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 |