National Clinical Laboratory Research Articles

Drug Misuse and Hepatitis C Virus Infection Profiles for Three Generations of Patients Being Monitored for Prescription Drug Adherence.

Objectives:Two epidemics in the United States are related: opioid drug injection and hepatitis C virus (HCV) infection. This study quantifies the relationship between illicit/prescription drug misuse and HCV infection in 3 population generations: baby boomers (born 1945–1965, inclusive), pre-baby boomers, and post-baby boomers.Methods:This retrospective study included prescription drug consistency (March–December 2015) and HCV (2011–2015) patient test results performed at a large national clinical reference laboratory. HCV positivity, drug use consistency/inconsistency with prescribed drug information, type of inconsistent use, and inconsistent use of individual drug classes were assessed.Results:This study evaluated 39,231 prescription drug monitoring and HCV sets of test results from 18,410 patients. Of these patients, 25.1% tested positive for HCV and 57.3% demonstrated drug test results that were inconsistent with the prescribed medication(s). The types of drug test inconsistency differed substantially between HCV-positive and -negative patients, particularly testing positive for both non-prescribed drugs and prescribed drugs. Specimens from HCV-positive baby boomer and post-baby boomers demonstrated non-prescribed use of opioids and many other drug classes more often than from HCV-negative patients.Conclusions:The rates of inconsistent drug test results and types of drugs misused suggest that HCV-positive patients are more likely than HCV-negative patients to display high-risk behavior, even beyond opioid use. This difference is most pronounced in the post-baby boomer generation. Healthcare professionals should consider these patterns and how they differ by generation when monitoring for both prescription and illicit drugs, the results of which can impact treatment decisions including prescribing analgesics.

Predictors for a dementia gene mutation based on gene-panel next-generation sequencing of a large dementia referral series

Next-generation genetic sequencing (NGS) technologies facilitate the screening of multiple genes linked to neurodegenerative dementia, but there are few reports about their use in clinical practice. Which patients would most profit from testing, and information on the likelihood of discovery of a causal variant in a clinical syndrome, are conspicuously absent from the literature, mostly for a lack of large-scale studies. We applied a validated NGS dementia panel to 3241 patients with dementia and healthy aged controls; 13,152 variants were classified by likelihood of pathogenicity. We identified 354 deleterious variants (DV, 12.6% of patients); 39 were novel DVs. Age at clinical onset, clinical syndrome and family history each strongly predict the likelihood of finding a DV, but healthcare setting and gender did not. DVs were frequently found in genes not usually associated with the clinical syndrome. Patients recruited from primary referral centres were compared with those seen at higher-level research centres and a national clinical neurogenetic laboratory; rates of discovery were comparable, making selection bias unlikely and the results generalisable to clinical practice. We estimated penetrance of DVs using large-scale online genomic population databases and found 71 with evidence of reduced penetrance. Two DVs in the same patient were found more frequently than expected. These data should provide a basis for more informed counselling and clinical decision making.

Concordance analysis of paired cancer antigen (CA) 15-3 and 27.29 testing.

Cancer antigens (CA) 15-3 and 27.29 are used in the clinical management of many breast cancer patients. Given that immunoassays for CA 15-3 and CA 27.29 target epitopes on the same glycoprotein-Mucin 1 (MUC1)-the present analysis was conducted to evaluate the potential concordance of tumor marker results when both tests were ordered by providers on the same specimens. A retrospective limited dataset of paired CA 15-3 (Roche Diagnostics) and CA 27.29 (Siemens Diagnostics) test results was obtained from a national clinical reference laboratory. Concordance according to reference interval (RI) status and percent (%) change between consecutive test results was analyzed. 37,652 paired results from 12,470 distinct patients were obtained. The correlation between CA 15-3 and CA 27.29 results was high (correlation coefficient: Pearson, 0.967), although across the dataset a significant difference between CA 15-3 and CA 27.29 results was observed (P<0.05). RI concordance between CA 15-3 and CA 27.29 results was observed in 93.7% of pairs (35,280 of 37,652). Correlation was also observed in the % change of CA 15-3 and CA 27.29 results between consecutive specimens for individual patients. Using doubling or halving thresholds (i.e., 100% increase or 50% decrease), concordance in % change was observed between CA 15-3 and CA 27.29 in approximately 90% of cases. Individual patient results trended similarly across both markers over time. While generally concordant, CA 15-3 and CA 27.29 results should not be used interchangeably. The present report provides no evidence for added value in performing both tests routinely for individual patients.

Serum Concentrations of Sex Hormone–binding Globulin Vary Widely in Younger and Older Men: Clinical Data from a Men’s Health Practice

BackgroundThe testosterone (T) status of a man is influenced by serum concentrations of sex hormone–binding globulin (SHBG). Specifically, tight binding of T to SHBG is believed to render the SHBG-bound T fraction biologically unavailable, meaning that interpretation of T levels in the clinical setting depends in part on knowledge of SHBG concentrations. Although SHBG levels have been reported in population studies, there is scant information for men presenting with clinical symptoms. ObjectiveTo report SHBG values for a large cohort of men presenting to a men’s health center. Design, setting, and participantsMedical records were reviewed for 1000 consecutive patients seen at our center with a reported SHBG value. SHBG concentrations were measured by a national clinical laboratory using an immunoassay run on a Beckman Coulter DXi system. Outcome measurements and statistical analysisPatients were age-stratified and data were plotted in the form of comparative histograms. Results and limitationsThe mean age (±standard deviation) of the total cohort was 53.5±13.5 yr (range 17–91). The mean SHBG was 31.8±15.2nmol/l (range 6-109), with a nearly 20-fold difference from the lowest to the highest values. SHBG was >60nmol/l in 5.6% of the men. Patients were stratified according to age. A total of 535 patients were ≤54 yr old. In this younger cohort, the mean age was 40.52±7.9 yr (range 17–54) and mean SHBG was 27.7±13.3nmol/l (range 6–88), and 2.2% of patients had SHBG >60nmol/l. A total of 465 patients were ≥55 yr old. In this older cohort, the mean age was 64.8±7.23 yr (range 55–91) and mean SHBG was 36.6±15.8 nmol/l (range 11–109), and 9% of patients had SHBG >60 nmol/l. Mean SHBG was significantly higher in the older group (p<0.001). ConclusionsA remarkably wide distribution of SHBG concentrations was observed in a clinical population of men presenting to a men’s health center, among both younger and older men. Since SHBG concentrations greatly influence test results for hormones that bind to SHBG, recognition of this large interindividual variability should be considered in the clinical interpretation of these hormone results, particularly for T. Routine SHBG testing should be considered for men suspected of T deficiency. Patient summarySex hormone–binding globulin (SHBG) levels vary widely among both older and younger men. This may impact the interpretation of test results for hormones that bind to SHBG, such as testosterone, since the portion that binds to SHBG is believed to not be biologically available.

Trends in Laboratory Rotavirus Detection: 2003 to 2014.

We assessed the impact of rotavirus vaccination at national and state levels by evaluating the change in rotavirus antigen detection after vaccination licensure. We examined herd immunity in an unlikely vaccinated cohort and waning immunity with aging in a likely vaccinated cohort. We proposed a new approach to estimate the length of season by contrasting with what is recently reported by the Centers for Disease Control and Prevention. We analyzed 11-year results of rotavirus testing (n = 276 342) conducted at Quest Diagnostics, a national clinical reference laboratory, spanning from September 2003 to August 2014. An enzyme immunoassay was used to test children's stool specimens for the presence of rotavirus antigen; results were reported as not detected or detected. Nationally, there was a significant reduction in the number of positive results (82.4%) and positivity rate (73.3%) after vaccination availability. The reductions were seen in all major states, although with geographic variability. The declining positivity rate in unlikely vaccinated children suggests herd immunity. Among those who were likely vaccinated, the positivity rate was higher in older children, indicating potential waning immunity with aging. Seasonal outbreaks continued in the postvaccine period, with peaks in alternating years. Seasons were longer in the postvaccine period than the prevaccine period. Our findings show a marked reduction in rotavirus detection throughout the nation after vaccine licensure, consistent with herd immunity. Postvaccine effectiveness may wane with aging. Seasons appear to be longer in the postvaccine period.

Investigation and Analysis of Reference Intervals for Blood Cell Parameters in a Healthy Population from Daxingan Region Inner Mongolia.

Blood cell parameters in a healthy population of different ages and genders from the Daxingan region of Inner Mongolia were evaluated to establish reference intervals (RIs) for venous blood parameters for healthy individuals from this region. Venous blood specimens were collected from 1757 healthy individuals aged 7-65 years and analyzed by an XE-5000 automated hematology analyzer. Results were statistically analyzed by gender and age group. RIs for venous blood parameters of children were compared to the National Clinical Laboratory Procedures and those of adults were compared to the Health Industry Standards of the People's Republic of China (WST405-2012). In the Daxingan region, WBC, RBC, MCV, and NEUT%, MONO%, and EO% of healthy children were significantly different between genders (p < 0.05). Other parameters were not significantly different (p > 0.05). All parameters of adults were significantly different between different genders (p < 0.05) except for LYMPH% and BASO%. Comparison of mean values between children and adults of the same gender revealed significant differences in each blood cell parameter (p < 0.05). RBC, MCV, MCH, MCHC, PLT, MONO%, and BASO% of adult men were significantly different between different age groups (p < 0.05), and HGB, HCT, and EO% of adult women were significantly different between different age groups (p < 0.05). For children, only the mean of MCHC and EO% were close to the National Clinical Laboratory Procedures. Mean of RBC, HGB, PLT, LYMPH%, and MONO% were higher and the remaining parameters were lower than the National Clinical Laboratory Procedures. Compared with WST405-2012 for adults, PLT of women aged 18-40 years and NEUT% of adults were higher, whereas the mean of EO% and BASO% were significantly lower. RIs for venous blood parameters change with age, geographic region, ethnic group, and gender. There is a great necessity to establish RIs for venous blood parameters among the healthy population in the Daxingan region.

Comparison of cardiometabolic risk biomarkers from a national clinical laboratory with the US adult population

Clinical laboratory patient databases are an untapped source of valuable diagnostic and prognostic information. However, the lack of associated clinical and/or demographic information and questionable generalizability to nonpatient populations often limit utility of these data. This study compared levels of cardiometabolic biomarkers between a national clinical laboratory patient cohort (Health Diagnostic Laboratory [HD Lab]) and the US population as inferred from the National Health and Nutrition Examination Survey (NHANES, 2011-2012). Sample sizes for HD Lab ranged from 199,000 to 739,000 and for NHANES from 2200 to 5300. The latter were weighted to represent the adult US population (∼220 million). Descriptive statistics were compared for body mass index, 5 lipid biomarkers, and 3 glycemic biomarkers. Using age- and sex-matched data, mean biomarker values (mg/dL unless noted) and percent differences (%) for HD Lab vs NHANES were body mass index (kg/m(2)), 29.1 vs 28.6 (1.7%); total cholesterol, 185 vs 193 (-4.1%); apolipoprotein B, 92 vs 90 (2.2%); low-density lipoprotein cholesterol, 107 vs 115 (-7%); high-density lipoprotein cholesterol, 53 vs 53 (0%); triglycerides, 128 vs 127 (0.8%); glucose, 99 vs 108 (-8.3%); insulin (uU/mL), 13.7 vs 13.4 (2.2%); and hemoglobin A1c (%), 5.6 vs 5.8 (-3.4%). Although all differences were statistically significant, only low-density lipoprotein cholesterol and glucose differed by more than 5%. These may reflect a greater use of medications among HD Lab patients and/or preanalytical factors. Cardiometabolic risk markers from a national clinical laboratory were broadly similar to those of the US population; thus, with certain caveats, data from the former may be generalizable to the latter.

등온증폭법을 이용한 돼지인플루엔자바이러스 신속 진단법 개발

In this study, we developed a rapid, sensitive and specific reverse-transcriptase loop-mediated isothermal amplification (RT-LAMP) assay for detection of swine influenza viruse (SIV) including major subtypes of swine influenza viruses H1N1, H1N2 and H3N2, and a novel subtype of influenza A virus that accidentally infected in pig population. The RT-LAMP was completed in 40 min at 58C and the sensitivity of the RT-LAMP (1 copy/L) was 10-fold higher than conventional reverse transcription-polymerase chain reaction (RT-PCR) (10 copy/L) and the same to real time RT-PCR (1 copy/L). Also, the result of the RT-LAMP can be confirmed without any detection system. Therefore, the RT-LAMP could be a alternative diagnostic method for SIV detection in national SIV monitoring system and clinical diagnostic laboratory in the future.

Reference Intervals for Routine Blood Tests in 468 Healthy Mongolian Children.

To establish reference intervals for routine blood parameters of healthy Mongolian children in the Inner Mongolia Daxingan region. Venous blood samples from 468 children aged 7 - 13 years were analyzed with a Sysmex XE-5000 Automated Hematology Analyzer. Statistical analysis was used to compare findings with the National Clinical Laboratory Procedures and to analyze according to gender and ethnic group. The reference range for each blood cell parameter is as follows: WBC (x 109/L): 3.44 - 9.27 for males, 3.79 - 9.79 for females; RBC (x 1012/L): 4.25 - 5.36 for males, 4.20 - 5.21 for females; HGB (g/L): 118 - 149. HCT (%): 34.9 - 43.4; MCV (fl): 75.1 - 88.2 for males, and 76.6 - 90.6 for females; MCH (pg): 25.5 - 30.3 for males, and 25.7 - 31.0 for females; MCHC (g/L): 327 - 356 for males, 323 - 353 for females; PLT (109): 109 - 209; NEUT %: 34.6 - 71.9; LYMPH %: 19.8 - 56.8; MONO %: 2.8 - 9.5 for males, and 3.1 - 7.9 for females; EO %: 0.0 - 3.6; BASO %: 0.0 - 1.0 for males, and 0.0 - 0.9 for females. There were significant differences between genders with respect to the WBC, RBC, MCV, MCH, MCHC, MONO %, and BASO % parameters (p < 0.05), but not other parameters (p > 0.05). The blood parameters of children can vary with geography, nationality, gender, and other variables. Therefore, it is necessary to obtain reference intervals for Mongolian children according to their gender and age.

Analysis and comparison of reference intervals of complete blood cell count with the published standards

Objective To analyze the status of reference intervals（RIs）of complete blood cell count（CBC）in China and compare them with the published standards. Methods The RIs information of CBC（containing the items of WBC, RBC, Hb, HCT, MCV, MCH, MCHC and PLT）were collected by the External Quality Assessment（EQA）software from laboratories participated in the Second Complete Blood Cell Count EQA Program in 2013, which including the sources of RIs, the lower and upper limits of RIs and the validation information of RIs. The sources and validation information of RIs were analyzed by Microsoft Excel 2007 using all data except those from maternal and child care service center, children′s hospital and corporations. The outliers of limits of RIs were excluded according to the International Federation of Clinical Chemistry（IFCC）guidelines ，then data were analyzed by SPSS 13.0. The mean of the upper and lower limits of the RIs were compared with the published standards by the t-test. Results Totally 299（57.72%）of 518 laboratories reported were using RIs according to National Clinical Laboratory Operation Rules, while 112（26.62%）labs were using RIs from instrument/reagent manufacturer instructions, 411（80.00%）labs did not validate the RIs they used, of which 258（50.00%）did not know how to validate RIs. The deviation of the maximum and the minimum ranged from 16% to 70%. More than one third laboratories did not separate RIs of RBC, Hb and HCT according to the gender. The upper and lower limits of WBC and MCV of most laboratories were higher, while those of RBC(male/female), PLT and Hb(male) were lower than that from the published standard. The RIs of MCH was narrower than that from the published standard. Meanwhile, HCT, MCHC (male/female) and Hb (female) were near the upper and lower limits of published standards. Conclusions At present, the RIs of CBC used in laboratories is chaotic, which is significantly different from the published standard. On the basis of standardization, the RIs of published standard result from a multi-center study in Chinese people should be preferred.（Chin J Lab Med,2014,37:539-543） Key words: Blood cell count; Reference values; Quality control

Blood Cholesterol Trends 2001–2011 in the United States: Analysis of 105 Million Patient Records

ObjectivesWe report annual trends in low density lipoprotein cholesterol (LDL-C) from an in-care patient population of nearly 105 million adults across the United States (U.S.), from 2001 through 2011.BackgroundAverage blood cholesterol values have declined in the U.S. since at least 1960. The National Health and Nutrition Examination Survey (NHANES) reported declining blood cholesterol values from 1999 through 2010. In the absence of more recent published data, we examined LDL-C values from a single clinical laboratory database to determine whether these values continued to decline through 2011.Methods and ResultsWe extracted almost 247 million LDL-C results from nearly 105 million adults who received diagnostic testing from a single national clinical laboratory. Annual age-adjusted mean LDL-C values were calculated, and analyzed by gender. Piecewise regression analysis of the total study population indicates a breakpoint, or change in slope, in the years following 2008 (F = 163.13; p<0.05). Between 2001 and 2008, the average rate of annual decline was −2.05 mg/dL (95% CI [−2.35, −1.75]). After 2008, mean LDL-C levels flattened out, with a slope not statistically different from zero (slope = −0.10 mg/dL/year; 95% CI [−1.46, 1.26]). This stabilization was observed in both genders and all age ranges, and was also reflected in the percentage of results in low- and high-risk categories.ConclusionsThe trends reported suggest historical progress in decreasing LDL-C levels, observed from 2001–2008, may have stalled in recent years. Further research is needed to determine the cause of the observed trends and develop new strategies to reduce lipid-based cardiovascular risk further.

Guidance on the development and validation of diagnostic tests that depend on nucleic acid amplification and detection

In order to comply with national and international clinical laboratory accreditation standards (e.g. the ISO 15189, Clinical Pathology Accreditation standards) and with the joint code of practice for research, there must be a method of assessing that test methods are “fit for purpose”. This document gives guidance on development and describes how a validation file is produced. A test method may be a commercial kit, an in-house assay or reagent or a set of reagents bought separately and used to prepare an in house assay.A validation file is needed for both current and new test procedures. The file may refer to data recorded in workbooks, papers and reports. Modifications to assays (including commercially available assays) necessitate either an update to the validation file or creation of a new file.This paper is intended to provide a generic framework for in-house assay development and validation of new nucleic acid amplification assays including real-time polymerase chain reaction (PCR).

Company Profile: NeoGenomics Laboratories, Inc.

NeoGenomics Laboratories, Inc. is a publicly traded high-complexity national clinical laboratory company that specializes in cancer diagnostic testing, focused on molecular and genomic approaches. NeoGenomics has been associated with innovation in providing world-class pathology and cancer genetic diagnostic services for pathologists, oncologists, urologists and gastroenterologists, as well as hospitals throughout the USA. The company mission also includes the integration of technical advances in molecular methodologies including computer-aided pattern-recognition mathematical algorithms in order to integrate data from multiple analytes and thereby develop precise (personalized) predictive tools for the diagnosis of disease, prognosis and response to therapy. The company has a unique business model in that it is committed to partnering with routine diagnostic laboratories, thereby providing them with the option of technical-component-only testing for esoteric biomarkers and allowing local control of the professional component, in the interpretation and the review of raw data. The company, through innovative research and development, is dedicated to the cost-effective delivery of leading-edge, high-quality patient care through the application of precise and personalized laboratory medicine.

Diabetes mellitus abolishes the cardioprotective effect of ischemic postconditioning against ischemia/reperfusion injury in rat: Role of lipid peroxidation

The testosterone (T) status of a man is influenced by serum concentrations of sex hormone–binding globulin (SHBG). Specifically, tight binding of T to SHBG is believed to render the SHBG-bound T fraction biologically unavailable, meaning that interpretation of T levels in the clinical setting depends in part on knowledge of SHBG concentrations. Although SHBG levels have been reported in population studies, there is scant information for men presenting with clinical symptoms.To report SHBG values for a large cohort of men presenting to a men’s health center.Medical records were reviewed for 1000 consecutive patients seen at our center with a reported SHBG value. SHBG concentrations were measured by a national clinical laboratory using an immunoassay run on a Beckman Coulter DXi system.Patients were age-stratified and data were plotted in the form of comparative histograms.The mean age (± standard deviation) of the total cohort was 53.5 ± 13.5 yr (range 17–91). The mean SHBG was 31.8 ± 15.2 nmol/l (range 6-109), with a nearly 20-fold difference from the lowest to the highest values. SHBG was >60 nmol/l in 5.6% of the men. Patients were stratified according to age. A total of 535 patients were ≤54 yr old. In this younger cohort, the mean age was 40.52 ± 7.9 yr (range 17–54) and mean SHBG was 27.7 ± 13.3 nmol/l (range 6–88), and 2.2% of patients had SHBG >60 nmol/l. A total of 465 patients were ≥55 yr old. In this older cohort, the mean age was 64.8 ± 7.23 yr (range 55–91) and mean SHBG was 36.6 ± 15.8 nmol/l (range 11–109), and 9% of patients had SHBG >60 nmol/l. Mean SHBG was significantly higher in the older group (p < 0.001).A remarkably wide distribution of SHBG concentrations was observed in a clinical population of men presenting to a men’s health center, among both younger and older men. Since SHBG concentrations greatly influence test results for hormones that bind to SHBG, recognition of this large interindividual variability should be considered in the clinical interpretation of these hormone results, particularly for T. Routine SHBG testing should be considered for men suspected of T deficiency.Sex hormone–binding globulin (SHBG) levels vary widely among both older and younger men. This may impact the interpretation of test results for hormones that bind to SHBG, such as testosterone, since the portion that binds to SHBG is believed to not be biologically available.

The clinical laboratory fee schedule yesterday, today, tomorrow.

1. Joan Longberry, CLDir (NCA)[⇑][1] 1. is a retired clinical laboratory manager and consultant and an advisor for the ASCLS Government Affairs Committee 1. Address for Correspondence: Joan Longberry, 45 West Dunedin Road, Columbus, Ohio 43214, JoanLongberry{at}aol.com 1. Describe at least three changes in Medicare payment methodology for laboratory services following the implementation of the clinical laboratory fee schedule (CLFS) in 1984. 2. List the key provisions of the Balanced Budget Act of 1997 affecting payment for Medicare laboratory services. 3. Compare the initial mechanism for annual inflation adjustments to the CLFS with the actual updates between 1991 and 2007. 4. Discuss two reasons for the actual decreases in reimbursement for laboratories since the CLFS was implemented. 5. Explain the difference between the “cross-walking” and “gap-filling” processes used to set CLFS payment amounts for new tests. 6. List five recommendations in the IOM Report “Medicare Laboratory Payment Policy: Now and in the Future”. 7. Describe the key elements of the design for the Competitive Bidding for Medicare Clinical Laboratory Services demonstration project. 8. List the specific purposes for an alternative payment system outlined in the Medicare Clinical Diagnostic Laboratory Fee Schedule Modernization Act of 2008. Introduction For well over two decades, the laboratory community has been confronted with a myriad of legislative and regulatory changes in payment policies and reimbursement levels for services provided to Medicare beneficiaries for outpatient clinical laboratory services. When Medicare was first implemented, clinical laboratories were reimbursed according to usual, customary and reasonable charges and beneficiaries were responsible for a copayment. Following the enactment of the Deficit Reduction Act in 19841, payment to laboratories providing Part B services to Medicare changed to a national clinical laboratory fee schedule (CLFS) system. Although the fee schedule established in 1984 bears little resemblance to the actual cost of laboratory testing in 2009, it remains the mechanism by which laboratories are reimbursed. An Institute of Medicine study in 2000 made several recommendations for reimbursement that have yet to be implemented. This article will review the many problems and challenges to the CLFS that have occurred since its inception in 1984. The Beginning Initially under Medicare, clinical laboratories were paid for outpatient Part B services based on customary and reasonable charges. Each state had fiscal intermediaries (which reimbursed hospital laboratories) and carriers (which reimbursed independent and physician office laboratories) and each had different ranges of customary and reasonable charges. Clinical laboratories found collecting the then-required beneficiary co-payments of 20% to be exceedingly difficult, as most did not have a billing relationship with patients. In addition, the costs of billing and collecting such small amounts were financially and administratively burdensome. Thus, the laboratory industry supported the fee… ABBREVIATIONS: ASCLS = American Society for Clinical Laboratory Science; BBA = Balanced Budget Act; CLFS = clinical laboratory fee schedule; CMS = Centers for Medicare & Medicaid Services; CPI = consumer price index; CPT = current procedural terminology; FY = fiscal year; HCFA = Health Care Financing Administration; HHS = Department of Health & Human Services; HR = House of Representatives; IOM = Institute of Medicine; MSA = metropolitan statistical area; MMA = Medicare Prescription Drug, Improvement, and Modernization Act; NLA = national limitation amount; PL = public law 1. Describe at least three changes in Medicare payment methodology for laboratory services following the implementation of the clinical laboratory fee schedule (CLFS) in 1984. 2. List the key provisions of the Balanced Budget Act of 1997 affecting payment for Medicare laboratory services. 3. Compare the initial mechanism for annual inflation adjustments to the CLFS with the actual updates between 1991 and 2007. 4. Discuss two reasons for the actual decreases in reimbursement for laboratories since the CLFS was implemented. 5. Explain the difference between the “cross-walking” and “gap-filling” processes used to set CLFS payment amounts for new tests. 6. List five recommendations in the IOM Report “Medicare Laboratory Payment Policy: Now and in the Future”. 7. Describe the key elements of the design for the Competitive Bidding for Medicare Clinical Laboratory Services demonstration project. 8. List the specific purposes for an alternative payment system outlined in the Medicare Clinical Diagnostic Laboratory Fee Schedule Modernization Act of 2008. [1]: #corresp-1

Characteristics of Laboratory Screening Suggest That Paroxysmal Nocturnal Hemoglobinuria (PNH) Is Perceived Primarily as a Bone Marrow Failure Syndrome Rather Than as a Hemolytic Anemia

PNH is a hematopoietic stem cell disorder in which the predominant clinical manifestations are hemolysis, bone marrow failure and thrombophilia. PNH arises as a result of somatic mutation of PIGA, an X-linked gene required for synthesis of the glycosyl phosphatidylinositol (GPI) moiety that anchors some proteins to the cell surface; and consequently, progeny of affected stem cells are deficient in all GPI-anchored proteins (GPI-APs). The hemolysis of PNH is the result of deficiency of CD55 and CD59, GPI-APs that normally inhibit complement activation on the red cell surface, but the relationship between GPI-AP deficiency and the bone marrow failure and thrombophilia of PNH are enigmatic. The peripheral blood of patients with PNH is a mosaic of normal and abnormal cells, and the degree of mosaicism varies greatly among patients. By using fluorescently labeled antibodies, GPI-AP deficient cells (GPI-AP−) can be distinguished form GPI-AP sufficient cells (GPI-AP+) cells by flow cytometric analysis, allowing quantitation of mosaicism. Flow cytometry has been used diagnostically for more than a decade, and technical modifications have improved resolution so that very small populations of GPI-AP− peripheral blood cells can be accurately detected. The purpose of these studies was to generate insights into how PNH is perceived in the community by analyzing the results of a commercially available screening assay using data from a national clinical diagnostic laboratory (ARUP Laboratories, Salt Lake City, UT). The flow cytometric method used in these studies is a modification of the high-resolution two-color assay of Sugimori and colleagues (Blood 2006, 107:1308–1314). Clients are given the choice of testing for PNH by analyzing peripheral blood RBCs or PMNs (or both). The acidified serum test (Ham's test) and the sucrose lysis test (sugar water test) are also available for screening for PNH. For flow cytometric analysis of RBCs, a value of ≥0.005% GPI-AP− cells is considered abnormal, while for PMNs ≥0.003% is abnormal. From January 1, 2008 to June 30, 2008, 1,113 RBC assays and 133 PMN assays were performed. An abnormally large population of GPI-AP− RBCs was identified in 55 cases (5%). The percentage of GPI-AP− RBC ranged from 0.009–69.603% with a median of 1.405%. Twenty-two cases (40%) had >5% GPI-AP− RBCs, while 18 cases (33%) had >10% GPI-AP− RBCs. Of the 133 PMN assays performed, 15 (11%) were abnormal. The range of GPI-AP− PMNs was 0.004–97.727% with a median of 18.327 %. Eight samples (53%) had >10% GPI-AP− PMNs. During the 1-year period from July 1, 2007-June 30, 2008 the acidified serum lysis test (Ham's test) was performed on 212 samples while the sucrose lysis test was performed on 148 samples. These studies suggest that screening for PNH is common (~43 RBC assays/week compared to 44 assays/week for flow cytometric screening of peripheral blood for lymphoproliferative disorders and leukemia), but the vast majority of samples tested show normal expression of GPI-APs. That so many of the test samples are negative, and that the median for abnormal RBC samples is ~1.5 % GPI-AP− cells, suggest that most of the screening is done because of the association of PNH with bone marrow failure syndromes rather than because of evidence of intravascular hemolysis. These studies underscore the need to understand the pathophysiological basis and clinical implications of small populations of GPI-AP deficient cells in patients with bone marrow failure syndromes. Nonetheless, 18 cases with >10% GPI-AP− RBCs were detected during the 6 months of observation, indicating that the prevalence of classic PNH in the US is substantial. That PNH clone size is best determined by analysis of GPI-AP expression on PMNs does not appear to be widely appreciated in the community as the PMN assays is requested 12% as often as the RBC assay. Flow cytometry has largely, but not completely, replaced Ham's test and the sucrose lysis test as screening assays for PNH.