category cells showed that the DVI category was recognized only by hmAb 214. The reactivity pattern of this antibody is that of an anti-epD4, although the reaction strength varied greatly with different DIVa cell samples. Results obtained with hmAb 257 and 115 using papain-treated D category cells suggest that booth react as anti-epD6/7.(ABSTRACT TRUNCATED AT 250 WORDS)