Semi-responsive IMHA

Re: Semi-responsive IMHA

Dalya Livy — Thu, 12 Dec 2013 23:33:21 GMT

You're right Andrew, I managed to miss Jane's second post with the retic count :(

Re: Semi-responsive IMHA

Andrew Kent — Thu, 12 Dec 2013 18:05:32 GMT

[quote user="Dalya Livy"]

Some great suggestions have been made already.

I would also consider non-regenerative IMHA at this point (auto-immune destruction of erythrocytes and/or red cell precursors in the bone marrow). You would need a bone marrow biopsy to diagnose, but treatment is similar to standard IMHA treatment and most dogs do need more than just pred to control the IMHA (i.e. add azathioprie or cyclosporine). Non-Regenerative IMHAs are at less risk of thromboembolism at least, as the disease is not in the periphery. Response may take up to 3m, and 70% of dogs are expected to recover.

There is a good article on non-regen IMHA in JAVMA, which I can't attach but the reference is:

STOKOL, T., BLUE J.T., FRENCH, T.W. (2000) Idiopathic pure red cell aplasia and nonregenerative immune-mediated anemia in dogs: 43 cases (1988-1999). Journal of the American Veterinary Medical Association Vol. 216 (9), pp 1429-1436.

I do also agree with Martin that it's worth looking for occult GIT bleeding in this dog.

Hope some of that helps, and good luck with the case!

Dalya

[/quote] The reticulocyte count in this case is pretty appropriate making a PRCA or non-regenerative anaemia unlikely. It would be nice to know if there was morphological changes consistent with regeneration on the blood film as well.

Re: Semi-responsive IMHA

Robin Grimmer — Wed, 11 Dec 2013 22:40:32 GMT

If they don't want to do any more diagnostics I would add azathioprine, bearing in mind it takes quite a long time to have an effect, but you should then be able to reduce the dose of preds.

Re: Semi-responsive IMHA

Dalya Livy — Wed, 11 Dec 2013 22:29:35 GMT

Some great suggestions have been made already.

There is a good article on non-regen IMHA in JAVMA, which I can't attach but the reference is:

I do also agree with Martin that it's worth looking for occult GIT bleeding in this dog.

Hope some of that helps, and good luck with the case!

Dalya

Re: Semi-responsive IMHA

Laurence Webb — Wed, 11 Dec 2013 19:03:55 GMT

I'd be keen to demonstrate that there is still active haemolysis present at this stage.

In house you can readily check for auto agglutination by mixing a drop of EDTA blood with 5 drops of saline and mixing them on a slide. Drop a cover slip on and see if it is clumping. Make sure you don't mistke rouleaux formation with agglutination although they are fairly obvious to tell apart. IF that isn't present then a Coombes may be of benefit (as Andy says if is is clumping on it's own there is little benefit to running a Coombes, which is effectively a way of enhancing agglutination)

Red cell morphology is the other thing I'd look at - spherocytes are not too difficult to recognise yourself as are other signs of there being red cell membrane damage such as eccentrocytes, ghost cells and other strange looking red cells. Phagocytosed red cells are supposedly the holy grail of IMHA diagnosis although I can't say I've ever found them. If you're not used to checking blood smears then it can take a bit of practice to get your eye in but it is well worth the time as there are cheap tests that can be done in a couple of minutes. If you're not sure then send blood away and speak to the haematologist. I often make slides to compare with a haemtologist's report which is a useful learning technique.

Hyperbilirubinaemia or bilirubinuria may be present but normally more with more significant haemolysis. Is the spleen big, is there pyrexia? Does the dog look well?

The immunosuppression can itself suppress red cell production so you may find mild anaemia continues whilst on treatment anyway - I have had a couple who have had better PVCs once medication has been weaned off. As has been mentioned, also check for other causes of blood loss such as GI ulceration secondary to the steroids.

If you still think there is active haemolysis then start looking for underlying causes as suggested. If you hare happy there is no haemolysis then I would slowly wean off the preds.

Re: Semi-responsive IMHA

Jane Anderton — Wed, 11 Dec 2013 15:43:31 GMT

Hi Andy,

Thanks for the reply. On last Idexx report Absolute Retic Count was 135.8 (Normal <110) which indicates a regenerative response although not a great response. Will suggest an abdominal scan for neoplasia and possibly add in ciclosporin. The only slightly odd behaviour is an increase in penile erections. He was castrated at 8 weeks old so not sure if this is a side-effect of steroid or production of androgenous hormone?

Jane

Re: Semi-responsive IMHA

Andrew Kent — Wed, 11 Dec 2013 15:40:06 GMT

[quote user="Martin Atkinson"]

[quote user="Andrew Kent"]But if there was positive agglutination then there is no point in a Coomb's test and is pretty suggestive of IMHA[/quote]My case I'm referring to had auto-agglutination and a negative Coombes test. It almost certainly was not AIHA and the previous vet nearly killed it by over-treating. I'll admit this one is more likely with a PCV as low as it was to start (mine only went that low when it started to bleed internally due to the preds) but auto-agglutination could occur for other reasons.

[/quote]

But a coomb's test looks for agglutination, so if there is genuinely positive agglutination of the sample (which persists after washing/saline etc etc) then you can't technically run a Coomb's test as agglutination is already present. So your case doesn't make sense from that point.

Re: Semi-responsive IMHA

Martin Atkinson — Wed, 11 Dec 2013 15:35:01 GMT

Re: Semi-responsive IMHA

Andrew Kent — Wed, 11 Dec 2013 15:17:51 GMT

[quote user="Martin Atkinson"]Do you have historical results for its PCV prior to this condition? - it may be it just has a low normal. Was there any other tests done for AIHA i.e. Coombes test ?- it might not be AIHA![/quote]

But if there was positive agglutination then there is no point in a Coomb's test and is pretty suggestive of IMHA

Re: Semi-responsive IMHA

Martin Atkinson — Wed, 11 Dec 2013 15:11:51 GMT

Do you have historical results for its PCV prior to this condition? - it may be it just has a low normal. Was there any other tests done for AIHA i.e. Coombes test ?- it might not be AIHA!

The case I inherited with a spurious diagnosis of AIHA, which was the subject of a long thread a few weeks ago, was being treated on immuno-suppressive doses of preds and it made it worse. There was occult blood in the faces but no ongoing melaena and It had gastric ulceration on endoscopy. Once we'd treated it with antacids and started weaning if off the preds the owners realised that the faeces had been darker than normal and the PCV slowly returned to normal but only just at 37%.

So my advice would be to wean it off the preds, do a test for occult faecal blood and use antacids. Do an abdominal ultrasound by all means if it makes you happier. Monitor PCV and if it doesn't start going down and the dog is clinically well hang on in there, I'd say its far too early to worry about giving potentially more toxic drugs without good indication.

Re: Semi-responsive IMHA

John Flynn — Wed, 11 Dec 2013 15:02:53 GMT

r the in-house pcv's definitely reproducible and reliable?

Re: Semi-responsive IMHA

Andrew Kent — Wed, 11 Dec 2013 14:53:09 GMT

Hi Jane,

Any history of travel with regard to possible infectious causes?

Is there still evidence of agglutination?

The initial findings (agglutination & spherocytes) is certainly suggestive of IMHA. It may be a good idea to look for underlying 'triggering' diseases, e.g. neoplasia as that may reduce the chance of response to therapy.

Have you run an external haematology recently? And is there adequate signs of regeneration? If the dog isn't regenerating then it may be worth looking in the bone marrow.

Otherwise I would think about a second immunosuppressive drug, for example ciclosporin or azathioprine.

Andy