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262 Laboratory Medicine in Psychiatry and Behavioral Science
Triglycerides (continued)
Cross-references Cardiovascular Risk Assessment (Appendix C)
Lipid Panel
Metabolic Syndrome
Pancreatitis, Acute
Arnett DK, Blumenthal RS, Albert MA, et al: 2019 ACC/AHA Guideline on the Primary Prevention of
Cardiovascular Disease: a report of the American College of Cardiology/American Heart Association
Task Force on Clinical Practice Guidelines. Circulation 140(11):e596–e646, 2019
Brunzell JD: Clinical practice: hypertriglyceridemia. N Engl J Med 357:1009–1017, 2007
Fischbach FT, Fischbach MA: A Manual of Laboratory and Diagnostic Tests, 10th Edition. Philadelphia,
PA, Wolters Kluwer Health/Lippincott Williams and Wilkins, 2018
Lee Y, Siddiqui WJ: Cholesterol levels, in StatPearls. Treasure Island, FL, StatPearls Publishing, 2021.
Available from: https://www.statpearls.com/ArticleLibrary/viewarticle/19466
. Accessed Septem-
ber 2021.
Masana L, Correig E, Ibarretxe D, et al: Low HDL and high triglycerides predict COVID-19 severity. Sci
Rep 11(1):7217, 2021
Nordestgaard BG: A test in context: lipid profile, fasting versus nonfasting. J Am Coll Cardiol
70(13):1637–1646, 2017
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263 Laboratory Tests
Troponins
Type of test Blood
Background and explanation
of test
Troponins are proteins found in the heart and skeletal mus-
cle that regulate muscle contraction. Of three subtypes, only
troponin I and troponin T have cardiac-specific forms (ab
-
breviated as cTnI and cTnT); the form of troponin C is the
same in both the heart and skeletal muscle. With cardiac
muscle injury, cTnI and cTnT are released into the blood,
where they can be measured. Since 2017, high-sensitivity
tests for cTnI and cTnT have been available in the United
States, and these assays are now the tests of choice to diag
-
nose acute MI and other conditions. Most laboratories offer
one test or the other, and although they are not interchange
-
able, they reflect the same information about myocardial in-
jury. After an MI, the levels of these cardiac-specific
troponins are elevated within hours of heart injury and re
-
main elevated for 10–14 days. Serial measurements can help
distinguish MI from other conditions such as myocarditis
and cardiomyopathy.
Relevance to psychiatry and
behavioral science
These high-sensitivity tests for cTnI and cTnT can detect
very low serum troponin levels and small changes in levels
within a short time. Recent research has found the tests use
-
ful in predicting adverse cardiovascular events in patients
with arterial hypertension, pre-hypertension, and hyperten
-
sive crisis and in those with acute neurological injuries such
as ischemic stroke. The term stroke-heart syndrome has been
coined to emphasize the cardiac effects of stroke. Myocar
-
dial injury can also occur in other acute and severe neuro-
logical conditions involving the “brain-heart axis,”
including TBI, status epilepticus, intracerebral hemorrhage,
and subarachnoid hemorrhage. The utility of these tests in
psychiatric disease remains to be explored.
Indications •
Workup for chest pain
• Suspected MI
• New symptoms in patient with stable angina
• Evaluating the cardiac complications of acute stroke and
other acute neurological insults
• Evaluating the severity of myocardial injury from other
causes (e.g., COVID-19 infection)
•
Excluding myocardial injury in atypical chest pain syn-
dromes
Preparation of patient None needed
Reference range Depends on the particular assay and technique; see labora-
tory reference values.
Critical value(s) See laboratory reference values.
Increased levels • MI
•
Unstable angina
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264 Laboratory Medicine in Psychiatry and Behavioral Science
Troponins (continued)
Increased levels (continued) • Myocarditis
• Cardiomyopathy
• Congestive heart failure
• Stroke-heart syndrome and other acute neurological
conditions
Decreased levels Not applicable
Interfering factors Biotin may interfere with cTnT assay.
Patients with chronic renal failure may have elevated high-
sensitivity troponin levels (especially cTnT) in the absence
of myocardial injury. Patients with chronic skeletal muscle
injury (e.g., muscular dystrophy or chronic myositis) should
be evaluated with cTnI for the same reason. Serial testing of
these populations that show changing patterns may help
distinguish abnormalities due to these chronic diseases
from acute myocardial injury.
Cross-references Myocardial Infarction
American Association for Clinical Chemistry: Lab Tests Online. Available at: https://www.testing.com.
Accessed September 2021.
Azar RR, Sarkis A, Giannitsis E: A practical approach for the use of high-sensitivity cardiac troponin as-
says in the evaluation of patients with chest pain.Am J Cardiol 139:1–7, 2021
Bielecka-Dabrowa A, Cichocka-Radwan A, Lewek J, et al: Cardiac manifestations of COVID-19.Rev Car-
diovasc Med 22(2):365–371, 2021
Chaulin A: Clinical and diagnostic value of highly sensitive cardiac troponins in arterial hyperten-
sion.Vasc Health Risk Manag 7:431–443, 2021
Frame IJ, Joshi PH, Mwangi C, et al: Susceptibility of cardiac troponin assays to biotin interference.Am J
Clin Pathol 151(5):486–493, 2019
Mair J, Lindahl B, Müller C, et al: What to do when you question cardiac troponin values.Eur Heart J
Acute Cardiovasc Care 7(6):577–586, 2018
Scheitz JF, Stengl H, Nolte CH, et al: Neurological update: use of cardiac troponin in patients with stroke.
J Neurol 268(6):2284–2292, 2021
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265 Laboratory Tests
Tuberculosis (TB) testing
Type of test Skin test (Mantoux, also known as purified protein derivative
[PPD])
Blood test (IGRA)
Sputum smear/culture
Chest X-ray
CSF
Other body fluid or tissue samples, as indicated (e.g., biopsy
tissue, urine, joint aspirate)
Background and explanation
of test
Tests used to detect TB infection include the Mantoux test and
the IGRA. The latter is a blood test that measures immune
response to the presence of the TB bacillus. When the skin test
or one of the IGRA tests is positive, a workup for TB disease
is done, including a
medical
history, physical exam, chest X-
ray, and sputum sampling
for
acid-fast bacilli (AFB). Other
body fluids
and tissues are sampled as indicated.
For the Mantoux skin test, a small amount of PPD of TB anti-
gens is injected under the skin of the forearm. If the person
has been exposed to TB, antibodies will form an inflamma
-
tory skin reaction
that is assessed by a trained professional
48–72 hours later. Skin tests are used in preference to blood
tests for patients who have
received the bacillus Calmette-
Guérin (BCG) vaccine, and the IGRA
is used for those
who
are unable to return for a reading of the skin test.
When sputum is collected, a standard practice is to obtain
three morning samples on consecutive days. Each sample is
viewed immediately as a smear; if AFB are present on any
smear, a mycobacterial infection is likely. The sample is cul
-
tured to identify the mycobacterium, and its sensitivity to
various drugs is determined. Positive identification of a spe
-
cies may take days to weeks, and negative results of no my-
cobacterial growth may take up to 8 weeks. In patients treated
for TB, AFB cultures can be used to monitor the effectiveness
of treatment and to determine when the disease is no longer
communicable.
Relevance to psychiatry and
behavioral science
TB is a considerable public health risk for certain populations,
including the homeless and those in nursing homes or correc-
tional facilities. Elderly, very young, and immunocompro-
mised patients are at particular risk. The index of suspicion
for TB should be high in all psychiatric settings.
Preparation of patient None needed
Indications •
Exposure to a person with active TB disease
• HIV-positive or otherwise immunocompromised
patient
• Symptoms of active
TB disease: persistent cough, spu-
tum or phlegm (may be blood-tinged), unexplained
weight loss, night sweats
• Recent immigration from country where TB is endemic
• Residence in long-term care facility
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266 Laboratory Medicine in Psychiatry and Behavioral Science
Tuberculosis (TB) testing (continued)
Indications (continued) • Homelessness
• Residence in correctional facility
• IV drug use
Reference range <10-mm area of induration on TB skin testing
For IGRAs (blood tests), see r eport form.
Sputum samples negative for AFB
Chest X-ray negative f or TB
Other tissue/fluid samples negative for AFB
Critical value(s) None
Positive test TB infection indicated by positive skin test or blood test(s).
TB disease indicated by positive chest X-ray or presence of
AFB in sputum or other tissue.
Negative test When AFB culture is negative in a patient suspected of hav-
ing TB, either the patient does not have mycobacterial infec-
tion, the sampling did not successfully capture the bacilli, or
the organism is present in some other body tissue. A nega-
tive culture several weeks after treatment indicates a posi-
tive response to treatment; in this case, the patient’s
infection is no longer communicable.
Interfering factors IGRA tests require viable WBCs, so the blood sample must
be refrigerated and sent to
the lab on the same day.
Several conditions decrease responsiveness to TB skin and
blood tests: diabetes, silicosis, chronic renal failure, leuke-
mia, and lymphoma. Treatment with immunosuppressive
drugs also decreases responsiveness to TB skin test.
Cross-references Tuberculosis
American Association for Clinical Chemistry: Testing.com. Available at: https://www.testing.com. Ac-
cessed September 2021.
ARUP Consult: Mycobacterium tuberculosis—tuberculosis, in ARUP Consult: The Physician’s Guide to
Laboratory Test Selection and Interpretation. Salt Lake City, UT, ARUP Laboratories, 2020. Available
at: https://arupconsult.com/content/mycobacterium-tuberculosis. Accessed September 2021.
Carranza C, Pedraza-Sanchez S, de Oyarzabal-Mendez E, Torres M: Diagnosis for latent tuberculosis in-
fection: new alternatives. Front Immunol 11:2006, 2020
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267 Laboratory Tests
Uric acid
Type of test Blood
Background and explanation
of test
Uric acid is produced by the degradation of injured and dy-
ing cells and the breakdown of dietary purines. Most is ex-
creted by the kidneys and the remainder through the GI
tract. Blood levels of uric acid can be elevated because of
overproduction (e.g., with gout or leukemia) or underexcre
-
tion (e.g., with renal impairment). High uric acid levels are
associated not only with gout but also with cardiovascular
and cerebrovascular disease, hypertension, type 2 diabetes,
chronic kidney disease, and the metabolic syndrome.
Relevance to psychiatry and
behavioral science
Uric acid may be elevated in patients with alcohol use dis-
order. High levels are associated with heart attack, stroke,
and vascular dementia. High levels likely have a role in the
development of the metabolic syndrome, possibly because
of proinflammatory and pro-oxidative effects.
Preparation of patient Ideally, patients should fast for 8 hours and avoid strenuous
exercise before testing.
Indications • Suspected gout
• Workup for recurrent kidney stones
• Evaluating renal dysfunction
• Monitoring effects of cytotoxic therapy (chemotherapy
or radiation)
Reference range Adult males: ≤7 mg/dL
Adult females:
≤6 mg/dL
Levels are based on the saturation point of uric acid used
in
gout management.
Dose-dependent inflammatory action of uric acid occurs
with levels >4 mg/dL.
Critical value(s) > 12 mg/dL
Increased levels • Gout
• Leukemia, lymphoma, multiple myeloma
• Hemolytic anemia, sickle cell anemia
• Polycythemia vera
• Psoriasis
• Cytotoxic therapy (e.g., chemotherapy, radiation)
• Starvation, anorexia nervosa, severe dieting
• Renal failure
• Excessive alcohol consumption
• Liver disease
• Hyperlipidemia, obesity, metabolic syndrome
• Metabolic acidosis, diabetic ketoacidosis
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268 Laboratory Medicine in Psychiatry and Behavioral Science
Uric acid (continued)
Increased levels (continued) • Pernicious anemia
• Kidney stones
• Lead poisoning
• Purine-rich diet (enriched with red meat, seafood)
• Drugs: diuretics, β-blockers, low-dose aspirin
Decreased levels • Fanconi syndrome
• Wilson’s disease
• SIAD
• Low-purine diet
• Certain malignancies (e.g., Hodgkin’s disease, broncho-
genic carcinoma)
• Xanthinuria
Interfering factors High levels of stress and strenuous exercise cause increased
uric acid levels.
Cross-references Alcohol Use Disorder
American Association for Clinical Chemistry: Testing.com. Available at: https://www.testing.com. Ac-
cessed September 2021.
Borghi C, Agabiti-Rosei E, Johnson RJ, et al: Hyperuricaemia and gout in cardiovascular, metabolic and
kidney disease. Eur J Intern Med 80:1–11, 2020
Cortese F, Scicchitano P, Cortese AM, et al: Uric acid in metabolic and cerebrovascular disorders: a re-
view. Curr Vasc Pharmacol 18(6):610–618, 2020
Fischbach FT, Fischbach MA: A Manual of Laboratory and Diagnostic Tests, 10th Edition. Philadelphia,
PA, Wolters Kluwer Health/Lippincott Williams and Wilkins, 2018
Kaul S, Gupta M, Bandyopadhyay D, et al: Gout pharmacotherapy in cardiovascular diseases: a review
of utility and outcomes. Am J Cardiovasc Drugs 21(5):499–512, 2021
Lohr JW, Batuman V: Hyperuricemia. Medscape, July 1, 2022. Available at:
https://
emedicine.medscape.com/article/241767-overview. Accessed September
2021.
Maloberti A, Giannattasio C, Bombelli M, et al: Hyperuricemia and risk of cardiovascular outcomes: the
experience of the URRAH (Uric Acid Right for Heart Health) Project.High Blood Press Cardiovasc
Prev 27(2):121–128, 2020
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269 Laboratory Tests
Urinalysis
Type of test Urine
Background and explanation
of test
Urinalysis is a basic laboratory test most often used to eval-
uate urinary tract infection (UTI) or kidney dysfunction.
Findings can also indicate glucose dysregulation, liver prob
-
lems, and other conditions. A complete urinalysis reports
the following characteristics of urine: color, appearance, spe
-
cific gravity, pH, glucose, ketones, blood, protein, bilirubin,
urobilinogen, nitrite, leukocyte esterase, and the results of a
microscopic exam. The microscopic exam detects RBCs,
WBCs, casts, crystals, and epithelial cells.
Physical characteristics of the specimen are first noted,
chemical tests are performed, and finally the specimen is ex
-
amined microscopically. The first two steps can be done us-
ing a dipstick and automated methods, which makes this
test quick and inexpensive. A urinalysis is often a standard
component of the hospital admission workup or presurgical
evaluation.
Relevance to psychiatry and Urinalysis is a routine component of the workup for mental
behavioral science status changes, particularly in elderly patients in nursing
homes or hospital settings. UTIs can be associated with de
-
lirium, even in the absence of sepsis.
Preparation of patient A first morning urine specimen may be requested because it
is more concentrated and thus more likely to show abnor-
malities. If a random sample is used, it should be collected
≥4 hours after last voiding to ensure adequate contact time
between bacteria and nitrates. Practice varies as to the
amount collected; some labs request a 30–60 mL sample,
whereas others request only 10 mL.
If a midstream, clean-catch sample is requested, antibacte-
rial wipes should be used to clean the area between the labia
or around the meatus of the penis. A small amount of urine
is voided to the toilet, then urine is captured in the container
provided. Medications must be noted on the urinalysis re
-
quest form to aid in crystal identification by the laboratory.
Indications • Routine component of workup for hospital admission or
preoperative surgical evaluation
• Symptoms of UTI: irritation, burning, pain, change in
frequency, or change in appearance of urine
•
•
Symptoms in elderly patients: fever, dysuria, inconti-
nence, urgency, or change in frequency
Symptoms in catheterized patients: fever, rigors, vomit
ing, confusion, or costovertebral angle tenderness
-
• Suspected pyelonephritis or kidney dysfunction
• Screening for asymptomatic bacteriuria in pregnancy (at
first antenatal visit)
Reference range Color: pale yellow to amber
Appearance: clear to slightly hazy
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270 Laboratory Medicine in Psychiatry and Behavioral Science
Urinalysis (continued)
Reference range (continued) Specific gravity: 1.002–1.035;
pH: 4.5–8.0
Negative for glucose, ketones, blood, protein, bilirubin, uro-
bilinogen, nitrite, and leukocyte esterase. Negative for casts
or occasional hyaline. Negative or rare for RBCs. Negative
for crystals. Negative or rare for WBCs. Few epithelial cells.
Critical value(s) See entries for urinalysis components.
Increased levels See entries for urinalysis components.
Decreased levels See entries for urinalysis components.
Interfering factors Improper specimen handling invalidates the results. Urine
must be examined within 1 hour of collection or refrigerated
immediately and examined within 24 hours. If the first
morning specimen is not used, inadequate contact time can
yield a false-negative nitrite test. Even with clean-catch
specimens, feces, vaginal discharge, or menstrual blood can
contaminate the specimen.
Cross-references See entries for urinalysis components.
Urinary Tract Infection
American Association for Clinical Chemistry: Testing.com. Available at: https://www.testing.com. Ac-
cessed October 2021.
Fischbach FT, Fischbach MA: A Manual of Laboratory and Diagnostic Tests, 10th Edition. Philadelphia,
PA, Wolters Kluwer Health/Lippincott Williams and Wilkins, 2018
Simerville JA, Maxted WC, Pahira JJ: Urinalysis: a comprehensive review. Am Fam Physician 71:1153–
1162, 2005
https://t.me/med1917
271 Laboratory Tests
Urine appearance
Type of test Component of routine urinalysis
Background and explanation
of test
Appearance refers to the observed clarity of the specimen.
Relevance to psychiatry and
behavioral science
See Urinalysis.
Preparation of patient See Urinalysis.
Indications See Urinalysis.
Reference range Normally, fresh urine is clear to slightly hazy.
Abnormal test • Range: hazy→slightly cloudy→cloudy→turbid→milky
• Abnormal urine is often turbid or cloudy. These findings
can indicate the presence of urinary tract infection.
Interfering factors After a meal, normal urine can appear cloudy if allowed to
stand, due to the presence of urates, carbonates, and phos-
phates.
Vaginal discharge, semen, and fecal material all cause tur -
bidity in urine.
Skin cream, vaginal cream, talcum powder, and radio-
graphic contrast dye may cause turbidity.
Greasy turbidity can be seen with large amounts of fat in
urine.
Normal urine can develop haziness or turbidity after stand-
ing (even with refrigeration) due to precipitation of calcium
oxalate or urate crystals.
Cross-references Urinalysis
American Association for Clinical Chemistry: Testing.com. Available at: https://www.testing.com. Ac-
cessed October 2021.
Fischbach FT, Fischbach MA: A Manual of Laboratory and Diagnostic Tests, 10th Edition. Philadelphia,
PA, Wolters Kluwer Health/Lippincott Williams and Wilkins, 2018
Simerville JA, Maxted WC, Pahira JJ: Urinalysis: a comprehensive review. Am Fam Physician 71:1153–
1162, 2005
https://t.me/med1917
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