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Objective: To examine changes in parentage testing practices since the introduction of DNA polymorphisms., Methods: Comparison of data from American Association of Blood Banks (AABB) annual questionnaires and the responses of participants to AABB-College of American Pathologists proficiency test panels., Results: DNA polymorphisms have led to a complete change in the technical methods used by parentage testing laboratories., Conclusions: The widespread use of DNA methods has increased the power of the information routinely provided to the courts in cases of disputed paternity, to agencies needing information about relatedness, and to the individuals who are tested.

Enormous strides have been made to reduce the risk of transfusion-transmitted disease. Additional tests to eliminate transfusion-transmitted disease are costly, in terms of both health care resources and availability of volunteer donors. Future improvements in safety probably will require postdraw treatment of blood and components and the use of pharmacologic agents as a substitute for transfusion.

A discrepancy in duplicate anti-K1 typing in a parentage case led to the discovery of an unusual K1 blood group antigen. Red blood cells from the propositus (JC) express a rare variant of the K1 antigen that is detectable by only 8 of 72 sera containing anti-K1. Absorption and elution studies using reactive anti-K1 confirmed the presence of a K1 antigen. Nonreactive anti-K1 was not absorbed by or eluted from JC's red blood cells. Red cells from 3 of the propositus's siblings also had the variant K1 antigen. The variant antigen exhibited qualitative as well as quantitative differences as compared to normal K1, and we have named it K1var.

The performance of participants on the 1990 Comprehensive Blood Bank Surveys of the College of American Pathologists was consistent with the high quality of past surveys. The surveys include challenges in ABO and Rh typing, crossmatching, transfusion decisions, unexpected antibody detection and identification, and supplemental questions to assess contemporary practices. As in previous years, a recurrent serologic problem has been the reporting of antibodies not present in serum (anti-E in Set J-B, and anti-K in Set J-D). Such overidentification of antibodies has little implication for transfusion safety and may, in fact, represent an artifact of the survey's samples and reporting practices.

The benefits of transfusion therapy must always be weighed against the unavoidable chance of an infectious complication. Strategies to minimize the infectious risks inherent in the use of human blood and blood components can be categorized under four general headings: donor selection, testing, appropriate use, and follow-up and reporting of complications. The application of these strategies in the context of their role in the prevention of some of the infectious complications of transfusion therapy is discussed in this article.

Complementary genetic and demographic analyses estimate the total proportion of European-American admixture in the Gila River Indian Community and trace its mode of entry. Among the 9,616 residents in the sample, 2,015 persons claim only partial Native American heritage. A procedure employing 23 alleles or haplotypes at eight loci was used to estimate the proportion of European-American admixture, m(a), for the entire sample and within six categories of Caucasian admixture calculated from demographic data, md. The genetic analysis gave an estimate of total European-American admixture in the community of 0.054 (95% confidence interval [CI] .044-.063), while an estimate from demographic records was similar, .059. Regression of m(a) on md yielded a fitted line m(a) = .922md, r = .959 (P = .0001). When total European-American admixture is partitioned between the contributing populations, Mexican-Americans have provided .671, European-Americans .305, and African-Americans .023. These results are discussed within the context of the ethnic composition of the Gila River Indian Community, the assumptions underlying the methods, and the potential that demographic data have for enriching genetic measurements of human admixture. It is concluded that, despite the severe assumptions of the mathematical methods, accurate, reliable estimates of genetic admixture are possible from allele and haplotype frequencies, even when there is little demographic information for the population.

An average of 2211 laboratories reported results in this comprehensive blood bank survey. In general, the participant performance remains strong in ABO and D typing, unexpected antibody detection and identification, crossmatching, and antigen identification. However, certain samples achieved less than the usual performance levels. In one sample, anti-C, which was not present, was reported by many participants. In a third sample, only 90% of the participants correctly recorded that no antibody was detectable. Two cross-match challenges did not reach the required participant consensus for grading purposes. The ungraded samples and the supplementary questions provide mock clinical situations and are used to determine current practices and procedures in transfusion medicine. The results of these studies and the participant responses are included.

The American Association of Blood Banks/College of American Pathologists Viral Marker Survey program added samples to evaluate participant performance with test systems for the detection of antibodies to human immunodeficiency virus type 1 in 1985. On the 80 challenges sent through April 1989, the major problem observed with enzyme immunoassay testing was unexpected reactivity on samples that did not contain anti-human immunodeficiency virus type 1. One manufacturer's testing system accounted for most of the specificity problems. The sensitivity of the enzyme immunoassay for anti-human immunodeficiency virus type 1 is close to 99%, based on the multiple reactive samples used on the 16 panels. Between 1985 and 1989, there was a 14-fold increase in participants reporting Western blot results. The introduction of a licensed system for Western blots increased the number of samples that contained antibody to human immunodeficiency virus type 1 interpreted as indeterminate. Answers to supplementary questions showed that the rate of repeatably reactive and confirmed positives on blood donors dropped to less than 0.1%.

Many antibody identifications require testing with cells of rare or uncommon phenotypes. To expedite the resolution of these identifications, we developed a microcomputer database using Lotus 123 to enter antigen phenotypes from our frozen cell inventory. Data is entered into a customized screen input form and automatically copied to the database The use of an input form protects the database from inadvertent errors made while entering data. The database can be searched for any combination of red cell phenotypes. When found, the selected cells are extracted tu a predesigned worksheet. Panel worksheet forms are created with Allways, a software program used in conjunction with Lotus 123, Allways is specifically designed to generate quality printouts with a laser printer. The program has many formatting features that simplify horizontal and vertical ruling for the worksheet. In addition, the program provides degrees of shading to highlight specific antigens or entire columns or rows of information. Once the worksheet template has been designed, it is automatically saved with the database file. More than one worksheet template can be stored in the database file. This program reduces the amount of time spent searching through records to find the necessary cells for testing, It also reduces potential error in hand copying antigen phenotypes to a worksheet. This application can also he used for HLA panels.

Two high frequency antigens, Hy (Holley) and Gy-a (Gregory), show an apparent association. All individuals lacking Gy-a are whites and these individuals are Hy-negative. A second group of Hy-negative individuals are blacks. All of these react weakly with anti-Gy-a. Neither Gy-a nor Hy are well developed on cord cells, although antibodies to both factors have been stimulated by pregnancy. Anti-Gy-a and anti-Hy antibodies react best in the antihuman globulin test. These antibodies have low avidity, high titers, and have been implicated as causing transfusion reactions.

A method for isoelectric focusing of phosphoglucomutase (PGM1) using agarose was found to have significant advantages over published acrylamide technics. Gene frequencies determined on samples from 1,780 Minnesota Caucasians were PGM1(1+) = 0.6118, PGM1(1-) = 0.1441, PGM1(2+) = 0.1910, PGM1(2-) = 0.0531. The use of the isoelectric focusing technics in 700 cases of disputed parentage resulted in an exclusion rate slightly in excess of the calculated probability of exclusion (P value) of 27%.. In addition, the proportions of direct exclusions was increased from 485 observed with the conventional starch technic to 75% with IEF.

There is little question that Frozen-Thawed-Deglycerolized Red Cells (Human) has the least amount of HLA antigen found in any red cell component. Units prepared by any of the several availables methods are indicated for patients with repetitive nonhemolytic febrile reactions, probably should be used in patients waiting for reanl allografts and in immunodeficient patients in whom there is a risk of GVH disease. Still unresolved are questions on the minimal dose of HLA needed to sensitize a recipient, the role of the debris and viable cells and whether transfusion with a small dose of HLA antigen has a beneficial effect on the survival of renal allografts.

Serial serum specimens from 149 patients with clinically diagnosed hepatitis were tested for five hepatitis B serological markers: hepatitis B surface antigen and its antibody (anti-HBs); hepatitis B e-antigen and its antibody (anti-HBe); and antibody to hepatitis B core antigen (anti-HBc). The times of appearance, disappearance, and persistence of these markers were used to differentiate various serological profiles obtained from the study. Four distinctive profiles were found to be associated with acute hepatitis B followed by recovery, and three with chronic hepatitis. These serologic profiles were assessed as diagnostic and prognostic guides for clinical management of the disease.

We describe the gene frequency distributions for 29 different blood group, serum, and erythrocytic proteins for three Mennonite communities from Kansas and Nebraska and compare their gene frequencies with those of Amish, Hutterite, and Mennonite populations using the topological method of Harpending and Jenkins (1973). Subdivision of these communities into congregations reveals that the "fission-fusion'h model best characterizes the relationship between the genetic patterns and historical events. These Mennonite populations, although reproductively isolated at the turn of this century, are presently entering the mainstream of US rural culture.

Immunoglobulin allotyping in 925 cases of disputed paternity provided evidence of exclusion for 70 alleged fathers. Combining results from erythrocytic antigen, enzyme, and serum protein tests, 230 men were proven to be falsely accused; in 15 cases the immunoglobulin allotype provided the only evidence for exclusion, in 67 no exclusion would have been identified if testing had been limited to ABO, Rh, and MNSs. Various cases in this study illustrate the importance of using an extensive battery of immunoglobulin reagents in order maximally to exclude falsely accused men, and to identify infrequent haplotypes, which might erroneously be interpreted as indirect exclusions or may indicate a high likelihood of paternity. The problems of Gm typing of very young children are described. When child is less than 6 months of age, direct exclusions may be missed by the Gm allotypes; indirect exclusions are valid only when the phenotype differs from that of the mother. Km allotypes are not age-dependent.

The results obtained by referees and participants on nine HBsAg survey panels are reviewed. Comparison of the two methods used by the majority of participants, counterelectrophoresis (CEP) and radioimmunoassay (RIA), shows that the latter consistently identifies a larger number of the positive samples. The RIA results show some problems with specificity, but these were reduced during the two-year period. The performance of the participants using CEP improved during the two-year period. The Survey documents the change in popularity of the methods.

Current serologic tests occasionally fail to identify women needing more than one vial of Rh immune globulin. We compared the indirect antiglobulin test after incubation with anti-D and a rosetting technique using enzyme treated Rh2Rh2 erythrocytes as methods for identifying significant fetal maternal hemorrhage (FMH). Artificial mixtures containing 0.05 to 1.2 percent Rh1rh (CcDe) fetal red blood cells mixed with rh (ce) adult red blood cells were tested. The indirect antiglobulin test of the 0.6 percent mixture (approximately 30 ml FMH) was reported to be microscopically positive by 17/20 technologists; whereas, 20/20 found the rosetting test to be strongly positive. The volume of FMH in 118 postpartum Rh immune globulin candidates was quantified using Kleihauer's test and formula. The results of the rosetting and Kleihauer tests of blood specimens from these patients were negative 1.4 ml for two, and strongly positive rosetting test and FMH of 6.5 ml for one. The rosetting test utilizes routine blood banking skills and requires 5 minutes more "hands on" time than an indirect antiglobulin test. Confirmation and quantification of positive results by an acid-elution test is necessary.

The results of the 1979 Comprehensive Blood Bank Survey of the College of American Pathologists are summarized in tabular form and analyzed. Approximately 2400 laboratories participated in this program. Results of ABO grouping, Rh D typing, and compatibility testing were excellent--over 95% of the participating laboratories obtained the correct responses. Some problems were evident in the recognition of an anti-B in a group B individual, and in the identification of an anti-Cw and an anti-Jka. Sixteen percent of participants reported false positive results in typing with anti-N a cell whose phenotype was M. Other ungraded samples were supplied to provide additional unusual challenges and to review the results of the participants. Many of the questionnaires used in 1978 and 1979 contained additional questions which help define blood bank practices during these years. The responses to these questions are also listed.

Enzyme immunoassay (EIA) and radioimmunoassay (RIA) methods for HBsAg were compared on the basis of responses to the AABB-CAP Viral Hepatitis Marker proficiency survey. Conversion of laboratories to the EIA method was documented for the period studied. Using standard incubation procedures, participants using the EIA method reported results comparable to those reported by laboratories using RIA methods. The short incubation procedures for RIA and EIA were both less sensitive and less specific than standard incubation procedures.

Isoelectric focusing (IEF) as a method for differentiating macromolecules with minor differences in isoelectric points has demonstrated an increase in the degree of genetic polymorphisms of the blood. Studies over the last 5 to 6 years have shown that genetic marker systems such as transferrin (TF), phosphoglucomutase (PGM1), the vitamin D-binding globulin (GC), and A1 antitrypsin (PI) are a great deal more polymorphic than observed using conventional electrophoresis. Additional genetic variants have been detected or further defined in such systems as esterase D (ESD) and hemoglobin (HB) to name a few. The increased heterozygosity levels of these genetic marker systems identified by IEF have added to their value in forensic medicine and resulted in further resolution of racial and population affinities. IEF should prove to be a valuable anthropological tool for measuring population structure and genetic distances.

Detection of the ESD*5 gene products was simplified by the use of isoelectric focusing (IEF). Gene frequencies for ESD*5 in whites, blacks and Amerindians from the State of Minnesota were 0.019, 0.002 and 0.000, respectively. The gene frequencies observed in the white data set were similar to those reported for European whites.

51Chromium-labeled Er(a+) red cells survived nearly normally (T1/2 of 21 days) in a patient with allo-anti-Era. Transfusion of Er(a+) blood was without significant reaction and did not affect the anti-Era titer.

A 1977 College of American Pathologists survey of hospitals has been analyzed to compare Rh immune globulin usage (RhIgG) with methods used to screen and confirm fetomaternal hemorrhage (FMH). The survey data show that there is a correlation between the rate of multiple vial usage and the confirmation method used. Laboratories using Fetaldex administered multiple vials of Rh immune globulin significantly more often than laboratories using other acid elution technics. This difference was independent of the screening methods used and was not related to the number of patients tested in laboratories giving fewer than 300 vials of Rh immune globulin per year. The incidence of fetomaternal hemorrhages of greater than 30 ml has been reported to be 0.3% by various groups using Kleihauer procedures to test large numbers of women after delivery. In 61 of 374 laboratories using Fetaldex and 15 of 253 laboratories using Kleihauer-Betke procedure more than ten times the expected number of recipients were given multiple vials.

Two serologic markers, anti-HBs, -HBc, are useful to determine whether individuals at risk for hepatitis B virus infection are candidates for hepatitis B vaccination. To evaluate the usefulness of these markers in detecting immunity from prior infection (usually asymptomatic), 192 anti-HBs positive health care workers were tested for anti-HBc. In the 68% of individuals with anti-HBs RIA ratios greater than 10, anti-HBc was found in only 75%. In the group with anti-HBs ratios less than 10, only 6.6% had anti-HBc. Health care workers with frequent contact with blood and other body fluids were more likely to have both markers present. The incidence of the markers in this group was similar to that observed in 520 homosexually active males. The authors conclude that anti-HBs is more likely to identify prior immunity, particularly in individuals with infrequent HBV exposures.