Laboratory Medicine Updates - June 7, 2005

University of Virginia Health System

Medical Laboratories

“Quality You Expect, Service You Deserve”

 

LABORATORY MEDICINE UPDATE

June 7, 2005

 

Core, Clinical Microbiology, and Molecular Diagnostics Laboratories Move

The Core, Microbiology, and Molecular Diagnostics Laboratories are scheduled to move into the newly constructed Main Street Laboratory facility over the weekend of June 11-12.  Following the move, specimens sent to the Clinical Laboratories via pneumatic tube will automatically be re-routed to the new facility.  Messenger delivery of specimens that cannot be transported by pneumatic tube will continue as before.  Laboratory results will be reported electronically in the usual fashion.  Telephone queries to the laboratories should still be directed to the 4-LABS (924-5227) telephone number.   All phone and fax numbers will remain the same.

Every attempt has been made in planning this move to minimize disruptions to laboratory services.  Assuming that the move proceeds as planned, it should be virtually invisible to users of laboratory services.  In case of problems, chief residents on each clinical service will be contacted and contingency plans implemented.

Concurrent with this laboratory move, the Clinical Laboratories will begin using new instruments for chemistry/immunoassay testing.  Methodologies for a few tests will give considerably different results than the current assays.  These are presented below in separate, more-detailed paragraphs.  Some of the new assays may have slightly different reference intervals from those currently in use.  Changes to reference intervals are detailed in the Table below and will become effective on June 13 at 12:01 am at the same time the instrumentation is placed into service.

Major Reference Interval Changes

Please note the following:

Troponin – Troponin results reported by the new analyzer will be approximately half the concentrations of results currently being reported.  However the new assay will be more sensitive (a lower limit of detection approximately equal to 0.01 ng/mL) and its results will be more precise in the lower concentration ranges (<0.10 ng/mL).  The upper limit of the reference interval for the new assay (0.02 ng/mL) is the 99th percentile of the healthy population in line with recent recommendations of the American College of Cardiology and the European Society of Cardiology.

Ferritin – The new instrumentation provides significantly lower absolute values for Ferritin.  The new reference intervals are Males: 20-250 ng/mL and Females: 10-120 ng/mL.

T-Uptake – The new analyzer measures the total binding capacity present in the sample rather than the %T3-Uptake.  Thus, rather than reporting results as percent, the new test will report in “Units” representing T-Uptake Units.  When this test is ordered with the Total T4, the Free Thyroxin Index (FTI) can be calculated using the following formula:

FTI = (Total T4)/T-Uptake Unit

Free T4 – The new instrumentation provides results that are approximately 25 percent lower than the current analyzer.  As a result, the new reference interval will be 0.70 to 1.50 ng/dL (based on analysis of 411 controls patients with normal thyroid function).

Salicylate – With the new instrumentation, the reporting units for Salicylate will change from mg/dL to mg/L.  This will result in numbers with an absolute value of one-tenth the previous (50 would become 5).  Reference intervals will be appropriately modified in all computer systems and on patient reports

Percent Free PSA

The new chemistry instrumentation will allow the UVa Core Laboratory to offer testing for Free PSA as an in-house test.  Ordering this test will result in an initial Total PSA determination.  If the result is between 4 and 10 ng/mL, a Free PSA determination and a calculation for % Free PSA will be performed and reported.  If the Total PSA is outside of this range, the request for Free PSA will be cancelled as current data suggest the diagnostic utility of this test is limited to this range.

PSA

Results by the new assay compare much more favorably with the Hybritech Tandem-R assay (upon which most of the currently used PSA screening limits are based)*.  Thus the new results will be higher than the PSA results obtained with our current analyzer.  Analysis of 64 patient samples in parallel on the two analyzers suggest that values from the Abbott analyzer will be approximately 1.3 times as high as the current analyzer due to differences in calibration between the two manufacturers.

The detection limit for the Architect total PSA assay is 0.05 µg/L compared to the current assay limit of 0.06 µg/L.

As with all markers of tumor recurrence, the current instrument will remain operational for a period of time following our move to allow re-baselining any prostatectomized patients.  Requests for such duplicate testing (at no charge to the patient) should be made on the outpatient test request form.

*Sokoll, et al.  Differences in Free PSA and Total PSA Results Based on Multiple Method Comparison.  Presented at 53rd Annual Meeting, AACC/CSCC, 2001

Tube-Type Changes

Concurrent with the instrumentation changes, only the following tube types will be acceptable for certain tests:

Gold-Top Tubes: LH, PSA, Free PSA, TSH, and FreeT4

Red-Top Tubes: Total T3

Purple-Top TubesCEA


Serum/Plasma Reference Intervals

Olympus/Centaur to Architect/AxSym change 2005

 

Analyte(units)

Current Reference Interval

New Reference Interval

Albumin(g/dL)

3.5-5.7

3.5 – 5.0

Alk Phos(U/L)

34-100

40-150

ALT(U/L)

9-61

<55

Amylase(U/L)

29-103

25-125

AST(U/L)

13-39

<35

Conj. Bilirubin (mg/dL)

Neonate: 0-0.6

Adult: 0-0.3

0.0-0.5 (all ages)

Calcium(mg/dL)

8.5-10.5

8.4 – 10.0

CEA(ng/mL)

<5.0

No change

Cholesterol (mg/dL)

Male Female

0-19Y: <170           0-19Y: <175

>20Y: <200            20-29Y: <195

>30Y: <200

No change

CK(U/L)

32-237

Male:              Female:

30-200             30-170

CK-MB(ng/mL)

<5

Male:              Female:

<7.2                <3.4

Cl(mmol/L)

98-107

No change

CO2(mmol/L)

Newborn: 13-22

Child: 18-27

Adult: 19-27

0-30d: 13-22

30d-18Y: 20-28

18Y-60Y: 22-29

>60Y: 23-31

Cortisol(µg/dL)

Normal AM: 5-18

Normal PM: 2-9

Dex suppression: <4

Cortrosyn Stimulation: >18

Critical value: <3

No Change

Creatinine(mg/dL)

Male:                          Female

0.7-1.3                        0.6-1.2

Male:              Female:

0.7-1.3            0.6-1.1

Estradiol(pg/mL)

Male                           Female

prepubertal:<20  prepubertal:<30

Adult: ND-56      Early Foll:30-65

Mid-foll: 30-130

Late-foll/midcycle: 50-320

Early lut: 20-100

Mid-lut: 30-200

Late lut: 20-160

Postmenop: ND-30

Male               Female

11-44        Pre-pubertal: <20

Foll: 21-251

Mid-cycle: 38-649

Luteal: 21-312

Postmenop: <10-28

On HRT: <10-144

Ferritin(ng/mL)

Male:              Female

18-311             9-204

Male:              Female

20-250             10-120

Free PSA(ng/mL)

 

% free: >25%

Free T3(pg/mL)

2.3-4.2

No change

Free T4(ng/dL)

0.8-1.8

0.7-1.5

FSH(mIU/mL)

Male                           Female

pre-pub: <9.0        pre-pub: <9.0

13-70Y:0.9-15.0  Foll: 1.1-9.6

>70:2.8-55.5        Mid-Cy: 2.3-20.9

Lut: 0.8-7.5

Postmenop:34.4-95.8

No change

GGT(U/L)

9-64

Male:              Female:

<55                 <38

Glucose(mg/dL)

0-13Y: 60-100

>14Y: 74-100

No change

Haptoglobin(mg/dL)

16-200

<12Y: 20-160

>12Y: 30-200

hCG(U/L)

<10.0

<5.0

HDL(mg/dL)

Male:                          Female:

0-19Y: 30-65          0-19Y: 30-70

20-29Y: 35-70       20-29Y: 35-75

>30Y: 30-65          30-39Y: 35-80

40-49Y: 40-95

>50Y: 35-85

No change

Iron(µg/dL)

Male:                          Female

0-1Y: 40-100        0-1Y: 40-100

1-11Y: 50-120      1-11Y: 50-120

>11: 50-160          >11Y: 40-150

Toxic: >300

Male               Female

30-145             25-160

 

 

Toxic: >300

K(mmol/L)

3.5-5.0

Male               Female

3.5-4.5             3.4-4.4

Lactate(mmol/L)

0.7-2.1

0.5-2.2

LDH(U/L)

140-271

180-360

Lipase(U/L)

11-82

8-78

LH(mIU/mL)

Male                           Female

pre-pub: <6.0       pre-pub: <6.0

20-70Y: 1.5-9.3   Foll: 1.9-12.5

>70: 3.1-34.6       Mid-Cyc:8.7-76.3

Lut : 0.5-16.9

Postmenop:5.0-52.3

No change

Mg(mg/dL)

1.9-2.7

1.6-2.6

Na(mmol/L)

135-145

136-145

NH3(µmol/L)

11-35

11-32

Phos(mg/dL)

Child: 4.0-7.0

Adult: 2.5-5.0

0-6d: 4.5-9.0

7d-24m 4.5-6.7

24m-12y 4.5-5.5

12Y-18Y: 2.3-4.7

­>19Y: 2.3-4.7

Progesterone(ng/mL)

 

Male Female

ND-0.6             early/mid Fol:0.2-1.1

Lat foll/Mid:  0.2-1.7

Early lut: 0.4-14

Mid lut: 4.5-20

Lat lut: 1.0-14

Postmenop: ND-0.7

 

1st trim : 8.1-42

2nd trim : 15.2-130

3rd trim : 49.1-227

Male Female

<0.2      early/mid Fol:0.2-1.1

Lat foll/Mid:  0.2-1.7

Early lut: 0.4-14

Mid lut: 4.5-20

Lat lut: 1.0-14

Postmenop: <0.2

 

1st trim : 8.1-42

2nd trim : 15.2-130

3rd trim : 49.1-227

Prolactin(ng/mL)

<20

No change

PSA(ng/mL)

Male                           Female:

<40Y: <4.0                  <4.0

40-50Y: <2.5

50-60Y: <3.5

60-70Y: <4.5

>70Y: <6.5

No change

T Uptake

23-37

0.69-1.41 T Uptake units

Total Bilirubin(mg/dL)

Newborn: <12.9

Adult:0.3-1.2

No change

Total Protein(g/dL)

6.0-8.3

0-6d: 4.6-7.0

7d-<7M: 4.4-7.6

7M-12M: 5.1-7.3

1Y-2Y: 5.6-7.5

>3Y-18Y: 6.0-8.0

18Y-60Y: 6.0-8.3

>60Y: 5.8-6.1

Total T3(ng/dL)

60-180

58-159

Total T4(µg/dL)

4.5-10.9

4.9 – 11.7

Transferrin(mg/dL)

213-360

Male:              Female <60Y:190-315  <60Y: 200-340

>60Y: 130-315 >60Y: 140-330

Triglycerides(mg/dL)

Male:                          Female:

0-19:  30-140              30-140

20-29: 45-250             40-170

30-39:  50-320                        40-195

40-49: 55-320             45-230

50-59: 60-300             55-250

>60: 55-260                 60-240

No change

Troponin I(ng/mL)

<0.1

<0.02

TSH(mU/L)

0.45-4.50

No change

Urea(mg/dL)

7-25

<3Y: 5-17

4-13Y: 7.0-17

14-18Y: 8-21

Male Female

19-<50Y: 8.9-20.6      7.0-18.7

>50Y: 8.4-25.7            9.8-20.1

Uric Acid(mg/dL)

3.3-8.7

Male:              Female

3.5-7.2             2.6-6.0

 

 

Analyte

Current Reference Interval

New Reference Interval

Na - Spot

Diet Dependent

No change

Na – 24 Hr

Diet Dependent

40-290 mmol/24 Hr

K - Spot

Diet Dependent

No change

K – 24 Hr

Diet Dependent

25-125 mmol/24 hr

Mg- Spot

Diet Dependent

No change

Mg – 24 Hr

Diet Dependent

6.0-10.0 mg/24 Hr

Phos - Spot

Diet Dependent

No change

Phos – 24 Hr

Diet Dependent

0.1-1.3g/24 Hr

Uric Acid - spot

Diet Dependent

No change

Uric Acid – 24 Hr

Diet Dependent

No change

Amylase

5-27 U/24 Hr

No Change

Amy/Creat Clear

1.3-4.2%

No change

Ca

100-300 mg/24 Hr

Diet Dependent

Cl

None determined

Diet Dependent

Creatinine

Male: 0.8-2.8 g/24hr

Female: 0.8-1.8 g/24hr

No change

Urine Total Protein - spot

<119 mg/24hr

10-140 mg/L

Urine Total Protein – 24 Hr

<119 mg/24H

<100 mg/24 Hr

Myoglobin

Negative

No change

 

CSF Protein

(mg/dL)

Lumbar: 12-40

Ventricular: 8-15

Lumbar: 15-25

Ventricular: 5-15

CSF Glucose

(Mg/dL)

12-60

0-12Y:60-80

>12Y: 40-70

CSF Lactate

(mmol/L)

0.8-2.8

0.5-2.2

 

Therapeutic Drug Reference Interval Summary - Olympus/Centaur to Architect/AxSym change 2005

 

No changes to be made in either total or “free” drugs as these are therapeutic targets established by clinical practice.