A national Transfusion Register of Irregular Antibodies and Cross (X)-match Problems: TRIX, a 10-year analysis.

BACKGROUND: The Transfusion Register of Irregular Antibodies and Cross-match Problems (TRIX) is a unique national database in the Netherlands that was launched in 2007. Transfusion laboratories register the presence of irregular RBC alloantibodies for their patients and can consult the database for information that is relevant for pretransfusion testing, unknown in their own laboratory information system. STUDY DESIGN AND METHODS: Data from the TRIX database 10 years after implementation have been analyzed to demonstrate the added value of TRIX for transfusion practice. TRIX antibody registration, antibody disappearance likelihood, and differences between men and women have been analyzed and evaluated. RESULTS: In the 10-year period 2007 to 2016, a total of 80,164 alloantibodies have been identified and registered in 62,110 individuals. Of the antibodies, 81% were reported in women and 19% in men (female:male, 4.3:1). Rh (DCcEe and Cw ), K, Fya , and Jka antibodies account for 65.6% of all antibody registrations. M and Lewis antibodies account for 18.6% of all antibodies. Antibody disappearance likelihood is relatively high for the clinically relevant antibodies directed against Jkb , s, Fyb , and e. Antibodies directed against D, Fya , and K have a relatively low antibody disappearance likelihood. CONCLUSION: TRIX is a unique and useful tool for transfusion laboratories for timely and up-to-date information on the presence of erythrocyte antibodies, which improves pretransfusion testing and compatible blood selection. TRIX also provides macro data on the prevalence of individual antibodies and antibody disappearance likelihoods that can be used for developing blood type matching strategies for patient groups at risk. © 2019 AABB.

Reasons for ordering laboratory tests and relationship with frequency of abnormal results.

OBJECTIVE: Laboratory tests are ordered on a daily basis, even though disease probability is often very low. Abnormal results, especially mildly abnormal results, can be difficult to interpret in these circumstances. Further insights into the occurrence of abnormalities can help improve rational test ordering and test interpretation. The objective was therefore to examine the frequency of mildly and markedly abnormal results and their relationship with physicians' reasons for ordering tests. DESIGN: Prospective study. Participants. A total of 87 primary care physicians in the Netherlands collected data on 1775 patients. MAIN OUTCOME MEASURES: The physicians recorded the reason for ordering the tests, the most probable diagnosis and the pretest probability. The laboratories' reference values and specified "action limits" were used to assess the number of abnormal results and markedly abnormal results, respectively. RESULTS: Laboratory results were received for 1621 patients and 15,603 tests were reported (mean 9.6). The proportion of abnormal test results increased with increasing pretest probability (from 13.9% to 34.7%) and was 13.4% for tests ordered to reassure the patient and 13.3% for psychosocial diagnoses. The proportion of patients with at least one abnormal test result was high: 53.1% for tests ordered to reassure and 57.7% in patients with low pretest probability. Corresponding values for a marked abnormality were 11.1% and 12.4%, respectively. CONCLUSION: Abnormal laboratory test results were frequent, even when pretest probability was low. Physicians should therefore carefully consider when tests are necessary. Future research could explore physicians' interpretation of test results and its impact on diagnosis and management.

Predicting the need for further thrombosis diagnostics in suspected DVT is increased by using age adjusted D-dimer values.

INTRODUCTION: Negative D-dimer values combined with clinical decision rules by Wells can help in excluding the diagnosis deep vein thrombosis (DVT). However, with increasing age D-dimer levels increase, possibly leading to false positive results. MATERIALS AND METHODS: In this prospective study we compared the specificity and sensitivity of conventional D-dimer levels and age adjusted D-dimer levels in the diagnosis of DVT. We included 528 patients, all over 50years of age, of whom 117 had a DVT confirmed by duplex ultrasound. RESULTS AND CONCLUSION: Age adjusted D-dimer cut-off values had higher specificity compared to conventional D-dimer values (24.6% vs. 8.5%) as well as a higher negative predictive value (91,8% vs. 89,7%). Therefore we conclude that age adjusted D-dimer levels could be used to exclude the diagnosis of DVT. Ultimately this could lead to the performance of less duplex ultrasounds reducing health care costs and discomfort for the patient.