Clinical Context
A patient in their 30s–60s presents to a neurology clinic with progressive axial stiffness, painful spasms, exaggerated startle response, and intermittent autonomic symptoms such as anxiety or respiratory difficulty. The neurologist performs a focused neurologic examination and documents concern for an autoimmune stiff‑person spectrum disorder (including progressive encephalomyelitis with rigidity and myoclonus or classic stiff‑person syndrome). A serum sample is ordered; cerebrospinal fluid (CSF) may be submitted when lumbar puncture is clinically indicated. The clinician orders the specialized antibody test reported with 0431U — Glycine Receptor Alpha1 IgG (Mayo Clinic Laboratories) — to identify IgG autoantibodies targeting the glycine receptor alpha‑1 subunit using a live‑cell binding assay.
Specimen collection: peripheral venous blood in appropriate serum tube; if CSF is being tested, sterile collection and prompt transport to the reference lab. The sample is sent to Mayo Clinic/Mayo Clinic Laboratories with test 0431U ordered and relevant clinical history (stiffness, spasms, startle, suspected autoimmune neurologic disorder) provided. Typical site of service is an outpatient neurology clinic or hospital inpatient unit when evaluation is inpatient; testing is performed by the reference laboratory (off‑site). Results inform diagnosis of glycine receptor–associated autoimmune stiff‑person spectrum disorders and guide immunotherapy decision making and further neurologic workup.
Related CPT Codes
| CPT Code | Description | Relationship to This Procedure |
|---|
0431U | Glycine Receptor Alpha1 IgG, Mayo Clinic Laboratories (Proprietary Laboratory Analyses) | Primary PLA code for the live‑cell binding assay detecting IgG to glycine receptor alpha‑1 in serum or CSF. |
86038 | Antibody; immunoassay for infectious agents, quantitative or semi‑quantitative, each agent | May be performed in other labs as different immunoassay methodologies; not specific to this PLA but conceptually related lab technique.
86355 | Assay of immunoglobulins or complement (e.g., autoantibodies) by non‑automated method | Related immunologic testing for autoimmune neurology panels; often ordered alongside specific antibody assays.
99213 | Office or other outpatient visit for the evaluation and management of an established patient, typically 15 minutes | Represents a typical neurology outpatient visit during which the clinician documents suspicion for autoimmune stiff‑person disorder and orders 0431U.
62270 | Spinal puncture, diagnostic (lumbar puncture) | If CSF is required for testing, lumbar puncture is performed prior to sending CSF for 0431U.