Acid Phosphatase 

Updated: Feb 13, 2020
Author: Anas K Gremida, MD; Chief Editor: Thomas M Wheeler, MD 

Reference Range

In adults and elderly persons, the normal findings for acid phosphatase are 0.13-0.63 U/L (Roy, Brower, Hayden; 37°C) or 2.2-10.5 U/L (SI units).[1]

Normal findings in children are 8.6-12.6 U/mL (30°C), while normal findings in newborns are 10.4-16.4 U/mL (30°C).[1]

 

Interpretation

Conditions associated with elevations in prostatic acid phosphatase (PAP) include the following:

  • Prostate cancer

  • Benign prostatic hyperplasia

  • Prostatic infarction

  • Manipulation of the prostate through a massage or rectal examination

 

Collection and Panels

Specifics for collection and panels are as follows:

  • Specimen type: Blood serum

  • Container: Vacutainer, red/black top (preferred) or red top (see image below)

    empty para to satisfy content model empty para to satisfy content model
  • Collection method: Venipuncture

  • Specimen volume: 1 mL

  • Other instructions:

Related tests: Prostate-specific antigen (PSA)

 

Background

Description

Acid phosphatases are enzymes that are capable of hydrolyzing phosphate esters in an acidic environment.

Prostatic acid phosphatase (PAP), which is produced in the prostate, was the first major serum marker for prostate cancer. Metastasis of prostate cancer beyond the capsule, particularly to the bone, causes a rise in acid phosphatase level, with the level increasing in correspondence to the extent of the disease.[1] PAP was used widely for screening, staging, and posttreatment monitoring in prostate cancer, but its use has largely been displaced by that of PSA.[2, 3, 4]

Indications/Applications

Indications for testing of PAP include the following:

  • Additional prognostic information for predicting recurrence after radical prostatectomy for clinically localized prostate cancer

  • Additional monitoring of therapeutic response in prostate cancer treated by androgen ablation

  • Can also be used medicolegally as presumptive test to indicate the presence of semen in cases of sexual abuse