Evaluating automated titre score as an alternative to continuous flow analysis for the prediction of passive anti-D in pregnancy.

OBJECTIVES: To evaluate the potential of the automated titre score (TS) as an alternative method to continuous flow analysis (CFA) for the prediction of the nature of anti-D in pregnancy. BACKGROUND: The 2016 revised British Society for Haematology (BSH) antenatal guidelines recommended a measurement of anti-D concentration by CFA to ensure the detection of potential immune anti-D. Due to high referral costs and resource pressures, uptake has been challenging for hospital laboratories. Serious Hazards of transfusion (SHOT) data have previously shown that this has contributed to missed antenatal follow ups for women with immune anti-D and neonates affected by haemolytic disease of the fetus/newborn. METHODS/MATERIALS: In this multicentre comparative study, samples referred for CFA quantification were also tested by an ORTHO VISION automated anti-D indirect antiglobulin test (IAT) serial dilution and then converted to TS. CFA results and history of anti-D prophylaxis were used to categorise samples as passive or immune, with the aim of determining a potential TS cut-off for CFA referral of at risk patients. RESULTS: Five UK National Health Service (NHS) trusts generated a total of 196 anti-D TS results, of which 128 were classified as passive and 68 as immune. Diagnostic testing of CFA and TS values indicated a TS cut-off of 35 to assist in distinguishing the nature of anti-D. Using this cut-off, 175 (89%) results were correctly assigned into the passive or immune range, giving a specificity of 92.19% and a negative predictive value of 91.47%. CONCLUSION: TS in conjunction with clinical and anti-D prophylaxis history can be used as a viable and cost-effective alternative to CFA in a hospital laboratory setting.

Cost-effectiveness analysis of diagnostic-therapeutic strategies for visceral leishmaniasis in Brazil.

INTRODUCTION: Visceral leishmaniasis (VL) is fatal if not diagnosed and treated. This study aimed to estimate the cost-effectiveness of diagnostic-therapeutic alternatives for VL in Brazil. METHODS: A decision model estimated the life expectancy and costs of six diagnostic-therapeutic strategies. RESULTS: IT LEISH + liposomal amphotericin B emerged the best option, presenting lower costs and higher effectiveness. DAT-LPC + liposomal amphotericin B showed an incremental cost-effectiveness ratio of US$ 326.31 per life year. CONCLUSIONS: These findings indicate the feasibility of incorporating DAT and designating liposomal amphotericin B as the first-line drug for VL in Brazil.

Cost-effectiveness analysis of diagnostic-therapeutic strategies for visceral leishmaniasis in Brazil

Abstract INTRODUCTION: Visceral leishmaniasis (VL) is fatal if not diagnosed and treated. This study aimed to estimate the cost-effectiveness of diagnostic-therapeutic alternatives for VL in Brazil. METHODS: A decision model estimated the life expectancy and costs of six diagnostic-therapeutic strategies. RESULTS: IT LEISH + liposomal amphotericin B emerged the best option, presenting lower costs and higher effectiveness. DAT-LPC + liposomal amphotericin B showed an incremental cost-effectiveness ratio of US$ 326.31 per life year. CONCLUSIONS: These findings indicate the feasibility of incorporating DAT and designating liposomal amphotericin B as the first-line drug for VL in Brazil.

Cost-benefit analysis of indirect antiglobulin screening in Rh(D)-negative women at 28 weeks of gestation.

OBJECTIVE: To estimate the potential economic benefit of reduced indirect antiglobulin screening for Rh(D)-negative pregnant women. METHODS: A chart review of all Rh(D)-negative mothers delivering at the University of Washington from 2002 to 2012 was conducted to determine the rate of gestational seroconversion to anti-D antibodies before 28 weeks of gestation. A decision tree was constructed to estimate the economic effects of eliminating the indirect antiglobulin screen at 28 weeks of gestation and instead immunizing all Rh(D)-negative, anti-D antibody-negative women with anti-D immune globulin at that time. A theoretical cohort of 100,000 women was modeled. Probabilities and costs were derived from published literature, chart review, and expert opinion. Univariate sensitivity analyses followed by a Monte Carlo analysis examined assumptions and uncertainties in our model across entire distributions. RESULTS: The seroconversion rate of development of anti-D antibodies before 28 weeks of gestation in the cohort analyzed was 0.099% (2/2,029 women). From a societal perspective, the expected cost savings from implementing the reduced indirect antiglobulin screening strategy, per 100,000 women, ranged from $6 to $7.7 million. The overall cost savings for implementing this strategy in the United States for 1 year ranged from $34.7 to $35.6 million. This strategy remained cost-beneficial when varying our parameters (eg, anti-D immune globulin, antibody test cost) to their logical extremes. The Monte Carlo analysis verified the cost savings of our strategy. CONCLUSION: The updated seroconversion rate and our model suggest that eliminating the 28-week antibody screen would be cost-beneficial from a societal perspective while posing minimal potential harm to the recipients.

Outcome and cost analysis of implementing selective Coombs testing in the newborn nursery.

OBJECTIVE: (1) To determine whether infants born to O+ mothers who had selective cord-blood testing would have higher rates of clinically significant hyperbilirubinemia compared with those newborns who had routine cord-blood testing. (2) To determine the amount of cost savings by implementing a policy of selective cord-blood testing in newborns born to O+ mothers. STUDY DESIGN: We conducted a retrospective pre/post intervention chart review on all infants in the normal newborn nursery at Loyola, born to blood type O+ women between 1 April 2008 and 1 April 2009. The pre-intervention group (routine testing) included infants born within 6 months before implementation of a new policy. The post-intervention group (selective testing) included infants born within 6 months following the implementation of a new policy. Data were collected for each of these groups regarding clinically significant hyperbilirubinemia. RESULT: All 250 of the infants in the routine testing group had a cord-blood type and Coombs done, whereas 42 of 164 (25%) infants in the selective group had testing done. By the end of the 6 months following the policy change, only 8% of infants were undergoing cord testing. When comparing routine vs selective testing, there was no statistically significant difference in the 24-h serum bilirubin, rate of phototherapy during the birth hospitalization, rate of readmission for hyperbilirubinemia or peak serum bilirubin level at readmission. The 92% reduction of cord-blood typing and Coombs testing would lead to a cost saving of $4100 per year to our hospital and $18 900 per year to our patients, and 95 h per year of technician time to perform these tests. When extrapolated to Illinois births in 2008, this would lead to an annual cost saving of almost $800 000 to Illinois hospitals and about $3.6 million to patients. CONCLUSION: Selective newborn cord testing of infants born to O+ mothers can decrease the use of resources and costs without increasing the risk of clinically significant hyperbilirubinemia.

Do patients with autoantibodies or clinically insignificant alloantibodies require an indirect antiglobulin test crossmatch?

BACKGROUND: Compatibility testing is the standard protocol that identifies suitable blood for patients requiring transfusion. If the antibody screen is negative or no clinically significant antibodies are detected, BCSH guidelines and AABB standards allow an immediate-spin crossmatch (IS XM) or even electronic issue. The testing requirement is less clear where autoantibodies or non-clinically significant alloantibodies compromise the indirect antiglobulin test crossmatch (IAT XM). Performing an IAT XM will give a mismatched result anyway, delays the supply of blood to the patient, and provides no additional benefit or safety. STUDY DESIGN AND METHODS: From January 2002 to April 2006, the provision of blood for autoimmune hemolytic anemia (AIHA) patients with autoantibodies and no alloantibodies as well as patients with alloantibodies that exhibited a "high-titer, low-avidity" (HTLA) mode of reactivity was reviewed. RESULTS: A total of 222 AIHA patients (428 samples) with autoantibodies had 1585 units of red cells supplied after IAT XM; 1308 (82.5%) were mismatched. In 50 patients (80 samples) with HTLA-like antibodies, 286 units of 328 (87.2%) were mismatched by IAT XM. CONCLUSION: No adverse reactions were reported for the study groups where "suitable" blood was provided after a serologically mismatched IAT XM. No additional benefit for these patients can be claimed by performing an IAT XM over an IS XM, as a check of ABO match. The IAT XM is both costly and time-consuming. It is proposed that for these study group patients, a reduction to an IS XM can be applied and can be beneficial.

Evaluation of 2-column agglutination versus conventional tube technique for antibody screening.

The study aimed to determine the specificity and sensitivity of the Ortho BioVue two-column agglutination system for the detection of low concentrations of clinically significant antibodies in serum. The BioVue system was compared with the conventional tube technique (LISS-Coombs indirect antiglobulin test), and the two-stage Papenzyme test was used to resolve discrepancies between the two methods. We tested 3000 serum samples from randomly selected patients at King Hussein Medical Centre. Both the antibody screening and identification gave negative results in 2952 patients and positive results in 48 patients. We found the BioVue system to be the more sensitive technique. However, if papain enzyme-treated cells were included in the conventional tube technique when applied to antibody screening and identification, both methods would be of comparable sensitivity.

Revisiting the issue: can the reading for serologic reactivity following 37 degrees C incubation be omitted?

BACKGROUND: Omitting the 37 degrees C reading from screening tests for unexpected antibodies results in failure to detect some Rh, K, and Jk agglutinins of potential significance (wanted positives). However, this measure avoids unwanted positive tests due to cold agglutinins. STUDY DESIGN AND METHODS: Using data from prior publications, actual risk calculations (ARCs) were made to predict the risk of eliminating the 37 degrees C reading, pretransfusion direct antiglobulin test (DAT), and routine indirect antiglobulin crossmatch (IAT-XM). ARCs used the equation: wanted positives missed x 0.34 (or 0.80) x 5 x percent antigen-positive, where 0.34 = percent of patients transfused (ARCs for 37 degrees C reading and DAT); 0.80 = percent of crossmatched patients transfused (ARCs for IAT-XM); 5 = average number of units transfused. Following elimination of the 37 degrees C reading, the impact of this change on patient care was monitored. Antibody detection and identification data and transfusion reaction reports for 6 months after the change were reviewed. Recently transfused patients with new antibodies were evaluated for immune hemolysis by review of clinical and laboratory data. The findings were compared with those from the same dates of the preceding year. RESULTS: The risk of transfusing incompatible blood by eliminating the DAT, IAT-XM, and 37 degrees C reading is approximately 1:13,000, 1:2,000, and 1:2,400 units transfused, respectively. The cumulative risk from eliminating all three tests is approximately. 1 :1,000 units. With respect to the 37 degrees C reading, there were no differences between the pre-change and post-change study periods in the incidence of reported transfusion reactions or cases of immune hemolysis associated with newly formed antibodies. However, unwanted positive tests decreased from 162 to 61 following elimination of the 37 degrees C reading. This represents a decrease of 20 percent in the number of samples requiring antibody identification annually. CONCLUSIONS: Eliminating the 37 degrees C reading from pretransfusion antibody screening tests imposes less risk than omitting the routine IAT-XM, and it avoids the time and costs of evaluating unwanted positive tests, thus reducing expenditures and delays in patient care.

Wasted health care dollars. Routine cord blood type and Coombs' testing.

OBJECTIVE: To determine if selective newborn cord blood testing (NCBT) could contain costs without increasing morbidity of hemolytic disease of the newborn (HDN). DESIGN: A national telephone survey confirmed the common practice of routine blood type and Coombs' NCBT. Two 12-month study arms, retrospective and prospective, were conducted. Hemolytic disease of the newborn was studied retrospectively under an unrestricted NCBT policy. Then, HDN was studied after a policy change that restricted NCBT to patients in newborn intensive care units and normal newborns with clinical jaundice or Rh-negative mothers, and/or positive maternal antibody screenings, or unavailable maternal blood testing. PARTICIPANTS: All newborns (N = 8501) at the Metro-Health Medical Center, Cleveland, Ohio, were studied (retrospective arm, all 1989 admissions; prospective arm, all July 1990 to June 1991 admissions). OUTCOME MEASURES: Blood type and Coombs' NCBT, maternal blood type and antibody screening, Hobel risk scores for clinical severity of newborn hospitalization, duration of hospitalizations, and peak serum bilirubin levels. RESULTS: No quantitative or qualitative increases in morbidity from jaundice were detected by retrospective analysis with unrestricted NCBT, or prospectively after selective testing on 4498 newborns. Each study arm resulted in 15 readmissions for jaundice; these included two patients with ABO HDN. Furthermore, selective testing resulted in performance of NCBTs on only 390 infants in the "normal" nursery (24% of the original sample). Estimates projected on 1991 US births (4,111,000) showed that selective NCBT offers potential yearly savings above $30.8 million of patient charges, savings above $11.3 million of hospital costs, and the reassignment of more than 112 personnel full-time equivalents. CONCLUSION: Selective NCBT decreases the use of resources and costs without apparent additional patient morbidity from HDN.