Immune mediated Flashcards
Is Pentaglobulin mostly IgM, IgA, or IgG?
Mostly IgG
IgM 12%, IgA 12%, IgG 76%
JVIM 2021, Bestwick
In a small study of IMHA dogs, what effect did Pentaglobulin have on outcome?
No effect – but tiny study, very underpowered
JVIM 2021, Bestwick
What are at least 3 possible adverse effects of Pentaglobulin documented in dogs?
Swelling at IVC
Volume overload
Erythema
Anaphylaxis
Hypercoag/pro-inflamm state
JVIM 2021, Bestwick
One small study found that IMHA +/- ITP dogs treated with therapeutic plasma exchange (TPE) had (better, worse, or similar) outcome compared with dogs not treated with TPE.
Similar – but bias toward treating more severe cases with TPE, so arguably may have had a positive impact.
JVIM 2021, Francey
What is the most common serious adverse effect of therapeutic plasma exchange and how do you treat?
Laryngeal edema – presumed allergic reaction. Resolves with antihistamine + steroid.
JVIM 2021, Francey
Incr IgG is a (common vs inconsistent) finding in PIMA dogs and (does vs does not) correlate with the targeted RBC precursor.
Incr phosphatidylserine (PS) exposure is a (common vs inconsistent) finding in PIMA dogs and (does vs does not) correlate with the targeted RBC precursor.
IgG and PS (do vs do not) correlate with each other in PIMA dogs.
IgG: Inconsistent, does
PS: Common, does
Do not correlate
JVIM 2021, Lucidi
What are at least two mechanisms that increase phosphatidylserine exposure on RBCs and precursors? Does this increase or decrease phagocytosis?
Oxidative stress
Apoptosis-like mechanisms
Normal during metarubricyte maturation (occurs nuclear extrusion –> signals macs to phagocytose it)
Incr PS –> phagocytosis
JVIM 2021, Lucidi
Which is/are true about anti-platelet Ab:
A) Specific for primary ITP (vs secondary)
B) Specific for primary or secondary ITP (vs other causes of thrombocytopenia)
C) Degree of elevation correlates with plt count
D) Degree of elevation correlates with tx response
E) Should not persist with effective tx
F) Recurrence can be associated with ITP relapse
Only F is true
Regarding A, B: 100% of ITP dogs had anti-plt Ab, 20% of non-ITP thrombocytopenic dogs had it
JVIM 2020, Shropshire
Which saline : blood ratio for saline slide agglut has the highest sensitivity for IMHA?
–1:1
–4:1
–9:1
–49:1
49:1
JVIM 2020, Sun
True or False:
Even very dilute saline slide agglut still retains large RBC clumps in IMHA samples.
True
JVIM 2020, Sun
Regarding dogs with nonregenrative immune mediated hemolytic anemia (nrIMA):
–What proportion had features suggestive of IMHA?
–What was the most common bone marrow finding?
–True or false: breed predisposition paralleled that of IMHA.
–59%
–Phagocytosis of precursors (>90%)
–False
JVIM 2020, Woolhead
Which were prognostic indicators in dogs with nonregenrative immune mediated hemolytic anemia (nrIMA)? Elaborate where indicated.
–CBC finding at presentation (and caveat)
–Bone marrow findings (and how this impacts recommendation to perform the test)
–IMHA prognostic indicators
–Corrected retic % (CR%) >0.2 at presentation –> longer survival BUT may bias (many dogs euth’d within 2 weeks)
–BM findings did not correlate with survival (incl presence of fibrosis). If dog has markers of peripheral hemolysis (suggestive of concurrent IMHA), may be reasonable to skip it.
–IMHA prognostic indicators did not apply to nrIMA dogs
JVIM 2020, Woolhead
Regarding treatment of dogs with nonregenrative immune mediated hemolytic anemia (nrIMA):
–When do most dogs become regenerative? What is around the longest you’d expect a response?
–When are most dogs in full remission?
–Proportion that survive at least 3mo?
–Most respond by 1mo, some take as long as 4mo
–7.5mo
–2/3
JVIM 2020, Woolhead
Regarding acquired myasthenia gravis:
–Two predisposed breeds
–True or false: A majority of acquired MG dogs have megaesophagus.
–Any correlation between AChR-Ab titer and remission?
–Effect of pred on clinical remission and prognosis?
–Labs, goldens
–True – 70-90%
–AChR-Ab declines over the course of tx and once clinically in remission, usually also in immunologic remission
–Dogs on pred take longer to go into clinical remission compared to other studies where they were not on pred. Possible confounding by side effects (muscle weakness). It did not improve remission rate.
JVIM 2020, Forgash
True or False: Urinary 11-dehydrothromboxane B2 is predictive of thromboembolic risk in dogs with IMHA.
False
JVIM 2022 Conway
11yr FS lab with IMHA. AUS showed hepatosplenomegaly. Which is true?
A) This is probably a reactive change
B) This is probably round cell neoplasia
C) This is probably tick borne disease
A
In this study of N=50 dogs, none with big liver/spleen/LNs had neoplasia
JSAP 2020 De Laet
Regarding plasma mean platelet component (MPC):
–What is it?
–How does MPC in IMHA dogs compare with healthy and non-IMHA sick dogs?
–Any prognostic significance?
MPC: protein density of plt. Activated plt –> degranulate –> decr MPC.
IMHA dogs have lower MPC and <19 is associated with nonsurvival
JAVMA 2019 Zoia
How does giving pred as a divided dose BID instead of a single dose SID affect severity of side effects?
BID dosing –> worse side effects
Study was not able to assess dosing effect on survival (IMHA)
2019 Swann
True or False: Systemic hypertension is common in newly diagnosed IMHA dogs.
True
JVECC 2022 Hall
Dogs with PIMA:
–Most common BM finding and its frequency?
–Effect of myelofibrosis on tx response? Survival?
–Effect of thromboembolism on survival?
Rubriphagocytosis 92%
None
Decr survival time
JAVMA 2019 Assenmacher
True or False: ITP dogs who relapse once are more likely to relapse again compared to other ITP dogs.
True
JSAP 2018 Simpson
What two conditions are associated with acquired MG in cats?
Usually also have a cranial mediastinal mass
Sometimes have immune mediated polymyositis
JVIM 2019 Mignan
What is the most common physical exam finding in cats with acquired MG and no mediastinal mass?
Prognosis?
Fatigue with wheelbarrow, usually within 1min
Otherwise highly variable and often vague CS (duration, quality, severity, progression) – so keep MG in mind!
Small study of N=8 cats, all spontaneously resolved w/o meds of any kind
JVIM 2019 Mignan
Which is a negative prognostic indicator in septic dogs? Cats?
A) Elevated cell free DNA
B) Cardiac involvement
C) Respiratory involvement
D) Azotemia
E) Elevated LEs
F) High angiopoietin 2
Dogs - A, C
Cats - B, C, D; also just the overall number of affected organ systems
A not tested in cats
JVECC 2021 Summers
JFMS 2019 Troia
JVECC 2019 Letendre
JVIM 2019 Konig
Venous oxygen saturation and central venous oxygen:
–What are they?
–Which is more accurate?
–Which is easier to measure?
–How to their measurements compare in normalcy? During shock?
SvO2: O2 in the pulmonary artery, measures balance between O2 delivery and consumption
ScvO2: O2 in the RA or cranial vena cava
SvO2 is more accurate but ScvO2 is easier to measure (central line)
Can use ScvO2 to est SvO2. ScvO2 is 2-5% LESS than SvO2 under normal conditions. Relationship is less predictable during shock (may be 20% HIGHER than SvO2).
JVECC 2019 Walton
