Parathryoid (HYPERcalcemia)

Question 1

Loss of function seen in FHH is

Answer 1

Psuedo-hypoparathyroidism

Question 2

ADH acts on CaSR of the parathyroid cell to cause release of:

Answer 2

Parathryoid hormone

Question 3

What can we use to treate severe hyperparathyroidism

Answer 3

A calcimimetic; cinacalcet

Question 4

Excess PTH leads to excess Calcium… what are symptoms of excess Ca?

Answer 4

• Fatigue, weakness • Nausea, vomiting, constipation • Anorexia • Polyuria, polydipsia • Dehydration • Memory impairment • Drowsiness, confusion, coma

Question 5

Hypercalcemia is caused by an increase in PTH secretion, we see this in:

Answer 5

Primary hyperparathyroidism (usually a parathyroid adenoma)

Question 6

Hypercalcemia results in a suppression of PTH secretion; what are some causes

Answer 6

Vitamin D intoxication, Hypercalcemia of malignancy (caused by PTHrp)

Question 7

Hypercalcemia that is PTH Dependent is:

Answer 7

Primary hyperparathyroidism (PHPT)

Question 8

Some causes of Primary hyperPT

Answer 8

–Sporadic (single and multiple gland disease, carcinoma) – Multiple endocrine neoplasias (MENs) – will be discussed in a subsequent session – Hyperparathyroidism jaw tumor syndrome

Question 9

HOw do PTH secreating cells respond to high Ca++ in Primary HyperPT?

Answer 9

Decreased sensitivity of PTH-secreting cells to inhibition by plasma Ca++ and

Increased or “inappropriately not suppressed” serum PTH levels.

Question 10

What kind of Ca++ and Phosphate levels do we see in pts with Primary HyperPT?

Answer 10

Hypercalcemia (due to effects of PTH on bone resorption, calcium reabsorption, and increase in 1,25(OH)2D production in the kidneys).

• Hypophosphatemia due to phosphaturic effects of PTH in the proximal tubules.

Question 11

Some patients with PHPT are hypercalciuric despite PTHmediated increase in Ca++ reabsorption in the distal tubules because

Answer 11

the filtered load of calcium exceeds the Tm for reabsorption.

Question 12

Causes of Hypercalcemia PTH DEPENDENT

Answer 12

• Familial isolated hyperparathyroidism
• Familial hypocalciuric hypercalcemia (FHH)
• Ectopic PTH – RARE!

Question 13

• Asymptomatic, modest, lifelong hypercalcemia
• Hypocalciuria
• PTH not suppressed
• Autosomal dominant
• Surgery not indicated

Answer 13

Familial Hypocalciuric Hypercalcemia (FHH)

Question 14

Mutation seen in FHH

Answer 14

• CaSR (chromosome 3) (~2/3)

• Codominant - neonatal severe hyperparathyroidism

Question 15

Two findings in the bone you see with severe Primary Hyper Parathyroidism

Answer 15

Hyperpara osteitis: fibrous tissue in bone

Brown tumor: see lytic lesion anf ofteh multinucleated osteoclasts

Question 16

What does a scanning EM of the bone look like in pt with PHPT

Answer 16

see cortical bone is thinned out, controverys over wheter trabeculated bone is spared or not

Question 17

Causes of PTH-INDEPENDent Hypercalcemia

Answer 17

Malignancy

Calcitiro mediated; granulmos or inflammation

Yperthyroidism

milk alkali or calcium alkali syndrome

Question 18

Has – N-terminal homology with PTH, use in assays, found in high conc in normal tissue and key for fetal development

Answer 18

Parathyroid-Hormone-Related Peptide (PTHrP)

Question 19

Calcitriol (1,25[OH]2D)-Mediated Hypercalcemia can be caused by:

Answer 19

sarciod and lympohma

Question 20

Your pt has elevated Ca+ levels, what test do you order next?

Answer 20

Order PTH

Question 21

Hypercalcemic pt had PTH labs done, they have elevated PTH, what is our next step?

Answer 21

Most likely dx – primary hyperparathyroidism

Measure 24 hour urine calcium & creatinine to rule out FHH

Question 22

A primary process causing too much____ (primary hyperparathyroidism) will cause hypercalcemia [increased bone resorption and increased production of 1,25(OH)2D)].

Answer 22

PTH

Question 23

A process which raises the serum calcium independent of PTH (for example a tumor producing PTH related protein or lytic bone lesions) will suppress ____

Answer 23

PTH.

Question 24

Pt has Hypercalcemia and LOW PTH, what could be going on?

Answer 24

PTH independent HyperPT;

excess 1,25-D suggets cancer, sarcoid or hyperthyroidism

Question 25

How do you tx pt with Hypercalcemia?

Answer 25

IV fluids; normal saline

Loop diuretics; furosemide but waith till AFTER pt is rehydrated

Calcitonin

Bisphosphonates

Question 26

used to tx hypercalcemia, potently inhibit osteoclastic bone resorption.

Answer 26

Bisphosphonates

Question 27

A drug to tx hypercalcemia: see a rapid reduction in Ca2+ can occur. “Escape” from the hormone commonly occurs within several days. Calcitonin can lower serum calcium by 1-2 mg/dL

Answer 27

Calcitonin