Molecular Diagnostics DOLS Inselspital Bern
Molecular Diagnostics Unit of the Divisions of Hematology, Immunology and Clinical Chemistry of
Editorial Contents
5-Fluorouracil (5-FU)-toxicity – molecular
detection of a G>A-splice site mutation in intron 14 of the gene encoding for dihydropyrimidin-
Welcome to the first newsletter of the Laboratory of
Molecular Diagnostics of the Insel hospital. With this
newsletter we wish to start an exchange of information and
Irinotecan-toxicity – molecular detection of a
views directly with you as a customer, both inside and
TA-insertion in the UGT1A1 promoter used for
the determination of the initial therapeutic dose of irinotecan
The newsletter will provide you regularly with informations of new analyses, new equipment and new services. On our
Pharmacogenetic tests for clinical studies
homepage http://moleculardiagnostics.insel.ch you will find
our news, a list of analyses as well as the order forms as
leukemia with normal karytoype: NPM1, CEBPA,
pdf files for download. Please note the new order forms.
Our molecular diagnostic laboratory was founded in 2001 as
EPO-receptor mutations in familial polycythemia
a collaboration of the main laboratories of the University
Hospital of Bern. From this point, all molecular analyses in
the fields of Hematology, Immunology and Metabolic disorders are performed under one roof with a qualified
Leukemia samples: Use of PAXgene tubes on
team and up-to-date equipment. In 2005, the laboratory
was certified according to the ISO 17025 guidelines. We
continuously broadened the spectrum of our analyses of
LUMINEX® – Multiplex-analysis with fluorescent
In the future, we would like to continue to be your
competent and innovative partner for molecular genetic
analyses. For a successful collaboration it is our aim to
provide services which are customer friendly and practically oriented and a partnership based on a personal relationship.
We hope that our newsletter stimulates your interest in our work and that it will support our collaboration. We welcome
Impressum
Ms Dr. pharm. Elisabeth Oppliger Leibundgut,
MDD Geschäftsstelle
Mr PD Dr. phil. nat. Carlo R. Largiadèr
Fax 031/632 03 10 e-mail [email protected] www.moleculardiagnostics.insel.ch
New Analyses Pharmacogenetics
5-Fluorouracil (5-FU)-toxicity – Irinotecan-toxicity – molecular molecular detection of a G>A-splice detection of a TA-insertion in the site mutation in intron 14 of the gene UGT1A1 promotor used for the encoding for dihydropyrimidine determination of the initial therapeutic dehydrogenase as a cause of severe 5- dose of irinotecan FU-toxicity
The anti-metabolite 5-FU is one of the most frequently used
UDP-glucuronyltransferase (UGT1A1) is one of the key
chemotherapeutic agents in the treatment of solid tumors.
enzymes fort he degradation of irinotecan, a topoisomerase
The efficacy of 5-FU is mainly dependent on the speed of
I-inhibitor. The active substance of irinotecan, SN38 is
inactivation of 5-FU into non-active metabolites. Because
glucuronidated by UGT1A1. The excretion of metabolized
ca. 80% of 5-FU is directly inactivated to β-alanin by
and inactive SN38G is hepatobiliarily or renally, respectively,
dihydropyrimidin-dehydrogenase (DPD) degradation, a
whereas SN-38 rests in the gastrointestinal region, and
reduced enzyme activity of DPD may lead to an increased
causes severe and long-lasting diarrhea by direct injury of
cytotoxicity of the administered doses of 5-FU. Severe
the intestinal mucosa. It has been shown that the
adverse effects of 5-FU toxicity are neutro- and
expression-level of UGT1A1 is directly linked to the toxic
thrombocytopaenias, as well as different gastrointestinal
side-effects of irinotecan. A frequent polymorphism in the
and neurological disorders. Lethal side-effects by 5-FU
promoter (7 instead of 6 TA-repeats in the TATAA-Box,
treatment due to DPD deficiency have also been described.
UGT1A1*28) is associated with a decreased enzyme
It has been estimated that about 50% of the adverse
activity. Individuals who are homozygous for the
effects are due to mutations in the DPD-Gene (DPYD) (1).
UGT1A1*28 allele (approximately 11% in Europe) are at
The most frequent mutation is a G->A-transition at position
increased risk for neutropenia and diarrhea following
+1 in the splice donor site of intron 14 (DPYD*2A), which
initiation of irinotecan treatment. A reduced initial dose
results in the skipping of exon 14 and leads to a non-
should be considered for patients known to be homozygous
functional enzyme. About 1-2 % of Caucasians are
for the UGT1A*28 allele. Heterozygous patients may be at
carriers of this exon 14-skipping-mutation. Carriers have an
increased risk of neutropenia; however clinical results have
increased risk to suffer from 5-FU-toxicity.
been variable and such patients have been shown to
In two studies, 24-28% of all patients with 5-FU-toxicity
tolerate normal starting doses. See FDA-Guidelines; URL:
grade 3 or 4 were either hetero- or homozygous carriers of
http://www.fda.gov/cder/genomics/genomic_biomarkers_ta
the DPD*2A allele (2). Other mutations associated with 5-
FU-toxicity have been described, but appear to be less
Analysis: Genomic DNA is isolated from whole blood. The
frequent than the exon 14-skipping-mutation. These
genomic region containing the TATAA-Box of UGT1A1 is
mutations may also be analyzed on request in our
PCR-amplified and analyzed by fragment analysis.
Analysis: Genomic DNA is isolated from whole blood. Exon
Iyer, L. et al. (1999). Clin Pharmacol Ther 65(5): 576-82.
14 and the adjacent intronic sequences of the DPYD-Gene
Iyer, L. et al. (2002). Pharmacogenomics J 2(1): 43-7.
are amplified by polymerase chain reaction (PCR). The
Beutler, E. et al. (1998). Proc Natl Acad Sci U S A 95(14):
mutation is detected by direct sequencing. This method is
more accurate than TaqMan- or Light-Cycler- SNP-Assays, since false-positive results due to a polymorphism at a
neighboring sequence position have been described (3).
Determination of the initial dose before the
1. van Kuilenburg AB, et al. (2000). Clin Cancer Res
2. van Kuilenburg AB. (2004). Eur J Cancer 40(7): 939-50.
3. Lazar AS, et al. (2003). Clin Chem 49(4): 707-8.
Of topical interest Pharmacogenetics
Pharmacogenetic tests for clinical MTHFR 1298A>C: The MTHFR 1298A>C transition
converts glutamine at position 429 into alanine, resulting in a reduced enzyme activity suggesting that carriers of the MTHFR 1298C allele could be treated with lower doses of
The following listing contains brief descriptions of different
MTX in order to optimize the therapeutic effect.
genetic markers associated to the efficacy and/or toxicities of particular drugs (methotrexate, 5-fluorouracil (5-FU, see
Method: TaqMan® SNP-Assay. Costs: 250 TP (or according
above) and tacrolimus). Methotrexate (MTX), a folate
antagonist, is the most frequently used drug in the basic treatment of rheumatoid arthritis (RA). Furthermore, it is
Thymidylat-Synthetase (TS), 28-bp duplication within
also used as a cytostatic agent in chemotherapy of various
the enhancer region: TSER*2 (2 copies) or TSER*3 (3
hematologic (acute lymphoid Leukemia (ALL), Burkitt’s
copies). TS is also inhibited by MTX. Individuals carrying the
lymphoma, CNS lymphoma) and solid neoplasias
*3 allele have higher expression of TS, and thus seem to
(osteosarcoma, trophoblastic tumors, and others).
require higher MTX-doses to effectively inhibit TS. The
Tacrolimus is a frequently used immunosuppressant
duplication also influences 5-FU metabolism, since the
(calcineurin-inhibitor) in transplantation medicine.
inhibition of TS is the main mechanism of action of 5-FU.
The below-given genotype-phenotype relationships with
The TSER*2/*2 genotype is described to be correlated with
respect to drug metabolism are based on the data
an efficient inhibition of TS by 5-FU, however, this genotype
interpretation of current literature. The precise clinical
is also associated with a higher risk for adverse side effects
implications of the described markers with respect to
indications, dosing, interactions between markers etc. need
Method: PCR, qualitative analysis. Costs: 150 TP (or
to be assessed in further clinical studies.
Assays for all these markers have been established in our
UMPS 638G>C: The mutation 638G>C in the uridine
laboratory in the framework of a clinical study and are
monophosphate synthetase converts an alanine at position
offered for clinical studies or research collaborations.
213 into a glycine. Homozygous carriers of the 638C-allele
ATIC 347C>G:
have a higher activity of UMPS. Thus, these carriers might
ribonucleotide formyltransferase/IMP cyclo-hydrolase (ATIC)
be at higher risk of suffering from 5-FU-toxicity (grade 3-4
is directly inhibited by MTX-polyglutamate, resulting in
higher levels of the anti-inflammatorically active adenosine.
Method: TaqMan® SNP-Assay. Costs: 250 TP (or according
The ATIC 347C>G mutation results in a threonine to serine
coding change at position 116. Individuals carrying the ATIC 347G-allele have been described to have a higher risk to
Cytochrome P450 3A5 (CYP3A5) is responsible for the
suffer from MTX-toxicity and homozygous 347CC carriers
metabolism of tacrolimus. As tacrolimus has a relatively
narrow therapeutic range, dose adjustment is performed by continuous determination of the serum concentration. An
Method: TaqMan® SNP-Assay. Costs: 250 TP (or according
A>G transition in intron 3 of the CYP3A5-gene (CYP3A5*3;
non-expressors) results in a defective and inactive protein.
RFC1 80G>A: MTX is mainly internalized by the receptor
In non-expressors the metabolism of tacrolimus is
reduced folate carrier 1 (RFC1). The RFC1 80G>A transition
significantly slower. Recently, a study in kidney-transplant-
results in an arginine to histidine coding change at position
patients suggested that genotyping of CYP3A5 could be
27 of the RFC1 gene. This mutation is associated with a
used for the determination of the initial dose of tacrolimus,
higher affinity for folic acid, and thus with a reduced
in order to more quickly achieve the target dose.
capacity to internalize MTX. Homozygous individuals for the
Suboptimal levels of tacrolimus may result in a partial
80G allele show higher MTX levels in the serum, and
immunosuppression, and thus, in an increased risk for graft
therefore lower therapeutic effects. This genotype seems to
In addition to tacrolimus, many other immunosuppressive
Method: TaqMan® SNP-Assay. Costs: 250 TP (or according
(e.g. cyclosporine) or cytostatic drugs are metabolized by
CYP3A5. Method: TaqMan® SNP-Assay. Costs: 250 TP (or according
MTHFR 677C>T: Methylenetetrahydrofolate reductase
(MTHFR) is not directly inhibited by MTX, but the expression-level, as well as the enzyme activity of MTHFR might have an influence on the therapeutic effect of MTX.
The MTHFR 677C>T transition results in an alanine to valine
Ulrich, C. M. et al. (2002). Pharmacogenomics 3(3): 299.
coding change at position 222. The mutation in the
Ulrich, C. M. et al. (2003). Nat Rev Cancer 3(12): 912-20.
heterozygous or homozygous state correlates with reduced
Kremer, J. M. (2004). Arthritis Rheum 50(5): 1370-82.
enzyme activity and increased thermolability. Individuals
Robien, K. et al. (2005). Pharmacogenomics 6(7): 673-89.
homozygous for the mutation have significantly elevated
Iacopetta, B. et al. (2001). Br J Cancer 85(6): 827-30.
plasma homocysteine levels. The 677C>T mutation may be
Zhang, X. et al. (2005). Clin Transplant 19(5): 638-43.
associated with an increased risk for adverse side effects of
MTX-therapy. Furthermore, this mutation has also an
influence on the 5-FU metabolism, as carriers of the MTHFR
677T-allele respond better to 5-FU, whereby homozygous
carriers respond better than heterozygous ones.
Method: TaqMan® SNP-Assay. Costs: 250 TP (or according to individual arrangement)
New Analyses Hematology
New prognostic markers in acute NPM1: screening by PCR, sequencing myeloid leukemia (AML) with normal CEBPA: sequencing analysis BAALC: quantitative real-time PCR (Taqman) karyotype: NPM1, CEBPA and BAALC NPM1quantitative: allele-specific real-time PCR (Taqman®) for type A
The analyses of NPM1 mutations, CEBPA mutations and
5 ml of bone marrow (EDTA or heparin), or 10
BAALC provide a new prognostic score in acute myeloid
leukemia with normal karyotype (for details on these markers see below).
Sequential approach: Based on the frequency of NPM1
and CEBPA mutations (ca. 50% vs. 15% of AML patients with normal karyotype), a sequential approach is applied.
Taxpoints: Qualitative analysis: 250-650 (excluding RNA
The first panel contains the analysis of NPM1 mutations (ca.
50%). The second panel of CEBPA mutations and BAALC is
only performed in patients without NPM1 mutations and
1) Nucleophosmin (NPM1) Mutations
negative NPM1 Mutations
Nucleophosmin (NPM1) is a nucleocytoplasmic shuttling protein. Mutations in the NPM1 gene cause cytoplasmic
dislocation of the NPM protein. Since NPM is thought to have a tumor suppressor function, the aberrant localization of the protein may be critical for malignant transformation. NPM1 mutations are the most frequent mutations in acute
bad prognosis good prognosis
myeloid leukemia occuring in about 30% of patients, especially in the presence of a normal karyotype. NPM1 mutations are most often insertions of 4 basepairs or
deletions in exon 12 of the NPM1 gene. About 40
heterozygous mutations have been identified to date. The mutation of type A that is due to a TCTG insertion at
position 956, accounts for 80% of adult cases. Larger insertions have been described, as well as deletions and
insertions occuring at the same site. NPM1 mutations always result in a frameshift. NPM1 mutations are associated with high leucocyte count, AML subtypes M4 und
CEPBA Mutations, BAALC
M5, and associate frequently with FLT3 mutations but rarely with other mutations. Prognostic significance: NPM1 mutations are associated
with a favourable outcome in AML patients with a normal karyotype without FLT3 mutation. The NPM1+/ FLT3 ITD– genotype is a highly significant predictor for response to
good prognosis low = good prognosis high = bad prognosis Analysis: a screening method allows the detection of a NPM1 mutation directly after the PCR reaction. The mutation is then identified by subsequent sequencing of the Monitoring: NPM1 mutations are attractive targets for a molecular monitoring and minimal residual disease
detection by real-time PCR. An allelespecific PCR allows
quantification of the mutant allele only. To date,
quantitative PCR for the mutation type A is available.
The analyses are preferably ordered retrospectively when a normal karyotype is confirmed. The analyses can be performed
Falini B, et al. N Engl J Med. 2005; 352(3): 254-66.
from frozen diagnosis material (cDNA).
Thiede C, et al. Blood. 2006; 107(10): 4011-20. Gorello P, et al. Leukemia. 2006; 20(6): 1103-8.
New Analyses Hematology
2) CEBPA Mutations EPO-Receptor Mutations
The myeloid transcription factor C/EBPα (CCAAT/enhancer
Familial erythrocytosis is due to a mutation in the
binding protein-α) is an inhibitor of proliferation and a
erythropoietin receptor (EPOR) gene in some families. EPOR
tumor suppressor. The mutated protein inhibits the DNA
mutations are located in the cytoplasmatic domain of the
binding of wild-type C/EBPα and differentiation of
EPOR gene (exon 7 und 8) leading to a loss of the negative
regulatory C-terminus of the receptor. Typical mutations are
Mutations of the CEBPA gene are found in ca. 18% of
nonsense mutations, where an amino acid is changed to a
patients with acute myeloid leukemia with normal
stop codon leading to a truncated protein. Mutated EPO-
cytogenetics. Various types of mutations are detected
receptors are hypersensitive for EPO resulting in an
including missense und nonsense mutations, 1-3 bp
increased proliferation of red cells while EPO levels are
insertions und deletions. Recurrent mutations are rare.
normal to low. The mutation is typically transmitted in an
Prognostic significance: CEBPA mutations are associated
with a good prognosis in AML patients with a normal
Analysis: screening of EPO-R mutations is performed from
karyotype and no FLT3 ITD. These patients have a long
peripheral blood. DNA is extracted and exons 7 and 8 of the
disease-free survival and a significantly longer overall
EPOR gene are amplified by PCR and sequenced.
Analysis: the coding sequence of the CEBPA gene is
amplified by PCR in two separate reactions and then
Percy M, et al. Br J Haematol. 1998; 100(2): 407-10.
Kralovics R, et al. Am J Hematol. 2001; 68(2): 115-21.
http://uwcmml1s.uwcm.ac.uk/uwcm/mg/search/125242.ht
Bienz M, et al. Clin Cancer Res. 2005 Feb 15;11(4):1416-24.
Preudhomme C, et al. Blood. 2002 Oct 15;100(8):2717-23.
Pabst T, et al, Nat Genet. 2001 Mar;27(3):263-70.
3) BAALC Expression
BAALC (brain and acute leukemia, cytoplasmic), a recently
identified gene located on chromosome 8q22.3 encodes for
a protein that shows no homology to any known proteins.
BAALC was implicated in neurectodermal and hematopoietic
development. In blood and unselected bone marrow cells
from healthy individuals there is no or very low BAALC expression. High levels of BAALC expression were found to
be restricted to leukemic blasts in AML, ALL and in the blast crisis of CML.
The JAK2 V617F mutation is a clonal Prognostic significance: low BAALC expression in molecular marker of MPDs
patients with normal cytogenetics and no FLT3 mutation is associated with a good prognosis. High BAALC expression in
The BCR-ABL negative myeloproliferative disordes (MPD)
AML patients is associated with aggressive disease and a
include polycythemia vera (PV), essential thrombocythemia
(ET) and chronic idiopathic myelofibrosis (CIMF). Until
Analysis: the expression of the BAALC gene is analyzed by
recently, no molecular marker of these diseases has been
known. In 2005, a somatic point mutation in the Janus
Monitoring: in case of high BAALC expression, the marker
kinase 2 (JAK2) has been shown to be responsible for
can be used to monitor minimal residual disease.
characteristic features of PV, ET und IMF such as increased
cell proliferation (1,2,3,4). The acquired mutation in exon
12 of the JAK2 gene causes a substitution of valine at
Mrozek K, et al. Blood. 2007; 109(2): 431-48.
Baldus CD, et al. J Clin Oncol. 2006; 24(5): 790-7.
JAK2 is a cytoplasmic tyrosine kinase with a key role in the
Bienz M, et al. Clin Cancer Res. 2005; 11(4): 1416-24.
signal transduction of a variety of hematopoietic growth
Baldus CD, et al. Blood. 2003; 102(5): 1613-8.
factor-receptors. The JAK2 V617F mutation is located in the
JH2-pseudokinase region of the JAK2 gene involved in the
autoinhibition of the tyrosine kinase activity. The autoinhibition is abrogated by the JAK2 V617F mutation.
Mutant JAK2 is a constitutively activated tyrosine kinase
that confers erythropoietin hypersensitivity and growth
factor independent proliferation of hematopoietic cells.
These findings are consistent with a pathogenic role of
mutated JAK2 in the MPD, however, it is not clear yet how a
single mutation may be responsible for the different clinical phenotypes.
Or topical interest Hematology
The presence of the JAK2 V617F mutation is very highly Leukemia samples: Use of PAXgene
correlated with the ability to form endogenous erythroid
tubes for stabilization on weekends
colonies in all 3 subtypes of MPD (5). The JAK2 V617F mutation was detected in 81% (65-97%) of PV patients, 39% (23-57%) of ET-patients and 43% (35-
For shipping of leukemia samples for RNA-based analyses
50%) of CIMF patients, but was not detected in patients
from friday until sundayand on holidays we
with secondary erythrocytosis or thrombocytosis. Therefore,
recommend the use of PAXgene tubes. PAXgene tubes
the specificity of the mutational analysis is 100%. However,
contain a reagent that immediately stabilizes intracellular
recently it has been shown that the JAK2 V617F mutation is
RNA. However, PAXgene tubes are not suitable for routine
detectable at very low level in the peripheral blood of
diagnostics since a storage of backup samples (cells) is not
healthy donors by using a special and highly sensitive
possible, the maximal volume is 2.5 ml of blood, and the
The majority of published data are based on direct
sequencing. However, Baxter et al. showed an increase in
Blood and bone marrow samples for the following analyses:
sensitivity from 20% (by sequencing) to 3% by using an
allelespecific PCR method (3,4). We adapted and optimized the allelespecific PCR method further and transferred it into
a quantitative real-time PCR method on the TaqMan®
machine. By this method, a reproducible sensitivity of
1:1000 alleles is reached, i.e. one nuclear cell in 500 cells
can be detected. This method may as wel be used for
quantification of mutated alleles. The intensity of the signal
indicates a hetero- or homozygosity. The analysis is
performed on DNA extracted from peripheral blood. This is
in contrast with the current method of choice that starts from purified granulocytes (1,2,3). Interestingly, the analysis from mononuclear cells or whole blood resulted in
Storage of empty tubes
similar mutation frequency (4,7). Recently, it was
Empty tubes should be stored at room temperature.
demonstrated, that the JAK2 V617F mutation can be present exclusively in the erythroid cell lineage in PV but
Collection of blood and bone marrow
can be absent in the granulocytes. Depending on the purity of the granulocyte fraction, a JAK2 V617F mutation could be
The PAXgene system is standardized on BD Vacutainer
technology. If no Vacutainer is available, tubes are
The JAK2 V617F mutation analysis is suggested as a first-
line test in the diagnostic work-up of patients with
Collection of bone marrow: draw bone marrow by using
suspected MPD by several authors (9). This simple, non-
a syringe. Transfer 2.5 ml of bone marrow into a
invasive and cost-efficient analysis should be done in all
PAXgene tube. Note: if the bone marrow is
cases of suspected myeloproliferative disease and unclear
hypercellular, reduce the volume of bone marrow to 1
proliferation of one or more cell lineages.
Then collect 2.5 ml blood into a second PAXgene tube as a backup. If the PAXgene tube is the only tube to be
drawn, draw a first tube to discard prior to using the
1. Kralovics R, et al. Blood. 2003; 102: 1869-71.
PAXgene tube. The PAXgene tube should be the last
2. Levine R, et al. Cancer Cell. 2005; 7: 387-97.
3. Baxter EJ, et al. Lancet. 2005; 365: 1054-61.
After marrow/ blood collection, gently invert the
4. Jones AV, et al. Semin Hematol. 2005; 42(4): 196-205.
5. Goerttler PS, et al. Blood. 2005; 106(8): 2862-4.
Store the tubes upright at 4°C, stabilized for 5 days
6. Sidon P, et al. Leukemia. 2006; 20(9): 1622.
7. Zhao R, et al. J Biol Chem. 2005; 280(24): 22788-92.
Shipping
8. Zehentner BK, et al. Am J Hematol. 2006; 81(10): 806.
9. Ganly P, et al. Am J Hematol. 2007; 82(1): 80-1.
Priority shipment (A-Post) or courier at room temperature
Questions / Ordering of tubes
Allele-specific PCR (TaqMan®), from DNA
Molecular Diagnostics, Sahli-Haus 2 114, Inselspital, 3010
JAK2 V617F and BCR-ABL: express delivery or courier
Of topical interest Immunology
LUMINEX® – Multiplex-analytics using
The PRA test is equivalent to the microcytotoxicity assay.
fluorescent bead-arrays
Every bead is covered with HLA-antigens of class I or II
from an individual donor (55 individual beads of class I and 32 individual beads of class II). The results are analyzed
The Luminex®100™ IS platform which has been validated in
using the HLA Visual Software from One Lambda.
our laboratory since mid 2006 delivers a platform adaptable
The advantages of the Luminex® technology to the
• multiple PCR-products (nucleic acid detection)
conventional microcytotoxicity assay are the following:
• antigen-antibody interactions as diagnostic tools
• in addition to class I antigens the Luminex® test also
• protein-protein interactions (receptors and ligands)
detects class II antigens, which might be more
Due to the extreme flexibility of fluorescent bead assays
important in the case of organ rejection.
(FBA) – in principle – every parameter can be measured
• using one single test, multiple patient sera can be
that can be characterized by the specific interaction of two
• the software based test analysis is much less time-
The multi-parameter test systems based on FBA available
consuming than the microscopic readout of the
on the Luminex® instrument permit the simultaneous
quantification of up to 100 different analytical properties of
the analysis software also accounts for so called cross-reactive groups (CREG’s) in the case of class I HLA-
The Luminex® xMAP®-Technology (liquiware) is based on
the final readout and classification of the immune
single polystyrene micro spheres (beads) are defined
status of patients is equivalent to the microcytotoxicity
by their content of two different fluorochromes (red
test. The same classification is used by the Swiss
• each bead bears specific detection molecules (e.g.
The most important difference in comparison to the
oligonucleotide probes, recombinant antigens, specific
microcytotoxicity assays is the detection method. The
proteins) of only one specificity or of multiple
Luminex® assay is an antigen-capture assay, i.e. all binding
IgG antibodies are detected. In contrast, the
• analytes (e.g. antibodies, cytokines, PCR-products)
microcytotoxicity assay only detects biologic active
contained in the test sample bind to the detection
antibodies. This means that only immunoglobulins which
can bind and activate complement would lead to a positive
• a reporter molecule which is coupled to phycoerythrin
result, even if they are not specific for HLA antigens. The
(PE) quantifies the reaction on the surface of the
Luminex® assay is insensitive to such undesired cross-
reactions and delivers a more specific result.
the biomolecular interaction of the capture and target molecules are quantified on the Luminex®100™
In terms of research we have established various cytokine
assays on the Luminex® system. In the near future we will
The system in our laboratory can be used on two different
validate more tests and offer them in our test portfolio. We
software platforms, Either the Luminex®100™ IS (Luminex
also propose this new technology as a basis of clinical
Corporation, www.luminexcorp.com) or the Bio-Plex-
studies and research collaborations for partners in and
Manager 4.1 (Bio-Rad, www.bio-rad.com) is chosen for the
analysis of the samples, depending on the application.
These new routine tests have been validated according to
the ISO17025 standard in our laboratory. We have already
used this new technology for the regular examination of
sera from possible organ recipients of the Swiss transplant
waiting list. The purpose of these tests is the search for
antibodies directed against HLA-class I and II antigens in
the sera of patients on the transplant waiting list The results were in excellent concordance with results from standard methods used in the laboratory. The test kits used are provided by One Lambda, Inc. (www.onelambda.com). As a first analysis the patient sera are screened for the presence of anti-HLA antibodies. The beads in this screening test are coupled with mixed HLA-antigens of class I and II from 8 donors, each. If the result of the screening test is positive for the presence of class I or II anti-HLA antibodies, these can then be identified by more specific tests, using beads coupled with more specific HLA-Antigens separated for class I or II (panel-reacting antigen test: PRA). Using this test the antibodies directed against class I or II can be directly identified.
Hematology Hypereosinophilia Leukemia Follow-up Lymphoma MPS/ Erythrocytosis Thrombophilia Metabolic diseases Pharmacogenetics Immunology
Wohnungs- und Siedlungsgesellschaft Kärnten GmbH. Neubau von 2 Wohnhäusern mit je 9 Wohneinheiten in der Gemeinde Brückl MALEREI: BAUWEISE: Stiegenhaus: Weiße scheuerbeständige Innendispersion Fundamente: Plattenfundament in Stahlbeton lt. Statik Außenwände: Mantelbetonwände 25 cm mit 16 cm starken FENSTER: Kunststofffenster weiß, mit Isolierverglasung I
Les troubles métaboliques, une affaire salée ! – Le sodium L’hypernatrémie une conséquence salée de la déshydratation Lundi matin, 8 h. À la Clinique du Quartier, le Dr Mie est quelque peu surpris de trouver sur son télé- copieur un résultat de natrémie à 160 mmol/l chez M. Natré, un patient de 88 ans qu’il connaît de longue date et qu’il suit pour une maladie