Changes in Mean Corpuscular Volume and RBC Distribution Width Predict Erythrocyte Engraftment Following ABO-Incompatible Hematopoietic Stem Cell Transplantation.

OBJECTIVES: The purpose of this study was to identify laboratory parameters representing erythrocyte engraftment to be used as an indicator to change the recipient to donor ABO group and Rh type following an ABO-incompatible hematopoietic stem cell transplant (HSCT). Studies have shown that ABO incompatibility does not have an effect on outcome of HSCT; however, the serologic consequences of these ABO-incompatible transplants can make it difficult to decide when to begin support with donor ABO/Rh-type blood products. METHODS: This study explored the use of RBC distribution width (RDW), mean corpuscular volume, and hemoglobin as regularly tested laboratory parameters that could be used as surrogate markers for RBC engraftment in 65 patients who received ABO/Rh-incompatible HSCT. RESULTS: The appearance of engrafted donor RBCs correlated with a peak in RDW (P = .002). In addition, our findings suggest that serologic changes in ABO/Rh appear to correspond with a peak in RDW (P = .002). CONCLUSIONS: High values of RDW likely result from a substantial proportion of large, young erythrocytes from recent engraftment with smaller, older pretransplant erythrocytes from the recipient. Our findings suggest that peak RDW may be an indicator of erythrocyte engraftment, following an ABO/Rh-incompatible HSCT.

Iron Deficiency Anemia in Patients Undergoing Extracorporeal Photopheresis for Cutaneous T-Cell Lymphoma.

OBJECTIVE: To describe the indicidence and severity of iron deficiency anemia (IDA) in patients who have received extracorporeal photopheresis (ECP) treatment of cutaneous T-cell lymphoma (CTCL). METHODS: We performed a retrospective study during a 9-year period of patients with CTCL who were treated with ECP. ECP was performed with UVAR XTS and CELLEX (Therakos Inc). IDA was defined by a drop in hemoglobin (Hb), mean cell volume (MCV), and increased red blood cell distribution width (RDW). RESULTS: We identified a total of 36 patients; 1 patient was excluded due to severe anemia. In 35 patients, initial hemoglobin values ranged from 9.8 g per dL to 15.9 g per dL, and patients received 4 to 327 ECP treatments. In all, 28 patients showed decreases in Hb of 0.8 g per dL to 6 g per dL during treatments. CONCLUSION: Chronic ECP led to IDA in 28 of 35 patients with CTCL. IDA occurs due to blood loss when ECP equipment does not return full blood volume to patients.

Widely Used Types and Clinical Applications of D-Dimer Assay.

D-dimers are formed by the breakdown of fibrinogen and fibrin during fibrinolysis. D-dimer analysis is critical for the diagnosis of deep vein thrombosis, pulmonary embolism, and disseminated intravascular coagulation. Modern assays for D-dimer are monoclonal antibody based. The enzyme-linked immunosorbent assay (ELISA) is the reference method for D-dimer analysis in the central clinical laboratory, but is time consuming to perform. Recently, a number of rapid, point-of-care D-dimer assays have been developed for acute care settings that utilize a variety of methodologies. In view of the diversity of D-dimer assays used in central laboratory and point-of-care settings, several caveats must be taken to assure the proper interpretation and clinical application of the results. These include consideration of preanalytical variables and interfering substances, as well as patient drug therapy and underlying disease. D-dimer assays should also be validated in clinical studies, have established cut-off values, and reported according to the reagent manufacturers recommendations.

Harvesting autologous stem cells from a patient with red blood cell abnormalities of ß-thalassemia intermedia.

BACKGROUND: Autologous stem cell transplants in patients with hemoglobinopathies are limited. Previous reports used granulocyte-colony-stimulating factor (G-CSF) for mobilization of stem cells; there are no reported cases undergoing plerixafor mobilization. We report such a patient, providing guidance for peripheral blood stem cells collection when aberrant red blood cells (RBCs) disrupt normal separation. STUDY DESIGN AND METHODS: A patient with ß-thalassemia intermedia and hereditary persistence of fetal hemoglobin presented for peripheral blood stem cell collection for autologous transplant for myeloma. He underwent splenectomy for anemia secondary to hemoglobinopathy and chemotherapy, ceasing RBC transfusions. The patient was mobilized using plerixafor after collection with G-CSF failed. RESULTS: Collections were performed using an apheresis system, processing 24 L daily. Peripheral blood and apheresis product CD34 determinations were performed daily. On Day 1, the product yield was 0.04 × 10(6) CD34 cells/kg, less than expected based on white blood cell count and CD34-positive cells. Peripheral blood smear showed nucleated RBCs and RBC morphologic abnormalities. Changes in instrument variables were made after consultation with Terumo BCT to adjust for variable distribution of mononuclear and stem cells during centrifugation. Collecting stem cells at a deeper location and centrifuging faster improved collection, and a cumulative total of 4.40 × 10(6) CD34 cells/kg was achieved after four collections. The patient underwent tandem autologous transplantation and engrafted within 12 to 13 days of each transplant. CONCLUSIONS: Adjustments in apheresis variables allowed successful collection of peripheral blood stem cells from a patient with RBC anomalies of ß-thalassemia that interfered with standard stem cell harvesting.

Investigation of heparin-related hypotensive adverse events during photopheresis: utility of a patient care database.

BACKGROUND: Extracorporeal photopheresis (ECP) is a procedure in which leukocytes are harvested from a patient's whole blood, treated with a DNA binding dye and ultraviolet light to inactivate lymphocytes, and then returned into the patient's circulation. In January 2008, we observed moderately severe anaphylactoid reactions in eight of 16 patients undergoing ECP. CASE STUDY: Each affected individual exhibited hypotension of sudden onset, usually with tachycardia, during the return of heparin-anticoagulated blood at the end of the first cycle of collection of leukocytes. A systematic investigation of possible contributing factors revealed that all reactions were associated with administration of a single new lot of heparin. RESULTS: Changing to a different manufacturer of heparin eliminated the occurrence of further such hypotensive reactions during ECP. Although the symptoms were initially attributed to vasovagal reactions or dehydration, their temporal association with exposure to a new lot of heparin suggested a procedure-related phenomenon. Of particular note, was the finding that of the eight patients who had reactions at any time, six had initial exposures without reactions, suggesting a process of sensitization. CONCLUSION: This study demonstrated the value of a patient database listing lot numbers of all medications and components used in each routine ECP procedure for facilitating rapid determination of common patient exposures, making it easier to determine the cause of adverse events, in this case, a particular lot of heparin responsible for the hypotensive adverse events.

Fecal occult blood testing.

Colorectal cancer (CRC) is the third most common cancer in the United States. A reduction in cumulative mortality occurs when patients are routinely screened by fecal occult blood tests (FOBT) and early lesions are removed. These point-of-care tests detect minute amounts of blood released from precancerous and cancerous colon lesions. Positive test results should be followed up with complete diagnostic testing to treat precancerous lesions and diagnose patients at earlier stages of cancer, thereby increasing overall survival. More complex assays are designed to detect genetic changes in cells released from malignant and even premalignant lesions. This article provides information on the screening and diagnostic tests available for CRC detection as well as the advantages and disadvantages of each.

Check Sample Abstracts.

The following abstracts are compiled from Check Sample exercises published in 2008. These peer-reviewed case studies assist laboratory professionals with continuing medical education and are developed in the areas of clinical chemistry, cytopathology, forensic pathology, hematology, microbiology, surgical pathology, and transfusion medicine. Abstracts for all exercises published in the program will appear annually in AJCP.

Call subject patterns among on-call clinical pathology residents in an academic institution: how can tracking changes in patterns over time benefit resident education?

CONTEXT: On-call responsibility is an important part of residency training in clinical pathology. This task provides important consultative services for the hospital and serves as a valuable learning experience for the resident. OBJECTIVE: To identify the types of calls received by residents at a large teaching hospital, to assess how and why these calls have changed over time, and to determine the educational value in tracking such changes. DESIGN: A retrospective review of resident on-call records from 2 periods (2005-2006 and 1997-1998) was performed. Calls were classified based on the call subject and the caller. RESULTS: Although some general patterns remained similar, several differences were identified between the time periods. Calls regarding mislabeled specimens fell, while calls concerning panic values and the blood bank (specifically therapeutic apheresis) increased. CONCLUSIONS: The different patterns identified in calls between the 2 periods reflect the ever-changing role of the clinical pathologist within the hospital system and provide evidence that monitoring these shifting patterns could be a valuable tool in the education of clinical pathology residents.

Lack of autoantibody production associated with cytomegalovirus infection.

To confirm an association between cytomegalovirus (CMV) infection and the presence of antibodies to Smith (Sm), to ribonucleoprotein (RNP), and to a component of the U1 ribonucleoproteins (U1-70 kD), we measured antibodies to these protein antigens using an enzyme immunoassay and an immunoblot. The antibodies were measured in the sera of 80 healthy subjects, one-half of whom were naturally CMV seropositive and one-half were CMV seronegative, and in eight subjects immunized with a live attenuated strain of CMV. None of the vaccinees developed antibodies to Sm, to RNP, or to U1-70 kD at either 4 or 12 months after immunization. Additionally, there was no statistically significant association between levels of antibodies to Sm or to RNP and between sera obtained from vaccinees, natural CMV seropositive individuals, and CMV seronegative individuals. One CMV seropositive serum and one CMV seronegative serum tested positive for antibodies to U1-70 kD. These data indicate that neither wild-type infection nor the live-attenuated Towne vaccine frequently induce autoantibody production.