Min Xu

Implementation of FilmArray respiratory viral panel in a core laboratory improves testing turnaround time and patient care

Abstract The FilmArray respiratory virus panel detects 15 viral agents in respiratory specimens using polymerase chain reaction. We performed FilmArray respiratory viral testing in a core laboratory at a regional children’s hospital that provides service 24 hours a day 7 days a week. The average and median turnaround time were 1.6 and 1.4 hours, respectively, in contrast to 7 and 6.5 hours documented 1 year previously at an on-site reference laboratory using a direct fluorescence assay (DFA) that detected 8 viral agents. During the study period, rhinovirus was detected in 20% and coronavirus in 6% of samples using FilmArray; these viruses would not have been detected with DFA. We followed 97 patients with influenza A or influenza B who received care at the emergency department (ED). Overall, 79 patients (81%) were given oseltamivir in a timely manner defined as receiving the drug in the ED, a prescription in the ED, or a prescription within 3 hours of ED discharge. Our results demonstrate that molecular technology can be successfully deployed in a nonspecialty, high-volume, multidisciplinary core laboratory.

Application of the Toyota Production System Improves Core Laboratory Operations

To meet the increased clinical demands of our hospital expansion, improve quality, and reduce costs, our tertiary care, pediatric core laboratory used the Toyota Production System lean processing to reorganize our 24-hour, 7 d/wk core laboratory. A 4-month, consultant-driven process removed waste, led to a physical reset of the space to match the work flow, and developed a work cell for our random access analyzers. In addition, visual controls, single piece flow, standard work, and 5S were instituted. The new design met our goals as reflected by achieving and maintaining improved turnaround time (TAT; mean for creatinine reduced from 54 to 23 minutes) with increased testing volume (20%), monetary savings (4 full-time equivalents), decreased variability in TAT, and better space utilization (25% gain). The project had the unanticipated consequence of eliminating STAT testing because our in-laboratory TAT for routine testing was less than our prior STAT turnaround goal. The viability of this approach is demonstrated by sustained gains and further PDCA (Plan, Do, Check, Act) improvements during the 4 years after completion of the project.

Under-filled blood collection tubes containing K2EDTA as anticoagulant are acceptable for automated complete blood counts, white blood cell differential, and reticulocyte count.

Current laboratory standards from Clinical Laboratory Standards Institute (CLSI) and manufacturer’s (Becton Dickinson) data indicate that under‐filling K2EDTA blood collection tubes can result in erroneous hematology values. To accommodate under‐filled tubes and reduce collection volumes while optimizing our automation, we explored the acceptable limit of under‐filled tubes for hematology values. We collected 8.0u2003ml of blood from 30 normal adult volunteers. Each donation was aliquoted in the following volumes: 4.0, 2.0, 1.0, 0.5u2003mlu2003×u20032. These samples were analyzed within 1u2003h of blood collection on Sysmex XE‐2100 (Sysmex America Inc., Mundelein, IL, USA) for complete blood count, reticulocyte, and white blood cell differentials. Results of the under‐filled tubes were compared to those of the standard volume. The Deming regression analysis show excellent correlation for all parameters between each under‐filled blood collection volume compared to a standard 4u2003ml volume. The Bland and Altman analysis shows good agreement between both 1.0 and 2.0u2003ml compared to a 4.0u2003ml volume. The 0.5u2003ml compared to a 4.0u2003ml volume, however, shows increased variation on many parameters. In addition all three collection volumes show negative bias compared to the standard volume for platelet count, but the difference is considered insignificant with a percent difference of 5.5%, 3.2%, and 1.5% for 0.5, 1.0, and 2.0u2003ml collection volume respectively. Finally for 0.5u2003ml collection volume we noticed a low level of false positive flagging rate for white blood cell. Acceptable complete blood count values of under‐filled powdered K2EDTA tubes can be obtained with as little as 1.0u2003ml of blood.

Flow cytometric validation of automated differentials in pediatric patients

Manual differential white blood cell (WBC) counting has been considered the gold standard and is routinely used to validate differentials obtained with other methodologies. To validate the accuracy of automated lymphocyte counts, we compared 2-part differentials using a Coulter HmX hematology analyzer and a Coulter XL flow cytometer to analyze 57 pediatric samples with WBC counts ranging from 0.7 k to 33.4 k. These data were compared with manual differential counts. We found excellent correlation between the two automated lymphocyte and monocyte counting methods that surpassed the manual correlations, indicating manual lymphocyte or monocyte counts are unnecessary in the setting of quality scatterplots. To evaluate the use of automated differentials for our most labor-intensive cases (low WBCs, which frequently require manual differentials) we then compared 3-part differentials using the HmX hematology analyzer and flow cytometer for 51 samples with total WBC < or = 1.1 x 10(9)/L. Manual differentials (< or = 100-cell counts) were available on 27 samples. Although the correlations for manual versus automated or flow differentials were good for all cell types, the correlation between the two automated methods was better, irrespective of the hematology analyzer scatterplot quality. Preliminary data provide additional evidence that automated differentials in samples with WBC of < or = 1.1 x 10(9)/L are acceptable for reporting, thus saving technologist time and improving patient care by decreasing the resulting turnaround time. These studies suggest that comparison with a standardized procedure like flow cytometry would be a better method for validation of automated differentials than comparison with the less precise, more laborious manual differential.

Pure Erythroid Leukemia Following Precursor B-Cell Lymphoblastic Leukemia

Therapy-related acute myeloid leukemia is an unfortunate sequel to current multimodal intensive chemotherapy. The patient described was diagnosed with pure erythroleukemia, AML-M6b, during therapy for precursor B-cell acute lymphoblastic leukemia. To the best of our knowledge, this is the first report of this unusual association.

Evaluation of Multiplex Antinuclear Antibody Assay in Pediatric Patients

Objective: To determine whether multiplex antinuclear assay (ANA) can replace immunofluorescence assay (IFA) in pediatric patients. Methods: Archived frozen serum samples from patients with suspected autoimmune diseases were selected based on the availability of leftover serum samples with corresponding results. These samples had been previously tested for ANA using IFA methodology (101 samples), dsDNA (93 samples), and ENA (27 samples) by ELISA methods. Antinuclear assay screen was performed on these samples using the AtheNA Multi-Lyte ANA Test System. Results: There was a high level of discordance (45.5% concordance) between multiplex ANA screen and IFA method but strong correlation between multiplex ANA and specific autoantibody assays (89% to 96% concordance). All patients with positive ANA by IFA method, who were either diagnostic or suspicious for juvenile idiopathic arthritis (JIA), were negative by multiplex ANA assay. Conclusion: Multiplex ANA testing is an efficient and reliable method for detecting specific antinuclear antibodies; however, it cannot replace IFA as an ANA screening method in the pediatric population, especially for children with JIA.

Comparison of molecular detection methods for pertussis in children during a state-wide outbreak

A state-wide pertussis outbreak occurred in Washington during the winter–spring months of 2012, concurrent with respiratory viral season. We compared performance characteristics of a laboratory-developed pertussis PCR (LD-PCR for Bordetella pertussis, Bordetella parapertussis, and Bordetella holmesii) and rapid multiplex PCR (RM-PCR) for respiratory viruses (FilmArray™, BioFire, B. pertussis data unblinded following FDA approval post outbreak). We analyzed three cohorts of patients using physician testing orders as a proxy for clinical suspicion for pertussis or respiratory viruses: Cohort 1, tested by LD-PCR for pertussis pathogens only by nasopharyngeal swab; Cohort 2, by RM-PCR for respiratory viruses only by mid-nasal turbinate swab; and Cohort 3, by both methods. B. pertussis was detected in a total of 25 of the 490 patients in Cohort 3 in which LD-PCR detected 20/25 (80xa0%) cases and the RM-PCR detected 24/25 (96xa0%; pxa0=xa00.2). Pertussis pathogens were detected in 21/584 (3.6xa0%) of samples from Cohort 1 where clinicians had a relatively strong suspicion for pertussis. In contrast, B. pertussis was detected in only 4/3071 (0.1xa0%) specimens from Cohort 2 where suspicion for pertussis was lower (pxa0<xa00.001 for comparison with Cohort 1). In summary, the two laboratory methods were comparable for the detection of B. pertussis.

Improving Time to Antibiotics for Pediatric Oncology Patients With Suspected Infections: An Emergency Department–Based Quality Improvement Intervention

Objective Studies in pediatric patients with fever and neutropenia demonstrate that shorter time to antibiotics is associated with a decrease in pediatric intensive care unit admissions and in-hospital mortality. In 2012, a 2-phase quality improvement intervention was implemented in a pediatric emergency department (ED) to improve care for this high-risk patient population. The objective was to determine if the introduction of (1) a rapid absolute neutrophil count (ANC) test and (2) a standardized prearrival process decreased time to antibiotics for febrile hematology/oncology(heme/onc) patients presenting to the ED. Methods The rapid ANC test introduced in February 2012 decreased turn-around-times in the laboratory from 60 to 10 minutes. The standardization of the prearrival communication between the heme/onc team and ED was implemented in August 2012 as part of a clinical standard work pathway for heme/onc patients who presented to the ED with fever and possible neutropenia. Time from arrival to the ED to administration of first antibiotic was measured. Data from January 2011 to December 2013 were analyzed using statistical process control. Results Seven hundred eighteen encounters for 327 patients were included. After the rapid ANC test, the proportion of patients who received antibiotics within 60 minutes of arrival increased from 47% to 60%. There was further improvement to 69% with implementation of the clinical standard work pathway. Mean time to antibiotics decreased from 83 to 65 minutes (21% decrease). Conclusion This 2-phase quality improvement intervention increased the proportion of patients who received antibiotics within 60 minutes of arrival to the ED. Similar processes may be implemented in other pediatric EDs to improve timeliness of antibiotic administration.

Is Identification of Lupus Erythematosus Cells Still Useful? A Case Report:

A 13-year-old girl presented with significant weight loss, depression, anemia, and neutropenia. The preliminary diagnosis was anorexia nervosa combined with depression. Due to peripheral cytopenia, a bone marrow biopsy was performed to rule out leukemia. Lupus erythematosus (LE) cells were found in the bone marrow aspirate, which prompted autoantibody testing, although clinically it was not suspected the patient had systemic lupus erythematosus (SLE). Further testing demonstrated very high levels of antinuclear antibodies (ANA) (>12 U) and anti–double strand DNA (dsNDA) (>1000 IU/mL), which confirmed the diagnosis of SLE. The patient was treated with steroids for SLE, and symptoms improved quickly. In conclusion, although the identification of LE cells as one of the diagnostic criteria for SLE has been obsolete, careful examination of bone marrow to identify LE cells is still very important in the diagnosis of unsuspected SLE.

Hematoxylin Bodies in Pediatric Bone Marrow Aspirates and Their Utility in the Diagnosis of Systemic Lupus Erythematosus.

In our recent case report, the finding of lupus erythematosus (LE) cells in a bone marrow aspirate led to the diagnosis of systemic lupus erythematosus (SLE) and appropriate treatment, although the patient was not clinically suspected to have SLE. To determine whether LE cells are present in the bone marrow aspirates of SLE patients, but overlooked in routine bone marrow morphology review, bone marrow aspirates from 30 pediatric patients (15 with SLE and 15 with other diagnoses) evaluated by rheumatologists were reviewed. LE cells were found in the bone marrow aspirates of only 1 SLE patient and none in non-SLE patients. However, hematoxylin bodies were identified in 53% (8/15) of SLE patients. Neither hematoxylin bodies nor LE cells were found in the aspirates from patients with other disorders. Three additional pediatric patients identified prospectively were found to have hematoxylin bodies in the bone marrow aspirates. Although the diagnosis was not initially suspected, 2 of the 3 patients were subsequently diagnosed with SLE. All patients with hematoxylin bodies and SLE had antinuclear antibody titers ≥1:640 with a homogeneous staining pattern. In addition, bone marrow aspirates of 9 adult patients were reviewed, and neither LE cells nor hematoxylin bodies were identified. In summary, hematoxylin bodies were present in the bone marrow aspirates of many pediatric SLE patients, while LE cells were rare. The finding of hematoxylin bodies in pediatric bone marrow aspirates is a helpful and specific diagnostic clue that may lead to the diagnosis of SLE when other clinical features are nonspecific.