IMHA treatment consensus

Question 1

What type of blood product is recommended if transfusion is needed? and why?

Answer 1

fresh pRBCs - ideally no older than 7-10d
pRBC as usually euvolemic. Units older than 10d associated with greater risk of complications (hemolytic transf reaction) and increased mortality

Question 1

what are the breeds more affected by IMHA?

Answer 1

Cocker and Springer Spaniels
Old English Sheepdogs
Bichon Frises
Bearded and Rough-coated Collies
Poodles
Flatcoated Retrievers

Question 2

What’s the max pred dose for dogs >25kg?

Answer 2

40-60mg/m^2/d

Question 3

What are reported side effects of bovine hemoglobin solutions (BHS)?

Answer 3

BHS scavenge nitric oxide, potentially
activating platelets and causing vasoconstriction, which increases risk
of hypertension + BHS exert a greater colloid osmotic (oncotic) pressure than do RBCs, increasing the risk of IV volume expansion and hypertension.37 Transfused RBCs also are likely to have
a longer circulating half-life than BHS, although the half-life of trans

Question 4

When is it recommended to ass a second immunosuppressive agent?

Answer 4

• severe or immediately life threatening dz
• PCV does not remain stable (absolute decrease >5% within 24h during first 7d)
• blood transfusion dependent after 7d
• severe adv effects to glucocorticoids

Question 5

What are the parameters identified as indipendent predictors of mortality?

Answer 5

increased TBil
increased BUN

Question 6

What is the MOA of azathioprine?

Answer 6

purines antagonist: causing breaks in DNA and RNA secondary to incorporation into nucleic acids and termination of the replication process. Azathioprine specifically targets lymphocytes due their lack of a salvage pathway for purine biosynthesis.

Question 7

What is the MOA of Mycophenolate?

Answer 7

noncompetitively, but reversibly, inhibits inosine monophosphate dehydrogenase (IMPDH) type 2 which is the enzyme involved in the synthesis of the purine guanosine nucleotides inhibiting proliferation of T and B cells

Question 7

What is the MOA of cyclosporine?

Answer 7

Calcineurin inhibitor= immunosuppressive agent that focuses on cell-mediated immune responses, with some humoral immunosuppressive action. Binds to T-cell cyclophilin and blocks calcineurin-mediated T-cell activation. T-helper lymphocytes are the primary target, but T-suppressor cells are also affected. Cyclosporine can also inhibit cytokine production and release.

Question 7

When is IVIG recommended?

Answer 7

as a salvage measure
in dogs not responding to treatment with 2 immunosuppressive
drugs, but not for routine treatment

Question 7

Why is it not recommended to use mycoph and azath together?

Answer 7

target same immune pathway

Question 8

When and how is it recommended to start reducing pred?

Answer 8

PCV/Hct stable and >30% for 2w + improvement of measures of disease activity (including spherocytosis, agglutination, tBil and
reticulocyte count).
Decrease by 25% every 3w

Question 9

What about a second agent?

Answer 9

Dosage of this drug
should not be changed, but a greater reduction in the dose of pred (of 25%-33%), or a shorter interval between reductions (2w), may be possible if the dog shows
a good response to tx.
A typical duration of 3-6m of tx is expected for
pred in the majority of cases, with an
expected duration of 4-8m for all immunosuppressive
tx.

Question 10

While tapering pred, when are rechecks recommended?

Answer 10

min PCV/HCT every 1-3 w + spherocytes, agglutination, and TBil

Question 11

How often is urinalysis recommeded during tx?

Answer 11

q8-12 w

Question 12

What do you do in case of bacteriuria?

Answer 12

If clinical or
active sediment associated with bacterial growth is found-> antimicrobial tx.
If bacterial growth without
active sediment is found in the absence of clinical signs, we do not make
any recommendation regarding treatment, but, if treatment is not implemented,
we recommend more frequent review of clinical signs and urinalysis

Question 13

How to monitor azathioprine?

Answer 13

minimum CBCs + ALT
q 2w during the first 2m of tx, and then every 1-2m until treatment is discontinued

Question 14

What are poss side effects of azathioprine?

Answer 14

• GI: mild and self limiting
• Hepatotoxicity (high ALT): severe, usually in first few w of tx.
• Myelosuppression: uncommon, with chronic use

Question 15

What about cyclosporine? (how to monitor and side effects?)

Answer 15

monitor for GI effects and gingival overgrowth. Liver values q2-3m.
Hepatotoxicity is idiosyncratic and not dose dep.
Migh activate platelets.

Question 16

Mycophenolate?

Answer 16

monitor GI effects.
CBCs q2-3w for the first m of tx, then q2-3m until
tx is discontinued

Question 17

What is it recommended to do in case of myelosuppression?

Answer 17

For asymptomatic neutropenic patients: if neutrophil count is between 1000 and 3000
cells/μL, antibiotics are not needed unless other independent risk factors for infection are present. When the neutrophil
count is <1000 cells/μL, prophylactic antibiotics are indicated.
Recombinant granulocyte colony stimulating factor could be considered
for use in patients that have received an inadvertent overdose
with a myelosuppressive drug or when profound neutropenia persists
for >1 week.

Question 18

When is therapeutic drug monitoring recommended?

Answer 18

• poor response to tx
• poss interaction between drugs
• emerging secondary infection

Question 19

What’s the rate of relapse?

Answer 19

Retrospective studies with
long-term follow-up suggest a relapse rate of 11%-15%

Question 20

When is splenectomy recommended?

Answer 20

in dogs requiring continuous immunosuppressive treatment, or
suffering repeated relapses

Question 21

When is thromboprophilaxis recommeded?

Answer 21

All IMHA pt with plt >30k

Question 22

When is the maximum risk period for mortality associated with IMHA?

Answer 22

first 2 weeks after initiation of treatment

Question 23

Why are anticoagulant preferred over antiplatelets?

Answer 23

Thrombosis in IMHA predominantly affects the venous system (red clots), where thrombi form under low-shear conditions. Such thrombi typically are rich in fibrin, and their formation is less dependent upon platelet number or function

Question 24

What is the drug of choice?

Answer 24

unfractionated heparin

Question 25

How is it recommended to monitor dog in remission?

Answer 25

CBCs for 4 w to confirm
tx-free remission. Beyond this period of time, not required as relapse is usually acute.