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Pretransfusion testing practices in North America, 2005-2010: an analysis of the College of American Pathologists Interlaboratory Comparison Program J-Survey data, 2005-2010.

Red cell, pretransfusion compatibility testing is performed to prevent incompatible transfusions that may result in immune-mediated, hemolytic transfusion reactions and to identify any patient whose fetus would be at risk for hemolytic disease of the newborn. The process of pretransfusion compatibility testing involves many steps: receipt of orders for testing, sample acceptability criteria review, ABO grouping, rhesus (Rh) typing, red cell antibody screening, unexpected antibody identification, selection of appropriate donor red blood cell units, and, for some patients, crossmatching with the unit to be transfused. The federal government regulations for the pretransfusion tests of ABO grouping, Rh typing, antibody detecting, antibody identifying, and crossmatching includes the requirement for laboratories to participate in proficiency testing for those procedures. (1) The College of American Pathologists (CAP) Interlaboratory Comparison Program Transfusion Medicine (J) Survey assesses the proficiency of laboratories that perform regulated tests using manual methods (data from the CAP Transfusion Medicine Proficiency Testing Survey for automated testing [JAT] were not included in the present study). The results from this survey represent the largest, most-comprehensive data set currently available about pretransfusion testing practices in North America. In 2001, the J survey was formatted to facilitate collection of information about methodologies employed in pretransfusion testing. In 2005, Shulman et al (2) published an analysis of the CAP Interlaboratory Comparison Program J-Survey data that were collected between the beginning of 2001 and the end of 2004. The present report extends the analysis of CAP J-Survey data from the beginning of 2005 through the end of 2010.

MATERIALS AND METHODS

Overview of J-Survey Materials

The CAP Transfusion Medicine J Survey is mailed to subscribing participants 3 times per calendar year (JA, JB, JC). Each survey has 5 "wet challenges," which represent 5 hypothetical patients with corresponding brief histories. To assess the analytes regulated by the Clinical Laboratory Improvement Amendments of 1988 (CLIA) in each "challenge," each survey contains 5 red blood cell samples for determination of ABO group and Rh D type, 5 corresponding serum samples for antibody detection and identification, and 1 red blood cell sample that serves as the "donor sample" for crossmatching against each of the 5 serum samples. The performance limits of acceptability required by CLIA for proficiency testing of participants are as follows: ABO grouping, 100%; Rh D typing, 100%; antibody detecting, 80%; antibody identifying, 80%; and crossmatching, 100%.

Grading and Consensus

Participants submit their answers to each of the challenges, and results are compiled as they are received. After the data submission deadline, if participant consensus for a specific challenge (.95% agreement) is achieved, the results are graded. If participant consensus is not achieved, 40 referee laboratories must achieve 100% agreement for the survey to be graded. The use of referee laboratories to determine consensus is derived from the Federal Register, (1) which states that "to determine the accuracy of a laboratory's response, a program must compare the laboratory's response for each analyte with the response that reflects agreement of either 100% of 10 or more referee laboratories or 95% or more of all participating laboratories except for unexpected antibody detection and antibody identification." According to the Centers for Medicare and Medicaid Services requirements, (1) any response on the proficiency testing survey answer form left blank is considered unacceptable and is graded as wrong. The graded results are initially mailed to participants in the form of a participant summary report; subsequently, a more detailed survey summary is mailed in a final critique.

J-SURVEY FORMAT, DATA COLLECTION, AND DATA SELECTION

All data presented in this article are from the CAP J Surveys (2005-2010) Final Critiques JA, JB, and JC.3-20 For each survey, one "challenge sample" was chosen from the 5 included in the survey mailing for data analysis. The challenge sample with the most participant responses was selected.

ABO Grouping and Rh Typing

Methods reported in the final critique for ABO/Rh determination include tube testing, liquid microwell testing (LMWT), and column agglutination (gel) testing.

Antibody Screening

Results from the antibody detection challenge were reported as either "antibody NOT detected" or "antibody detected." The survey sample that had the most participants reporting a result was selected for inclusion in the study.

Crossmatching

For each serum sample, the participant reported crossmatch results as either "negative" or "positive," and the method employed (tube, solid phase red cell adherence [SPRCA], gel, electronic/computer, or LMWT); for tube testing, the phase of testing was also reported (immediate spin, antihuman globulin [AHG] crossmatch with immunoglobulin G AHG, or AHG crossmatch with polyspecific AHG) and the additive solution (saline, albumin, low ionic strength solution [LISS], or polyethylene glycol [PEG]). In 2004, the crossmatching data collection was expanded to include the electronic/ computer crossmatch as a reportable method. In the 2007-JB Survey, the reporting format was reconfigured and electronic crossmatching data were not included in the reconfiguration. Surveys 2009-JB and 2010-JC contained supplemental questions that asked participants about the use of electronic crossmatching in their laboratories.

The selection of a particular crossmatch method is determined by the alloimmunization history and current status (as determined by the antibody screen) of the patient. If a clinically significant antibody is present, participants should select a crossmatch method that includes incubation at 37[degrees]C preceding an AHG test using unpooled reagent cells.[sup.21(p34)] Consequently, the CAP J-Survey data were analyzed based on whether the challenge sample contained an alloantibody (alloimmunized) or not (nonalloimmunized). For data analysis, crossmatch methods were then grouped into those with (1) alloantibody present (considered "alloimmunized patients"), or (2) alloantibody absent (considered "non-alloimmunized patients") (Figure). The graded sample that had the most respondents reporting the correct answer was selected for analysis. An exception was made to data collection design whenever a sample contained an ABO antibody incompatible with the donor sample. In those instances, some laboratories reported an immediate-spin crossmatch as their crossmatch method, even though an alloimmunized patient sample was used. In those cases, the sample with the second-most respondents was selected for data analysis (2005-JB, 2006-JA, 2007-JB). Similarly, in 2 surveys, laboratories reported immediate spin as their crossmatch method for alloimmunized samples when anti-D was present in the sample and the corresponding donor sample was Rh[(D).sup.+]; in those instances, the sample with the second-most participants was selected for analysis (2007-JA, 2010-JB). Finally, one survey did not achieve consensus on the sample with the most participants reporting a result; this sample had an anti-[C.sup.w] present (2009-JB) and was not graded. For that survey, the sample with the second-most respondents was selected.

Database Structure

An Excel Microsoft Windows 2007 (Microsoft Corporation, Redmond, Washington) program was used to construct a database (see Tables 1 through 6 for data presentation).

Data Limitations

Because of the nature of the data collection, individual or grouped correlation with the size or type of institution or laboratory was not possible. These reported survey data were obtained from the final critique. Some participants submitted their results too late to be included in the final critiques. Thus, most, but not all, participant practices were included in the trend analysis.

RESULTS

ABO Group

From 2005 to 2010, the most respondents reporting an ABO grouping result was 3793. The percentage of participants not reporting methods ranged from 0.1% to 0.5%. From 2005 to 2010, the use of the gel method for ABO grouping increased from 8.6% to 23.1%. A decrease was seen in the reported use of tube testing from a high of 90.7% in 2005 to 76.7% at the end of 2010. The use of the LMWT method remained constant at 0.7% or less, ranging from 0.1% to 0.7% of users (see Table 1).

Rhesus Type

The most participants reporting Rh results was 3785. Unknown or not reported methods ranged from 0% to 0.4%. From 2005 to 2010, the use of the gel method more than doubled, from 8.7% participants at the start of 2005 to 23.2% in 2010.

[FIGURE OMITTED]

From 2005 to 2010, the use of the tube method decreased from 90.7% to 76.6% (see Table 2).

Antibody Detection

During the study period, the most participants reporting antibody detection was 3786. The use of the gel method increased from 43.7% participants in 2005 to 64.3% in 2010 with a concomitant decrease in tube LISS-AHG from 38.6% participants in 2005 to 21.1% in 2010. By the beginning of 2010, most participants were using the gel method. The SPRCA and LMWT methods remained constant at 3.4% or less and less than 0.3%, respectively. The various testing strategies are listed in Table 3.

Screening Cells

At the end of 2010, most participants reported using a 3-cell set of reagent red cells for antibody-detection testing.

Participants who used the gel method for antibody detection were almost evenly divided between a 2-cell screen (45.5%) and a 3-cell screen (54.3%) in 2010, and that has not changed significantly since 2005 (2-cell screen, 46.2%; 3-cell screen, 53%). A similar pattern was found for laboratories using saline AHG. In 2005, the SPRCA method primarily (65.4%) used a 2-cell screen, but that decreased to 24.6% in 2010, whereas the use of a 3-cell screen increased to 61.1% by 2010 (see Table 4).

Crossmatching

Nonalloimmunized Patients (No Antibody Present in Sample).--The most participants reporting crossmatching results for nonalloimmunized patients was 3599.

Performance of crossmatching by participants when an antibody was not present was almost evenly divided at the end of 2010 between the gel method (49.3%) and all tube methods combined (50.2%). During the study period, the use of test tube crossmatching (all methods combined) decreased, with a corresponding increase in the use of the gel method. Table 5 lists the various crossmatch methods employed.

Alloimmunized Patients (Antibody Present in Sample).--The most participants reporting crossmatching results method for alloimmunized patients was 3477.

Performance of crossmatching when an antibody was present was almost evenly divided in 2010 between use of the gel method (49.8%) and the combination of all tube methods (53.4%), reflecting a decrease in the use of test-tube crossmatching and a corresponding increase in the use of the gel method. Table 6 lists the various crossmatch methods employed for samples with an antibody. Use of SPRCA and LMWT remained constant at 1% or less each. By the end of the study period, the tube crossmatch method using LISS remained the most-common tube-based method used for alloimmunized patients (32.6%). The use of PEG AHG remained fairly constant throughout the study period (approximately 11%).

Electronic Crossmatching.--From 2005 until the start of 2007, 0.1% or fewer participants reported using an electronic crossmatch for alloimmunized patients. The electronic or computer crossmatch is computer-based analysis of data entered from testing done on both the donor unit and recipient blood samples, including ABO/ Rh typing and an antibody screen of the intended recipient. This type of crossmatching can only be used when the recipient has a negative antibody screen.

In 2007, the J Survey reporting design was reconfigured and did not include the electronic crossmatch as a method, reflecting the intent of the survey as serologic testing. Surveys 2009-JB and 2010-JC included supplemental questions for participants about current practices in computer and electronic crossmatching. In the 2009 survey, of 3221 laboratories responding, 422 (13.1%) reported that they currently perform electronic crossmatching; about half of laboratories (1598; 49.6%) reported requiring samples from 2 different collections from a patient to perform electronic crossmatching. In 2010, the number and percentage of laboratories reporting the use of an electronic crossmatch had increased to 565 laboratories (16.5% of 3410 survey respondents).

COMMENT

Pretransfusion compatibility-testing requirements are defined and delineated in the United States by accreditation, regulatory, and standard-setting organizations. Although each laboratory may not, therefore, have the flexibility or choice in certain requirements for pretransfusion compatibility testing, the selection of which method to use for the testing rests with the laboratory. The selection of a particular method for performing pretransfusion compatibility testing may be driven by cost, ease of use, familiarity, or test performance or for a combination of reasons.

Proficiency testing requirements in the United States dictate that a laboratory uses its primary method for patient testing during proficiency testing and that proficiency testing samples be tested in the laboratory in the same manner as a patient sample. Thus, a limitation of this report is that these data reflect the primary method used in laboratories that subscribe to CAP as their proficiency-testing provider and do not capture the alternate or other methods that may be in use in the laboratory. Another limitation of this study is that the data analyzed are the results from a single provider of proficiency-testing material for pretransfusion compatibility testing in the United States. Thus, it is not clear whether there is a selection bias regarding the laboratories that subscribe to the CAP proficiency-testing program because a laboratory "self-selects" when it makes the decision to use a proficiency testing provider.

Tables 1 through 6 display the various pretransfusion testing methods used by the laboratories participating in the CAP 2005 through 2010 JA surveys. This analysis used, as its basis, the largest data set of US laboratories performing and reporting pretransfusion compatibility testing methods.

ABO Grouping

The test tube is the preferred ABO grouping method. An upward trend (from 8.6% to 23.1% of participants) in gel-based ABO-grouping methods has been observed.

Rhesus Typing

The survey data show that the preferred Rh(D) typing method is the tube test. An upward trend (from 8.7% to 23.2% of participants) in gel-based Rh(D)-typing methods has been noted.

Antibody Screening (Detection)

The preferred antibody detection method is the gel method, followed by tube testing, with LISS as an enhancement reagent. A downward trend by participants in the use of all tube-testing methods and a corresponding upward trend in gel testing for antibody screening were observed (see Table 3).

Crossmatching

Crossmatches for Nonalloimmunized Patients.--The gel crossmatch is the most commonly used crossmatch method (49.9%) for patients who are not alloimmunized, followed by the immediate spin and the LISS-AHG methods. Performance of an electronic/computer crossmatch, which is an acceptable method for such patients, was also assessed in 2004, when fewer than 2.5% of laboratories reported the use of this methodology. In 2010, in a supplemental-question survey, the reported use of electronic/computer crossmatches had increased to 16.5% of respondents to the survey question.

Crossmatches for Alloimmunized Patients.--The survey data suggest that the preferred crossmatch method for alloimmunized patients is the gel method. Of the available tube test methods (LISS-AHG, PEG-AHG, ALB-AHG, or saline-AHG), the LISS-AHG method appears to be the most frequently used. There has been a downward trend in the use of the tube tests for crossmatching of alloimmunized patients, with a corresponding upward trend in the use of gel-AHG method of crossmatch. The use of the immediate spin crossmatch and electronic crossmatch are not appropriate in the setting of an alloimmunized patient; on the J-Surveys, less than 4% of laboratories reported using those methods for alloimmunized patients. The use of the immediate spin method for crossmatch of alloimmunized patients is very low and is likely used only when a laboratory fails to detect an unexpected antibody on the antibody screen on the proficiency-testing sample (see the Figure). Use of the PEG method remained fairly stable during the study period, whereas use of the LISS method decreased more than the other tube methods (from 47.3% to 32.6%).

Global Context

The increased use of column agglutination methodology observed in our report has been observed in laboratory practice outside of the United States. In 2007, Milkins (22) described, in a report of the UK National External Quality Assessment Scheme (proficiency testing) data, (23) that technology used for grouping and screening had shifted from tubes and liquid-phase microplates to gel technology, with 65% of participants using gel methods for ABO grouping and 90% using gel methods for screening. Our report shows an increase in the use of gel methods across all analytes, with greater use of tube testing in North America compared with data from the United Kingdom.

SUMMARY

Most North American laboratories participating in the CAP proficiency-testing program currently favor tube methods when performing the standard, manual pretransfusion tests for ABO grouping and Rh typing. However, the gel method is preferred for antibody screening. Laboratories are currently about evenly split between gel and tube methods when performing crossmatching. The significant upward trend in the use of gel-based methodologies, identified in an analysis of 2001-2004 proficiency testing data (Shulman et al (2)), persists. Data collection and analysis of results from the CAP Interlaboratory Comparison Program Survey provide insights into current trends in North American practices of pretransfusion compatibility testing.

We acknowledge the College of American Pathologists Transfusion Medicine Resource Committee (TMRC). The following TMRC members, who authored one or more of the J Surveys Final Critique discussions from 2005 (Survey JA) through 2010 (Survey JC), are acknowledged collaborators: Kristin Alcorn, MD; James P. AuBuchon, MD; Mark E. Brecher, MD; Jerome L. Gottschall, MD; Thomas G. Hirose, MD; Lesley Kresie, MD; Susan D. Roseff, MD; S. Gerald Sandler, MD; Zbigniew M. Szczepiorkowski, MD, PhD; Lowell Tilzer, MD, PhD; and Lee Ann Weitekamp, MD.

References

(1.) Department of Health and Human Services. Clinical laboratory improvement amendments of 1988: final rule. Fed Regist. 1992; 57(40):7001-7186. Codified at 42 CFR 1493.959. http://edocket.access.gpo.gov/cfr_2010/octqtr/pdf/ 42cfr493.959.pdf. Accessed July 18, 2011.

(2.) Shulman IA, Maffei LM, Downes KA. North American pretransfusion testing practices, 2001-2004: results from the College of American Pathologists Interlaboratory Comparison Program survey data, 2001-2004. Arch Pathol Lab Med. 2005; 129(8):984-989.

(3.) Downes KA, Shulman IA. 2005 CAP Surveys: Comprehensive Transfusion Medicine Survey--2005 Set JA, Interlaboratory Comparison Program. Northfield, IL: College of American Pathologists; 2005.

(4.) College of American Pathologists. 2005 CAP Surveys: Comprehensive Transfusion Medicine Survey--2005 Set JB, Interlaboratory Comparison Program. Northfield, IL: College of American Pathologists; 2005.

(5.) AuBuchon JP. 2005 CAP Surveys: Comprehensive Transfusion Medicine Survey--2005 Set JC, Interlaboratory Comparison Program. Northfield, IL: College of American Pathologists; 2005.

(6.) Downes KA, Shulman IA. 2006 CAP Surveys: Comprehensive Transfusion Medicine Survey--2006 Set JA, Interlaboratory Comparison Program. Northfield, IL: College of American Pathologists; 2006.

(7.) Aqui NA, AuBuchon JP. 2006 CAP Surveys: Comprehensive Transfusion Medicine Survey--2006 Set JB, Interlaboratory Comparison Program. Northfield, IL: College of American Pathologists; 2006.

(8.) Alcorn KW. 2006 CAP Surveys: Comprehensive Transfusion Medicine Survey--2006 Set JC, Interlaboratory Comparison Program. Northfield, IL: College of American Pathologists; 2006.

(9.) Gottschall JL. 2007 CAP Surveys: Comprehensive Transfusion Medicine Survey--2007 Set JA, Interlaboratory Comparison Program. Northfield, IL: College of American Pathologists; 2007.

(10.) Hirose TG. 2007 CAP Surveys: Comprehensive Transfusion Medicine Survey--2007 Set JB, Interlaboratory Comparison Program. Northfield, IL: College of American Pathologists; 2007.

(11.) Szczepiorkowski ZM. 2007 CAP Surveys: Comprehensive Transfusion Medicine Survey--2007 Set JC, Interlaboratory Comparison Program. Northfield, IL: College of American Pathologists; 2007.

(12.) Roseff S. 2008 CAP Surveys: Comprehensive Transfusion Medicine Survey--2008 Set J-A, Interlaboratory Comparison Program. Northfield, IL: College of American Pathologists; 2008.

(13.) Kresie L, Pirumyam G. 2008 CAP Surveys: Comprehensive Transfusion Medicine Survey--2008 Set JB, Interlaboratory Comparison Program. Northfield, IL: College of American Pathologists; 2008.

(14.) Gottschall JL. 2008 CAP Surveys: Comprehensive Transfusion Medicine Survey--2008 Set J-C, Interlaboratory Comparison Program. Northfield, IL: College of American Pathologists; 2008.

(15.) Downes KA, Boral L. 2009 CAP Surveys: Comprehensive Transfusion Medicine Survey--2009 SetJA, Interlaboratory Comparison Program. Northfield, IL: College of American Pathologists; 2009.

(16.) Weitekamp L. 2009 CAP Surveys: Comprehensive Transfusion Medicine Survey--2009 Set JB, Interlaboratory Comparison Program. Northfield, IL: College of American Pathologists; 2009.

(17.) Kresie L 2009 CAP Surveys: Comprehensive Transfusion Medicine Survey--2009 Set JC, Interlaboratory Comparison Program. Northfield, IL: College of American Pathologists; 2009.

(18.) Brecher MB. 2010 CAP Surveys: Comprehensive Transfusion Medicine Survey--2010 Set JA, Interlaboratory Comparison Program. Northfield, IL: College of American Pathologists; 2010.

(19.) Tilzer, LA. 2010 CAP Surveys: Comprehensive Transfusion Medicine Survey--2010 Set JB, Interlaboratory Comparison Program. Northfield, IL: College of American Pathologists; 2010.

(20.) Downes KA, Sandler, SG. 2010 CAP Surveys: Comprehensive Transfusion Medicine Survey--2010 Set JC, Interlaboratory Comparison Program. Northfield, IL: College of American Pathologists; 2010.

(21.) Carson TH, ed. Standard 5.13.3: Pretransfusion testing of patient blood. In: Carson TH, ed. Standards for Blood Banks and Transfusion Services. 27th ed. Bethesda, MD: American Association of Blood Banks; 2011.

(22.) Milkins C. Performance and practice in UK hospital transfusion laboratories. Transfus Apher Sci. 2007; 36(2):129-131.

(23.) Knowles SM, Milkins CE, Chapman JF, Scott M. The United Kingdom National External Quality Assessment Scheme (blood transfusion laboratory practice): trends in proficiency and practice between 1985 and 2000. Transfus Med. 2002; 12(1):11-23.

Katharine A. Downes, MD; Ira A. Shulman, MD

Accepted for publication August 23, 2011.

From the Department of Pathology, University Hospitals Case Medical Center, Case Western Reserve University, Cleveland, Ohio (Dr Downes); and the Transfusion Medicine Services Group, Keck School of Medicine, University of Southern California, Los Angeles and the Department of Pathology, Los Angeles County-University of Southern California Medical Center (Dr Shulman).

The authors have no relevant financial interest in the products or companies described in this article.

Reprints: Ira A. Shulman, MD, Department of Pathology, Los Angeles County-University of Southern California Medical Center, 1100 N State Street, Clinic Tower A7E-115, Los Angeles, CA 90033 (e-mail: ishulman@usc.edu).
Table 1. Percentage of Laboratories Using Each Method for ABO
Group Determination

 Proficiency Test, y

 2005 2006 2007
Method
Used JA JB JC JA JB JC JA JB JC

Tube 90.7 89.7 89.7 89 88 87.7 85.8 84.5 83.6
Gel 8.6 9.6 9.7 10.4 11.5 11.9 13.7 15 15.9
LMWT 0.7 0.7 0.6 0.6 0.5 0.4 0.5 0.5 0.5
SPRCA NR NR NR NR NR NR NR NR NR

 Proficiency Test, y

 2008 2009 2010
Method
Used JA JB JC JA JB JC JA JB JC

Tube 83.2 82 81.5 79.8 78.7 78.1 77.5 76.5 76.7
Gel 16.5 17.8 18.3 20 21.1 21.8 22.4 23.3 23.1
LMWT 0.3 0.2 0.2 0.2 0.2 0.1 0.1 0.2 0.2
SPRCA NR NR NR NR NR NR NR <0.1 NR

Abbreviations: JA, JB, JC, College of American Pathologists
Interlaboratory Comparison Program Transfusion Medicine (J)
Survey is mailed to subscribing participants 3 times per calendar
year (JA, JB, JC);LMWT, liquid microwell test; NR, not reported;
SPRCA, solid phase red cell adherence.

Table 2. Percentage of Laboratories Using Each Method for Rh
Determination

 Proficiency Test, y

 2005 2006 2007
Method
Used JA JB JC JA JB JC JA JB JC

Tube 90.7 89.7 89.7 88.9 88 87.7 85.9 84.7 83.8
Gel 8.7 9.7 9.8 10.6 11.6 11.9 13.6 15 15.8
LMWT 0.6 0.6 0.5 0.5 0.4 0.4 0.5 0.3 0.4
SPRCA NR <0.1 NR NR NR NR NR NR NR

 Proficiency Test, y

 2008 2009 2010
Method
Used JA JB JC JA JB JC JA JB JC

Tube 83.2 82 81.5 79.8 78.6 78.1 77.5 76.6 76.6
Gel 16.5 17.8 18.4 20 21.2 21.8 22.4 23.3 23.2
LMWT 0.3 0.2 0.1 0.2 0.2 0.1 0.1 0.1 0.2
SPRCA NR NR NR NR NR NR NR <0.1 NR

Abbreviations: JA, JB, JC, College of American Pathologists
Interlaboratory Comparison Program Transfusion Medicine (J)
Survey is mailed to subscribing participants 3 times per calendar
year (JA, JB, JC); LMWT, liquid microwell test; NR, not reported;
SPRCA, solid phase red cell adherence.

Table 3. Percentage of Laboratories Using Each Method
for Antibody Detection

 Proficiency Test, y

 2005 2006
Method
Used JA JB JC JA JB JC

Tube-LISS 38.6 36.7 35.9 35.2 34.2 33.3
Tube-PEG 7.5 7.8 7.7 7.6 7.7 7.8
Albumin AHG 5.5 5.3 4.9 4.8 4.4 4.3
Tube-saline 2.1 2.2 2 2 1.7 1.7
Gel 43.7 45.5 47 48 49.6 50.6
LMWT 0.3 0.2 0.3 0.2 0.2 0.2
SPRCA 2.3 2.3 2.2 2.2 2.2 2.1

 Proficiency Test, y

 2007 2008
Method
Used JA JB JC JA JB JC

Tube-LISS 30.3 29 28.4 26.6 25.3 24.4
Tube-PEG 7.8 7.2 7.2 7.2 6.9 6.9
Albumin AHG 3.8 3.8 3.7 3.3 3.3 3.2
Tube-saline 1.5 1.5 1.4 1.4 1.3 1.2
Gel 53.8 55.7 56.3 58.7 60.4 61.2
LMWT 0.3 0.2 0.2 0.1 0.1 0.1
SPRCA 2.5 2.6 2.8 2.7 2.7 3

 Proficiency Test, y

 2009 2010
Method
Used JA JB JC JA JB JC

Tube-LISS 23 22.3 22.1 21.6 21.1 21.1
Tube-PEG 6.7 7.3 7.5 7.6 7.7 7.9
Albumin AHG 2.9 2.5 2.3 2 1.9 1.9
Tube-saline 1.3 1.3 1.2 1.1 1.2 1.3
Gel 62.7 63.3 63.5 64.2 64.6 64.3
LMWT 0.1 0.1 0.1 0.1 0.1 0.1
SPRCA 3.3 3.2 3.3 3.4 3.4 3.4

Abbreviations: JA, JB, JC, College of American Pathologists
Interlaboratory Comparison Program Transfusion Medicine (J)
Survey is mailed to subscribing participants 3 times per
calendar year (JA, JB, JC); AHG, antihuman globulin; LISS,
low ionic strength solution; LMWT, liquid microwell test;
PEG, polyethylene glycol; SPRCA, solid phase red cell adherence.

Table 4. Antibody-Detection Screening Cells Used (2 Cells,
3 Cells, or Other) by Method Selected

 2005-JA

Method 2-Cell 3-Cell Other
Used Screen, % Screen, % Screen, (a) %

LISS-AHG 31.7 67.4 0.9
PEG-AHG 32 67.7 0.3
Albumin-AHG 48.5 50 1.5
Saline AHG 45.3 53.3 1.4
Tube overall 33.9 65.2 0.9
Gel 46.2 53 0.8
LMWT 16.7 25 58.3
SPRCA 65.4 3.7 30.9

 2010-JC

Method 2-Cell 3-Cell Other
Used Screen, % Screen, % Screen, (a) %

LISS-AHG 29.8 69.3 0.9
PEG-AHG 24.1 74.1 1.8
Albumin-AHG 55.9 42.6 1.5
Saline AHG 33.3 64.4 2.3
Tube overall 30.1 68.7 1.2
Gel 45.5 54.3 0.2
LMWT 0 50 50
SPRCA 24.6 61.1 14.3

Abbreviations: JA and JC, College of American Pathologists
Interlaboratory Comparison Program Transfusion Medicine (J)
Survey is mailed to subscribing participants 3 times per
calendar year (JA, JB, JC); AHG, antihuman globulin; LISS,
low ionic strength solution; LMWT, liquid microwell test;
PEG, polyethylene glycol; SPRCA, solid phase red cell
adherence.

(a) Other screen methods included both 4-cell screening
and one suspension of pooled cells prepared by the
manufacturer.

Table 5. Percentage of Laboratories Using Each Crossmatch
Method for Nonalloimmunized Patients/Samples

 Proficiency Test, y

 2005 2006

Method Used JA JB JC JA JB JC

Tube-LISS 18.1 17.8 15.8 15.4 15.9 14.9
Tube-PEG 2.9 2.8 2.8 2.8 2.9 3
Albumin-AHG 3.7 3.7 3.3 3.4 3.1 3.2
Tube-saline 1.4 1.5 1.3 1.1 3.1 1.2
Gel 30.8 31.8 32.6 33.9 35.4 35.8
LMWT 0.1 0.1 <0.1 <0.1 0.1 0.1
SPRCA 0.1 0.1 0.2 0.1 0.1 0.1
IS 40.5 39.6 40.8 40.3 38.5 39.2
EXM/CXM 2.4 2.6 3.2 3 2.8 2.5

 Proficiency Test, y

 2007 2008

Method Used JA JB JC JA JB JC

Tube-LISS 7.3 13.6 13.3 7.3 11.7 10.6
Tube-PEG 1.2 2.6 2.8 1.5 2.8 2.7
Albumin-AHG 1.7 3.1 2.7 1.6 2.6 2.3
Tube-saline 0.7 0.8 0.9 0.6 0.9 0.8
Gel 38.3 41.4 41.6 43.6 44.6 45.2
LMWT 0.2 <0.1 0.1 0.1 <0.1 0.1
SPRCA 0.1 0.2 0.3 0.3 0.3 0.3
IS 48.4 38.3 38.3 45 37.1 38
EXM/CXM 2.1 NR NR NR NR NR

 Proficiency Test, y

 2009 2010

Method Used JA JB JC JA JB JC

Tube-LISS 6.5 11.6 9.8 10.2 9.4 9.7
Tube-PEG 1.5 3.1 2.3 2.2 2.6 2.4
Albumin-AHG 1.5 1.6 1.5 1.4 1.5 1.4
Tube-saline 0.5 1.3 0.6 0.6 0.6 0.6
Gel 46.9 47.8 49.1 49.3 49.8 49.3
LMWT 0.1 <0.1 <0.1 <0.1 0.1 0.1
SPRCA 0.3 0.4 0.4 0.3 0.4 0.4
IS 42.7 34.2 36.3 36 35.6 36.1
EXM/CXM NR NR NR NR NR NR

Abbreviations: JA, JB, JC, College of American Pathologists
Interlaboratory Comparison Program Transfusion Medicine (J)
Survey is mailed to subscribing participants 3 times per
calendar year (JA, JB, JC);AHG, antihuman globulin; EXM/CXM,
electronic/computer crossmatch; IS, immediate spin; LISS,
low ionic strength solution; LMWT, liquid microwell test; NR,
not reported; PEG, polyethylene glycol; SPRCA, solid phase
red cell adherence.

Table 6. Percentage of Laboratories Using Each Crossmatch
Method for Alloimmunized Patients/Samples

 Proficiency Test, y

 2005 2006

Method Used JA JB JC JA JB JC

Tube-LISS 47.3 44.6 43.6 42.1 42.8 41.5
Tube-PEG 11 11.2 11.5 10.9 11.3 11.3
Albumin-AHG 5.9 5.4 4.7 4.8 4.7 4.8
Tube-saline 3.7 3.8 4.3 3.3 3.9 3.3
Gel 31.6 33.4 34.5 35.1 36.3 37.4
LMWT 0.1 0.1 0.3 <0.1 0.1 0.1
SPRCA 0.2 0.2 0.3 0.3 0.2 0.1
IS 0.2 1.3 0.8 3.5 0.7 1.5
EXM/CXM 0 <0.1 <0.1 <0.1 <0.1 0

 Proficiency Test, y

 2007 2008

Method Used JA JB JC JA JB JC

Tube-LISS 39.7 39.2 39.2 37.0 36.2 36
Tube-PEG 10.9 10.9 11 11 11.4 11.4
Albumin-AHG 4.2 4.3 4.3 3.9 4.2 3.8
Tube-saline 3.9 3.4 3.3 3.2 3.2 3
Gel 39.8 41.5 41.3 43.8 44.4 45.1
LMWT 0.2 0 0.1 0.1 <0.1 0.1
SPRCA 0.2 0.2 0.3 0.3 0.3 0.3
IS 1.1 0.5 0.5 0.7 0.3 0.3
EXM/CXM 0 NR NR NR NR NR

 Proficiency Test, y

 2009 2010

Method Used JA JB JC JA JB JC

Tube-LISS 34.6 34.1 33.2 33 32.1 32.6
Tube-PEG 10.9 11.4 11.4 11.6 11.9 11.9
Albumin-AHG 3.3 2.9 3 2.9 2.8 2.7
Tube-saline 2.9 2.8 2.8 2.4 2.4 2.4
Gel 47.2 48 48.9 49.4 50.1 49.8
LMWT 0.1 0.1 <0.1 <0.1 0.1 <0.1
SPRCA 0.3 0.3 0.4 0.3 0.4 0.4
IS 0.7 0.4 0.3 0.4 0.2 0.2
EXM/CXM NR NR NR NR NR NR

Abbreviations: JA, JB, JC, College of American Pathologists
Interlaboratory Comparison Program Transfusion Medicine (J)
Survey is mailed to subscribing participants 3 times per
calendar year (JA, JB, JC);AHG, antihuman globulin; EXM/CXM,
electronic/computer crossmatch; IS, immediate spin; LISS,
low ionic strength solution; LMWT, liquid microwell test; NR,
not reported; PEG, polyethylene glycol; SPRCA, solid phase red
cell adherence.
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Title Annotation:CAP Laboratory Improvement Programs
Author:Downes, Katharine A.; Shulman, Ira A.
Publication:Archives of Pathology & Laboratory Medicine
Date:Mar 1, 2012
Words:5474
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