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Run
27 (General module) was
accomplished September to December 2009. 142 laboratories participated
and a total of 614 slides were assessed and the
corresponding protocols analyzed. The overall distribution of marks
were: optimal 37 %, good 31 %, insufficient 31 % (borderline or poor).
ASMA
(alpha smooth muscle actin): 64 % sufficient results. The
insufficient stains were mostly weak
or false negative reactions due to incomplete heat induced epitope retrieval
(HIER),
too diluted antibody, and poor ready-to-use (RTU) systems. The mAb
clone 1A4 in a RTU system calibrated by Dako (IS611/IR611)
showed excellent performance. On the other hand,
staining with the same clone 1A4 (both as a concentrate and a RTU format) on
the BenchMark XT, Ventana, based on HIER in CC1 buffer caused
a widespread nuclear cross reaction. It is highly recommended to use liver perisinusoidal cells for protocol calibration.
CD10:
74 % sufficient results. The insufficient stains were mainly
charaterized by too weak or false negative reactions due to
insufficient HIER or too a diluted primary antibody. It
is highly recommended to use germinal centre B-cells for protocol
calibration.
CDX2:
Only 46 % sufficient results in this rather challenging
test. The insufficient stains were mainly too weak or false negative
reactions with the most used 'old' mAb clones CDX2-88 and AMT28. In
contrast, the
new mAb clone DAK-CDX2 showed superior performance, both as a
concentrate and in an RTU
system (IS080/IR080, DAKO). Also the rabbit
mAb clone EPR2764Y seems promising.
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CEA (Carcinoembryonic
antigen): 75 % sufficient results. The insufficient stains were mostly due to
the mAb clones
PARLAM 4 and TF3H8-1 giving an unacceptable cross reaction with
other CEA-like proteins. In contrast the mAb clones COL-1 and II-7
performed well both as concentrates and in RTU
systems.
Prostein (P501S): 11 labs took the opportunity to use this alternative
to PSA.
73 % sufficient result. The insufficient stains were due to
inappropriate calibration of the Ab concentration.
PSA
(prostate specific antigen): 76 % sufficient results. The
insufficient stains were mostly due to inapopropriate calibration of the Ab
concentration.
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| The General module assessor
group, from left: Elin Borgen, Heikki Helin, Mogens
Vyberg, Jan Klos and Søren Nielsen. |
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Run B8 (Breast cancer module) was accomplished in parallel with run
27 (see above). 157 laboratories participated and a total of 443 slides
were assessed.
ER (Estrogen
receptor alpha): In this 8th test, 74 % of the 144 stains were
sufficient (marked optimal or good). The insufficient stains were mostly
too weak reactions due to
too diluted antibody or insufficient
HIER. However, impaired morphology due to excessive HIER was also seen. Taken into consideration the therapeutic consequences
of ER testing, it is not satisfying that about 1 out of 4 labs still
produce borderline or poor results.
HER-2: In
this 9th test 72% of the 136 stains were
marked optimal or good. PATHWAY® (rabbit mAb clone
4B5, Ventana) continuously give a very high rate of sufficient results: 95 %
optimal and 5 % good in this test. HercepTest™
(Dako)
gave 81 % sufficient results when adjusted for labs not following
the company's protocol guidelines. As for the poor results, Dako will offer
detailed analysis of staining procedures in each lab, on site where
feasible. Once again NordiQC must warn against using in house systems,
which have unacceptable low pass rates.
p63: 95
% sufficient results, which is one of the most successful tests. Still many
protocols could be optimized, particularly by increasing the
Ab concentration.
SMH
(smooth muscle heavy chain myosin): In
this first test, 79 % of 19 stains were sufficient.
Efficient HIER is mandatory: an alkaline buffer
is recommended. Follicular dendritic cells are low expressing cells
and should be used as the critical indicator in tonsils/lymph nodes
used for control.
Run C2 (CISH/SISH HER-2
pilot module) was accomplished in parallel with run
B8. 34 laboratories participated in this second pilot run.
CISH/SISH HER-2: 68 % of the
stains were sufficient. Both dual and single colour systems could be
used to obtain an optimal staining. NordiQC is grateful to Dako,
Ventana/Roche and Zymed/Invitrogen for
sponsoring this testmodule (runs C1 and C2).
CISH/SISH tests will in 2010 be
offered as a part of the Breast cancer module.
7th December 2007
Mogens Vyberg
Scheme director Visitors to www.nordiqc.org January-November 2009
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