LOINC Code 53949-4: HPA 1a/1a+HPA 3b/3b Ql (Bld)

What is this code?

LOINC codes identify tests, measurements, observations, survey items, and clinical questions in a standardized way. It is associated with the component HPA 1a-1a+HPA 3b-3b. It is commonly used with the system or sample type Bld.

When is it used?

• Used in lab systems, EHRs, and clinical data exchange.
• May identify a test, observation, survey item, or clinical document request rather than a diagnosis.
• Status: ACTIVE
• Order vs observation: Both

What it does not mean

• The code identifies the observation or test, not the actual result.

Key facts

• HPA 1a/1a+HPA 3b/3b [Presence] in Blood
• HPA 1a-1a+HPA 3b-3b
• Blood; HPA 1a/1a+HPA 3b/3b; HPA antigen; HPA-1a; Human Platelet Antigen; Ordinal; Pl-a1; Point in time; PR; QL; Qual; Qualitative; Random; Screen; WB; Whole blood; Zw-a

Where you may see this code

You may see this code in lab systems, lab reports, EHR exports, interoperability feeds, or other structured clinical data exchanges.

Common synonyms

Frequently asked questions