How Useful are Laboratory Practice Guidelines?

Clinical practice guidelines (CPGs) relating to laboratory diagnostic testing are increasingly produced with the aim of standardizing practice and improving patient care based on the best available evidence. However, the production of a CPG is merely the first step in the process of getting evidence into practice, to be undertaken by laboratories and other stakeholders. This process should evaluate the information provided in the guidelines on laboratory tests, devise a strategy for implementing the CPG or the laboratory aspects of the CPG and finally, once implemented, assess the impact of the CPG on clinical practice, patient outcomes and costs of care. The purpose of CPG evaluation by the laboratory is to determine whether sufficient information is provided on the particular test recommended. CPGs may not always be written with the involvement of a laboratory specialist and this underlies the paucity of relevant information in some national guidelines. When laboratory specialists are involved, CPGs can provide practical information which supports local laboratories as well as clinicians in the implementation and appropriate use of recommendations. Implementation of CPGs is an often neglected area that needs attention and thought. There are many barriers to successful implementation, which may vary at local level. These need to be identified early if CPGs are to be successfully adhered to. The effectiveness of CPGs also needs to be audited using process and health outcome indicators. Clinical audit is an effective tool for assessing adherence to recommendations and for measuring the impact and success of the CPG.

Evaluation of ICSH schistocyte measurement guidelines in France.

INTRODUCTION: The schistocytes are fragmented red blood cells mainly observed in the setting of hemolytic anemias where they remain an important criterion for the diagnosis. As the identification of these cells is still problematic, the International Council for Standardization in Hematology (ICSH) set up a consensus report in November, 2011. The French Group of Cellular Hematology (GFHC) aimed to collect the opinion of French biologists directly confronted to schistocytes measurements, about these guidelines. METHODS: Among the 578 professionals, 169 (29%) answered to the 10 questions dealing with the identification and measurements of schistocytes as proposed by the ICSH. RESULTS: A consensus was reached for the urgent need of such guidelines documents, especially in the current background of the European accreditation EN ISO 15189 rules. A traduction in native (French) language was warmly wished in order to facilitate the diffusion of the information. The pathologic threshold for the diagnosis of thrombotic microangiopathic anemia (TMA) (>1%) remained questionable. For half of the biologists, the new fragmented red blood cell (FRC) parameter recently provided by two manufacturers of automated blood cell counters was still doubtful for routine use. CONCLUSION: This survey assessed the impact of international 'guidelines' on the French biological community. The will to implement validated recommendations was strong, reflecting the awareness of the biologists to standardize the laboratory investigations.

Self-monitoring of blood glucose in patients with diabetes who do not use insulin--are guidelines evidence-based?

AIMS: To evaluate if clinical practice guideline recommendations regarding self-monitoring of blood glucose in patients with diabetes not using insulin follow the principles of evidence-based medicine. METHODS: After a search from 1999 to 2011, 18 clinical practice guidelines were included. Recommendations regarding self-monitoring of blood glucose were graded on a scale from one (strongly against self-monitoring) to four (strongly in favour of self-monitoring) and compared with the similarly graded conclusions of systematic reviews that were cited by the clinical practice guidelines. We also investigated how clinical practice guideline characteristics, for example funding sources, and quality of references cited could be related to the guideline recommendations. RESULTS: The clinical practice guidelines cited in total 15 systematic reviews, 14 randomized controlled trials, 33 non-randomized controlled trials papers and 18 clinical practice guidelines or position statements. The clinical practice guideline recommendations had an average grade of 3.4 (range 2.0-4.0). Higher grades were seen for clinical practice guidelines that acknowledged industry funding (mean value 4.0) or were issued by organizations depending on private funding (mean value 3.6 vs. 3.0 for governmental funding). The conclusions of the 15 systematic reviews had a mean grade of 2.2 (range 1.0-3.8). Systematic reviews with low grades were less cited. In total, 21 randomized controlled trials were included in the systematic reviews. Approximately half of these evaluated an educational intervention where the effect of self-monitoring of blood glucose could not be clearly isolated. CONCLUSIONS: Clinical practice guidelines were more in favour of self-monitoring use than the systematic reviews that were cited. The citation practice was non-systematic and industry funding seemingly led to a more positive attitude towards use of self-monitoring of blood glucose.

The value of the Thomas-plot in the diagnostic work up of anemic patients referred by general practitioners.

In patients with inflammatory conditions, diagnosing classic iron deficiency or anemia of chronic disease is challenging. In this study, we assessed the diagnostic value of the so-called Thomas'-plot [soluble transferrin receptor (sTfR)/log ferritin (sTfr/log Ferr) and the reticulocyte hemoglobin equivalent (Ret-HE)] in the anemia work up of patients referred by general practitioners. During July 2008-March 2009, 337 consecutive patients were included because of lowered Hb values. The laboratory results of the first 133 consecutive patients were used to determine the cut-off values for the diagnostic plot. The laboratory results of these patients were assessed and interpreted independently by two investigators, blinded from sTfR/log Ferr and Ret-HE values. The following 204 patients were used to test the plot in practice. In 32% of the first 133 patients, no indication of the cause of anemia could be found. However, when using the diagnostic plot in the following 204 patients, this fraction decreased to 14%. The 'Thomas'-plot is of diagnostic value for distinguishing functional iron deficiency from classic iron deficiency in a patient population referred by general practitioners.

[Prospective comparison of the flow chart for laboratory investigations for anaemia from the Dutch College of General Practitioners' guideline 'Anaemia' with a self-developed, substantive and logistical alternative flow chart]. / Prospectieve vergelijking van het stroomschema voor laboratoriumonderzoek van anemie uit de NHG-standaard 'Anemie' met een eigen, inhoudelijk en logistiek alternatief stroomschema.

OBJECTIVE: To compare the flow diagram for the diagnosis of anaemia from the guideline 'Anaemia' from the Dutch College of General Practitioners (NHG) with a substantive and logistical alternative protocol. DESIGN: Prospective. METHOD: For evaluation of anaemia, 124 patients from primary care reported to the laboratories of the St. Elisabeth Hospital in Tilburg (n = 94) and the Scheper Hospital in Emmen (n = 30), the Netherlands. Two flow charts were used: the NHG's flow chart and a self-developed chart in which not mean corpuscular volume, but ferritin concentration occupies the central position. All the laboratory tests mentioned in both flow charts were carried out in every patient with, for practical reasons, the exception of Hgb electrophoresis and bone marrow investigations. General practitioners were approached and patient dossiers were consulted to obtain further clinical data. RESULTS: According to the NHG protocol, on the grounds of the laboratory investigations, 64 (52%) of patients could not be put in a specific category. The majority were patients with normocytary anaemia who did not fulfil the criteria for iron deficiency anaemia or the anaemia of chronic disease. According to the alternative chart, in 36 (29%) patients no diagnosis was made. These were patients in whom no abnormal laboratory findings were observed, other than low haemoglobin values. The majority of the patients had normocytary anaemia, in some cases this was interpreted as the anaemia of chronic disease, but more often the anaemia could not be assigned to a particular category. A large number ofpatients had a raised creatinine value. This value did not appear in the NHG protocol. In 15% of patients, more than one cause for anaemia was found. The NHG protocol did not enable these multiple diagnoses to be made. Accordingly, the NHG protocol was difficult to implement in the laboratory. CONCLUSION: Using the NHG flow diagram a large percentage of patients could not be assigned to a particular category. Using the alternative flow diagram, which procedure is easier to carry out in the laboratory, it was possible to make multiple diagnoses.

Human tissue research: EORTC recommendations on its practical consequences.

Improvement in cancer care is possible by applying new treatment modalities, which are emerging from knowledge and discoveries coming from laboratory research. This is possible through international collaboration and the collection of tumour tissues. Creation of a European Organisation for Research and Treatment of Cancer (EORTC) Tumor Bank is a natural step in this direction, by offering tumour sample collection from patients entered in EORTC trials. The aim of such a bank is not only to improve the diagnostic review process, but also to facilitate translational research by allowing clinicians and basic scientists to enter into close collaborations. The EORTC Tissue Research Policy is developed to assure, under the EORTC legal framework, an ethical and scientific review of research projects, guarantee adequate information is given to patients, establish procedures on the use of materials, including legal aspects, and publication policies. Being part of the EU TubaFrost project, the EORTC will provide a common international platform for the use of tissues for research purposes, finding a balance between different laws and assuring scientific progress.

The EORTC Laboratory Research Division. European Organisation for Research and Treatment of Cancer.

The Laboratory Research Division (LRD) of the EORTC currently consists of five Groups with expertise that includes pre-clinical drug development, all aspects of cancer pharmacology, clinically-relevant receptor and biomarker studies, functional imaging and contemporary pathology. The LRD provides a Europewide resource for cancer clinical trials with particular expertise in the evolving field of translational research. In the development of therapies designed to exploit the molecular and cellular pathology of cancer, it is essential that translational research is included at all stages and the EORTC, through the LRD, has access to such expertise. In addition to providing support for drug development and clinical trials, the LRD represents a unique forum for the development of contemporary translational research expertise, the establishment of quality standards and the education of young laboratory and clinical scientists embarking on careers in oncology.

Reactivity of germ cell maturation stage-specific markers in spermatocytic seminoma: diagnostic and etiological implications.

It is generally accepted that testicular seminomas and spermatocytic seminomas have separate pathogeneses, although the origin of these two types of germ cell tumors of the adult testis remains a matter of debate. Although an embryonic germ cell origin seems to be most likely for seminomas, a spermatogonia-spermatocyte origin has been suggested for spermatocytic seminoma. To shed more light on the etiology of spermatocytic seminomas, we undertook an immunohistochemical and molecular approach using SCP1 (synaptonemal complex protein 1), SSX (synovial sarcoma on X chromosome), and XPA (xeroderma pigmentosum type A) as targets. Although a stage-specific expression pattern has been reported for SCP1 and SSX in normal spermatogenesis, we demonstrate here that it also exists for XPA. In fact, immunohistochemistry shows that the proteins of SCP1 and XPA are specifically present in the stage of primary and pachytene spermatocytes. In contrast, SSX was found in spermatogonia and primary spermatocytes, as well as in germ cells, from at least the 17th week of intrauterine development onward. Although no protein encoded by any of these genes was detected in tumor cells of a series of testicular seminomas, all tested spermatocytic seminomas were positive, in agreement with expression analysis. These data support the model that seminomas originate from an embryonic germ cell, and they imply that the cell of origin of spermatocytic seminomas is at least capable of maturing to the stage of spermatogonia-pachytene spermatocyte.

Evaluation of LabRespond, a new automated validation system for clinical laboratory test results.

BACKGROUND: Manual validation of laboratory test results is time-consuming, creating a demand for expert systems to automate this process. We have started to set up the program "LabRespond", which covers five validation levels: administrative, technical, sample, patient, and clinical validation. We present the evaluation of a prototype of an automated patient validation system based on statistical methods, in contrast to the commercially available program "VALAB", a rule-based automated validation system. METHODS: In the present study, 163 willfully altered, erroneous test results out of 5421 were submitted for validation to LabRespond, VALAB, and to a group of clinical chemists (n = 9) who validated these test results manually. The test results rejected by three or more clinical chemists (n = 281) served as a secondary reference standard. RESULTS: The error recovery rates of clinical chemists ranged from 23.9% to 71.2%. The recovery rates of LabRespond and VALAB were 77.9% and 71.8%, respectively (difference not significant). The false-positive rates were 82.7% for LabRespond, 83.6% for VALAB, and 27.8-86.7% for clinical chemists. Using the consensus of three or more clinical chemists as the secondary reference standard, we found error recovery rates of 64.8% for LabRespond and 72.2% for VALAB (P = 0.06). Compared with VALAB, LabRespond detected more (P = 0.003) erroneous test results of the type that were changed from abnormal to normal. CONCLUSIONS: The statistical plausibility check used by LabRespond offers a promising automated validation method with a higher error recovery rate than the clinical chemists participating in this study, and a performance comparable to VALAB.

The science of systematic reviewing studies of diagnostic tests.

BACKGROUND: Systematic reviews have gradually replaced single studies as the highest level of documented effectiveness of health care interventions. Systematic reviewing is a new scientific method, concerned with the development and application of methods for identifying relevant literature, analysing the material while increasing validity and precision, and presenting and discussing the results in a way that does justice to the research question and to the available evidence. The objective of this study was to review the systematic reviews in laboratory medicine, to evaluate the methods applied in these reviews and the applicability of guidelines of the Cochrane Methods Working Group on Screening and Diagnostic Tests, and identify areas for future research. METHODS: All the systematic reviews in the field of clinical chemistry and laboratory haematology that could be identified in Medline, EMBASE and other literature databases up to December 1998, were evaluated. RESULTS: We studied 23 reviews of diagnostic trials. Although all reviews share the same basic methodology, there was a wide variation in the methods applied. There was no consensus on the quality criteria for inclusion of primary studies. The results of the primary studies were heterogeneous in most cases. This was partly due to design flaws in the primary studies, but was also inherent in the diverse study designs in diagnostic trials. We observed differences in the analysis of the factors that cause heterogeneity of the results, and in the summary statistics used to pool the data from the primary studies. The additional diagnostic value of a test, after other test results are taken into consideration, was only addressed in one study. CONCLUSION: This overview of 23 reviews of diagnostic trials identifies areas in the methods of systematic reviewing where consensus is lacking, such as quality rating of primary studies, analysis of heterogeneity between primary studies and pooling of data. Guidelines need to be improved on these points.

Comparative genomic and in situ hybridization of germ cell tumors of the infantile testis.

Chromosomal information on germ cell tumors of the infantile testis, ie, teratomas and yolk sac tumors, is limited and controversial. We studied two teratomas and four yolk sac tumors using comparative genomic hybridization (CGH) and in situ hybridization. No chromosomal anomalies were found in the teratomas by any of the methods, not even after CGH on microdissected tumor cells. All yolk sac tumors showed aneuploidy, loss of parts of 4q and 6q, and gain of parts of 20q. Underrepresentation of parts of 8q and overrepresentation of parts of 3p, 9q, 12p, 17, 19q, and 22 were detected in most cases. In addition, one recurrent yolk sac tumor after a sacral teratoma was studied, showing a highly similar pattern of imbalances. While CGH demonstrated loss of 1p36 in one testicular yolk sac tumor, in situ hybridization revealed loss of this region in all yolk sac tumors. High-level amplification of the 12q13-q14 region was found in one yolk sac tumor. MDM2, of which the encoding gene maps to this chromosomal region, was found in all cases using immunohistochemistry, whereas no p53 could be detected. Accordingly, no mutations within exons 5 to 8 of the p53 gene were observed. These data prove the absence of gross chromosomal aberrations in teratomas of the infantile testis and show a characteristic pattern of gains and losses in the yolk sac tumors. Besides confirmation of previously found anomalies, recurrent losses of 1p21-31 and 4q23-33 and gains of 9q34 and 12p12-13 have not been reported before. While genetic inactivation of p53 seems unimportant in the pathogenesis of these tumors, biochemical inactivation by MDM2 might be involved. These data support the existence of three entities of germ cell tumors of the human testis: teratomas and yolk sac tumors of infants, seminomas and nonseminomas of adolescents and young adults, and spermatocytic seminomas of the elderly, each with its own specific pathogenesis.

Diagnostic value of the mean corpuscular volume in the detection of vitamin B12 deficiency.

In clinical practice, the finding of an elevated mean corpuscular volume (MCV), macrocytic anaemia or specific neurological symptoms is often the reason to test for vitamin B12 (B12) deficiency. Use of the MCV as a test for the detection or exclusion of B12 deficiency is only justified if the diagnostic accuracy is sufficiently high. However, the sensitivity and specificity are not well known. We performed a systematic review of the diagnostic value of an elevated MCV for B12 deficiency in both anaemic and non-anaemic patients. Of approximately 3500 titles and/or abstracts that were screened, 37 original papers contained usable data. The population under study proved to be the characteristic of major influence on the study outcome. Pooling of data from different studies was performed in subsets of the data corresponding to the different populations studied. The cut-off levels of both MCV and serum B12 had a significant influence on the study outcomes. The data, however, were pooled without taking these cut-off levels into account. The pooled estimates should be interpreted with this limitation in mind. The reference standards were (1) a low serum B12 concentration and (2) a B12 deficiency confirmed by low serum B12 combined with additional diagnostic investigations. In the population that was randomly screened for low serum B12, the sensitivity of the MCV for B12 deficiency was 17%, whereas the sensitivity was 30% for B12 deficiency in patients with anaemia. When measurement of serum B12 was ordered to exclude B12 deficiency as part of the patients' treatment, the sensitivity was 30% for low serum B12 concentration, 58% for B12 deficiency and 75% for B12 deficiency in patients with anaemia. In the population with pernicious anaemia, the sensitivity was far from perfect (77%). In the five studies that reported data on the positive predictive value of the MCV for B12 deficiency, this ranged from 0% (0/6) to 55% (11/20). This systematic review shows that a considerable number of B12-deficient patients will remain unnoticed when the MCV is used to rule in patients for further evaluation. Depending on the population studied, up to 84% of cases will than be missed. The MCV can be used to make the diagnosis of B12 deficiency more--or less--probable. An elevated MCV justifies the measurement of serum B12. The MCV should not be used as the only parameter ruling out the diagnosis of B12 deficiency.

Relationship between human papillomavirus type 16 in the cervix and intraepithelial neoplasia.

OBJECTIVE: To evaluate a temporal relationship between the presence of cervical human papilloma virus (HPV) type 16 and the risk of developing cervical intraepithelial neoplasia (CIN). METHODS: Fifty-four women with HPV 16 polymerase chain reaction (PCR)-positive tests were selected from the gynecologic outpatient clinic of the Reinier de Graaf Hospital, Delft, The Netherlands. At least three successive PCR tests were performed in each woman at intervals of 6 months. The PCR HPV 16 assay was performed in conjunction with cervical smear, and colposcopy and biopsy, if indicated. Women with at least three consecutive positive PCR tests were defined as having persistent HPV 16 infections. Women with one positive test followed by two negative tests were defined as having transient infections. Subdivided into two groups, 25 women had persistent infections and 29 had transient infections. RESULTS: In significantly more women in the persistent group compared with the transient group, CIN developed (11 of 25 versus six of 29, P = .036). Lesions in women with persistent HPV 16 infection were more severe (six of 11 were CIN III versus one of six P = .041). CONCLUSION: Persistent infection with HPV 16 is associated with a higher risk of developing CIN, which is often high-grade.

Reflex sympathetic dystrophy: is the immune system involved?

OBJECTIVE: Evaluation of immune system function in patients with reflex sympathetic dystrophy (RSD). DESIGN: Survey on blood samples obtained from RSD patients and from a randomly selected control group. The lymphocyte populations (T, B, NK cells), and the activated T cells (CD25, and HLA-Dr-positive CD4 and CD8 cells) were analyzed by flow cytometry with dual-color direct immunofluorescence after whole-blood lysis. Clinical chemistry parameters were analyzed in additional serum samples. SETTING: Tertiary care center (outpatient rehabilitation clinic). SUBJECTS: Thirteen patients (nine women) with RSD and a control group of 21 healthy individuals. MAIN OUTCOME MEASURES: The results of the flow cytometry analysis of RSD patients were related to those of the control subjects. Means were analyzed, and confidence intervals for differences of the means were calculated. The means of the clinical chemical analysis were related to local reference values. RESULTS: The flow cytometry analysis did not differ between RSD patients and healthy controls. Although in some patients an individual parameter of clinical chemical analysis differed from its reference value, all of the mean values were within reference limits. Stratification on medications with immunomodulatory effects and on probability of a definite diagnosis of RSD had no influence on the results. CONCLUSION: No association between immunologic indices and RSD was found. This finding is relevant, because recent theories stress that it is not the sympathetic nervous system but a local inflammatory reaction that is fundamental in the pathogenesis of RSD. The results of this study do not support this theory.

Cytogenetic and molecular analysis of cellular atypical mesoblastic nephroma.

Cytogenetic and molecular analyses were performed on three cellular (atypical) congenital mesoblastic nephromas (CMNs). Two cases had trisomy 11; in one, it was the sole karyotypic abnormality, and the other had additional numerical changes as well as an isochromosome for the long arm of chromosome 1. Markers for the 11p13 and 11p15 loci were present in three copies in these two CMNs. In the third CMN, two apparently normal copies of chromosome 11 were present together with additional numerical and structural chromosome changes. Because loss of heterozygosity was observed for both 11p13 and 11p15 markers, we assume that mitotic recombination occurred. Duplication and loss of imprinting of genes at 11p15 has also been observed frequently in Wilms' tumor. We therefore propose that CMN and Wilms' tumor might share common genetic pathways.

Systematic reviewing in laboratory medicine. Position Paper from the IFCC Committee on Systematic Reviewing in Laboratory Medicine.

Each year a vast number of biomedical articles and books are published and based on the articles reviews are written. Such reviews should be performed in a systematic manner. Systematic reviewing is a new discipline with its own methods for locating, appraising, and summarizing primary studies. Such methods have also been developed for studies on diagnostic test evaluations. It is important for the laboratory disciplines to engage in this work. IFCC has established a Committee for Systematic Reviewing in Laboratory Medicine. This committee will work to promote the understanding, the use and the performance of systematic reviewing.

The influence of torque and velocity on erector spinae muscle fatigue and its relationship to changes of electromyogram spectrum density.

The influence of contraction force and velocity during isokinetic contractions on the development of fatigue in the erector spinae muscle was studied. Seven male subjects performed a series of 250 contractions at 25% and 50% of their isometric maximal voluntary contraction (MVC) at 40 and 80 degree.s-1. Fatigue defined as a decrease of the contractile capacity of the muscles was studied by means of a 15-s maximal test-contraction following the exercise. Both the initial force and the force decrement during the test-contraction were studied. Surface electromyogram (EMG) signals of the main tracts of the erector spinae muscle were recorded. The frequency content was studied by calculating the zero-crossing rate for the signals obtained during dynamic contractions and by means of fast Fourier transformation for the test contraction. After the 50% MVC dynamic contractions the initial force during the postexercise test-contraction was significantly lower than after the 25% MVC contractions. No significant influence of contraction velocity on fatigue development was found. The force decrement during the test-contraction did not depend on the experimental conditions. The EMG amplitude indicated that the subjects were better able to relax their muscles during the counter movement (flexion) at high forces and high velocities compared to the other experimental conditions. The frequency content of the EMG signals during the dynamic contractions and the postexercise test-contraction showed only very weak relationships with fatigue. Therefore, spectrum EMG parameters as determined in the present study do not seem suitable as indicators of muscle fatigue as a consequence of dynamic contractions of trunk extensor muscles.

Cytogenetic evidence that carcinoma in situ is the precursor lesion for invasive testicular germ cell tumors.

A cytogenetic study of two cases of carcinoma in situ of the testis (CIS) and their adjacent invasive tumors, one a nonseminomatous germ cell tumor (NS) and one a seminoma (SE), revealed similarities in chromosomal pattern between the CIS and the invasive lesion in the same patient. These findings present for the first time cytogenetic evidence that CIS of the testis and its adjacent germ cell tumor are clonally related, which suggests that the CIS is indeed the precursor lesion of the invasive tumor.