Summary & Overview
CPT 86384: Nitroblue Tetrazolium Reduction Test
CPT code 86384 denotes a laboratory diagnostic assay that measures the reduction of nitroblue tetrazolium dye in a blood specimen to evaluate cellular oxidative burst activity. The test has clinical relevance for assessing neutrophil function and may be used in workups for suspected immunodeficiency or certain hematologic conditions. Nationally, this code is part of the laboratory services landscape where accurate coding supports clinical interpretation and claims processing.
Key payers considered in this coverage context include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. The publication provides a concise overview of clinical context, typical sites of service, common modifiers and billing considerations (input-provided), and where available, payer coverage patterns. Readers will gain a clear understanding of what CPT code 86384 represents, the clinical scenarios in which the assay is used, and the administrative elements relevant for laboratory billing and coding. Data not available in the input will be noted where applicable.
Billing Code Overview
CPT code 86384 describes a laboratory test in which a lab analyst measures the reduction of nitroblue tetrazolium (NBT) dye in a blood sample. This assay is used to assess certain cellular oxidative burst functions, typically performed on whole blood or neutrophil preparations.
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Service type: Diagnostic laboratory assay
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Typical site of service: Clinical laboratory or hospital laboratory setting
Clinical & Coding Specifications
Clinical Context
A patient with recurrent infections and concerns for neutrophil function is referred to a hospital outpatient laboratory for specialized testing. The clinician suspects a primary immunodeficiency such as chronic granulomatous disease (CGD) after a history of recurrent bacterial and fungal infections, abnormal wound healing, or unusual organisms. A phlebotomy is performed and the blood specimen is sent to the clinical laboratory where a laboratory analyst performs a nitroblue tetrazolium (NBT) reduction test (CPT 86384) to assess neutrophil oxidative burst activity. The workflow includes specimen receipt, verification, preparation of slides or reaction mixtures with NBT dye, incubation with stimulant (e.g., phorbol myristate acetate or bacterial opsonized particles), microscopic or spectrophotometric assessment of NBT reduction, result documentation, and communication of abnormal findings to the ordering clinician for confirmatory testing (for example, flow cytometry dihydrorhodamine [DHR] assay) and genetic referral if indicated.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional Component | Use when billing only the professional interpretation or laboratory professional's reporting portion, distinct from the technical component. |