Acid Phosphatase

What is the EC of ACP?

E.C. 3.1.3.2

What is the other name of ACP?

Orthophosphoric Monoester Phosphohydrolase (Acid Optimum)

Catalyzes the same type of reactions as ALP

ACID PHOSPHATASE

Optimal pH of ACP?

5.0

Activators of ACP?

Mg2+ & Zinc

Richest source and highest activity of ACP?

Prostate

ACP is for Prostatic Carcinoma Detection. (Y/N)

Yes.

ACP was historically used for detecting metastatic carcinoma of the prostate. (Y/N)

Yes.

ACP is less sensitive than newer markers like?

Prostate-Specific Antigen (PSA)

Other Conditions with ACP Elevations

Hyperplasia of the prostate, prostatic surgery, rectal examination, and prostate massage

Elevated ACP in vaginal washings as evidence of rape

Forensic applications

Paget’s disease, breast cancer with bone metastases, Gaucher’s disease

Bone diseases

Elevations in thrombocytopenia due to excessive platelet destruction

Platelet damage

In Chemical Inhibition of ACP what substrate is used?

thymolphthalein monophosphate

Chemical Inhibition differentiates prostatic ACP using?

tartrate inhibition

What is the Equation of Chemical Inhibition of ACP?

Total ACP - ACP after tartrate inhibition = Prostatic ACP

Chemical Inhibition is not entirely specific, as lysosomal ACP is also inhibited by tartrate. (Y/N)

Yes,

Uses antibodies specific for prostatic ACP

Immunologic Techniques

Improved sensitivity but not useful for screening non-metastasized cancer

Immunologic Techniques

Uses Quantitative Endpoint for ACP determination

Roy and Hillman (Quantitative Endpoint)

What is the Substrate of Roy and Hillman (Quantitative Endpoint)

Thymolphthalein monophosphate

Uses Continuous Monitoring for ACP determination

Babson, Read, & Phillips (Continuous Monitoring)

What is the Substrate of Babson, Read, & Phillips (Continuous Monitoring)

Alpha-naphthyl phosphate

What are the Immunochemical Techniques for prostatic ACP

Radioimmunoassay (RIA)

Counterimmunoelectrophoresis

Immunoprecipitation

Immunoenzymatic Assay (Tandem E)

Incubates sample with an antibody to prostatic ACP

Followed by washing and incubation with p-nitrophenylphosphate

Immunoenzymatic Assay (Tandem E)

p-Nitrophenol formed is measured photometrically and is proportional to prostatic ACP in the sample

Immunoenzymatic Assay (Tandem E)

What is the End Product of Babson, Reed, and Phillips

α-naphthol

Serum should be separated from red cells immediately after clotting to prevent leakage of erythrocyte and platelet ACP. (Y/N)

Yes.

Serum activity in ALP decreases within ________ hours at room temperature if no preservative (like acetate buffer) is added.

1 to 2. (Decrease is due to CO₂ loss and subsequent increase in pH.)

To Prevent Decrease in Serum Activity you must?

Freeze or acidify serum to a pH < 6.5.

Acidified serum remains stable at room temperature for up to 2 days.

Avoid hemolysis as it leads to contamination with erythrocyte ACP.(Y/N)

Yes.

Require nonacidified serum samples.

Stable for up to 2 days at 4°C.

RIA Procedures

Reference Range of Prostatic ACP

0 to 3.5 ng/mL

Reference Range of Tartrate-resistant ACP in adults

1.5–4.5 U/L (37°C)

Reference Range of Tartrate-resistant ACP in children

3.5–9.0 U/L (37°C) higher due to physiologic bone growth