Prepared By - Beckman Coulter



This procedure is valid for the following chemistry analyzers:

|AU400/AU400e |AU640/AU640e |

|AU480 |AU680 |

|AU600 |AU2700 |

|AU5400 |AU5800 |

|Prepared By |Date Adopted |Supersedes Procedure # |

| | | |

|Review Date |Revision Date |Signature |

| | | |

| | | |

| | | |

| | | |

| | | |

| |# of | |# of |

|Distributed to |Copies |Distributed to |Copies |

| | | | |

| | | | |

| | | | |

| | | | |

PRINCIPLE:

The spectrum of abnormalities in serum immunoglobulin concentrations is broad. Abnormal concentrations range from a virtual absence of one or more of the three major classes of immunoglobulin (IgA, IgG and IgM) to polyclonal increases in one or more immunoglobulins. Measurement of IgG aids in the diagnosis of abnormal protein metabolism and the body's lack of ability to resist infectious agents.

IgG determination in cerebrospinal fluid (CSF) is used for evaluation of infections involving the central nervous system, neoplasms, or primary neurological diseases.

INTENDED USE:

System reagent for the quantitative determination of IgG immunoglobulins in human serum and plasma on Beckman Coulter AU Clinical Chemistry analyzers.

METHODOLOGY:

Immune complexes formed in solution scatter light in proportion to their size, shape and concentration. Turbidimeters measure the reduction of incidence light due to reflection, absorption or scatter.

In the Beckman Coulter AU procedure, the decrease in intensity of light transmitted (increase in absorbance) through particles suspended in solution is the result of complexes formed during the antigen-antibody reaction.

SPECIMEN:

Patient Preparation:

An 8 to 12-hour fast is recommended but not required in order to minimize any possible lipemia.

|Additional instructions for patient preparation as designated by this laboratory: |

| |

| |

| |

Type:

Fasting serum specimen, free from hemolysis, is the recommended specimen. EDTA and Lithium heparin plasma as well as CSF may also be used. Avoid highly lipemic samples, which may produce excessively high scatter signals.1

|Additional type conditions as designated by this laboratory: |

| |

| |

| |

Handling Conditions:

Serum and plasma specimens are stable up to three days at 2 - 8(C or longer when stored at 30,000 mg/dL polyclonal) can generate false low results without appropriate “Z” flags due to excess antigen in the sample.

For CSF samples, a prozone or hook effect may occur with highly elevated IgG samples (> 6000 mg/dL polyclonal).

Interfering Substances:

Results of studies2 show that the following substances interfere with this IgG procedure.

Serum/Plasma Applications:

The criteria for no significant interference is recovery within 10% of the initial value.

|Bilirubin: |No significant interference up to 40 mg/dL Bilirubin |

|Hemolysis: |No significant interference up to 500 mg/dL Hemolysate |

|Lipemia: |No significant interference up to 1000 mg/dL Intralipid* |

|Rheumatoid Factor |No significant interference up to 1200 IU/mL Rheumatoid Factor |

* Intralipid, manufactured by KabiVitrium Inc., is a 20% IV fat emulsion used to emulate extremely turbid samples.

CSF Applications:

The criteria for no significant interference is recovery within 10% of the initial value.

|Bilirubin: |No significant interference up to 36 mg/dL Bilirubin |

|Hemolysis: |No significant interference up to 500 mg/dL Hemolysate |

The information presented is based on results from Beckman Coulter AU studies and is current at the date of publication. Beckman Coulter Inc., makes no representation about the completeness or accuracy of results generated by future studies. For further information on interfering substances, refer to Young4 for a compilation of reported interferences with this test.

|Laboratory specific procedure notes: |

| |

| |

| |

| |

| |

| |

REFERENCES:

1. Rose, N.R., Friedman, H, and Fahey, J.L., Manual of Clinical Laboratory Immunology, Third Edition, American Society for Microbiology, Washington, DC, 1986.

2. Tietz NW, ed Clinical guide to laboratory tests, 3rd ed. Philadelphia. WB Saunders Company, 1995: 360pp.

3. CLSI/NCCLS Interference Testing in Clinical Chemistry, EP7-A2, 2004.

4. Young, D.S., Effects of Drugs on Clinical Laboratory Tests, Fifth Edition, AACC Press, 2000.

5. Beckman Coulter, Inc. data on samples collected from 200 blood donors in North Texas.

6. Painter PC, Cope JY, Smith JL. Reference information for the clinical laboratory. In: Burtis CA, Ashwood ER, eds. Tietz textbook of clinical chemistry. Philadelphia. WB Saunders Company, 1999; 1820 pp.

7. CLSI/NCCLS, Determination of Limits of Detection and Limits of Quantitation. EP17-A, 2004.

8. CLSI/NCCLS, Evaluation of Precision: Performance of Quantitative Measurement Methods. EP5-A2, 2004

9. Data is on file for specific AU analyzers.

................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download