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Lab Dept:
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Chemistry
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Test Name:
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C4 (FOURTH COMPONENT OF COMPLEMENT)
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General Information
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Lab Order Codes:
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C4
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Synonyms:
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C’4; Fourth component of complement; Complement 4
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CPT Codes:
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86160 – Complement; antigen, each component
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Test Includes:
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C4 concentration reported in mg/dL.
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Logistics
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Test Indications:
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C4 is essential for the activation of the classical pathway. C4 deficiency is associated with very high prevalence of autoimmune or collagen vascular disease. It has been proposed that C4 may be critical for the clearance of viral infections.
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Lab Testing Sections:
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Chemistry (all testing is performed on the Mpls campus)
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Phone Numbers:
Minneapolis:
Saint Paul:
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612-813-6280
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651-220-6550
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Test Availability:
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Daily, 24 hours
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Turnaround Time:
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1 – 4 days, testing performed Tuesday, Wednesday and Friday.
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Special Instructions:
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N/A
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Specimen
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Specimen Type:
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Blood
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Container:
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Red top (plain, no gel) tube
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Draw Volume:
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0.6 mL blood
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Processed Volume:
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0.2 mL serum
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Collection:
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Routine venipuncture
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Special Processing:
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Lab Staff: Centrifuge specimen, remove serum aliquot into a plastic sample cup. Specimens can be stored at refrigerated temperatures for up to eight days. Centrifuge turbid or particulate samples prior to analysis.
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Patient Preparation:
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None
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Sample Rejection:
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Mislabeled or unlabeled specimens; specimens other than serum; lipemic or turbid specimens
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Interpretive
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Reference Range:
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10 - 40 mg/dL
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Critical Values:
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N/A
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Limitations:
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N/A
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Methodology:
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Nephelometry BN Prospec
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References:
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Herbert, L. E. et al (1991) Kidney International; 39: 811
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West, C D (1989) Complement Inflamm; 6: 4
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Dalmasso, P (1986) Critical Reviews in Clinical Laboratory Sciences; 4: 123
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Okumura, N. et al., Clinical Laboratory Science 1990; 3: 54
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Baudner, S. et al., J. Lab. Med. 1996; 20: 145
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Tietz, NW, Textbook of Clinical Chemistry (1986) WB Saunders Co., Philadelphia, PA, pp 52-53 (techniques and procedures to minimize laboratory infections) and pp 478-497 (specimen collection and storage recommendations).
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N Antisera to Human Complement Factors (C3c, C4) Package Insert (May 2008) Siemens Healthcare Diagnostics, Newark, DE
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N Protein Standard SL Package Insert (May 2008) Siemens Healthcare Diagnostics, Newark
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