Clinical Pathology in Endocrinopathies Flashcards

1
Q

Thyroid

A
  • Sets basal metabolic rate
  • req’d for growth/development of Skeletomuscular syst, and turnover for adults
  • Essential for Normal catecholamine actions
  • Maintenance of hair and coat, and sebaceous gland
  • Required for normal lipoprotein lipase activity
  • Maintains hepatic LDL receptor synthesis for rem of cholesterol from blood
  • Required for normal neural transduction
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2
Q

Hypothyroidism

about

A
  • Mostly dogs
  • Immune-mediated/idiopathic
  • Dec synth T3 and T4
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3
Q

Hypothyroidism

CS

A
  • Lethargy
  • Inactivity
  • Dullness
  • Weight gain w/o inc appetite

Other CS

  • alopecia
  • dull hair coat
  • seborrhea
  • cold intolerance
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4
Q

Hypothyroidism

Clin path

CBC

A
  • CBC
    • mild non-regenerative anemia (<50% dogs)
      • thyroid may have stim effect on EPO
      • Dec O2 consumption
    • May see codocytes (Target Cells)
      • Membrane change related to inc cholesterol
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5
Q

Hypothyroidism

Clin path

Chem

A
  • Fasting hypercholesterolemia (~75% dogs)
  • Fasting hypertriglyceridemia
  • Thyroid hormones stim lipid metabolism
  • Net effect of hypothyroidism: accumulation of plasma lipids
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6
Q

Hyperthyroidism

about

A
  • Most common in cats
  • hyperplasia or adenoma of thyroid tissue
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7
Q

Hyperthyroid

CS

A
  • Weight loss (92%)
  • Polyphagia (61%)
  • Polydipsia/polyuria (47%)
  • Inc activity/restlessness (40%)
  • GI (39%)
  • Vomiting (38%)
  • Skin changes (36%)
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8
Q

Hyperthyroid

PE findings

A
  • Palpable thyroid
  • Thin
  • Tachycardia
  • Hyperactivity/difficult to examine
  • Heart murmur
  • Skin changes
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9
Q

Hyperthyroid

CBC

A
  • RBC parameters can be normal
  • half may have MILD elevated PCV
    • stim EPO
    • Inc tis demand for O2
  • WBC: +/- stress leukogram
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10
Q

Hyperthyroid

Chem

A
  • Mild to moderate elevation of ALT and/or ALP
    • ​very common
    • both usually elevated, one almost always
  • Marked elevation in liver enzymes
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11
Q

Weight Loss despite good appetite

A
  • hyperthyroidism
  • Diabetes mellitus
  • Poor diet quality/starvation
  • GI dz
  • hyperadrenocorticism

*remember, Liver Dz not on this list, palpate THYROID

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12
Q

Hyperthyroidism

and Inc ALT

A
  • Possibly from hepatic hypoxia
    • inc O2 use in hyperthyroid state
    • concurrent heart dz and hepatic congestion possible
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13
Q

Hyperthyroidism

and Inc ALP

A
  • Inc ALP
    • some is from bone isoform
    • some may also be from liver (cholestasis)
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14
Q

Hyperthyroid

Other chem panel changes

A
  • Azotemia
    • hyperthyroidism inc renal blood flow and GFR
    • Could be due to concurrent underlying dz
      • chronic kidney dz
      • heart dz
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15
Q

Adrenal Glands

Layer nameses

A
  • Zona Glomerulosa (outside)
  • Zona Fasiculata
  • Zona Reticularis
  • Medulla
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16
Q

Adrenal glands

About the layerses

A
  • Zona Glomerulosa: SALT
    • secretes mineralocorticoids (aldosterone)
    • Na+, K+, and water homeostasis
  • Zona Fasiculata: SUGAR
    • Glucocorticoids (Cortisol)
    • Glucose homeostasis plus others
  • Zona Reticularis: SEX
    • secretes sex steroids (androgens)
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17
Q

Cushing’s

A
  • Hyperadrenocorticism
  • Overproduction of cortisol by adrenals
    • pituitary neoplasm
    • adrenal cortical neoplasm
  • CS due to excess cortisol
  • Most common in dogs
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18
Q

Glucocorticoid function

A
  • gluconeogenesis and glycogenesis
  • Insulin antagonist
  • Inc lipolysis
  • anti-inflammatory
  • inc appetite
  • dec neut migration => inc blood neuts
  • circulating lymphopenia and eosinopenia
  • maintains normal BP
  • inhibits wound healing
  • opposes ADH, dec release
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19
Q

Cushings dz manifestations

A
  • Thin skin
  • Bilateral, symmetrical alopecia
  • Acne
  • cutaneous hyperpigmentation
  • cacinosis cutis
  • Abdominal enlargement
  • muscle wasting of extremeties
  • hepatomegaly
  • Panting
  • bruising
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20
Q

Cortisol

CBC

A
  • RBC can be normal
  • Mild inc PCV (bone marrow stim)
  • WBC: Stress leukogram
  • +/- thrombocytosis (don’t know why)
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21
Q

Cushing’s

Chem

A
  • Inc alk phos (can be extreme)
    • steroid induced isoform DOG ONLY THING
    • some possibly from hepatopathy
  • Inc ALT (markedly less than ALP)
    • some leakage from liver if steroid hepatopathy
  • Inc cholesterol
    • cortisol imp in lipid metabolism
  • Inc fasting blood glucose
    • cortisol = insulin resistance
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22
Q

Cushing’s

UA

A
  • Proteinuria
    • mild
    • may be glomerular
    • May be due to UTI (culture urine)
  • UTI (silent UTIs)
    • immunosuppression
    • dilute urine
    • urine retention
    • may not see WBC inc
  • Dilute urine
    • cortisol interferes with ADH
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23
Q

Addison’s

A
  • Hypoadrenocorticism
  • Destructino of adrenal cortex
    • Immune-mediated
    • Idiopathic
  • Clinical signs from lack of
    • glucocorticoids (cortisol)
    • mineralocorticoids (aldosterone)
  • Most common in Dog
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24
Q

Mineralocorticoids

functions

A
  • aldosterone
    • produced by zona glomerulosa of adrenal cortex
    • produced in response to
      • stim of renin-angiotensin system
      • hyperkalemia
      • inc ACTH
    • promotes renal reabsorption of sodium and chloride
    • promotes excretion of potassium
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25
Q

Addison’s

CS

A
  • related to lack of cortisol
  • often waxes and wanes
    • Lethargy, weakness
    • Vomiting, diarrhea, GI bleeding
    • Polyuria/Polydipsia
  • Addisonian crisis
    • Hypobolemic/dehydrated
    • bradycardia
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26
Q

Addison’s

CBC

A
  • RBC parameters may be normal
  • Possible mild to moderate anemia
    • dec glucocorticoid stim on bone marrow
    • +/- GI blood loss (glucocorticoids imp for GI)
  • May have inc PCV: dehydration
    • can’t pull water back into body
    • not holding onto Na and Cl
  • WBC: lack of stress leukogram in sick patient
27
Q

Addison’s

Chem

A
  • Azotemia, Low Na and Cl, high K
    • lack of aldosterone
    • inability to conserve Na and Cl and excrete K in kidney
    • Less total body Na => less water conservation
      • dehydration
      • hypovolemic
    • Gi blood loss may contribute to inc BUN
28
Q

Dec sodium to potassium ratio

dDx

A
  • Na/K
  • Oliguric/anuric renal failure
  • Post-renal aotemia
  • DX (esp with whipworm infestation…pseudoaddisons)
  • Diabetes mellitus
29
Q

In acidosis, K moves

A

Out side of cell

30
Q

Addison’s

Other Chem values

A
  • Hypoglycemia (mild to moderate)
    • less cortisol = less insulin antagonism
  • Hypocholesterolemia
    • less cortisol (imp in lipid metabolism)
  • Hypercalcemia
    • ? inc renal conservation ?
31
Q

Addison’s

UA

A
  • USG not as concentrated as expected
    • despite azotemia and dehydration
32
Q

when unconcentrated urine + azotema

Doesn’t = renal disease

A
  • Things that interfere with ADH
    • hypercalcemia
    • hypercortisolemia
  • Concentration gradient
    • medullary washout
      • liver failure/dec function (low urea)
      • hypoadrenocorticism (low sodium)
    • osmotic diuresis
      • diabetes mellitus
33
Q

Endocrine pancreas

A
  • Diabetes mellitus most common dz
  • relative/absolute def of insulin secretion by beta cells
  • insulin def causes
    • dec tissue utilization of glucose, amino acids, and fatty acids
    • accelerated hepatic glycogenolysis and gluconeogenesis
    • accumulation of glucose in circulation => hyperglycemia
34
Q

Diabetes mellitus

Classic signs

DX

A
  • PU/PD
  • Polyphagia
  • Weight loss

DX

  • Clinical signs +
  • persistent hyperglycemia +
  • glucosuria
35
Q

Diabetes mellitus

CBC

A
  • uncomplicated diabetic => mild inc PCV if dehydrated
  • if inflammatory leukogram => worry about concurrent dz
36
Q

Diabetes Mellitus

Chem

A
  • Uncomplicated diabetic
    • hyperglycemia
    • possible hepatic lipidosis
      • hypercholesterolemia
      • elevated ALP (mild-mod)
      • elevated ALT (mild-mod)
  • ALP or ALT > 500 IU/L worry about concurrent dz
    • think hyperadrenocorticism
  • Pancreatitis another common concurrent dz (look out for chem changes)
37
Q

Dz that likes to accompany diabetes

A

Hyperadrenocorticism (Cushings)

38
Q

Diabetes Mellitus

UA

A
  • UA
    • glucosuria
      • hyperglycemia exceeds renal threshold
        • Dog: > 180 mg/dL
        • Cat: > 280 mg/dL in cat
    • May have inappropriately conc urine for hydration state
      • osmotic diuresis due to glucosuria
    • +/- Ketonuria (if ketosis or ketoacidosis)
    • +/- UTI
      • may see proteinuria, Bacteriuria, WBC, RBC
      • culture urine!!!!
39
Q

Normal Blood Glucose plus persistent glucosuria

A

Tubule problem

40
Q

Diabetic Ketoacidosis

A
  • Other diseases often make diabetes worse
    • insulin deficiency + insulin resistance
    • Increased mobilization of fats for energy => more ketones
  • Ketones contribute to acidosis (high anion gap)
    • ​makes you feel crummy
    • neg charged, will bind Na and maybe K
  • Ketones worsen osmotic diuresis and electrolyte depletion
41
Q

3 principle signs DKA

A

diabetic panel with

  • 1) high anion gap
  • 2) metabolic acidosis
  • 3) ketonuria
42
Q

Causes of Hypercholesterolemia

dDx

A
  • Diabetes mellitus
  • Hyperadrenocorticism
  • Hypothyroidism
  • Cholestasis
  • Pancreatitis
  • Nephrotic syndrome
  • Post prandial (mild increase)
  • Breed related (schnauzer and others)
43
Q

Causes of Hypocholesterolemia

dDx

A
  • Malabsorption/Maldigestion
  • Dec liver function or failure
  • Hypoadrenocorticism
44
Q

Addisons case

  1. Why does this dog have erythrocytosis?
  2. What is best interpretation of the leukogram
A

1) Erythrocytosis suggests dehydration
2) Unusual lymphocytosis, rather than lymphopenia normally seen in sick, stressed patients, indicates lack of a stress leukogram

45
Q

Addison’s Case

  • 1) calculate Na: K ratio and interpret electrolyte and acid/base changes.
A
  • 1) Na:K ration is 19.8, well below normal. Consistent with hypoadrenocorticism
    • other things cause low Na:K ration too tho
46
Q

Addison’s case

1) Why is this dog azotemic?

A

1) This is likely pre-renal azotemia likely with dx of hypoadrenocorticism.

  • Probs medullary washout and can’t conc urine
  • Always look for other causes of dilute urine before dxing a patient with true renal azotemia
47
Q

Addison’s case

  • 1) explain other chem panel abnormalities.
A
  • Hypercalcemia can be seen in dogs with hypoadrenocorticism
  • mild inc in ALT could reflect low level hepatocellular injury (from hypovolemia maybe)
48
Q

Addison’s case

  • Things we didn’t see but could have….(2 things)
A
  • Hypoglycemia
  • Hypocholesterolemia
49
Q

Most common cause of normochromic, normocytic, mild, non-regenerative anemia

A

anemia of chronic inflammatory dz

50
Q

microcytic, hypochromic, non-regenerative, fragmentation morphologies, and 50% of the time reactive thrombocytosis

A
  • iron deficiency anemai
  • look for the slow bleed (probs upper GI)
51
Q

Super high ALP….. =>

A

Maybe think Cushings…

52
Q

High PTHrp worry about…

A
  • Neoplasia
    • lymphoma
    • anal sac carcinoma
    • mulitple myeloma
    • some cat carcinomas
53
Q

Renal Chronic renal dz case

Renal dz and Ca…

A

It can do whatever it wants to Ca!

54
Q

Chronic renal dz case

Two things that affect phosphorus in opposite ways…

A
  • 1) Decreased GFR => promotes hyperphosphatemia and inc PTH
  • 2) Increased PTH promotes greater excretion of phosphorus in urine
55
Q

Calcium Panels

Total Ca : INC

Ionized Ca: INC

PTH: N/INC

PTHrP: norm

*Test Question

A
  • Primary Hyperparathyroidism
56
Q

Calcium Panels

Total Ca: INC

Ionized Ca: INC

PTH: L

PTHrP: INC

*Test Question

A
  • Neoplasia hunt
57
Q

Calcium Panels

Total Ca: DEC

Ionized Ca: DEC

PTH: N/DEC

PTHrP: Norm

*Test Question

A
  • Hypoparathyroidism
58
Q

Calcium Panels

Total Ca: INC/N/DEC

Ionized Ca: N/DEC

PTH: INC

PTHrP: Norm

*Test Question

A
  • Renal disease (2 hyperparathyroidism)
  • Horses often hypercalcemic with renal disease
  • Lots of different stuff can happen
59
Q

presurgical BW on 8 month old great dane whos in for a spay and pexy…

ALP: INC

Ca: INC

Phosphorous: INC

*Test Question

A
  • Normal for a puppy
  • ALP coming from bone isophorm, Ca, and P also bone growth
60
Q
  • High ALT, ALP, and Cholesterol….
    • 1) What are the most likely sources of patient’s elevated ALP?
    • 2) What is the most likely cause of this patient’s hypercholesterolemia

*Test Question

A
  • 1) Liver and steroid induced isoforms
  • 2) Hyperadrenocorticism

*possibly pancreatitis if other cholestatic markers present: inc bili, GGT

61
Q

New patient seen for peripheral lymphadenopathy…..

  • Inc BUN, Creatinine, Albumin, Globulin, very high Ca
  • Spec Grav 1.010

Most likely cause of inappropriately concentrated urine?

*Test Question

A
  • Inhibition of ADH
62
Q

Run a chemistry on a 5yo MC boston terrier presenting for weight loss and diarrhea

  • Low Ca, Albumin, and Globulin

Likely cause of the hypocalcemia? Are clinical signs likely to develop?

*Test Question

A
  • Hypoalbuminemia
  • No b/c hypoalbuminemia dec total Ca but ionized Ca should be normal
63
Q

Bloodwork from a 5yo FS DSH, what is your top differential for the hypocalcemia?

  • Inc: Glucose, BUN, Creatinine
  • Dec: Ca (1.0)
  • Inc: K (11), Phosphorus
  • Dec: ALP, ALP
  • USG: 1.050
A
  • Spurious => contaminated with EDTA
  • Ca of 1.0 is not compatible with life
  • K of 11 is crazy high
  • rerun this panel….Ca is used by the machine to do other analyses