Summary & Overview
CPT 0389U: Kawasaki Disease RNA Expression Risk Score Test
CPT code 0389U is a Proprietary Laboratory Analyses (PLA) code assigned to the KawasakiDx, OncoOmicsDx Laboratory test from mProbe. The assay analyzes RNA expression of two genes in a patient blood specimen and produces a risk score to aid evaluation of Kawasaki disease (KD), an important cause of prolonged fever in children. As a PLA code, 0389U is specific to a single manufacturer’s test and is intended to support accurate reporting and tracking of novel laboratory diagnostics nationwide.
Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of the clinical purpose of the test, the typical laboratory service setting, and the relevance of a PLA designation for payer policy and billing workflows. The publication outlines expected benchmarks for code adoption, considerations for coverage policy interpretation, and the clinical context in which the test may be ordered. Data not available in the input is noted where applicable, and the piece focuses on national implications rather than state-level specifics.
Billing Code Overview
CPT code 0389U is a Proprietary Laboratory Analyses (PLA) code for the KawasakiDx, OncoOmicsDx Laboratory test from mProbe. The test evaluates a patient blood specimen for RNA expression of two genes and reports a risk score for Kawasaki disease (KD), a cause of fever of unknown origin in children.
Service type: Proprietary laboratory molecular diagnostic assay (RNA expression test)
Typical site of service: Clinical laboratory or reference laboratory processing blood specimens
Clinical & Coding Specifications
Clinical Context
A pediatric patient aged 6 months to 5 years presents to an urgent care clinic or pediatric emergency department with persistent fever for more than 5 days, conjunctival injection, mucocutaneous changes, and possible lymphadenopathy. The clinician suspects Kawasaki disease (KD) as part of the differential for fever of unknown origin in a child. A peripheral blood specimen is ordered and sent to the laboratory performing the proprietary KawasakiDx, OncoOmicsDx assay from mProbe. The laboratory performs RNA expression analysis of the two genes specified by the proprietary test and returns a KD risk score. Results are reviewed by the ordering pediatrician or pediatric infectious disease specialist to inform risk stratification and further management, such as echocardiography referral, intravenous immunoglobulin consideration, or close outpatient follow-up.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
00 | Default; no modifier | Use when no special circumstances apply to the laboratory service |
26 | Professional component | Use if a separate professional interpretation component is billed by a physician or pathologist for the test report |
TC | Technical component | Use when billing the laboratory's technical component only (instrumentation, personnel, reagents) |
52 | Reduced services | Use if the lab service is partially reduced compared with the full test as described (rare for PLA codes) |
53 | Discontinued procedure | Use if specimen processing or testing was started but discontinued for clinical reasons |
59 | Distinct procedural service | Data not available in the input. |
62 | Two surgeons | Use rarely; Data not available in the input. |
78 | Unplanned return to OR | Data not available in the input. |
80 | Assistant surgeon | Data not available in the input. |
QK | Medical direction of two or more assistants | Use where applicable for services requiring medically directed assistants (rare for lab tests) |
QX | CRNA service performed with medical direction by physician | Use only if applicable in the care episode (not typical for lab billing) |
QY | Medical direction of one CRNA by anesthesiologist | Use only if applicable in the care episode (not typical for lab billing) |
SH | Diagnostic radiology services — supervising practitioner | Use if supervision by a qualified practitioner is billed for associated imaging studies (e.g., echocardiography) |
TC | Technical component | Duplicate entry suppressed — use as above |
| Taxonomy Code | Specialty | Notes |
|---|---|---|
208000000X | Pediatrics | Ordering clinicians for Kawasaki disease evaluation |
2083P0200X | Pediatric Infectious Disease | Specialists interpreting complex infectious or inflammatory presentations |
207L00000X | Pathology | May be involved for test interpretation or reporting in some institutions |
207Q00000X | Clinical Laboratory | Laboratories performing molecular diagnostic testing |
261QU0200X | Pediatric Cardiology | Frequently involved in follow-up (echocardiography) when KD is suspected |
Related Diagnoses
| ICD-10 Code | Description | Clinical Relevance |
|---|---|---|
R50.9 | Fever, unspecified | Common presenting symptom prompting evaluation with the KawasakiDx test |
M35.8 | Other specified systemic involvement of connective tissue | Used when systemic inflammatory processes are considered; can overlap with KD differential |
P92.9 | Neonatal disorder of feeding, unspecified | Data not directly relevant; included only if neonatal evaluation overlaps — Data not available in the input. |
R65.21 | Severe sepsis with septic shock | Severe infectious/inflammatory differential that may warrant exclusion when evaluating for KD |
I51.9 | Heart disease, unspecified | Used when cardiac involvement is suspected and cardiac evaluation is pursued after KD risk assessment |
Related CPT Codes
| CPT Code | Description | Relationship to This Procedure |
|---|---|---|
0389U | KawasakiDx, OncoOmicsDx Laboratory (mProbe) — RNA expression analysis of two genes with reported KD risk score | This is the proprietary PLA test that analyzes RNA expression to generate a Kawasaki disease risk score |
36415 | Collection of venous blood by venipuncture | Commonly performed immediately before sending the specimen to the reference laboratory for the KawasakiDx assay |
86328 | Antibody; serology for infectious agents (multiple types) | May be ordered in parallel to evaluate other causes of persistent fever in children (e.g., viral serologies) |
93975 | Echocardiography, transthoracic, real-time with image documentation — limited study | Often performed after a positive or concerning KD risk score to assess coronary artery involvement |
80053 | Comprehensive metabolic panel (CMP) | Frequently ordered alongside the KD-specific test to evaluate systemic inflammation and organ function |
85025 | Complete blood count (CBC) with automated differential | Common lab test ordered concurrently to evaluate for leukocytosis, anemia, or thrombocytosis associated with KD |