Summary & Overview
CPT 0446U: aiSLE DX Disease Activity Index, SLE Biomarker Panel
CPT code 0446U is a Proprietary Laboratory Analyses (PLA) code that represents the aiSLE® DX Disease Activity Index from Progentec Diagnostics Inc., an immunoassay-based plasma test measuring 10 biomarkers and producing an algorithmic risk score for systemic lupus erythematosus (SLE) disease activity. As a PLA code, 0446U identifies a single, manufacturer-specific laboratory test and matters nationally because it standardizes reporting for a proprietary SLE disease activity assay and supports clinical decision-making and utilization tracking.
Key payers discussed include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will learn the clinical context of the assay, how the test is reported using a PLA CPT code, and the typical sites of service for specimen collection and analysis. The publication provides benchmarks and policy-oriented information relevant to coverage and coding practices, highlights the implications of PLA coding for lab-specific tracking, and outlines the clinical utility of algorithmic risk scoring for monitoring SLE activity. Data not available in the input is noted where payer-specific coverage policies, fee schedules, or related taxonomies and ICD-10 mappings are absent.
Billing Code Overview
CPT code 0446U is a Proprietary Laboratory Analyses (PLA) code specific to the aiSLE® DX Disease Activity Index from Progentec Diagnostics Inc. The test uses an immunoassay on a plasma specimen to measure 10 biomarkers related to systemic lupus erythematosus (SLE) and reports individual component values plus an algorithmic risk score for current disease activity. Results assist the ordering provider in measuring SLE disease activity and assessing treatments.
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Service type: Clinical laboratory test (proprietary immunoassay with algorithmic interpretation)
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Typical site of service: Clinical laboratory or outpatient phlebotomy site where plasma specimens are collected and sent to the performing laboratory for analysis.
Clinical & Coding Specifications
Clinical Context
A 34-year-old woman with established systemic lupus erythematosus (SLE) presents to her rheumatologist for routine disease activity assessment after a change in immunomodulatory therapy. The ordering provider requests the aiSLE® DX Disease Activity Index (0446U) from Progentec Diagnostics to objectively quantify current SLE activity using a plasma specimen. A trained phlebotomist collects the blood specimen during an outpatient clinic visit or at an ambulatory lab; the specimen is processed and shipped per the manufacturer's instructions to the performing laboratory. Results include individual biomarker values and an algorithmic risk score to help the clinician evaluate disease activity, compare response to recent therapy changes, and consider treatment adjustments.
Typical site of service is an outpatient clinic, ambulatory phlebotomy center, or hospital outpatient laboratory. The specimen collection and test ordering occur during the clinic visit; the laboratory performs the proprietary immunoassay and returns a report that the rheumatologist reviews in follow-up or during the same visit if rapid turnaround is available.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
00 | Default/standard laboratory service | Use when no other modifier applies to the PLA test. |