PSA and Thyroid Hormones Flashcards
(40 cards)
1
Q
Region Specific Prostate Pathologies
(2)
A
BPH - 90% of cases develop in transition zone
Prostate cancer - 70% of cases develop in peripheral zone
2
Q
Major Prostate Gland Disorders
(3)
A
- Benign prostatic hyperplasia (BPH)
- Prostatitis
- Prostate cancer (ex - prostatic adenocarcinoma)
3
Q
Prostate Cancer Epidemiology
A
- Most commonly diagnosed solid tumor
- Second-most common cause of death due to malignancy in US males
- 233,000 projected new cases and 29,400 projected deaths in 2014
4
Q
American Urological Society Clinical Staging - Prostate Cancer
A
5
Q
PSA Structure and Prdctn
A
- **Structure: **Glycoprotein, functions as serine protease in the kallikrein amily (also hk3)
- Produced by epithelial cells in prostatic acini and ducts, secreted into seminal fluid
6
Q
PSA Synthesis
A
Note - some labs allow you to order any of these trunchated or native forms
7
Q
PSA-Containing Fluids
(7)
A
- Semen
- Male serum
- Amniotic fluid
- Breast milk
- Saliva
- Female urine
- Female serum
8
Q
Serum PSA Forms
(2, 1 c 3 specifics, include relative amounts)
A
- Free, unbound form (~ <30%)
- Bound to serine protease inhibitors (~ >70%)
- α1-antichymotrypsin (ACT)
- α2- macroglobulin (A2M)
- α1-protease inhibitor (API) - 0.5-2%
Note - you can test either of these
9
Q
PSA Evaluations to Dec. Biopsy Incidence
(3)
A
- PSA density – is an adjustment that divides the PSA measurement by the gland volume.
- fPSA/total PSA or tPSA ratio
- PSA velocity – monitors the change in PSA with time.
- Greater than 0.75 ng/mL per year is suggestive of cancer
10
Q
PSA Assays
(3)
A
- tPSA - measures free and complex forms, primarily ACT
- Free PSA
- Complex PSA - rarely used
11
Q
Conventional PSA Level Indicating “Low Risk” for Cancer
A
tPSA < 4.0 ng/ml
12
Q
PSA Level and Cancer Risk
A
- 2.6 ng/ml for low risk
- 4 – 10 ng/ml represents diagnostic gray zone
- > 10 ng/ml greater likelihood of cancer
Note - Mayo Clinic has its own system, attached
13
Q
Prostate Cancer Risk Factors
(3)
A
- Black race
- Family hx
- High fat/low vegetable diet
14
Q
Prostate Cancer Prevention
A
Annual PSA and DRE after age of 50 (40 if high risk)
15
Q
Prostate Cancer Clinical Presentaiton
A
- Most common is asymptomatic elevation in PSA
- DRE findings of asymmetric indurations (hardening) or nodules are suggestive.
- Less common are obstructive symptoms, new onset ED, hematuria or hematospermia
16
Q
%fPSA
(define, calculation)
A
Free-to-Total PSA ratio
Calculation:
fPSA/tPSA x 100 = %fPSA
*Note - the lab will do this for you *
17
Q
%fPSA Interpretation
A
- Men without PCa have a higher ratio (>25%) of free to tPSA
- %fPSA of < 25% detected 95% of PCa when tPSA is between 4 – 10 ng/ml.
- 20% of patients with tPSA between 2.6 – 4.0 ng/ml have significant PCa. Using a cutoff of 27% fPSA detected 90% of cancers.
*Note - good dx tool but there are a lot of assumptions associated c it *
18
Q
Age Adjusted PSA Ranges, Caucasian Males
A
0-2.5 aged 40-49 years
0-3.5 aged 50-59 years
0-4.5 aged 60-69 years
0-6.5 aged 70-79 years
Specificty of these adjustments = 95%
19
Q
Age Adjusted PSA Ranges, Black Males
A
0-2 for men aged 40-49 years
0-4 for men aged 50-59 years
0-4.5 for men aged 60-69 years
0-5.5 for men aged 70-79 years
*Specificity ranges from 78% in older men - 93% in younger men *
20
Q
PSA Screening Requirement
A
after they receive information about the uncertainties, risks, and potential benefits associated with prostate cancer screening
21
Q
PSA Assay Labels
(2)
A
- Chemiluminescent labels
- Fluorescent labels
*Note - these do not include the high (analytical) sensitivity (hs) assays that are used for extenuating circumstances *
22
Q
Prostate Cancer Tx
A
- Early stage disease
- Radical prostatectomy
- External beam radiation
- Brachytherapy (use of radioactive implants at the treatment site)
- Locally advance disease
- Can be treated with a combination of surgical, radiation, and hormonal therapy.
- Metastatic disease
- Is incurable but and can be managed with hormonal therapy for 2-10 years
23
Q
Thyroid Gland Structure
A
Gross Structure
- 2 lobes
- thin connecting isthmus
Functional Components
- Follicles - secretory units
- Colloid - amorphous material composed of thyroglobulin and iodinated thyroalbumin
- Parafollicular/C cells - calcitonin
24
Q
Thyroid Hormones
(list and describe 2)
A
- Hormones - T3 and T4*
- T3: biologically active thyroid hormone
- States in Circulation *
- Bound
- Thyroxin binding globulin (TBG)
- Thyroxin binding pre-albumin (TBPA)
- Albumin
- Free - correlates c functional thyroid state
- T3: 0.2 - 0.4%
- T4: 0.03%
25
Free Thyroid Hormones Functions
| (3)
1. Regulate normal growth and development by maintaining body temperature and stimulating calorigenesis
2. Affect carbohydrate, lipid and vitamin metabolism
3. Fetal and neonatal development
26
Total T4, TT4 (3,5,3',3',5'-tetraiodothyrodine)
(values, 4 clinical uses, varying factors)
Values
* Adult = 5-12 microgram/dL
* Cricital value \<2, may cause myxedema coma
* \> 20 may mean thyroid storm (untreated hyperthyroidism)
Clinical Uses
* **Confirm abnormal TSH results (should be opposite)**
* Dx hyperthyroidism
* Dx primary and secondary hypothyroidism
* Monitor TSH-suppression therapy
Variance
* Presence of carrier proteins, measured by T3 resin uptake test
27
Newborn Thyroid Screening Procedure
| (3 steps, medical emergencies)
Procedure
1. The hypothyroid screening procedure initially tests for T4.
2. Specimens with T4 values in the lowest ten percentile are retested for T4 and additionally for TSH.
3. Specimens with T4 below 2 standard deviations of the assay batch are retested for T4 as well as tested for TSH.
Medical Emergencies:
* T4 in the bottom tenth percentile and a TSH level ≥ 30 μU/ml for infants more than 24 hours of age at the time of specimen collection.
* T4 in the bottom tenth percentile and a TSH level ≥ 50 μU/ml for infants less than 24 hours of age at time of specimen collection.
28
False TT4 Elevations
| (2 categories, 1 c 3 specifics)
1. Patient has undergone iodinated contrast x-ray studies (if a RIA method is used)
2. Patient taking certain drugs:
* Patients with **increased TBG** due to:
1. Estrogens
2. Oral contraceptives
* Heroin, amphetamines
* Methadone
29
False TT4 Decreases
| (6)
Drug-related:
1. Anabolic steroids
2. Propylthiouracil
3. Barbiturates
4. Furosemide
5. NSAIDs
6. Androgens
30
Total T3 (3,5,3'-triiodothyronine)
(biological function, clinical usefulness, normal adult values)
_Function_: responsible for development of effects of thyroid hormone on various target organ. **Major biologically active thyroid hormone**
_Clinical Uses_:
1. Dx thyroid hormone imbalance (hyperthyroid\>hypothyroid)
2. Monitor thyroid replacement/suppression
_Normal Range_: 70-205 ng/dL
*_Note_ - Not frequently ordered. Only indicated to "referee" unmatching values*
31
False T3 Increase
| (3)
1. Radioisotope administration, if RIA assay is used
2. Pregnancy (serum protein increase)
3. Drugs
* Estrogen
* OCP
* Methodone
32
False T3 Decreases
| (6)
1. Radioisotope admin c RIA assay
2. Anabolic steroids
3. Androgens
4. Phenytoin
5. Propranolol (Inderal)
6. Salicylate (high doses)
33
Free T4 (FT4)
| (indications, results, normal ranges)
_Indications_ - changes in thyroid hormone binding proteins that make TT4 inaccurate
1. Estrogen-containing preparations
2. Pregnancy
3. Nephritic Syndrome
_Results_:
* High - hyperthyroidism
* Low - hypothyroidism
_Normal Ranges_: 0.9-1.7 ng/dL
*This is a common test!*
34
False Elevations, FT4
| (2, 1 c 3 specifics)
1. Exogenous T4 admin
2. Drugs
* Heparin
* Asprin
* Propanolol
35
False FT4 Decreases
| (3)
1. Furosemide
2. Phenytoin
3. Methadone
36
Free Thyroxine Index (FTI, FT4I)
| (3 Indications, calculation)
_Indications_:
1. Evaluate thryoid function
2. Correct for changes in thyroid hormone binding serum proteins that can affect total T4
3. Diagnose thyroid funciton imbalance (hyper/hypothyroidism)
_Calculation_: See attached, where THBR = thyroid hormone binding ratio
37
FT3
| (3 clinical indications, normal ranges)
_Indications_:
* Diagnosing T3 toxicosis (excess amount of T3 is secreted) – a synonym for hyperthyroidism.
* Determining the response to therapy
* Differentiate early progression of subclinical hyperthyroidism to overt thyrotoxicosis when FT4 is normal and TSH is suppressed. FT3 is usually increased first!
_Normal Ranges_: 200-400 pg/dL (2.0-400 pg/mL)
38
TSH (also Thyrotropin)
(Structure, Indication, Results Interpretation)
_Structure_: 30 kDa glycoprotein c 2 alpha and 2 beta units
* Alpha - same structure as LH, FSH, and hCG
* Beta - **confers specificity **
_Indication_: Initial test in thyroid dx for many clinicians
* sensitive and specific parameter for reassessing thyroid fctn (very slight FT3 or FT4 are exaggerated in this test)
* Detect primary hypothyroidism in newborns c low TT4
_Results_:
* Increased
* **Primary hypothyroidism**
* Thyroiditis
* Decreased
* Secondary hypothyroidism (pituitary or hypthalamus dysfunction)
* Primary hyperthyroidis
* Exogenous thyroid hormone therapy
* Grave's disease - treated
* Euthyroid sick syndrome
39
Additional Thyroid Tests
| (4)
* Thyroglobulin
* Thyroglobulin antibody
* Thyroxin binding globulin (TBG)
* Thyroperoxidase (TPO) antibodies
40
Don't forget to do the case studies in the PPT!!
Do them, you know you should
