A puzzling case of thrombocytopaenia

Re: A puzzling case of thrombocytopaenia

james herriot lied — Fri, 09 Nov 2012 13:52:44 GMT

Tough luck, Catherine, but you did all the right things. The next ten thrombocytopaenias will probably follow all the rules.

Re: A puzzling case of thrombocytopaenia

CatherineThomas — Thu, 08 Nov 2012 18:12:02 GMT

Thought I'd give you an update on this case, unfortunately not good news.

After a further blood test last week showed no improvement in platelets the owner agreed to referral which was arranged for Monday of this week. Her steroid dose was also increased to 5mg SID. Over the weekend she deteriorated, she started vomiting agian and went off her food. She also became ataxic and jaundiced. We took bloods first thing Monday morning which showed that she was still not anaemic but liver enzymes and bilirubin were raised. So she went for her referral appointment where they performed ultrasound and some basic blood work. They could see a small urolith in the bladder, they didn't think it was a mass. They could also see enlarged bile ducts and sludge in the bile ducts. They commented that they would like to do liver and bone marrow biopsies but couldn't due to the platelet issue. They felt that the neurological signs could be due to metabolic reasons but couldn't rule out brain lesions. They suggested medical treatment for cholangiohepatitis and stopping the steroids in case this was the reason for deterioration, and the owner opted to bring her back to us for this.

So we followed their instructions with regards medication - vetergesic, cerenia, ranitidine, synulox, metronidazole, destolit and denamarin plus fluid therapy.

After 3 days of this her neurological signs were deteriorating despite bilirubin levels reducing - she was severely ataxic, with circling and nystagmus. She would not eat anything despite mirtazipine. So unfortunately we made the decision to put her to sleep. And frustratingly we still don't have any idea of a diagnosis.

Re: A puzzling case of thrombocytopaenia

Martin Atkinson — Fri, 26 Oct 2012 17:06:42 GMT

[quote user="CatherineThomas"]yeah the rbc numbers were normal on all of the results although the morphology of the rbcs was suggestive of intravascular haemolysis.[/quote] Given what you've already said about the possible problem with client finances, their reluctance to accept that there is anything seriously wrong and the cat's aversion to treatment, I feel if it was my case it would time to have a frank discussion on the prognosis for this cat without considerable investment in investigative resources and money and invoke 'the rule of the 'roids' - never let anything die without the benefit of them. Up the preds to immunosuppressive dose and pray.

Re: A puzzling case of thrombocytopaenia

Rajat — Fri, 26 Oct 2012 17:02:55 GMT

I'd be quite suspicious for immune mediated destruction secondary to neoplasia

What RBC changes did they see- spherocytes?

The fact your platelets are so low with RBC destructions means its either IMT + IMHA or it is tumour in bone marrow

If RBC count is wnl, I wouldn't worry too much just yet...but if it is dropping personally I'd hit it hard with 3-4mg/kg preds per day for at least 4 weeks then taper very slowly on the basis of it prob being immune mediated iwth er 1' or 2' to neoplasia (latter prob more likely)

Still worth doing that catheter biopsy to get an idea of lymphoma or TCC or other

My 2 c

Re: A puzzling case of thrombocytopaenia

CatherineThomas — Fri, 26 Oct 2012 16:55:00 GMT

[quote user="Martin Atkinson"]

[quote user="CatherineThomas"]

The coombs test result has just come back as strongly positive

[/quote] Hmmm.... gets stranger then, given it doesn't seen to have AHA (I seem to recall you saying its RBC parameters were normal) and IMT shouldn't throw a +ve Coombes test IIRC.

[/quote]

yeah the rbc numbers were normal on all of the results although the morphology of the rbcs was suggestive of intravascular haemolysis.

Re: A puzzling case of thrombocytopaenia

Martin Atkinson — Fri, 26 Oct 2012 16:31:04 GMT

[quote user="CatherineThomas"]

The coombs test result has just come back as strongly positive

[/quote] Hmmm.... gets stranger then, given it doesn't seen to have AHA (I seem to recall you saying its RBC parameters were normal) and IMT shouldn't throw a +ve Coombes test IIRC.

Re: A puzzling case of thrombocytopaenia

CatherineThomas — Fri, 26 Oct 2012 15:57:34 GMT

The coombs test result has just come back as strongly positive

Re: A puzzling case of thrombocytopaenia

Anthony Dennison — Fri, 26 Oct 2012 14:39:51 GMT

any chance she had a sneaky paracetamol and the bladder mass is just coincidental?

Re: A puzzling case of thrombocytopaenia

CatherineThomas — Fri, 26 Oct 2012 11:24:51 GMT

We didn't do a culture of the urine. There were no bacteria noted on the cytology report and only very rare neutrophils.

I haven't given her any antibiotics so far as I couldn't see a justification for them, particularly as she seemed to improve clinically.

I spoke to one of the internal medicine specialists at our local referral centre before the last lot of tests and she said that she didn't think a bone marrow biopsy was suitable at the time but I haven't spoken to her again since the last lot of results.

Re: A puzzling case of thrombocytopaenia

CatherineThomas — Fri, 26 Oct 2012 11:13:27 GMT

[quote user="Martin Atkinson"]

[quote user="CatherineThomas"]Oh I forgot to say that she is already on preds, she has 5mg every 3rd day for asthma.[/quote] In this case it is unlikely she has IMT but if she has a UTI which is possible from your haematuria (did you do a culture from the urine?) the preds may be suppressing her immune response to that and some bacterial infections can cause thrombocytopaenia. In an ideal world you need a bone marrow aspirate and anti-platelet antibodies and a diagnosis of the bladder mass. So the preds could be a contributory factor or your saviour but is there any reason why you've not used inhaled steroids for treating the asthma? I can't see any logic in chlorambucil until you have a diagnosis.

[/quote]

I don't know, the investigation and treatment of the asthma was done by a previous vet and I haven't seen her for it.

Re: A puzzling case of thrombocytopaenia

CatherineThomas — Fri, 26 Oct 2012 11:09:12 GMT

I'm not at work today so I haven't got the picture of the scan. I don't think it looked like your description of a blood clot, it was just a white round mass, I didn't see any hypoechoic areas.

the catheter tip biopsy sounds rather complicated and we don't have a very good ultrasound machine. What kind of catheter do you use for this? Is the tip of the catheter sharp enough to go into the mass?

Would stopping the preds and starting nsaids be better than increasing the dose of preds?

I've just realised, isn't thrombocytopaenia a potential side effect of chlorambucil? So why is it a recommended treatment for IMT?

Re: A puzzling case of thrombocytopaenia

Martin Atkinson — Fri, 26 Oct 2012 10:56:27 GMT

Re: A puzzling case of thrombocytopaenia

CatherineThomas — Fri, 26 Oct 2012 10:56:22 GMT

The blood sample was analysed at the lab and the machine gave a reading of 0 so the platelet count was estimated based on a smear which we made at the time of sampleing on each occassion. On each of the 3 reports they have said that there is no evidence of platelet clumping. I've visited the lab in question and I know that they have a technician do the initial assessment and then a pathologist will look at any questionable smears for a second opinion. When we got the second results through I asked the pathologist to check the results and she said that she felt the platelet estimation was accurate.

Re: A puzzling case of thrombocytopaenia

Rajat — Fri, 26 Oct 2012 10:38:39 GMT

Hi Catherine

I would guess your ddx are platelet low due to bleeding (consumption) immune mediated (destruction) low production (BM issues whether neoplasia or other cause)

The bladder mass- can you post a US piccy of it~? Blood clots usually have amixed heterogenous appearance - with hypoechoic areas in the middle- and lookd poorly demarcated. TCCs look more like soft tissue. Isolated lymphoma of the UB has been reported I think in cats but is rare and if there was no regional lymph node enlargement it'd be lower on my list than TCC given what you described.

Sounds like neoplasia to me if the mass was same or similar in appearance after blodo clot was passed. My approach to biopsy without risking bleeding re low platelet count here would be mild sedation and a catheter tip biopsy. A surgical biopsy or a US guided needle biopsy risks seeding the tumour (TCCs seed especially well)...

Basically you scan the caudal bladder neck and visualise your urinary catheter entering the bladder (a linear hi frequency probe may be very useful here but definitely not a neccessity) Advance the catheter under direct visualisation towards the mass. use compression with your hand to move the bladder towards the catheter if needed. Once in make sharp vigorous stabbing motions into the mass at the same time applying negative suction

Then release the suction while youre still in the mass. remove the catheter carefully and spray just adrop at a time with the gentlest of pressure form a syringe onto slides and gently smear them across using least pressure possible(to avoid rupturing the (potentially) neoplastic cells.

Put the remainder of the fluid into an EDTA tube- ensure you get all the urine out of the catheter (the tip tho has the juiciest stuff, and I often use 1/2ml warm saline to flush this through - dilution wont hurt as one will do a cytospin exam of sediment anyways)

You can look at this inhouse- look for criteria of malignancy- or send out for cytology- or post here for Richard or us lesser mortals to examine

If the cat has TCC metacam longterm can help delay progression.

Was the blood smear looked at by a vet at the lab? Kitties love to clump their platelets. Some labs may use technicians, and sometimes with cats the platelets clump either at the point of the blood 'dot' or elsehwere on feathered edge and machines often read low. I'm sure it is a very well known fact to the technicians too but something I keep at the back of my mind with kitty platelets. If it is a genuine count of 25 the cat is at risk of spontaneous bleeding which is a bummer. Not much you can do with limited funds tho. NSAIDs also exert anti clotting effects so it'll be itneresting what happens if kitty does go onto it with such a low PLT count!

Cheers

Raj

Re: A puzzling case of thrombocytopaenia

Tim Cheyne — Fri, 26 Oct 2012 10:37:59 GMT

I cannot say whether this applies to small animals but in horses we occasionally get a false low platelet count with both KEdta and heparin anticoagulants. Citrate anticoagulant gives a true count. Of course the validity of the count can be checked with a blood film but I am a cynic, prepared to accept a report of many PLTs seen microscopically and less prepared to accept 'only very few'.

On the other points I can be of even less help to you!

Tim.

Re: A puzzling case of thrombocytopaenia

CatherineThomas — Fri, 26 Oct 2012 10:34:21 GMT

Oh I forgot to say that she is already on preds, she has 5mg every 3rd day for asthma. I can't remember how long she's been on this but it was before I started at the practice so at least 2 years. So I was thinking that we would increase the dose of preds, but would the fact she's already on a low dose reduce the effectiveness? The information I have found says that cats are not nearly as responsive to treatment as dogs but thrombocytoapenic cats rarely bleed spontaneously. I don't think iv chemotherapy would be suitable for this cat as she would have to be sedated each time. But the owner copes well with giving tablets so preds combined with chlorambucil might be an option. Do you think this would be suitable?

Re: A puzzling case of thrombocytopaenia

Martin Atkinson — Fri, 26 Oct 2012 10:09:16 GMT

You can't ignore this with a platelet count this low it is going to bleed sooner or later. Sounds to me like you need a biopsy from the bladder mass. A dose of vincristine at half chemo dose will temporarily boost platelets by releasing them from the bone marrow which may then give you greater confidence to do the surgery and I assume you are intending treating the thrombocytopaenia - when platelet count is this low it is usually immune mediated. Who knows - if it has lymphoma of the bladder and IMT the treatment will be the same for both!

Re: A puzzling case of thrombocytopaenia

CatherineThomas — Fri, 26 Oct 2012 09:58:45 GMT

The urine was taken by cysto after we had seen the mass on ultrasound.

Re: A puzzling case of thrombocytopaenia

James Laidlaw — Fri, 26 Oct 2012 09:49:49 GMT

Did you cysto or free catch the urine sample, and was it prior to the ultrasound or after? Could be blood clot from just cysto trauma? You call and speak to the vet for felimazole/vidalta's respective companies, maybe they have more info on the risks with thrombocytopenia? Someone else here will probably have an opinion though...