Laboratory Test Directory

SICKLE SCREEN: (089-0109)

Clinical Indication:

 To detect the presence of Hemoglobin S

Test Mnemonic:

 SICKLE

Methodology:

 The Sickle Screen Kit (Pacific Hemostasis) is a modified Nalbandian procedure  based on the differential solubility of Hemoglobin S (Hb S) and Hemoglobin A (Hb A) in concentrated phosphate solution.

Performed:

  Specimen accepted 24 hours per day at Sample Management, 5.136 McCullough.

Turnaround Time:

 STAT: 1 hour; Routine: 4 hours

Specimen Requirements:

Collect: Routine venipuncture;  Collect in EDTA (lavender tube, preferred), sodium heparin (green-top tube, acceptable). The minimum volume required is 90% of the stated tube volume.

If RBC transfusion anticipated, collect before transfusion.

Storage/Transport: Specimens not delivered to the laboratory within 2 hours should be refrigerated (stored at 2 - 8°C)

Stability:  Refrigerated  samples (at 2 - 8°C) are stable for 2 weeks.

Causes for Rejection: Specimen clotted; collection in wrong tube; identification error

Clinical Information:

Special Instructions: The test can be ordered only once per inpatient admission and once per month for outpatients. Additional requests require the approval of the laboratory director. Do not request on patients 0-6 months of age (Hgb-F level is too high; order Hemoglobin Electrophoresis).

Interfering substances: Erythrocytosis, hyperglobulinemia, extreme leukocytosis, and hyperlipidemia can cause false positive results. Anemia, high levels of Hgb F, and recent transfusions can cause false negative results.

Reference Range:

Negative: Hemoglobin-S not present.   Positive: Hemoglobin-S presumed present.

A positive result does not distinguish between Hgb SS, AS, S Beta Thalassemia, or other combinations of Hgb S with other hemoglobin variants. Follow-up with Hemoglobin Electrophoresis recommended.  Non sickling hemoglobins including Hgb A, F, C, D, G, E, Lepore, and A2 will give negative results.

Note:

CPT 4 Code:

 85660

Reviewed:9/20/12

A. Huerta, BS, MT (ASCP), MBA

When ordering tests for which Medicare or Medicaid reimbursement will be sought, physicians should only order tests that are medically necessary for the diagnosis or treatment of the patient.  Components of the organ or disease panels may be ordered individually.  The diagnostic information must substantiate all tests ordered and must be in the form of an ICD-9 code or its verbal equivalent.