Linda M. Sandhaus

How useful are CBC and reticulocyte reports to clinicians

We surveyed 1,353 attending and 689 house staff physicians of the University Hospitals of Cleveland to ascertain the parameters of the CBC, leukocyte differential, and reticulocyte reports perceived as useful in clinical practice. The response rate was 33% for attending and 22% for house staff physicians. Only 4 of 11 parameters routinely reported in the CBC battery were selected as frequently or always useful by more than 90% of physicians: hemoglobin, hematocrit, platelet count, and WBC count. Among primary care physicians, the mean cell volume also attained this level of usefulness for the evaluation of anemia. There were no differences between academic physicians and community physicians in the use of RBC indices; however, physicians who had been in practice for fewer than 10 years indicated higher use of the red cell distribution width than physicians practicing for more than 10 years. Most physicians prefer differentials reported as percentages rather than absolute counts. Among physicians who monitor reticulocyte counts, the immature reticulocyte fraction is not widely used. Our results indicate that many physicians do not use much of the data provided in routine CBC/differential and reticulocyte reports. Some modifications of report formats may facilitate physician perception of hematology laboratory results.

Platelet Counting by the Coulter LH 750, Sysmex XE 2100, and Advia 120 A Comparative Analysis Using the RBC/Platelet Ratio Reference Method

We compared the accuracy and precision of the impedance platelet counts generated by the Beckman Coulter LH 750 and the Sysmex XE 2100 and the optical platelet counts produced by the Advia 120 and the Sysmex XE 2100 withflow cytometric reference platelet counts. Samples analyzed had platelet counts less than 150 x 10(3)/microL (150 x 10(9)/L) with a platelet flag or less than 75 x 10(3)/microL (75 x 10(9)/L) on the Sysmex SE 9500. The 105 samples were run sequentially through each analyzer. Anti-CD41 and anti-CD61 monoclonal antibodies were used for flow cytometric determination of the reference platelet count by the RBC/platelet ratio method. The Beckman Coulter and the Sysmex impedance platelet counts showed better correlation with the reference method than the optical platelet counts by the Advia and the Sysmex. At platelet transfusion thresholds of 10 and 20 x 10(3)/microL (10 and 20 x 10(9)/L), the precision of the impedance methods was somewhat better than that of the optical methods. Current methods of optical platelet counting may not be superior to impedance platelet counts for all patient populations.

Fine-Needle Aspiration Cytology in the Diagnosis of Lymphoma

Since 1985, almost 200 articles have been published inthe medical literature on the subject of fine-needle aspiration(FNA) cytology and the diagnosis of lymphoma. Themajority of recent studies describe the usefulness of acombined approach using FNA cytology and immunopheno-typing by flow cytometry (FC) or immunohistochemistry.

Reporting BRCA test results to primary care physicians

Purpose: The main purpose of this study was to determine if comprehension of the cancer risk information presented in a hypothetical report for BRCA1/2 gene analyses was influenced by the format in which the information was presented. A secondary objective was to determine physician characteristics that might influence comprehension of the report.Methods: A survey was conducted in which a case vignette describing a young woman at high risk for carrying a BRCA mutation was presented. Survey participants, all primary care practitioners, were asked to interpret a laboratory report that provided the patients BRCA1/2 test result and accompanying data about the cumulative risk and incidence rates of breast cancer for BRCA1/2 mutation carriers and the general population. These data were presented in the report in either a tabular or a graphic format. The main outcome was measured by the responses to four questions that addressed the probabilistic cancer risk information. Physician predictor variables included medical specialty, practice setting, years in practice, continuing medical education in genetics, and knowledge of cumulative risk.Results: Knowledge of cumulative risk was the only physician variable that influenced comprehension of the cancer risk information (OR = 31.9;P < 0.001). After adjusting for this variable, the graphic format tended to perform better than the tabular format in conveying breast cancer risk information (OR = 3.1;P = 0.102).Conclusions: Many physicians may be unprepared to interpret genetic risk information, due to lack of understanding of basic epidemiologic terms used to express the risk of disease.

Absolute immature platelet count dynamics in diagnosing and monitoring the clinical course of thrombotic thrombocytopenic purpura

Thrombotic thrombocytopenic purpura (TTP) is a life‐threatening diagnosis requiring prompt initiation of therapeutic plasma exchange (TPE). Measurement of immature platelet (PLT) fraction (%‐IPF) differentiates PLT consumption or destruction from hypoproduction.

Measuring the clinical impact of pathologist reviews of blood and body fluid smears.

CONTEXT Despite the widespread practice of pathologist review of blood and body fluid smears, little is known about its impact on improving patient care. OBJECTIVE To assess the clinical usefulness of pathologist review of blood and body fluid smears. DESIGN Survey study. Pathology residents contacted the ordering physician after pathologist reviews were reported to assess their clinical impact. RESULTS Ninety-six pathologist reviews met criteria for study inclusion, and 64 ordering physicians were successfully contacted during the 2-month study period. Of the 64 cases, 19 reviews (30%) had been seen by the physician within 24 to 48 hours after the report was issued and 33 (51%) had not been seen; in 4 (6%) instances, physicians did not remember whether they had seen the review. Eight reviews (13%) were considered urgent enough to warrant immediate communication by the pathologist. Of the 27 reviews that were seen or directly communicated, 23 (85%) contributed to clinical diagnosis and/or patient management. CONCLUSIONS This study demonstrates the contribution of pathologist reviews of blood and body fluids to clinical diagnosis and patient management. The results also highlight the problem of a lack of physician awareness of clinical pathology results.

Assessment of neonatal hyperbilirubinemia using GEM premier 4000 total bilirubin assay: Impact on risk classification?

The American Academy of Pediatrics recommends measurement of total bilirubin (TBili) in newborns to assess the risk of developing severe neonatal hyperbilirubinemia and bilirubin-induced neurologic dysfunction. In this study, we evaluated the correlation of whole blood TBili results measured on a blood gas analyzer to serum results obtained on an automated chemistry analyzer. In addition, we determined the concordance of hyperbilirubinemia risk classification between the 2 methods. Seventy-nine blood samples were collected. The TBili (mg/dL) was measured on whole blood using the Instrumentation Laboratories GEM 4000 (GEM) and on simultaneously collected serum samples on the Siemens Dimension Vista chemistry analyzer (Vista). Twenty-four infants, aged younger than 7 days, were classified into categories for risk of sequelae of severe hyperbilirubinemia using an established postnatal hour-specific nomogram. GEM results showed a mean bias of +0.55 mg/dL compared with Vista. Eight (33%) of 24 infants were assigned different risk grades by the GEM; 4 were assigned higher risk grades, and 4 had lower risk grades; only 1 infant’s risk status was changed by more than 1 grade. Therefore, although the GEM method shows good overall agreement with the Vista chemistry analyzer in measurement of TBili levels, assignment of clinical risk categories may differ by the 2 methods.

Fine-Needle Aspiration Cytology in the Diagnosis of LymphomaThe Next Step

Since 1985, almost 200 articles have been published inthe medical literature on the subject of fine-needle aspiration(FNA) cytology and the diagnosis of lymphoma. Themajority of recent studies describe the usefulness of acombined approach using FNA cytology and immunopheno-typing by flow cytometry (FC) or immunohistochemistry.