Nicole D. Zantek

Detection of bacterial contamination in prestorage culture-negative apheresis platelets on day of issue with the Pan Genera Detection test.

BACKGROUND: Bacterial contamination is currently the most important infectious risk associated with transfusion of platelet (PLT) products. Prestorage culture has reduced but not eliminated this problem.

The direct antiglobulin test: a critical step in the evaluation of hemolysis.

The direct antiglobulin test (DAT) is a laboratory test that detects immunoglobulin and/or complement on the surface of red blood cells. The utility of the DAT is to sort hemolysis into an immune or nonimmune etiology. As with all tests, DAT results must be viewed in light of clinical and other laboratory data. This review highlights the most common clinical situations where the DAT can help classify causes of hemolysis, including autoimmune hemolytic anemia, transfusion‐related hemolysis, hemolytic disease of the fetus/newborn, drug‐induced hemolytic anemia, passenger lymphocyte syndrome, and DAT‐negative hemolytic anemia. In addition, the pitfalls and limitations of the test are addressed. False reactions may occur with improper technique, including improper washing, centrifugation, and specimen agitation at the time of result interpretation. Patient factors, such as spontaneous red blood cell agglutination, may also contribute to false results. Am. J. Hematol. 87:707–709, 2012.

Estrogen and Myc negatively regulate expression of the EphA2 tyrosine kinase.

Estrogen receptor and c‐Myc are frequently overexpressed during breast cancer progression but are downregulated in many aggressive forms of the disease. High levels of the EphA2 tyrosine kinase are consistently found in the most aggressive breast cancer cells, and EphA2 overexpression can increase metastatic potential. We demonstrate, herein, that estrogen and Myc negatively regulate EphA2 expression in mammary epithelial cells. These data reveal EphA2 as a downstream target of estrogen and Myc and suggest a mechanism by which estrogen and Myc may regulate breast cancer. J. Cell. Biochem. 85: 714–720, 2002.

An in situ forming biodegradable hydrogel-based embolic agent for interventional therapies

We present here the characteristics of an in situ forming hydrogel prepared from carboxymethyl chitosan and oxidized carboxymethyl cellulose for interventional therapies. Gelation, owing to the formation of Schiff bases, occurred both with and without the presence of a radiographic contrast agent. The hydrogel exhibited a highly porous internal structure (pore diameter 17±4 μm), no cytotoxicity to human umbilical vein endothelial cells, hemocompatibility with human blood, and degradability in lysozyme solutions. Drug release from hydrogels loaded with a sclerosant, tetracycline, was measured at pH 7.4, 6 and 2 at 37°C. The results showed that tetracycline was more stable under acidic conditions, with a lower release rate observed at pH 6. An anticancer drug, doxorubicin, was loaded into the hydrogel and a cumulative release of 30% was observed over 78 h in phosphate-buffered saline at 37°C. Injection of the hydrogel precursor through a 5-F catheter into a fusiform aneurysm model was feasible, leading to complete filling of the aneurysmal sac, which was visualized by fluoroscopy. The levels of occlusion by hydrogel precursors (1.8% and 2.1%) and calibrated microspheres (100-300 μm) in a rabbit renal model were compared. Embolization with hydrogel precursors was performed without clogging and the hydrogel achieved effective occlusion in more distal arteries than calibrated microspheres. In conclusion, this hydrogel possesses promising characteristics potentially beneficial for a wide range of vascular intervention procedures that involve embolization and drug delivery.

Use of therapeutic plasma exchange in the management of acute hemorrhagic leukoencephalitis: a case report and review of the literature.

BACKGROUND: Acute hemorrhagic leukoencephalitis (AHLE) is a rare, fatal, central nervous demyelinating disease characterized by a rapid fulminant clinical course. Successful management requires early diagnosis, aggressive management of cerebral edema, and immunosuppression. Therapeutic plasma exchange (TPE) is infrequently used and commences after initial management fails.

Anti-factor Xa and activated partial thromboplastin time measurements for heparin monitoring in mechanical circulatory support.

OBJECTIVES This study investigated the relationship between anti-factor Xa (anti-FXa) and activated partial thromboplastin time (aPTT) for monitoring intravenous unfractionated heparin (IV-UFH) in patients with continuous-flow left ventricular assist devices (CF-LVADs). BACKGROUND CF-LVADs have become mainstream therapy for patients with advanced heart failure. Thromboembolic events, device thrombosis, and bleeding continue to be a challenge with this technology. Adequate anticoagulation is required to prevent these adverse events. METHODS A prospective study of consecutive patients implanted with a CF-LVAD was conducted. Paired samples were considered concordant if aPTT values fell into expected ranges for subtherapeutic, therapeutic, and supratherapeutic anti-FXa levels. Heparin dosing was on the basis of anti-Xa levels. RESULTS A total of 340 paired values from 38 patients were evaluated. Anti-FXa and aPTT were discordant in 253 samples (74.4%), with a high degree of variability in aPTT for any given anti-FXa level (r(2) = 0.57). Results were discordant in 104 samples (63.8%) from patients undergoing bridging therapy with warfarin and in 149 samples (84.2%) from patients with device obstruction and/or hemolysis (p < 0.001). The most common pattern of discordance was a supratherapeutic aPTT value despite a therapeutic anti-FXa level (49.1% for bridging vs. 75.8% for device obstruction and/or hemolysis; p < 0.001). CONCLUSIONS Levels of aPTT were disproportionately prolonged relative to the corresponding anti-FXa levels in CF-LVAD patients, particularly those with device obstruction. Hemolysis and warfarin administration may falsely elevate aPTT, resulting in overestimation of heparin concentration and under-anticoagulation. Use of aPTT and anti-FXa to guide heparin therapy may lead to different estimates of heparin concentration in the same patient.

Haemolysis after treatment with intravenous immunoglobulin due to anti-A

Background: Intravenous immunoglobulin (IVIG) is used to treat an increasing number of conditions. IVIG contains immunoglobulin G (IgG) directed against many targets, including red blood cell (RBC) antigens.

A data-driven approach to patient blood management

Patient blood management (PBM) has become a topic of intense interest; however, implementing a robust PBM system in a large academic hospital can be a challenge. In a joint effort between transfusion medicine and information technology, we have developed three overlapping databases that allow for a comprehensive, semiautomated approach to monitoring up‐to‐date red blood cell (RBC) usage in our hospital. Data derived from this work have allowed us to target our PBM efforts.

Factor XIII Assays and associated problems for laboratory diagnosis of factor XIII deficiency: an analysis of International Proficiency testing results.

We analyzed results from the External quality Control of diagnostic Assays and Tests program to assess current clinical laboratory practice and performance of different methods for factor XIII (FXIII) testing internationally. FXIII proficiency testing data from all eight surveys conducted in 2010 and 2011 were analyzed (1,283 results), comparing the three available methods for detecting FXIII deficiency, thus including clot-solubility qualitative activity, quantitative activity, and antigen. Clot-solubility qualitative assays detected a deficiency in only 16% (11/69) of samples with less than 2% FXIII. Assays using added thrombin detected more deficiencies (33%) than did assays without added thrombin (11%). The most commonly used quantitative activity method tended to produce higher results for low FXIII samples than other quantitative activity methods. Antigen results generally showed good accuracy compared with expected levels. The mean interlaboratory coefficients of variation showed wide variability, especially for samples with less than 10% FXIII activity. Laboratory self-classification of results (as normal vs. abnormal) was good, and was slightly better for specimens with ≤ 25% FXIII than for specimens with 26 to 70% or those with >70% FXIII. We conclude that quantitative activity assays perform better for detecting FXIII deficiency than clot solubility assays, although some quantitative activity assays overestimate low FXIII levels.

Therapeutic plasma exchange in neuromyelitis optica: a case series.

Neuromyelitis optica (NMO) is a relapsing inflammatory disease of the central nervous system that predominantly affects the spinal cord and optic nerves. The clinical hallmark of the disease is a step‐wise deterioration of visual and spinal cord function. This study reviews patients with steroid resistant relapsing NMO presenting for therapeutic plasma exchange (TPE) at our institution from December 2005 to December 2012. A total of five patients were treated with single volume TPE. Both subjective and objective clinical response to TPE was estimated by three different sources (the patient, a Transfusion Medicine physician, and the treating Neurologist) with the patient and Transfusion Medicine physicians final assessment of response made at the time of the last TPE in the series and the treating neurologists assessment of response made at the time of the next neurological exam after the last TPE. A total of 17 TPE series were performed with the average course of therapy being three series (ranged 1–5) with five TPE (ranged 3–7) per series. All patients demonstrated improvement with each series of TPE and all procedures were well tolerated with only transient and well‐described reactions all of which were successfully resolved with minor or no sequelae. J. Clin. Apheresis 29:171–177, 2014.