Summary & Overview
CPT 0358U: Lumipulse β‑Amyloid 1–42/1–40 Ratio CSF Assay
CPT code 0358U designates the Lumipulse® G βAmyloid Ratio (1–42/1–40) Test, a proprietary cerebrospinal fluid (CSF) assay by Fujirebio Diagnostics that measures the ratio of β‑Amyloid 1–42 to 1–40 using chemiluminescence enzyme immunoassay. As a PLA code, 0358U is uniquely tied to a single manufacturer’s test and is used for reporting and billing that specific Alzheimer’s disease–related biomarker analysis. Nationally, PLA codes like 0358U matter because they standardize reporting for proprietary assays and influence coverage determinations, laboratory billing practices, and utilization monitoring.
Key payers discussed include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. The analysis covers payer coverage patterns, coding guidance, and the clinical context for CSF β‑Amyloid ratio testing in cognitive impairment and Alzheimer’s disease evaluation. Readers will find benchmarks for payer adoption, summaries of policy directions affecting proprietary CSF biomarker tests, and a clinical synopsis of the test’s intended use and typical laboratory setting. Data not available in the input are noted where applicable; the report focuses on clarifying what 0358U represents, its service setting, and how it is positioned within laboratory billing for Alzheimer’s disease diagnostics.
Billing Code Overview
CPT code 0358U is a Proprietary Laboratory Analyses (PLA) code that applies exclusively to the Lumipulse® G βAmyloid Ratio (1–42/1–40) Test from Fujirebio Diagnostics. The test evaluates a cerebrospinal fluid (CSF) specimen using a chemiluminescence enzyme immunoassay to determine the ratio of β‑Amyloid 1–42 to 1–40 as a marker for Alzheimer’s disease and other mild cognitive impairments.
Service type: Laboratory diagnostic test (proprietary CSF biomarker assay)
Typical site of service: Clinical laboratory or specialized diagnostic laboratory processing CSF specimens
Clinical & Coding Specifications
Clinical Context
A 68-year-old patient with progressive memory decline and mild cognitive impairment is referred by a neurologist for cerebrospinal fluid (CSF) biomarker testing to support evaluation for Alzheimer disease. The patient undergoes lumbar puncture in an outpatient neurology clinic or hospital outpatient setting; CSF is collected aseptically, labeled, and sent to a contracted clinical laboratory. The laboratory performs the Lumipulse® G βAmyloid Ratio (1–42/1–40) Test using chemiluminescence enzyme immunoassay on the Fujirebio Lumipulse platform to determine the CSF β‑amyloid 1–42/1–40 ratio. Results are reported to the ordering clinician and incorporated into the diagnostic evaluation alongside clinical exam findings, neuropsychological testing, and neuroimaging. Typical sites of service include hospital outpatient departments, specialty neurology clinics, and commercial reference laboratories. The service type is a Proprietary Laboratory Analysis (PLA) performed on a CSF specimen to aid biomarker-based assessment of Alzheimer disease or related cognitive disorders.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
00 | No modifier (standard) | Use when no special circumstance applies and both technical and professional components are included as applicable. |
26 | Professional component | Use when reporting only the physician or professional component of the laboratory test interpretation if separated. |
TC | Technical component | Use when reporting only the technical component (laboratory performance) of the test. |
52 | Reduced services | Use when the test was partially completed or results are limited compared with the full test procedure. |
53 | Discontinued procedure | Use if specimen was collected but testing was not completed due to cancellation or specimen loss. |
90 | Reference (external) laboratory (Note: not in provided list) | Data not available in the input. |
QK | Advanced Diagnostic Laboratory Test (ADLT) — performing lab meets CLIA/LDT criteria | Use if the performing laboratory meets ADLT criteria and specific payor reporting requires this modifier. |
QX | CLIA-waived test performed by non-waived lab personnel (Note: context-specific) | Use per payer rules when personnel/setting qualifications affect billing. |
QY | CLIA waived test performed in waived setting (Note: context-specific) | Use per payer rules when applicable. |
SH | Physician service limited due to patient, e.g., safe haven (Note: limited usage) | Use only when service limitations apply per payer guidance. |
SJ | Presumptive drug testing (Note: not applicable to this test) | Data not available in the input. |
22 | Increased procedural services | Use when test requires significantly greater effort or complexity than typical and documentation supports unusual effort. |
78 | Return to the operating/procedure room for a related procedure during the postoperative period | Rarely applicable; report only if a subsequent related procedure occurred in the OR. |
80 | Surgeon performed procedure; assistant surgeon waived (Note: rarely relevant) | Generally not applicable to laboratory-only services. |
| Taxonomy Code | Specialty | Notes |
|---|---|---|
| 2084P0800X | Neurology | Ordering and interpreting clinicians for cognitive disorders and dementia evaluation. |
| 207RC0000X | Pathology | Laboratory medical directors and pathologists overseeing CSF biomarker testing and QA. |
| 261QM0800X | Clinical Laboratory | Clinical laboratory technicians and specialists performing the assay and reporting results. |
| 2085R0200X | Geriatric Medicine | Clinicians managing older adults with suspected Alzheimer disease where CSF biomarkers inform diagnosis. |
Related Diagnoses
| ICD-10 Code | Description | Clinical Relevance |
|---|---|---|
G30.9 | Alzheimer disease, unspecified | Primary diagnosis where CSF β‑amyloid ratio aids diagnostic confirmation. |
G31.84 | Mild cognitive impairment, so stated | Common clinical scenario prompting CSF biomarker testing to evaluate Alzheimer pathology risk. |
F02.80 | Dementia in other diseases classified elsewhere without behavioral disturbance | Used when dementia is present and CSF biomarkers help subtype neurodegenerative disease. |
F03.90 | Unspecified dementia without behavioral disturbance | Broad dementia code where biomarker testing contributes to etiologic assessment. |
R41.3 | Other amnesia | Cognitive complaints such as amnesia may prompt CSF biomarker evaluation in differential diagnosis. |
Related CPT Codes
| CPT Code | Description | Relationship to This Procedure |
|---|---|---|
62270 | Spinal puncture, lumbar, diagnostic | Performed to obtain cerebrospinal fluid specimen before sending CSF to the lab for the Lumipulse® assay. |
80502 | Drug assay, presumptive, any method; qualitative, multiple drug classes (Note: example) | Data not available in the input. |
88360 | Immunohistochemistry or immunocytochemistry, each antibody; initial single antibody stain (Note: example) | Data not available in the input. |
36415 | Collection of venous blood by venipuncture | May be performed if concurrent blood tests are ordered for comparative or routine laboratory studies. |
99000 | Handling and/or conveyance of specimen to laboratory (Note: carrier) | Use when separate specimen handling or courier fees are billed by certain payers. |