CD4/CD8 COUNT ( lymphocytes surface marker analysis)

Sample type

whole blood , Lavender-top (EDTA) tube

Uses

This test identifies the CD4 – CD8 level in the body.

• CD4-CD8 is used in conditions like HIV.

Precautions

You don’t need to prepare for this test. But tell your healthcare provider if you are pregnant, are a heavy alcohol user, or are taking medicines that could affect your white blood cell count.

Interfering factors

1. The CD4 count tends to be lower in the morning and higher in the evening , acute illnesses such aspneumonia, influenza, or herpes simplex virus infection can cause the CD4 count to decline temporarily. Cancer chemotherapy can dramatically lower the CD4 count.

2. CD4/CD8 ratio increases with age.

3. Pregnancy can affect your results.

Pre analytical errors

1. patient identification errors

2. Inadequate amount of anticoagulant

Corrective action

1. Technologies such as barcodes, radiofrequency identificationcan help overcome mistakes in patient identification.

2. Follow instructions of using anticoagulant.

Post analytical errors

Errors in data transmission include relaying or hearing verbal information incorrectly.

Corrective action

Using technologies for interpreting data

Reference ranges

A normal CD4/CD8 ratio is greater than 1.0, with CD4 lymphocytes ranging from 500 to 1200/mm 3 and CD8 lymphocytes ranging from 150 to 1000/mm 3.