IMHA treatment consensus Flashcards
What type of blood product is recommended if transfusion is needed? and why?
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
what are the breeds more affected by IMHA?
Cocker and Springer Spaniels
Old English Sheepdogs
Bichon Frises
Bearded and Rough-coated Collies
Poodles
Flatcoated Retrievers
What’s the max pred dose for dogs >25kg?
40-60mg/m^2/d
What are reported side effects of bovine hemoglobin solutions (BHS)?
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
When is it recommended to ass a second immunosuppressive agent?
- 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
What are the parameters identified as indipendent predictors of mortality?
increased TBil
increased BUN
What is the MOA of azathioprine?
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.
What is the MOA of Mycophenolate?
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
What is the MOA of cyclosporine?
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.
When is IVIG recommended?
as a salvage measure
in dogs not responding to treatment with 2 immunosuppressive
drugs, but not for routine treatment
Why is it not recommended to use mycoph and azath together?
target same immune pathway
When and how is it recommended to start reducing pred?
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
What about a second agent?
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.
While tapering pred, when are rechecks recommended?
min PCV/HCT every 1-3 w + spherocytes, agglutination, and TBil
How often is urinalysis recommeded during tx?
q8-12 w
What do you do in case of bacteriuria?
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
How to monitor azathioprine?
minimum CBCs + ALT
q 2w during the first 2m of tx, and then every 1-2m until treatment is discontinued
What are poss side effects of azathioprine?
- GI: mild and self limiting
- Hepatotoxicity (high ALT): severe, usually in first few w of tx.
- Myelosuppression: uncommon, with chronic use
What about cyclosporine? (how to monitor and side effects?)
monitor for GI effects and gingival overgrowth. Liver values q2-3m.
Hepatotoxicity is idiosyncratic and not dose dep.
Migh activate platelets.
Mycophenolate?
monitor GI effects.
CBCs q2-3w for the first m of tx, then q2-3m until
tx is discontinued
What is it recommended to do in case of myelosuppression?
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.
When is therapeutic drug monitoring recommended?
- poor response to tx
- poss interaction between drugs
- emerging secondary infection
What’s the rate of relapse?
Retrospective studies with
long-term follow-up suggest a relapse rate of 11%-15%
When is splenectomy recommended?
in dogs requiring continuous immunosuppressive treatment, or
suffering repeated relapses
When is thromboprophilaxis recommeded?
All IMHA pt with plt >30k
When is the maximum risk period for mortality associated with IMHA?
first 2 weeks after initiation of treatment
Why are anticoagulant preferred over antiplatelets?
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
What is the drug of choice?
unfractionated heparin
How is it recommended to monitor dog in remission?
CBCs for 4 w to confirm
tx-free remission. Beyond this period of time, not required as relapse is usually acute.
