[Histonet] Re: Helicobacter stains and controls
rsrichmond <@t> gmail.com
Sat Jan 5 13:26:35 CST 2013
There are four broad choices for staining Helicobacter.
1. Rely on H & E alone. Some people claim it works, but I can't find
them unless they're all over the place.
2. Thiazine dye methods. The simplest is the blue dye mix Diff-Quik II
(or a generic equivalent, all of which work in my experience), the
next a Giemsa stain, and it's possible to complicate them considerably
3. Silver stains such as Steiner's. They work, but they're a lot of
trouble and the tissue often falls off the slide. I have almost no
experience with them.
4. Immunostains. More expensive to do, but a lot faster for the
pathologist to read.
I haven't seen a study comparing the sensitivity of these methods. My
personal opinion is that I'm OK with Diff-Quik II if I'm seeing one
gastric biopsy a day, but I want IHC if I'm going to be seeing ten of
them. With the dye method I often have to resort to oil immersion
magnification, where with IHC I barely need to use a high-dry lens.
Helicobacter controls: Not really necessary, but should be done
anyway. You need the co-operation of your pathologist in finding
positives suitable for use as controls. One gastrectomy specimen can
of course set you up for life, but these are pretty rare these days.
Some additional points: many pathologists don't understand that not
all bacteria they see in the stomach are Helicobacter - morphologic
criteria must be observed. (IHC gets around this problem.)
There is another, rather rare Helicobacter that causes peptic ulcer
disease, with different morphology (a tight corkscrew rather than a
"gull wing") - Helicobacter heilmanii. Supposedly IHC picks it up.
There's controversy as to whether all gastric biopsy specimens need a
stain of some kind, or only the ones with acute inflammation
(confusingly called chronic active gastritis).
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