
The slide to be stained for
Cyclin D1 comprised:
1: tonsil, 2: placenta, 3: B-CLL, 4-5: mantle cell lymphoma.
Criteria for assessing a Cyclin D1 staining as optimal included: A
moderate to strong distinct nuclear staining of the neoplastic cells
in the two mantle cell lymphomas, the proliferating squamous
epithelium of the tonsil, and
sub-trophoblastic cells in the placenta,
whereas the nuclei of the
large majority of lymphocytes and the
neoplastic cells in the B-CLL should be
negative. A slight cytoplasmatic reaction was accepted both in the
cells expected to react but also in other cell types. However the
interpretation of the specific nuclear reaction should not be
affected.
57
laboratories submitted stainings. At the assessment 13 achieved an
optimal score (23 %), 17 good (30 %), 14 borderline (25 %) and 13
(22%) poor.
25
laboratories used mAb clone DCS6 (DakoCytomation,
n=21,
Novocastra,
n=2, or NeoMarkers,
n=2), 24 used mAb clone P2D11F11
(NovoCastra,
n=20, or Ventana,
n=3), 3 laboratories used
mAb (rabbit) clone SP4 (NeoMarkers/LabVision),
4 laboratories used a
pAb (BioCare,
n=3, Upstate,
n=1).
In
this assessment optimal staining could only be obtained with the
mAb P2D11F11 (obtained in 10/23) and SP4 (obtained in 3/3).
All
laboratories achieving an optimal staining used HIER, most
frequently (11/13) with Tris-EDTA/EGTA pH 9 as the heating buffer.
MWO, pressure cooker and water bath could be used as the heating
device.
The
optimal dilution of mAb clone P2D11F11 was in the range of 1:10 –
100, and
that of the rabbit mAb SP4
was in the range of 1:50 - 500.
27/57
laboratories (47 %) submitted a staining
marked sub-optimal.
The causes were frequently a combination of several parameters in
the immunohistochemical protocol, such as an
The
most frequent causes of insufficient stainings (often in
combination) were:
-
Insufficient HIER: too short efficient heating time (MWO< 15 min.,
water bath <40 min.), use of citrate pH 6 as the heating buffer
-
Inappropriate calibration of primary Ab dilution (too
high or too low concentration).
- Inappropriate choice of primary Ab
The
insufficient epitope retrieval combined with an inappropriate
calibration of the primary Ab caused either a false positive reaction
in the B-CLL and a
generaly too high background
staining, or
a
false negative reaction in
the two mantle cell lymphomas. A very
important element in setting up an immunohistochemical
protocol for Cyclin D1 is the choice of
control tissue. In this assessment we chose
a tonsil as both positive
and negative control. In the sub-optimal stainings with a too
high background reaction, the lymphocytes showed a
moderate to strong
cytoplasmic reaction compromising the
interpretation in spite of a nuclear
reaction in the mantle cell lymphomas. In the
sub-optimal stainings with a false negative reaction
of the mantle
cell lymphomas, the nuclear staining of
the squamous epithelial cells
were weak or absent.
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