Alexander Kratz

Effect of Marathon Running on Hematologic and Biochemical Laboratory Parameters, Including Cardiac Markers

Participants in marathon races may require medical attention and the performance of laboratory assays. We report the changes in basic biochemical parameters, cardiac markers, CBC counts, and WBC differentials observed in participants in a marathon before, within 4 hours, and 24 hours after a race. The concentrations of glucose, total protein, albumin, uric acid, calcium, phosphorus, serum urea nitrogen, creatinine, bilirubin, alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, total creatine kinase, creatine kinase-MB, myoglobin, and the anion gap were increased after the race, consistent with the effects of exertional rhabdomyolysis and hemolysis. The increase in WBC counts was due mainly to neutrophilia and monocytosis, with a relative decrease in circulating lymphocytes, consistent with an inflammatory reaction to tissue injury. A significant percentage of laboratory results were outside the standard reference ranges, indicating that modified reference ranges derivedfrom marathon runners might be more appropriatefor this population. We provide a table of modified reference ranges (or expected ranges) for basic biochemical, cardiac, and hematologic laboratory parameters for marathon runners.

Performance evaluation of the ADVIA 2120 hematology analyzer: an international multicenter clinical trial.

Automated cell counters are widely used in modern clinical laboratories to provide reliable, fast, and cost-effective complete blood counts (CBCs), white blood cell differentials, and reticulocyte measurements. In addition, some advanced instruments provide novel parameters, such as the hemoglobin content of reticulocytes or the percentage of hypochromic cells, and are capable of analysis of a variety of body fluids. Bayer recently introduced the ADVIA 2120 system as an automation-ready cell counter for mid- to high-volume testing in the clinical laboratory. This instrument, which builds on the established technology of the ADVIA 120 system, operates with a cyanide-free method for hemoglobin measurement, has a new user interface, and can routinely analyze biological fluid samples in addition to blood. We used 749 samples from 6 worldwide trial sites to evaluate the clinical performance of this new device. Accuracy of the ADVIA 2120 system versus its predecessor model, the ADVIA 120 system, was excellent for all CBC and white cell differential parameters and reticulocyte counts (all correlation coefficients except for basophils >0.9). Correlation of the white cell differential with the standard manual method and within-run precision of the ADVIA 2120 system also was very good. Use of the novel cyanide-free method for hemoglobin measurement had no clinically significant impact on hemoglobin results, even in patients with hemoglobinopathies. We concluded that the ADVIA 2120 system has clinically equivalent performance to the ADVIA 120 system.

The ADVIA 2120 hematology system: flow cytometry-based analysis of blood and body fluids in the routine hematology laboratory.

The ADVIA 2120 Hematology System was recently released by Bayer HealthCare, Diagnostics Division, as a bench-top analyzer designed for medium- to large-volume laboratories. This flow cytometry-based system uses light scatter, differential white blood cell (WBC) lysis, and myeloperoxidase and oxazine 750 staining to provide a complete blood cell count, a WBC differential, and a reticulocyte count. A cyanide-free method is used to measure hemoglobin colorimetrically. The system is automation ready; in addition to its capability for analyzing peripheral blood specimens, the analyzer is also equipped to analyze cerebrospinal fluid samples. In this article we explain the underlying technology of the ADVIA 2120, provide linearity ranges, method-specific reference ranges, and stability data, and describe novel parameters and applications that are unique to the methodology used by this instrument. Finally, we discuss research applications and future directions, such as the use of this hematology analyzer in the determination of fetal lung maturity.

Effects of marathon running on platelet activation markers : direct evidence for in vivo platelet activation.

We used the ADVIA 2120 Hematology System (Bayer HealthCare, Diagnostics Division, Tarrytown, NY) to study the effects of vigorous exercise on CBC count, WBC differential, RBC fragmentation, and platelet activation parameters in 32 healthy participants in a 26.2-mile (42.2-km) marathon. The runners demonstrated increases in hematocrit and platelet count consistent with dehydration and leukocytosis indicative of demargination of neutrophils or inflammation secondary to tissue destruction (eg, rhabdomyolysis). The number of RBC fragments was increased after the race (P = .008), consistent with exercise-induced hemolysis. The mean platelet component, a measure of platelet granularity, was decreased (P < .0001), and the number of platelet clumps was increased (P = .0026), providing evidence for in vivo platelet activation during the marathon. By using direct measurement of platelet granularity, our study confirms the in vivo activation of platelets by vigorous exercise and establishes the usefulness of automated cell counters for the assessment of platelet activation and of RBC fragmentation in this setting.

Effects of a Pneumatic Tube System on Routine and Novel Hematology and Coagulation Parameters in Healthy Volunteers

CONTEXT Technologic advances affecting analyzers used in clinical laboratories have changed the methods used to obtain many laboratory measurements, and many novel parameters are now available. The effects of specimen transport through a pneumatic tube system on laboratory results obtained with such modern instruments are unclear. OBJECTIVE To determine the effects of sample transport through a pneumatic tube system on routine and novel hematology and coagulation parameters obtained on state-of-the-art analyzers. DESIGN Paired blood samples from 33 healthy volunteers were either hand delivered to the clinical laboratory or transported through a pneumatic tube system. RESULTS No statistically significant differences were observed for routine complete blood cell count and white cell differential parameters or markers of platelet activation, such as the mean platelet component, or of red cell fragmentation. When 2 donors who reported aspirin intake were excluded from the analysis, there was a statistically, but not clinically, significant impact of transport through the pneumatic tube system on the mean platelet component. There were no statistically significant differences for prothrombin time, activated partial thromboplastin time, waveform slopes for prothrombin time or activated partial thromboplastin time, fibrinogen, or fibrin monomers. CONCLUSIONS Although further study regarding the mean platelet component may be required, transport through a pneumatic tube system has no clinically significant effect on hematology and coagulation results obtained with certain modern instruments in blood samples from healthy volunteers.

A comparison of glass and plastic blood collection tubes for routine and specialized coagulation assays: a comprehensive study.

CONTEXT Blood collection tubes made from plastic are beginning to replace glass tubes. Coagulation test results can be influenced easily by preanalytic factors, including exposure to surfaces that activate the clotting cascade. OBJECTIVE To compare the effects of the blood collection tube material on 22 coagulation assays performed in clinical laboratories. DESIGN Paired blood samples from 28 healthy volunteers were drawn into BD Vacutainer Glass Citrate Tubes and BD Vacutainer Plus Plastic Citrate Tubes, and the results of coagulation assays were determined in parallel. RESULTS No statistically significant differences were observed between glass and plastic for 14 assays: prothrombin time (and international normalized ratio); activated partial thromboplastin time; activated protein C resistance; antithrombin activity; factors II, V, VIII, and IX; alpha2-antiplasmin; plasminogen activity; von Willebrand factor antigen; ristocetin cofactor; thrombin time; and reptilase time. Statistically significant differences were found for fibrinogen; chromogenic protein C activity; protein S activity; PTT-LA lupus anticoagulant-sensitive activated partial thromboplastin time; and factors VII, X, XI, and XII. Mean differences ranged from 0.4% to 5.5% and were unlikely to be of clinical significance. CONCLUSIONS The results of this study suggest that plastic tubes can be used in place of glass tubes for a wide variety of coagulation assays.

Prostate-specific antigen and the early diagnosis of prostate cancer.

With digital rectal examination (DRE), prostate-specific antigen (PSA) is a major screening tool for prostate cancer. PSA is specific for the prostate, but not for prostate cancer. Multiple factors influence PSA value. Determination of PSA levels is not 100% sensitive for prostate cancer, as PSA levels may be normal despite presence of prostate cancer. The cutoff value for PSA of 4.0 ng/mL gives the highest sensitivity and highest specificity. Several modifications of PSA testing have been developed and may be beneficial for select populations. Uncertainty about the natural progression of prostate cancer and inherent limitations of PSA testing make it unclear whether universal screening is beneficial, and the recommendations of various organizations conflict. Randomized studies are in progress to address the role of PSA testing and of modifications of this test in the early detection of prostate cancer.

Performance Evaluation of the CellaVision DM96 System

We evaluated the CellaVision DM96 (CellaVision AB, Lund, Sweden), an automated digital cell morphology and informatics system for peripheral blood smears. Technologists agreed with 82% of the instruments preclassifications. Correlation coefficients between final results released from the CellaVision and results obtained by direct microscopy were 0.96 (all neutrophils), 0.94 (lymphocytes), 0.88 (segmented neutrophils), 0.73 (eosinophils), 0.69 (bands), and 0.67 (monocytes). After correction for statistically and clinically insignificant variations, the CellaVision DM96 had 95% sensitivity and 88% specificity for immature myeloid cells. It was 100% sensitive and 94% specific for blasts, and 100% sensitive and 97% specific for unusual WBCs and nucleated RBCs. Advantages of the CellaVision DM96 over direct microscopy include the ability to review slides from a remote location, consultation and quality control on a cell-by-cell basis, and potential labor savings.

The Generation of Narrative Interpretations in Laboratory Medicine A Description of Service-Specific Sign-Out Rounds

The logistical details for organizing effective interpretive rounds in a laboratory medicine subspecialty must be carefully established so that expert opinions are provided in a timely fashion in a patient-specific report, rather than as a collection of fixed comments associated with a particular laboratory result generated by a computer This report describes the test batteries for interpretations, the billing for interpretations, clinical examples of interpretations, and interpretations for which billing is not typically performed in several clinical or laboratory areas in our institution. These include coagulation disorders, hemoglobin and anemia evaluations, autoimmune disorders, serum protein analysis, toxicology, molecular diagnostics, and transfusion medicine. The information in this report should provide sufficient detail to allow development of interpretive services with successful billing for the areas in laboratory medicine described.

Sensitivity of peripheral blood smear review for the diagnosis of Candida fungemia

CONTEXT Case reports have described detection of candidemia by examination of peripheral blood smears. It is unclear whether this method has wider applicability for early detection of fungemia. OBJECTIVE To determine the sensitivity of smear review for detecting candidemia. DESIGN Normal and cytopenic blood was spiked with increasing concentrations of yeast. Smears were prepared and reviewed by a pathologist and by technical staff. Staff members blinded to the purpose of the study first performed a routine slide review and then a targeted review for yeast. RESULTS The pathologist detected isolated yeast forms at a concentration of 1 to 5 x 10(5) colony-forming units (CFU)/mL. When blinded to the purpose of the study, technical staff could detect Candida in most samples when the yeast concentration was 1 to 5 x 10(7) CFU/mL, but found it in only a small fraction of samples with lower concentrations. When asked to examine the smears specifically for yeast, they could detect it in most samples containing 1 to 5 x 10(6) CFU/mL. CONCLUSIONS Detection of candidemia by peripheral blood smear examination requires a yeast concentration of 1 to 5 x 10(5) CFU/mL or greater. This degree of fungemia is unusual; therefore, detection of candidemia by blood smear review will not be possible in most cases. Sensitivity of smear review for yeast detection is greatly increased if the microscopist is specifically directed to look for the presence of yeast.