Immune Mediated Disease Literature Flashcards
In healthy SCWT, what has been noted to be increased in animals that have siblings with PLE/PLN?
• High prevalence of perinulcear antineutrophilic cytoplasmic autoantibodies (pANCA) in healthy Wheatens (21%)
○ Significantly association of + pANCA and diagnosis of PLE or PLN in sibling
Did immunosupression have an effect on Coomb’s?
NO!
Did storage have an effect on Coomb’s?
NO! Samples were stored chilled for up to one week!!!
Did blood transfusion have an effect on Coomb’s
NO! Did NOT result in a false + result
What is a sensitive and specific test for IMHA that is resilient to storage, immunosuppression, and transfusion artifacts?
Coomb’s (DAT - Direct Antiglobulin Test)
Sn: 50-89%
How often can blood donors donate blood?
• Donors >27 kg can donate 450 mls (16 ml/kg) every 3 weeks without experiencing adverse effects
How long can you store fresh whole blood and have the platelets still work?
About 72 hrs
Just don’t chill = KILLS platelets
If you give 10 ml/kg of fresh whole blood, how much will this increased your platelet count?
About 10K
If you give 1 unit of platelet rich plasma, how much will this increase your platelet count?
Max 40K
What happens to thrombocytopenia patient’s vessels over time?
Platelets are important for plugging gaps in endothelium - over time thrombocytopenic patients get “gaps” / thinning in their vessels
What did feline idiopathic pure red cell aplasia respond to?
Steroids and cyclosporine
MST: 31-406 d
Relapse common
But 4 cats went into remission
What composes IVIg?
90% biologically intact IgG (little IgA, IgM, CD4, CD8, human leukocyte antigen)
T1/2: Dogs 7-9 days
What is the MOA of IVIg?
○ Blocks Fc receptors, eliminates pathogenic autoantibodies, modulate cytokine synthesis, inhibit complement, mediate Fas-Fas ligand interactions
What are the uses of IVIg in vet med?
§ Use in vet med: IMHA, ITP, pemphigus foliaceus, SARDS, myasthenia gravis, cutaneous disease
What are adverse events with IVIg?
Type I hypersensitivity/anaphylaxis; hypercoagulation (TED), renal failure, hypotension, pseudohyponatremia
What had an effect on the plasma concentrations of prednisolone in healthy dogs?
• Modulation of P-glycoprotein expression influenced plasma concentrations of prednisolone PO (healthy beagles)
○ Rifampicin (induce P-gp) - Upregulated duodenal P-gp in dogs and reduced AOC of pred
○ Ketoconazole (inhibitor of P-gp) - Downregulated expression of duodenal P-gp and increased AOC of pred
What could be used to monitor immunosupression with cyclosporine?
Flow cytometery: • Direct T cell function (flow for IL-2, IL-4, IFN-gamma) may be effective/more sensitive to monitor immunosupprressive tx with cyclosporine in dogs
○ Low dose (5 mg/kg PO q24hrs): Significant decrease in IFN-gamma but IL_2 was unaffected
○ High dose (10 mg/kg PO q12hrs): Significantly decreased IL-2 and IFN-gamma, but NOT IL-4
○ T-cell function is suppressed at trough blood concentrations >600 ng/ml, at least partial suppression at lower doses
What effects do high doses of methylprednsiolone have on neutrophils?
• High doses of methylprednisolone (MPSS) suppressed major functions of neutrophils (including adhesion markers CD11b, CD18; decreased phagocytosis; reduction in oxidative burst) for at least 7 days after tx
No significant change in migration noted
Is transdermal cyclosporine recommended in cats?
NO! Inconsistent absorption
For IMHA patients, what is superior: aspirin. plavix, or both?
No difference in survival btwn groups in survival = All about 13% mortality and TED about 13%
For IMHA patients, what is superior: constant dose heparin or individually dosed heparin?
% mortality and incidence of TED significantly different btwn groups
MST: Constant heparin 68d vs individual dosed heparin >180 d
For IMHA patients, was plasma helpful for preventing TED?
No difference btwn groups (all dogs were on heparin too)
Why should we not call it “Evan’s syndrome”?
Since we cannot rule out IM process, bystander effect, vs onset of DIC
Which is better for IMHA, azathiaprine, cyclosporine, or cyclophosamide?
No evidence of azathiaprine vs cyclosporine
DO NOT use cyclophosamide
Did IVIg result in improved survival in IMHA dogs?
NO! But it did improve hematologic parameters
What antithrombotics were associated with improved survival in IMHA?
Individually dosed heparin and low dose aspirin
What are the major prognostic indicators in IMHA dogs?
Bilirubin and BUN (>56)
Others: □ Spherocytosis □ Sex (male) □ Season (warm) □ PCV (0.23 mg/dl □ Monocytes >100/ul □ aPTT □ IL-18
MCP-1
Is there a seasonality to IMHA?
Yes
Reported: ○ More cases in spring and summer at the San Diego office NOT true for LA practice
Can mycophenolate be used for IMHA?
Yes! - Reported in dogs and cats
• Mycophenolate in dogs with IMHA did result in remission BUT also horrible GI -toxicity (10-15 mg/kg PO q8hrs, HIGH DOSE)
○ In combination with pred and low dose aspirin (20.5 mg/kg/day)
What has been shown with using lactate in IMHA patients regrading prognosis?
lactate concentration at presentation was significantly higher in nonsurvivors than survivors
○ Serial lactate was a better measure (more predictive), If persistent hyperlactemia at 6 hours after admission they were less likely to survive
§ Optimal lactate cut off 4.4 mol/l (correctly predicting outcome 73%, sen 60%, spec 77%)
§ All dogs with lactate that normalized within 6 hrs survived, only 71% with high lactate at 6 hrs survived
Overall survival: 77%, 20% euthanized, 3% died
What is the prognosis of IMHA when there is severe thrombocytopenia (
○ Similar survival to either disease alone (75% survived and 25% euthanized)
○ Younger dogs were more likely to survive
What should pANCA not be used as a biomarker of IBD?
• Perinuclear antineutrophilic cytoplasmic autoantibodies (pANCA) were detected in a IMHA dogs (47%) and dogs with vector borne disease (48% esp if titer for Leishmania infantum), and 5% in healthy dogs
○ pANCA is a non-specific marker and should NOT be used for IBD
○ May be a biomarker of IM or infectious diseases