Gwen Clarke

The effect of prestorage WBC reduction on the rates of febrile nonhemolytic transfusion reactions to platelet concentrates and RBC.

BACKGROUND:  Febrile non‐hemolytic transfusion reactions (FNHTRs) are a common complication of platelet concentrate (PC) and RBC transfusions, usually ascribed to cytokines released by WBCs and perhaps the platelets themselves during storage. Prestorage WBC reduction should abrogate the accumulation of these cytokines reducing the number of FNHTRs.

Reference intervals of complete blood count constituents are highly correlated to waist circumference: Should obese patients have their own "normal values?"

Body mass index (BMI), the prevalent indicator of obesity, is not easily grasped by patients nor physicians. Waist circumference (WC) is correlated to obesity, is better understood and has a stronger relationship to the metabolic syndrome. We compiled WC, complete blood count (CBC) parameters as well as other pertinent data of 6766 25–55‐year‐old US volunteers sampled in the US National Health and Nutrition Examination Survey, in the years 2005–2010. To determine reference intervals of typical US patients visiting their clinician, we used minimal exclusion criteria. We compiled hemoglobin, red blood cell count, hematocrit, mean corpuscular volume (MCV), mean corpuscular hemoglobin concentration, mean cell hemoglobin (MCH), red cell distribution width (RDW), platelet count, mean platelet volume, and counts of white blood cells (WBC), neutrophils, lymphocytes, monocytes, eosinophils, and basophils. In addition, we also compiled serum C reactive protein and serum iron. The three major US races were studied and reference interval diagrams were constructed for each CBC parameter plotted against WC. WBC count, RDW, lymphocyte, neutrophil, and red blood cell count increase with WC. Conversely, serum iron and MCH and MCV decrease. These relationships may be related to insulin resistance and chronic activation of the immune system and the resulting low‐grade inflammatory state. WC is a strong predictor for many CBC parameters, suggesting that WC should be taken into account when evaluating blood count results. Clinicians who take care of obese patients should be aware of altered hematology and investigate and treat accordingly. Am. J. Hematol. 89:671–677, 2014.

Implementation of a Redistribution System for Near-Outdate Red Blood Cell Units

CONTEXT Many remote hospitals keep small on-site stocks of red blood cell (RBC) units for emergency use and to support patient care programs. In Canada, the blood supplier does not accept returned units into inventory. Discard rates can, therefore, be high. OBJECTIVE To transport near-outdate RBC units to a high-usage hospital site, which would reduce overall discard rates, thereby increasing overall stock levels available in the blood system. DESIGN A blood transportation system was developed and validated. The validation was presented to a high-usage site that agreed to accept near-outdate RBC units transported by this system. Stocks at the remote hospitals were optimized without increasing system-wide discard rates. The redistribution program was implemented in 4 remote sites in northern Alberta, Canada. The final disposition of each transported unit was tracked. Data from the first 2 years were analyzed. RESULTS Between April 1, 2003, and March 31, 2005, 106 RBC units were successfully transported to and transfused at the high-usage site. The majority of the units were group O. None of the transfused units were involved in any reported transfusion reactions. The success rate of the transportation system varied among the sites (59%-78% successfully transported and transfused). Changes to the transport system were implemented as problems were discovered. The use of a temperature monitor in each shipment allowed for concurrent revalidation after each change. CONCLUSIONS Redistribution systems can be an effective way to reduce RBC unit discard rates. Even simple transportation systems have many factors affecting the RBC unit temperature. Novel temperature stabilizing materials may make future transportation of RBC units more reliable.

Viability of AS-3 and SAG-M red cells stored in plastic syringes for pediatric transfusion

BACKGROUND: Pediatric patients may require small‐volume transfusions necessitating splitting of red cell (RBC) units. This process usually involves temporary storage of aliquots in pediatric blood bags or, in some cases, plastic syringes, until they are transfused. While many studies have been published on the efficacy of storage in blood bags, there is little evidence to show that RBCs are safe and effective for transfusion after separation into plastic syringe aliquots.

Transfusion‐related acute lung injury after transfusion of pooled immune globulin: a case report

Transfusion‐related acute lung injury (TRALI) is a severe transfusion reaction that manifests as acute respiratory compromise within 6 hours of the infusion of blood products. Intravenous immune globulin (IVIG) is prepared from large pools of human plasma and is commonly administered in the outpatient setting for the treatment of a wide range of diseases. As a plasma‐derived blood product, IVIG may also cause TRALI, although reports of this are exceedingly rare.

Alloimmune Red Blood Cell Antibodies: Prevalence and Pathogenicity in a Canadian Prenatal Population

OBJECTIVE The goals of this study were to determine the prevalence and relative frequencies of red blood cell antibodies in a Canadian prenatal population, and to evaluate the fetal and neonatal outcomes of affected pregnancies. METHODS We conducted a retrospective review of pregnancies that screened positive for red cell antibodies between 2006 and 2010. The following antibodies were included: anti-D, -C, -c, -E, -e, -Fya, -Fyb, -Jka, and-Jkb. Cases of anti-Kell as the sole antibody were excluded. Fetal and neonatal outcome data were then collected and analyzed. RESULTS The population prevalence of a positive antibody screen was 0.36%. Anti-E was the most frequent antibody at 48.5%, followed by anti-c and anti-Jka. Anti-D made up 6.8% of cases, but had significantly higher titres and was responsible for the majority of severely affected fetuses. Sixteen cases in our series experienced severe adverse fetal or neonatal outcomes. All severe outcomes occurred in cases that had a maximum titre of ≥ 8. CONCLUSION Despite the decreasing incidence of anti-D alloimmunization, anti-D remains responsible for the majority of severe cases of hemolytic disease of the fetus and newborn.

No. 343-Routine Non-invasive Prenatal Prediction of Fetal RHD Genotype in Canada: The Time is Here

The optimal management of the D-negative pregnant woman is now based on the non-invasive antenatal prediction of fetal D-blood group by cell-free DNA (cfDNA) in maternal plasma, with targeted prophylaxis for women carrying RHD-positive fetuses. This provides the optimal care for D-negative pregnant women and has been adopted as the standard approach in a growing number of countries around the world. This paper is the result of a consensus meeting of the Canadian National Rh Working Group, an interdisciplinary group formed to review the current status of fetal RHD genotyping based on cfDNA in Canada. The group, in collaboration with the SOGC Genetics committee, reviewed the benefits and challenges of implementing RHD genotyping with targeted prophylaxis in the context of the existing routine antenatal anti D prophylaxis program in Canada. The following summary statements and recommendations are based on this review. SUMMARY STATEMENTS RECOMMENDATIONS.

A Mother and Newborn with Brown Blood

A 33-year-old woman of Indian origin presented for prenatal care at term. An ultrasound report from earlier in her pregnancy indicated complete placenta previa and placenta increta, which were confirmed by repeat ultrasound. She was admitted to the hospital for monitoring and delivery planning. On admission, brown vaginal spotting was noted on the patients pad. Her nail beds and fingers were cyanotic, and a finger prick blood sample was rusty brown in appearance. Oxygen saturation by pulse oximetry on room air was 45% despite her appearing clinically well. She was otherwise asymptomatic. The patients husband remarked that her family has “brown blood, not red,” noting that the patients father, paternal grandfather, and sister also have brown blood but no clinical problems. Her 3-year-old daughter had a similar cyanotic appearance but was otherwise asymptomatic. Repeat oxygen saturation measurements by pulse oximetry consistently gave results between 40%–60%, and arterial blood P o2 was 95 mmHg. Methemoglobin measurement was attempted, but the cooximeter indicated “?Oximetry measuring error.” This was also confirmed by repeated measurements. Complete blood count results were as follows: hemoglobin, 12.5 g/dL (125 g/L; reference interval, 120–160 g/L); red blood cells (RBC),6 4.19 × 1012/L (reference interval, 3.80–5.20 × 1012/L); hematocrit (HCT), 38% (0.38; reference interval, 0.36–0.46); mean corpuscular volume (MCV), 90 fL (reference interval, 80–100 fL); mean corpuscular hemoglobin (MCH), 30 pg (reference interval, 26–35 pg); mean corpuscular hemoglobin concentration (MCHC), 33.3 g/dL (333 g/L; reference interval, 310–360 g/L); red cell width distribution (RDW), 13.2% (reference interval, <15.6%); platelets (PLT), 224 × 109/L (reference interval, 140–450 × 109/L); white blood cells (WBC) 9.6 × 109/L (reference interval, 4.0–11.0 × 109/L). ### QUESTIONS TO CONSIDER 1. What are causes of cyanosis and brown blood? 2. What additional laboratory tests could be useful in …

A Case of Alloimmune Thrombocytopenia, Hemorrhagic Anemia-Induced Fetal Hydrops, Maternal Mirror Syndrome, and Human Chorionic Gonadotropin–Induced Thyrotoxicosis

Fetal/neonatal alloimmune thrombocytopenia (FNAIT) can be a cause of severe fetal thrombocytopenia, with the common presentation being intracranial hemorrhage in the fetus, usually in the third trimester. A very unusual case of fetal anemia progressed to hydrops. This was further complicated by maternal Mirror syndrome and human chorionic gonadotropin–induced thyrotoxicosis. Without knowledge of etiology, and possibly due to associated cardiac dysfunction, fetal transfusion resulted in fetal demise. Subsequent testing revealed FNAIT as the cause of severe hemorrhagic anemia. In cases with fetal anemia without presence of red blood cell antibodies, FNAIT must be ruled out as a cause prior to performing fetal transfusion. Fetal heart may adapt differently to acute hemorrhagic anemia compared with a more subacute hemolytic anemia.

Severe hemolytic disease of the fetus and newborn due to allo-anti-D in a patient with a partial DEL phenotype arising from the variant allele described as RHD*148+1T (RHD*01EL.31) : HDFN IN MOTHER WITH RHD*148+1T ALLELE

RhD DEL variants may show complete or partial expression of RhD epitopes. There have been only rare reports of anti‐D causing hemolytic disease of the fetus and newborn (HDFN) in this context. We report a case of severe HDFN associated with a recently described DEL variant.