Survey of newborn direct antiglobulin testing practice in United States and Canadian transfusion services

Neonatal hemolytic disease: How should we use indirect and direct antiglobulin tests?

BACKGROUND

In newborns with hemolysis, the direct antiglobulin test (DAT) and indirect antiglobulin test (IAT) play a key role in demonstrating the presence of an immune cause. We aimed to emphasize the importance of IAT in mothers of DAT-positive babies.

METHODS

DAT was performed with forward blood grouping on cord blood in term babies who were born between September 2020 and September 2022. IAT was performed in the mothers of the babies who were found to have a positive DAT and antibody identification was performed in the mothers who were found to have a positive IAT. Specific antibodies detected and identified were associated with the clinical course.

RESULTS

The study included 2769 babies and their mothers. The prevalence of DAT positivity was found to be 3.3% (87 of 2661). In DAT-positive babies, the rate of ABO incompatibility was 45.9%, the rate of RhD incompatibility was 5.7% and the rate of RhD and ABO incompatibility in association was 10.3%. The rate of subgroup incompatibility and other red blood cell antibodies was 18.3%. Phototherapy was applied because of indirect hyperbilirubinemia in 16.6% of the DAT-negative babies and in 51.5% of the DAT-positive babies. The need for phototherapy was significantly higher in DAT-positive infants (p < 0.01). Severe hemolytic disease of the newborn, bilirubin level, duration of phototherapy and use of intravenous immunoglobulin were found to be significantly higher in the babies whose mothers were IAT positive compared with the babies whose mothers were IAT negative (p < 0.01).

CONCLUSIONS

IAT should be performed on all pregnant women. When screening with IAT is not performed during pregnancy, performing DAT in the baby plays a key role. We showed that the clinical course was more severe when mothers of DAT-positive babies were IAT positive.

Clinical value of combination detection of direct antiglobulin test and serum albumin globulin ratio in severe hyperbilirubinemia caused by ABO hemolytic disease of the newborn

Background To explore of a combination of antiglobulin test(DAT) and albumin globulin ratio(AGR) could predict the severity of ABO hemolytic disease of the newborn(ABO-HDN).Methods The measurement of DAT, AGR and combination detection of DAT and AGR was done to predict severe ABO-HDN hyperbilirubinemia in 270 full-term infants based on whether the infants received transfusions of blood components. The infants were divided into three groups according to the results of DAT and ARG and compared the differences of phototherapy day and hospitalization day of the three groups.Results Of the 270 cases enrolled in this study, 69 infants were DAT positive. Peak total bilirubin, AGR, and positive DAT were independently associated with the need for blood components transfusion. ROC curve analysis for blood components transfusion showed that DAT cutoff value >± with a sensitivity of 39.4% and a specificity of 83.9%, AGR cutoff value <2.05 with a sensitivity of 54.1% and a specificity of 85.7%, and combination detection of DAT and ARG with a sensitivity of 62.1% and a specificity of 91.2%. The AUCs for DAT, AGR, and combination detection of DAT and AGR were .621, .740, and .750 respectively. The phototherapy day and hospitalization day were significantly longer in group of AGR <2.05 and DAT >± than that of a group of AGR <2.05 and group of DAT >±.Conclusions DAT and ARG could be early predictors for the severity ABO-HDN hyperbilirubinemia and combination detection of DAT and AGR could further increase its predictive value.

Neonatal Blood Banking Practices

There is little formal guidance to direct neonatal blood banking practices and, as a result, practices vary widely across institutions. In this vulnerable patient population with a high transfusion burden, considerations for blood product selection include freshness, extended-storage media, pathogen inactivation, and other modifications. The authors discuss the potential unintended adverse impacts in the neonatal recipient. Concerns such as immunodeficiency, donor exposures, cytomegalovirus transmission, volume overload, transfusion-associated hyperkalemia, and passive hemolysis from ABO incompatibility have driven modifications of blood components to improve safety.

ABO hemolytic disease of the newborn: a need for clarity and consistency in diagnosis

The diagnosis of ABO hemolytic disease of the newborn (ABO HDN) has been the subject of considerable debate and clinical confusion. Its use as an overarching default diagnosis for hyperbilirubinemia in all ABO incompatible neonates regardless of serological findings is problematic and lacks diagnostic precision. Data on hemolysis indexed by carbon monoxide (CO) levels in expired air (ETCOc) and blood (COHbc) support an essential role for a positive direct antiglobulin test (DAT) in making a more precise diagnosis of ABO HDN. A working definition that includes ABO incompatibility, significant neonatal hyperbilirubinemia, and a positive DAT is needed to gain clarity and consistency in the diagnosis of ABO HDN. Absent a positive DAT, the diagnosis of ABO HDN is suspect. Instead, a negative DAT in a severely hyperbilirubinemic ABO incompatible neonate should trigger an exhaustive search for an alternative cause, a search that may require the use of targeted gene panels.

Immunohematology testing using umbilical cord blood: review of the literature, survey of practice and guidance development

BACKGROUND

Following delivery, blood tests are performed on umbilical cord blood (CB) to avoid neonatal venipuncture. Despite widespread and longstanding CB testing, no guidelines exist to suggest which immunohematology tests should be performed on CB.

STUDY DESIGN AND METHODS

We performed a scoping review, surveyed national practice, and developed guidance statements concerning CB testing. Database searches identified relevant articles. A survey was sent to all Canadian hospitals and transfusion laboratories that perform perinatal testing. A national panel of experts was convened to develop guidance statements.

RESULTS

A total of 116 articles met the inclusion criteria and were summarized. Literature on CB testing is limited; few studies have investigated laboratory testing methodologies or validated CB test results with peripheral samples. The survey was completed by 580/597 institutions (97%); 85% were community hospitals and 16% had a neonatal intensive care unit. There is diversity in the types of CB tests performed and variability in practice. While most centers order appropriately, some laboratories routinely perform CB tests that are not clinically indicated (e.g., direct antiglobulin testing for all neonates) and other do not perform CB tests when results would be beneficial (e.g., phenotype on CB when mother has a clinically significant antibody). Fifteen guidance statements were developed.

DISCUSSION

This study highlights variability in CB testing, likely reflecting evidence gaps, methodology differences between studies, and lack of guidelines. CB tests should only be performed when indicated and validated on this sample type. The presented guidance statements aim to standardize practice and encourage judicious CB sampling.

Hemolytic Disease of the Newborn: A Review of Current Trends and Prospects

Hemolytic disease of the newborn (HDN), also known as Erythroblastosis fetalis, is a hemolytic condition that predominantly affects rhesus-positive fetuses and infants born to rhesus-negative mothers. The pathophysiology of HDN begins with maternal antibodies attacking fetal red blood cells following alloimmunization due to rhesus or ABO incompatibility between the maternal and fetal blood. Previously, HDN was known to cause fetal death in 1% of all pregnancies, but with the advent of immunoprophylactic therapies, the condition can be currently fairly well managed with fewer complications if diagnosed early. Diagnosis calls for extensive history taking, physical examination, serological studies, and imaging modalities such as pelvic ultrasound scans. To prevent the disease, earlier intravenous immunoglobulin (IVIG) should be given to pregnant Rh- women who have not been sensitized. It is also vital to understand prospective complications such as severe hyperbilirubinemia and develop appropriate remedies. Because of its great incidence and nature, HDN has been thoroughly explored, and more studies are being conducted each year, revealing new insights about the condition. This review covers the disorder's etiology, diagnosis, and management, including the most current findings as of 2021, as well as trends and prospects, to help in future research and evidence-based medical practice.