What does this LOINC code represent?

This LOINC code identifies a lab observation, measurement, question, or clinical concept in a standardized format.

Is this enough to understand my test result?

No. The code identifies the test or observation, but the interpretation depends on the actual result, reference range, and clinical context.

LOINCActiveOrder

LOINC Code 77364-8: Tryptophan, kynurenin and 3-hydroxykynurenin panel

Name: LOINC Code 77364-8: Tryptophan, kynurenin and 3-hydroxykynurenin panel
Creator: HealthAssure Clinical Team
Published: 2026-05-21T08:59:57.648Z

77364-8 is a LOINC code used to identify Tryptophan, kynurenin and 3-hydroxykynurenin panel in laboratory and clinical observation data. You may see this code in lab systems, lab reports, EHR exports, interoperability feeds, or other structured clinical data exchanges. LOINC codes identify tests, measurements, observations, survey items, and clinical questions in a standardized way. It is associated with the component Tryptophan, kynurenin & 3-hydroxykynurenin panel. It is commonly used with the system or sample type Ser/Plas.

Reviewed by HealthAssure Clinical TeamUpdated 21 May 2026

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 Tryptophan, kynurenin & 3-hydroxykynurenin panel. It is commonly used with the system or sample type Ser/Plas.

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: Order
Panel type: Panel

What it does not mean

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

Key facts

Tryptophan, kynurenin and 3-hydroxykynurenin panel - Serum or Plasma

Tryptophan, kynurenin & 3-hydroxykynurenin panel

Determination of tryptophan, kynurenin and 3-hydroxykynurenin in serum or plasma for assessing several pathophysiological conditions, including neuroendocrine tumors, depression and schizophrenia.[PMID19196554]

3OH-kynurenin; c244; Chemistry; III; Kynurenine; L-tryptophan; Pan; PANEL.CHEMISTRY; Panl; Pl; Plasma; Plsm; Pnl; Point in time; Random; SerP; SerPl; SerPlas; Serum; Serum or plasma; SR; Trp; Tryptophan+metabolites Pnl

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

Tryptophan, kynurenin and 3-hydroxykynurenin panelTryptophan, kynurenin and 3-hydroxykynurenin panel - Serum or PlasmaTryptophan+metabolites Pnl SerPlTryptophan, kynurenin & 3-hydroxykynurenin panelPANEL.CHEMTryptophan, kynurenin and 3-hydroxykynurenin panel, Blood-

Frequently asked questions

Code details

Code77364-8

SystemLOINC

Display nameTryptophan, kynurenin and 3-hydroxykynurenin panel

DescriptionTryptophan, kynurenin & 3-hydroxykynurenin panel

Short nameTryptophan+metabolites Pnl SerPl

ComponentTryptophan, kynurenin & 3-hydroxykynurenin panel

Property-

TimingPt

System (specimen)Ser/Plas

Scale-

ClassPANEL.CHEM

StatusACTIVE

Order/ObservationOrder

Flags

BillableNo

Valid clinical useNo

Source

SourceLOINC

Version2.82

Releasemain

First released2.52

Last changed2.52

Consumer names

Tryptophan, kynurenin and 3-hydroxykynurenin panel, Blood

Part names

Tryptophan, kynurenin & 3-hydroxykynurenin panel-PtSer/PlasTryptophan, kynurenin and 3-hydroxykynurenin panelPoint in time (spot)Serum or Plasma

About this content

This page is prepared by HealthAssure's clinical team using official coding standards from LOINC. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.