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hematopoiesis
9/3/98

Today we are doing something together 
instead of him talking the whole time. It will not be a quiz. This course 
is hematopoiesis 0461 for zero credits (ha ha).  No, it's 2 credits. 
Hematopoiesis is a course Dr Weiss started years ago involving a number 
of professors interested in hematology. He doesn't organize it any more, 
but he's still a lecturer. We will discuss topics from the  human side of 
things as well as veterinary things. See handout for list of topics. 
There are no exams in this course. The course is for you. You should, 
however, show up and participate so the lecturers are not alone here. 
Usually it's 1-1.5 hrs instead of 2 hrs, with no break. 

Be actively 
involved. Ask questions. There is no agenda here other than giving you 
interesting information. TOday it is up to you how long you want to go 
with this. Don't get bored.

He's not requiring an attendance list but 
does appreciate your showing up. There is one other small requirement. 
You have to write a paper. You will choose an area of your own interest 
out of the recent literature, and write something about it. It can be 
anything in hematology, as long as you can defend the position that it 
has something to do with blood. One student did write one paper that was 
unrelated to blood...that didn't fly. It has to have something to do with 
hematology. You have to find some original literature. You have to go to 
- if you are thinking of some topic....say, laminitis...that sounds 
unrelated to hematology, but think about it. Look at laminitis. There is 
blood involved. There are aspects of laminitis you could look at from an 
inflammatory/thrombotic standpoint...the question is, is there any 
recent, original literature on the subject? You want to find some 
original papers, read them, advance your knowledge, then review them 
together. Ok, what about multiple myeloma? You're learning about that in 
medsurg2. If you find new research on it, in some area, it might be 
appropriate, but you don't want to write a paper on your 9002 notes. You 
have to find original studies - you can back those up with reviews, or 
class notes. It should be a brief paper. He has to read these all. Dr 
Weiss too. The quality of the paper and references is then graded. YOu 
can write your references however you want,but you should do it really in 
the scientific journal style. 

This is intimidating to some people. Yes. 
But there are many journals of hematology or internal medicine that you 
might like...

also, we will have a demo on how to do literature 
searches. this has been done for a few years and was originally popular 
and maybe you already know how to do it but if not, you will find out. 
the librarian has some tricks to show you. she'll show some examples. 
based on that you might  find it easier to find a topic. 

PAPER DEADLINE 
IS FIRM:::  Tuesday October 27th 1998 (or monday the 26th)

Ok, now. 
Usually he talks about RBC problems now. But, he thinks we are too quiet 
a class, not having any kind of interactions with the instructors. We 
show up on time and are pretty good but he wants to get us involved. So, 
to do this, he thinks that - he had to give an interactive case 
presentation elsewhere so he's going to present some non-straightforward 
cases that involve hematology. 

Slide: shaggy black dog :)

Shayna: 
kerry blue terrier, 9 yr old FS.
PCV 35%, TP 6.5
LVMD removed a skin 
tumor and she did fine but 2 days later started to ooze blood, got 
swollen. Abx were prescribed, but didn't resolve. PCV was dropping a 
little. She came here. Blood smear looked normal with adequate platelets. 
ACT = 5 minutes. 

What's going on? ACT is prolonged. Your coagulopathy 
is therefore intrinsic or common pathway (ACT doesn't evaluate extrinsic 
pathway). So, she could have a factor deficiency, liver disease, 
rodenticide toxicity, other...

more history: hematoma after lipoma 
removal, hemorrhage after spay surgery, 2 episodes of HGE.

PCV 35 TS 6.5

PT 7 (8)
PTT 37 (13)
ACT 5 min
plt 86,000

OK, we know there is a problem 
with the intrinsic pathway because the PTT is prolonged.. The PT is 
normal so the extrinsic and common pathways must be normal. 

remember 
ACT and PTT measure intrinsic and common pathways; PT measures extrinsic 
and common pathways. So, rodenticide poisoning is out - that would affect 
the extrinsic pathway and extend the PT. Liver disease is also unlikely. 


ok, what about hemophilia, deficiency of factor VIII or IX. this is 
unlikely in a female dog. 

Ok, what about factors XI and XII? Well, she 
had a severe factor XI deficiency. That's interesting. Factor 
deficiencies do not always cause bleeding in young age. She is 9 years 
old, but you can't rule out an inherited problem. One thing, though, when 
you have a specific factor deficiency and all others are normal, it is 
very likely inherited. You could also think of an Ab being made against a 
factor - so it could be acquired. But in Kerry Blue Terriers, factor Xi 
deficiency is well known. It results in postoperative or posttraumatic 
bleeding, delayed 1-2 days. We've seen several cases like this here. 


This is also seen in people, esp jews. It is a dominant trait. In dogs we 
aren't sure if it is dominant or recessive, but it is autosomal. 


Management: avoid surgery. give FFP (not cryoprecipitate) as needed. or 
you could use cryo-poor plasma, too, actually. They gave her four units 
of FFP. Her ACT dropped into normal range after getting those four units 
of FFP over 3 days. at the same time, her factor XI went from 9% to 100% 
and then slowly dropped off with a half life of about 30 hrs. She did 
great. She healed and didn't bleed anymore afterwards. 

If you are a 
breeder of Kerry Blues, which happened to be the case of an owner on 
Tuesday, you should test for this disease. 
There are many other 
hereditary coagulopathies common in our small animal practice. 

slide: 
cat with teeth showing.
Hank: 9 mo old DSH - presented for routine 
pediatric exam. came back for vaccines. then for castration. he was 
neutered and during the castration the surgeon became concerned because 
the testicle was very dark, very dark blood vessels. They put cat on O2 
but he remained cyanotic. why?

people are suggesting a hemoglobin 
problem. 
what's the differential for cyanosis?
-lung disease/inadequate 
ventilation - almost ruled out b/c cat not improved on O2
-shunts/heart 
defects - can't rule out
-toxic insult (acetaminophen) - ruled out b/c 
this lasted a few weeks
-Hb abnormality - rare but must consider

how do 
you separate cyanosis from polycythemia? 
PCV = 52 which is high (45 = 
normal upper range)

1. measure serum erythropoietin - useful but maybe 
not in this case
2. expose EDTA tube to air - will change color if normal 
Hb
3. arterial PO2 - difficult to do
4. cardiac evaluation - useful and 
appropriate
5. chest rads - useful for pulm or cariac disease

But 
really, expose the blood to air first. The patient's blood stayed dark. 
This means there is something wrong with the hemoglobin. 
Methemoglobinemia? The 3+ form can't carry O2. 

what does NOT cause 
metHb? carbon monoxide. that causes cherry red blood b/c it binds Hb. 
onions, methylene blue, tyelenol all do cause metHb.

They tested him for 
metHb reductase deficiency. Hank had 54% met-Hb- this is serious. Above 
60 is likely fatal. should be under 1%. He had 0% metHb reductase 
activity. So, he's accumulating metHb at about 2-3% per day. Because he 
has methemoglobin, he is always feelign a bit hypoxic. but O2 
administration won't help, he needs blood that can carry O2. but he's 
also polycythemic because he's trying to  make more RBCs to carry more 
O2. he also has a high reticulocyte count. This tells a lotabout the 
pathophysiology. If you do n't have oxyHb, you will be hypoxic. 

The 
MetHb reductase deficiency is reported in several dog breeds. The clinic 
that adopted out this cat Hank also had other kittens adopted out at the 
same time, and another one came in with the same problem. She had the 
same thing. She was at 54% metHb. why do both of these cats have the same 
enzyme deficiency? A third cat looked similar - it had 50% metHb 
reductase activity and no elevation of metHb. This was a carrier. The 
other two were affected. This was one family of cats in virginia. there 
was another report in another cat hospital too. Also reported in a couple 
of dog breeds, and a vet tech recently adopted a small dog that also has 
this. it was originally misdiagnosed as a congenital cardiac problem with 
a poor prognosis. 

you don't have to treat these animals unless they get 
into trouble - avoid exposure to onions, tyelenol, other oxidative 
agents. Then it would be in real trouble. they are working on treatment 
to use in emergencies...best tx probably methylene blue. or, 
acetylcysteine is also helpful to some extent. Vit C  and other things 
might also be useful. 

in the cat, it is autosomal recessive...in the 
dog, no family history is available. in humans it is autosomal recessive.


Another cat: this was also a case this year. this is max, an oriental 
shorthair from down south. came here b/c at 2 yrs old (male, neutered) he 
had episodes of weakness over 3 mos. he would be white and cold lasting 
for 1-2 days. he was pale and cold to the touch (his mms). he also had 
recurrent URI of about a year's duration, intermittent abdominal 
distention during the episodes of paleness and weakness, and not eating 
well then. no other probs. 

he came here and had no physical problems at 
that time. 

LVMD data: PCV 18%, TS 6.2, WBC 24,000, glucose 282, ALT 85. 
This was before he came here. So it is anemic, has leukocytosis, and 
elevated glucose and ALT.

VHUP data: HCT 41, MCV 45, MCHC 33,retic 
0.5,WBC 14,000 - all normal here. Some schistocytes present. Adequate 
platelets. 

the local vet was concerned - he thought this cat might have 
an infection, b/c white count was high. but we think this is stress or 
bone marrow stimulation. he also worried about diabetes. we think this is 
stress. it could have diabetes but it could also be stress. What about 
the liver disease? the vet was worried about the ALT of 85. well, that 
issomething to look into but the animal was sick so this could be 
nothing.

our results were pretty normal. so that wasn't a big help. 
elizabeth wants to know about the spleen. he says it was nonpalpable. he 
says we could do u/s, xrays, things like that. it's possible the 
distended abdomen before was a hemoperitoneum due to bleeding. why would 
cat bleed? could be neoplasia,but he's two years old. Parasites? 
typically not causing abdomen problem. what other possibilities are there 
for blood in the abdomen? coagulopathy. platelet problem (but we excluded 
thrompocytopenia)(could still have thrombobathia, that is hard to 
evaluate in cats). 

Platelet count 891,000 (high)
PT 10 
PTT 32 (high)

ACT 180 (high)
ALT (high)
alk phos (high)
bile acid 15 (high)
urine 2+ 
bilirubin; 1.025

Ok, there is a problem with the intrinic pathway. There 
are some elevated liver enzymes and bile acids. urine SG sort of low, and 
bili positive. what's next?
it's not rodenticide poisoning. Find out what 
factors are missing. what causes prolonged PTT? 	
Hemophilia A or B (F 
VIII or IX)
factor XII deficiency
rodenticide toxicity
liver disease
DIC


he turned out to be factor XII deficient (Hageman's factor - the first 
one in the intrinsic pathway). but what is the big deal about that? 
factor XII deficiency doesn't cause bleeding in other cats or in people. 
so what is max's problem? why is he bleeding? well, this factor XII 
deficiency was reported in the Oriental Shorthair once before. But the 
other cats with it have all been DSH cats. We get fooled b/c they have 
normal PT and prolonged PTT. But they do not bleed. But what's Max's 
bleeding problem and liver enzyme problem?

day 30: he came back during 
an episode
T 36 C (94 F), P 210, R 45
white mm, weak pulses
5 cm mass 
palpated on liver
abd fluid was bloody
PCV 15, TS 5
ALT 380, ALP 38

abdominal US- mottled liver parenchyma.

well, there seems to be some 
liver disease. can we do a liver biopsy? he's bleeding. consider giving 
plasma. Also, you could look in the literature and see if there are known 
liver disease in this breed. there is. amyloidosis - hepatic amyloidosis 
in oriental shorthairs causes a classic presentation of hemorrhage into 
the abdomen, and death. this is what happened to Max. he was prepared for 
a U/S guided biopsy but he died before it was done. the mass on the liver 
was just a hematoma.

This was a devastating problem. 
postmortem: 
hemoperitoneum, hepatic amyloidosis (also seen in abyssinian and somali. 
it's a reactive type of amyloidosis - SAA). yellow, tan, friable liver 
with capsular clots. 

they checked the family history of this cat - a 
related cat had pancreatic insufficiency, which is very rare in  cats. 
amyloidosis was suspected. The cat died 10 days later of hemoperitoneum. 
It was the same thing. there is no tx for amyloidosis as far as we know. 


slide: cute dog :)
this is lady. she presented to the AMC before coming 
to us. 2 yr old female k9x with recurrent signs of anemia and 
pigmenturia. she had mild exercise intolerance and no signs of bleeding 
at any time.

labs: HCT 24, MCV 85 (high), MCHC 31, WBC 24 (high), plt 
235

so she has macrocytic normochromic anemia with leukocytosis. this is 
a profile consistent with hemolysis (or blood loss into urine,but that 
would be unusual)

next step?
u/a and retic count. she has 9% retics 
(high) - 210,000 (40,000 = normal)
urine 4+ bili, 2+ blood, neg sediment

blood bili 1.7 (but dog not icteric), liver enzymes up a bit, K+ 
elevated, sodium normal. coombs' negative. 

this is consistent with a 
regenerative, intravascular hemolytic anemia.
blood smear: marked 
anisocytosis, otherwise nothing major. some polychromatophilic cells. no 
poikilocytosis or other abnormalities seen.

note: human rbcs contain 
high K+. dogs do not (except akita). normal RBC have low K+ and high Na+ 
like plasma...so hemolysis doesn't cause hyperkalemia - except if you 
lyse retics, then you get hyperkalemia. so that's why we have 
hyperkalemia with intravascular hemolysis - the retics are being lysed..


differential for hemolysis: IMHA primary or secondary
babesia neg
HW neg

zinc toxicity neg
chest rads neg
abd xray neg
no recent vaccine or other 
exposure

what's your diagnosis? IMHA - some can be Coombs' neg
what's 
the best treatment? prednisone?
after 14 days of pred,PCV was 42. but a 
month later the anemia recurred. PCV now 18, retics at 11%. They treated 
with pred and cytoxan. Within a week pcv was up to 44%. but then she came 
in a few months later with a PCV of 27 and they didn't treat it - and her 
PCV went up to 39 within a couple of weeks.

so, did she have IMHA? 
well...who knows? they say response to tx makes your diagnosis, but 
that's not always the case because this dog got better without treatment 
as well as with treatment. it is odd that this dog has so many episodes, 
responds so rapidly, and comes back with the same thing again.what does 
this make you think of???

hereditary defect? enzyme deficiency?
her 
family history included a littermate who had similar signs, was treated 
for AIHA, then euthanized after recurrence. They also questioned the 
owner regarding when the onset of signs occurred - she said the crises 
occured after strenuous exercise, excessive barking, panting. so, this 
dog turned out to have an enzyme deficiency.they looked at the glycolytic 
pathway which provides energy for the RBCs. PFK and PK are the important 
regulatory enzymes in this pathway. PFK is high up and PK blocks only the 
last step if missing. Lady's PFK activity was 12% of control, and her DPG 
was 1/3  of normal. Her Hb-O2 dissociation curve was shifted to left, 
too. she had a G--> A mutation, resulting in a stop codon instead of a 
tryptophan. bummer.

there is a PCR test to separate mutant allele from 
normal allele. 
PFK deficiency causes exertional myopathy and 
hyperventilation induced hemolytic crises.there is autosomal recessive 
inheritance. the membranes of the affected cells are very alkaline 
fragile. When dog pants a lot, it gets a respiratory alkalosis and that 
induces lysis of the PFK deficient red cells. we can induce this 
experimentally. that explains Lady's problem.now they can avoid 
situations that cause exertion, barking and panting (ha ha).

in people, 
muscle cramps is a prominent feature of this syndrome. the dogs are 
incapable of hunting (ESSP is a hunting dog). 

to test - can use blood 
on filter paper or cheek swab cells.

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