Causes of Monoclonal Gammopathies
¾ Waldenstrom’s macroglobulinemia
¾ Benign idiopathic monoclonal gammopathy
¾ Collagen disorders, autoimmune diseases
¾ Neoplasms of colon, prostate, breast, female genital
¾ Myeloproliferative disorders-CML, polycythemia,
myelofibrosis, erythrimic myelosis, erythroleukemia,
¾ Aberrations in lipid metabolism
1. Low levels of albumin occur normally in all trimester’s
2. Bromosulfalein may cause a false elevation. Therefore,
a serum protein test should not be done within 48 hours
3. See appendix for complete listing of drugs that
interfere with total protein levels.
(Courtesy: Tulip Group of Companies)
For the determination of cholesterol in serum or plasma
(for in vitro diagnostic use only).
Cholesterol is the main lipid found in blood, bile and brain
tissues. It is the main lipid associated with arteriosclerotic
vascular diseases. It is required for the formation of
steroids and cellular membranes. The liver metabolizes
the cholesterol and it is transported in the blood
stream by lipoproteins. Increased levels are found in
hypercholesterolemia, hyperlipidemia, hypothyroidism,
uncontrolled diabetes, nephrotic syndrome, and cirrhosis.
Cholesterol esterase hydrolyzes esterified cholesterols to
free cholesterol. The free cholesterol is oxidised to form
hydrogen peroxide which further reacts with phenol and
4-aminoantipyrine by the catalytic action of peroxidase to
form a red colored quinoneimine dye complex. Intensity
of the color formed is directly proportional to the amount
of cholesterol present in the sample.
Cholesterol esters + H2O Cholesterol + Fatty acids
Cholesterol + O2 Cholestenone + H2O2
H2O2 + 4 Aminoantipyrine + Phenol Red
Serum/plasma (Suspicious) : 220 mg/dL and above
(Elevated) : 260 mg/dL and above
It is recommended that each laboratory establish its
own normal range representing its patient population.
L1: Enzyme reagent 1 2 × 60 mL 2 × 120 mL
L2: Enzyme reagent 2 2 ×15 mL 2 × 30 mL
S: Cholesterol standard (200 mg/dL) 5 mL 5 mL
Contents are stable at 2–8°C till the expiry mentioned on
Working reagent: Pour the contents of 1 bottle of L2
(Enzyme reagent 2) into 1 bottle of L1 (Enzyme reagent
1). This working reagent is stable for at least 8 weeks when
stored at 2–8°C. Upon storage the working reagent may
develop a slight pink color however, this does not affect the
performance of the reagent. Alternatively for flexibility as
much of working reagent may be made as and when desired
by mixing together 4 parts of L1 (Enzyme reagent 1) and
1 part of L2 (Enzyme reagent 2). Alternatively 0.8 mL of L1
and 0.2 mL of L2 may also be used instead of 1 mL of the
working reagent directly during the assay.
Serum, EDTA plasma. Cholesterol is reported to be stable
in the sample for 7 days when stored at 2–8°C. The sample
should preferably be of 12 to 14 hours fasting.
482 Concise Book of Medical Laboratory Technology: Methods and Interpretations Procedure
Wavelength/filter : 505 nm (Hg 546 nm)/green
Pipette into clean dry test tubes labeled as blank (B),
Cholesterol standard (S) - 0.01
Mix well and incubate at 37°C for 5 minutes or at RT (25°C)
for 15 minutes. Measure the absorbance of the standard
(Abs S), and test sample (Abs T) against the blank, within
Cholesterol in mg/dL = ________ × 200 Abs S
This procedure is linear upto 750 mg/dL. If the value
exceeds this limit, dilute the serum with normal saline
(NaCL 0.9%) and repeat the assay. Calculate the value
using the proper dilution factor.
Anticoagulants such as fluorides and oxalates result in
false low values. The test is not influenced by Hb values
upto 20 mg/dL and bilirubin upto 10 mg/dL.
Reaction : End point Interval : ...
Zero setting : Reagent blank Reagent
: 37°C / RT Standard : 200 mg/dL
Delay time : — React slope : Increasing
Read time : — Linearity : 750 mg/dL
20–24 124–218 3.21–5.64 122–216 3.16–5.59
25–29 133–244 3.44–6.32 128–222 3.32–5.75
30–34 138–254 3.57–6.58 130–230 3.37–5.96
35–39 146–270 3.78–6.99 140–242 3.63–6.27
40–44 151–268 3.91–6.94 147–252 3.81–6.53
45–49 158–276 4.09–7.15 152–265 3.94–6.86
50–54 158–277 4.09–7.17 162–285 4.20–7.38
55–59 156–276 4.04–7.15 172–300 4.45–7.77
60–64 159–276 4.12–7.15 172–297 4.45–7.69
65–69 158–274 4.09–7.10 171–303 4.43–7.85
> 70 144–265 3.73–6.86 173–280 4.48–7.25
Cord blood 44–103 1.14–2.66 50–108 1.29–2.79
< 4 114–203 2.95–5.25 112–200 2.90–5.18
5–9 121–203 3.13–5.25 126–205 3.26–5.30
10–14 119–202 3.08–5.23 124–201 3.21–5.20
15–19 113–197 2.93–5.10 119–200 3.08–5.18
High-density lipoprotein cholesterol (HDL)
20–24 30–63 0.78–1.63 33–79 0.85–2.04
25–29 31–63 0.80–1.63 37–83 0.96–2.15
30–34 28–63 0.72–1.63 36–77 0.93–1.99
35–39 29–62 0.75–1.60 34–82 0.88–2.12
40–44 27–67 0.70–1.73 34–88 0.88–2.28
45–49 30–64 0.78–1.66 34–87 0.88–2.25
50–54 28–63 0.72–1.63 37–92 0.96–2.38
55–59 28–71 0.72–1.84 37–91 0.96–2.35
60–64 30–74 0.78–1.91 38–92 0.98–2.38
65–69 30–75 0.78–1.94 35–96 0.91–2.48
> 70 31–75 0.80–1.94 33–92 0.85–2.38
Cord blood 6–53 0.16–1.37 13–56 0.34–1.45
5–9 38–75 0.98–1.94 36–73 0.93–1.89
10–14 37–74 0.96–1.91 37–70 0.96–1.81
15–19 30–63 0.78–1.63 35–74 0.91–1.91
Low-Density lipoprotein Cholesterol (LDL)
20–24 66–147 1.71–3.81 57–159 1.48–4.12
25–29 70–165 1.81–4.27 71–164 1.84–4.25
30–34 78–185 2.02–4.79 70–156 1.81–4.04
35–39 81–189 2.10–4.90 75–172 1.94–4.45
40–44 87–186 2.25–4.92 74–174 1.92–4.51
45–49 97–202 2.51–5.23 79–186 2.05–4.82
50–54 89–197 2.31–5.10 88–201 2.28–5.21
55–59 88–203 2.28–5.26 89–210 2.31–5.44
60–64 83–210 2.15–5.44 100–224 2.59–5.80
65–69 98–210 2.54–5.44 92–221 2.38–5.72
> 70 88–186 2.28–4.82 96–206 2.49–5.34
blood 20–56 0.52–1.45 21–58 0.54–1.50
5–9 63–129 1.63–3.34 68–140 1.76–3.63
10–14 64–133 1.66–3.44 68–136 1.76–3.52
15–19 62–130 1.61–3.37 59–137 1.53–3.55
1. Increased levels of cholesterol
a. Levels above 250 mg/dL are considered elevated
and call for a triglyceride test.
b. Conditions related to elevated cholesterol
1. Cardiovascular disease and atherosclerosis
2. Type II, familial hypercholesterolemia
3. Obstructive jaundice (also an increase in
4. Hypothyroidism (decreased in hyperthyroidism)
c. Free versus esterified cholesterol.
There is a markedly abnormal ratio of free to esterified
cholesterol in disease of the liver biliary tract,
infectious disease, and extreme cholesterolemia.
2. Decreased levels of cholesterol
a. Conditions where cholesterol is not absorbed
from the gastrointestinal tract
7. Drug therapy such as antibiotics.
b. Other disorders related to decreased cholesterol
5. Terminal stages of debilitating diseases such as
c. Esterol fraction decreases in liver diseases,
liver cell injury, malabsorption syndrome, and
3. Increased levels of cholesterol esters are associated
with familial deficiency of Lecithin—cholesterol
4. Decreased levels of cholesterol are associated with
liver disease. This is because persons with liver
diseases may have impaired formation of LCAT with
a resulting deficiency of the enzyme.
5. Cholesterol ester storage disease causes accumulation
of cholesterol esters in the tissues, but it has no effect
on the percentage of esterified cholesterol in the
6. The higher the cholesterol phospholipid ratio, the
greater the possible risk of developing atherosclerosis.
1. Cholesterol is normally slightly elevated in pregnancy.
2. Estrogen decreases plasma cholesterol and oophorectomy increases it.
3. Many drugs may cause a change in the blood cholesterol
1. Advise patient about fasting for a night for 12 hours
3. Before fasting, the patient should be on a normal diet
5. Lipid lowering drugs such as estrogen, oral contraceptives,
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