Plasma cell leukemia producing monoclonal immunoglobulin E.

A 78-year-old male with lumbar pain and dim consciousness presented the clinical pictures of plasma cell leukemia (PCL) producing a large amount of monoclonal immunoglobulin E (IgE)/kappa protein. Laboratory investigation demonstrated an elevated serum calcium level and renal dysfunction. Systemic bone X-ray survey disclosed only a solitary osteolytic lesion. Circulating plasma cells demonstrated CD19(-)/CD56(-) and MPC-1(-)/CD49e(-)/CD45(+/-), the latter indicating the immature phenotype of the tumor cells. Bone marrow was occupied with immature, atypical plasma cells, of which cytoplasms were positive for IgE by direct immunofluorescence analysis. Chromosomes revealed a translocation of (11;14)(q13;q32), which is concordant with cyclinD1-protein overexpression by immunohistochemistry. He was treated with dexamethasone and vincristine, which somewhat improved the laboratory findings. He died of tumor progression after 4-month admission. The clinical and biological characteristics of IgE-producing PCL, a very rare type of plasma cell dyscrasia, are discussed, reviewing the past literature.

A cost-effectiveness evaluation of reticulocyte measurement in new outpatients with or without hematologic disorders.

BACKGROUND: Although reticulocyte counts provide very useful information, few studies have analyzed the cost-effectiveness of this testing. METHODS: The yield and cost of reticulocyte count testing were analyzed in 719 new outpatients who visited the comprehensive medicine clinics and received both reticulocyte and complete blood count (CBC) testing. A "useful result" (UR) of the testing was defined as a finding that contributed to a change in a physician's diagnosis or decision-making between the pre- and post-test diagnosis. Patients' medical records were thoroughly reviewed for the assignment of URs. A simulation study was performed, blinding the reticulocyte data to the examiners, for the determination of URs generated by CBC alone. RESULTS: CBC and reticulocyte testing generated a total of 838 URs in 719 patients, while the simulation study demonstrated 612 URs with CBC testing alone. When patients were grouped into 11 major disease categories according to a pre-test diagnosis, clinical effectiveness (UR/patient) varied from 1.69 (hematologic) to 0.13 (metabolic/endocrine patients), with a cost disparity from 206yen to 2784yen/UR. The cost-effectiveness (Deltacost/DeltaUR) of reticulocyte addition against CBC alone was 515yen per additional UR as a whole. Reticulocyte testing showed favorable cost-effectiveness in gastrointestinal ( 234yen) and hematologic patients ( 338yen/additional UR), while the test added few URs in metabolic/endocrine and neurologic patients, resulting in possibly unacceptable cost-effectiveness ( 3240yen and 2916yen/additional UR, respectively). CONCLUSIONS: Wide disparity in its cost-effectiveness among patients apparently indicated that reticulocyte count testing should be performed for selected patient groups on the basis of its cost-effectiveness.

Economic consequence of immediate testing for C-reactive protein and leukocyte count in new outpatients with acute infection.

BACKGROUND: There have been few well-designed studies that assess the cost-effectiveness of near-patient immediate testing. METHODS: We analyzed the economic outcome of immediate testing for C-reactive protein (CRP) and white blood cell count (WBC) in 305 new outpatients with acute infections. Patients were randomized into two groups: 147 patients were tested immediately for CRP and WBC before the physician's initial consultation (advance testing), and 154 patients were not subjected to advance testing. The subsequent prescribing decision and the drug/testing/personnel costs were compared between the groups. RESULTS: In the advance-testing group, the initial consultation was followed by a total of 84 prescriptions of oral antibiotics, against 158 in the other group. Comparing the total costs of oral and parenteral antibiotics between the two groups, a 30% reduction was achieved with advance testing ( yen105,830 vs. yen151,102). However, the savings were largely offset by frequent prescription of newer, expensive influenza neuraminidase inhibitors. Advance testing also significantly reduced additional laboratory use. More frequent urgent testing increased personnel costs in the non-advance-testing group. Overall, total cost was somewhat higher in the advance-testing group ( yen1,028,827 vs. yen984,105). CONCLUSIONS: The cost per antibiotic prescription reduced with advance testing was yen604 (approximately 5.8 US dollars) in our clinical setting. Judicious use of antivirals and introduction of a simple CRP test kit would improve cost-effectiveness.

Expression level of MDR1 message in peripheral blood leukocytes from healthy adults: a competitive nucleic acid sequence-based amplification assay for its determination.

Accurate quantification of multidrug resistance-1 gene (MDR1) expression in target cells would be of important therapeutic value in predicting cellular response to anticancer drugs. Because certain normal cells in peripheral blood physiologically express MDR1, increasing the sensitivity of the detection methods might result in confounding low-degree expression in tumor cells with physiologic expression in normal cells. The purpose of this study was to determine MDR1 mRNA expression levels in peripheral blood leukocytes obtained from healthy adult volunteers using a competitive nucleic acid sequence-based amplification (NASBA) assay. We determined the reference intervals of MDR1 mRNA expression in peripheral blood obtained from 98 healthy adults by measuring its expression with the quantitative NASBA assay between 5.50 x 10(4) copies/microg RNA and 6.76 x 10(5) copies/microg RNA. The new reference intervals were evaluated using a number of sensitive or resistant cell lines as control; positive or negative MDR1 expression was clearly demonstrated. We also reevaluated MDR1 expression levels in leukemia cells obtained from patient peripheral blood; 18 of 31 samples (58%) exceeded the newly established upper reference limit. The cutoff value established could be used to distinguish significant MDR1 expression in tumor cells from physiologic expression in certain normal cells coexistent in peripheral blood.

A competitive nucleic acid sequence-based amplification assay for the quantification of human MDR1 transcript in leukemia cells.

BACKGROUND: Because clinical drug resistance is caused by low-grade expression of a responsible gene, highly sensitive methods are desirable for its detection in clinical settings. We developed a quantitative nucleic acid sequence-based amplification (NASBA) assay for multidrug resistance-1 (MDR1) transcripts, and applied it to clinical samples. METHOD: MDR1 transcripts were amplified using the NASBA technique combined with sandwich hybridization of amplified MDR1 mRNA followed by chemiluminescence detection on an automated analyzer. Quantification of MDR1 mRNA was achieved through competitive coamplification of in vitro-generated RNA, which acts as an internal control. RESULTS: The competitive NASBA assay exhibited higher sensitivity (reliable detection limit was 100 copies of MDR1 mRNA) and linearity over a broader dynamic range (7 logarithmic orders) than the competitive reverse transcription-polymerase chain reaction assay. All 33 clinical samples obtained from patients with leukemia were successfully assayed, demonstrating its feasibility. MDR1 expression-compensated with beta-actin expression-ranged from 1.4 x 10(2) to 2.5 x 10(6) (median 4.8 x 10(5)) copies/microg RNA, while the range of MDR1 expression in peripheral blood samples from 15 healthy adults was from 8.9 x 10(4) to 5.2 x 10(5) (median 2.2 x 10(5)) copies/microg RNA. MDR1 expression in 8 of 33 clinical samples exceeded the median of healthy adult samples. CONCLUSIONS: The competitive NASBA assay is applicable to MDR1 mRNA quantification in clinical samples and would contribute to detection of clinical multidrug resistance.

[Special comments--problems in systematic review for diagnostic accuracy of high-sensitivity C-reactive protein assay in neonatal infection].

We conducted a systematic review for the diagnostic accuracy of high-sensitivity C-reactive protein assay for neonatal infection. In total, 558 relevant published reports were found in a search of MEDLINE and Igaku-Chuo-Shi. With our inclusion and exclusion criteria, we finally selected 30 primary studies for meta-analysis. We critically appraised the quality of selected clinical studies and then extracted sensitivity and specificity data from each article for meta-analysis. There was only one article that fulfilled our three major standards for quality assessment(rank A; high-quality), while 19 studies which fulfilled only one criterion were assigned to rank C(low-quality). Most studies neither took careful consideration of the blindness against the results of the index test nor described this methodological standard. Lack of qualified primary studies may have had substantial influence on the summary estimates. Insufficient number of primary studies for meta-analysis and their unsatisfactory quality would be improved by the addition of supplemental results retrieved from raw data, which the authors of clinical studies did not present in their articles.

Utilization of common inflammatory markers in new, symptomatic, primary care outpatients based on their cost-effectiveness.

Few studies have demonstrated the optimal usage of common inflammatory markers, alone or in combination, based on the cost-effectiveness. We analyzed the yield and cost of C-reactive protein (CRP), white blood cell count (WBC), erythrocyte sedimentation rate (ESR), sialic acid, and protein fractionation in 177 new primary care outpatients with inflammation-related symptoms. A useful result (UR) was assigned if tests contributed to a change in physician's diagnosis or decision-making. Costs of testing were calculated based on either single or simultaneous measurement. Five inflammatory markers generated 147 URs in 123 patients. CRP showed the best contribution to generation of UR, followed by sialic acid, protein fractionation, WBC, and ESR. CRP demonstrated poor correlation with WBC (r = 0.458), while sialic acid strongly correlated with total absolute amount of alpha1 and alpha2 fractions in protein fractionation (r = 0.855) and moderately with ESR (r = 0.651). The combination of CRP and WBC produced the best cost-effectiveness at a cost of Yen 1169 (US dollars 9.6 or Euro 9.7)/additional UR against CRP testing alone. Sialic acid, an automated multichannel analyzer-based test, demonstrated the favorable cost-effectiveness over ESR or protein fractionation when combined with CRP (and WBC). Our results indicate that the optimal usage of these inflammatory markers should involve careful cost-effectiveness considerations.

Large diversity in transport-mediated methotrexate resistance in human leukemia cell line CCRF-CEM established in a high concentration of leucovorin.

To elucidate the mechanism(s) of methotrexate (MTX) resistance as a possible reason underlying treatment failure in high-dose MTX regimens combined with leucovorin (LV) rescue, we established MTX-resistant human T-cell leukemia cell line CCRF-CEM cells in the presence of excess LV, and characterized their properties. Continuous exposure of the cells to escalating concentrations of MTX up to 20 microM in the presence of 1000 nM LV resulted in establishment of three MTX-resistant sublines with a wide disparity of resistance degree over a 4 logarithmic range (approximately 40-, 900- and 44,000-fold, respectively). Transmembrane transport of MTX in these sublines was diminished to 52%, 35% and 12%, respectively. Intracellular retention of MTX in these sublines was not different from that of the parent cells. A cell growth study in various concentrations of LV showed that cells with higher resistance to MTX required more LV for optimal growth. In parallel with the resistance levels, there was an increase in mRNA expression of dihydrofolate reductase gene and a decrease in that of thymidylate synthase gene, but no change in that of reduced folate carrier (RFC1) gene, as assessed by northern blot analysis. Sequencing of the RFC1 gene in all 3 sublines revealed a point mutation in codon 47 (TCC-->TTC) resulting in substitution of Phe for Ser residue, and additional deletion of CTG of codon 112 in the subline with the highest resistance. In summary, MTX exposure to CCRF-CEM cells in the presence of 1000 nM LV resulted in the establishment of heterogeneous cell populations with a wide range of transport-mediated MTX resistance, which was associated with differential alterations of RFC gene. These cell lines may serve as models for investigation of the molecular mechanism(s) underlying refractory tumors in high-dose MTX regimens with LV rescue.

[Common diagnostic tests under the Clinical Laboratory Improvement Amendments of 1988 (CLIA '88) in the United States].

The lower quality of laboratory testing in unlicensed physicians' office laboratories(POLs) had led to legislation of the Clinical Laboratory Improvement Amendments of 1988(CLIA '88) in the United States. This legislation extended laboratory regulations for quality control and assurance, personnel qualification, record-keeping, and proficiency testing to all laboratories regardless of size, complexity, or location, including POLs and ancillary testing sites in a hospital. According to the implementation of the CLIA '88 in 1992, all testing sites in this country must have inspections and a certificate issued by the federal government. The CLIA '88 has improved the quality of testing in POLs, forcing office physicians to deal with the problem of laboratory quality management, thereby increasing laboratory costs. Thus, compliance with the CLIA '88 standards is expensive. On-site testing in POLs has been reduced, discontinued, or changed as a result of the CLIA '88 legislation. A number of POLs have closed, and physicians have restricted test menus to those with simpler methodology(waived tests) because waiver laboratories do not require inspections by the government. Large portion of laboratory tests, which were formerly done in POLs, flow into the reference laboratory market as outreach tests. Currently, 77% of POLs are performing only waived tests or tests in the provider-performed microscopy procedures category, while only 23% have a certificate for moderate or high complexity methodology status. Thus, common diagnostic tests performed in POLs are predominantly based on the waived tests, which are largely different from those performed in Japan, with respect to test item and methodology.

Yield and cost of individual common diagnostic tests in new primary care outpatients in Japan.

BACKGROUND: Appropriate diagnostic testing involves considerations of cost-effectiveness. We examined the cost-effectiveness of individual tests in a panel of tests defined by the Japan Society of Clinical Pathology. METHODS: We studied 540 new, symptomatic primary care outpatients with a set of 30 common diagnostic tests [the Essential Laboratory Tests (2); ELT(2) panel] for clinical evaluation and identification of occult disease. A useful result (UR) of testing was defined as a finding that contributed to a change in a physician's diagnosis or decision-making relating to a "tentative initial diagnosis" obtained from history and physical examination alone. RESULTS: The ELT(2) panel testing yielded 398 URs and uncovered 261 occult diseases among 540 patients. In total, 1592 tests contributed to either UR-generation or discovery of occult disease. The cost per effective test (cost required per test that contributed to either definition of effectiveness) ranged from 108 yen (approximately 0.92 US dollars) for total cholesterol to 6200 yen (approximately 52.50 dollars) for chest x-ray. Contribution rates and the cost per effective test varied among disease categories. We restructured panel components considering the effectiveness of each test. Subsets of the ELT(2) would have improved cost-effectiveness and achieved cost savings in five of eight disease categories. CONCLUSIONS: Assembly of tests based on cost-effectiveness can improve clinical efficiency and decrease total cost of panel testing for selected patient groups.