CPT® Code 86052

Official Description

Aquaporin-4 (neuromyelitis optica [NMO]) antibody; cell-based immunofluorescence assay (CBA), each

Common Language Description

The CPT® Code 86052 refers to the testing for Aquaporin-4 (AQP4) antibodies using a cell-based immunofluorescence assay (CBA). These antibodies serve as a highly specific and sensitive serological marker for neuromyelitis optica (NMO), which is an autoimmune disorder characterized by inflammation and demyelination within the central nervous system (CNS). NMO primarily impacts the optic nerves and spinal cord, but it can also affect the brain, leading to a range of severe symptoms. These symptoms may include vision loss, limb weakness or paralysis, uncontrollable vomiting or hiccups, painful muscle spasms, and dysfunction of the bladder or bowel. In pediatric patients, NMO can manifest as seizures or even coma. The presence of AQP4 antibodies is critical for differentiating NMO from multiple sclerosis (MS), as these antibodies are typically found in NMO but not in classical MS. The testing process involves collecting a venous blood sample from the patient, which is then analyzed using a cell-based indirect immunofluorescence assay (CIIFA) or cell-based indirect fluorescent antibody (CBA by IFA). This method utilizes human embryonic kidney (HEK) cells that have been genetically modified to express green fluorescent protein (GFP)-tagged AQP4, which are fixed onto slides and serve as the antigen substrate. The patient’s serum is incubated with these cells, followed by the addition of a secondary anti-human IgG antibody that is conjugated with fluorescein isothiocyanate. After the labeling process, the cells are washed and examined under a fluorescent microscope to detect the presence of AQP4 antibodies. The resulting fluorescent signal is scored qualitatively, and further titration studies may be conducted to determine the dilution factor at which the specific fluorescence can be identified, providing a semi-quantitative result. This test may be performed alongside other separately reportable tests to assist in confirming a diagnosis of NMO.

1. Indications

The Aquaporin-4 (NMO) antibody test is indicated for the following conditions:

Neuromyelitis Optica (NMO) This test is primarily performed to diagnose neuromyelitis optica, an autoimmune disorder that leads to inflammation and demyelination in the central nervous system.
Differentiation from Multiple Sclerosis (MS) The presence of AQP4 antibodies is used to distinguish NMO from multiple sclerosis, as these antibodies are typically absent in classical MS.
Assessment of Symptoms The test may be indicated for patients presenting with symptoms such as vision loss, limb weakness, paralysis, or other neurological deficits that suggest a demyelinating disease.

2. Procedure

The procedure for testing Aquaporin-4 antibodies involves several key steps:

Sample Collection A venous blood sample is collected from the patient to obtain serum for testing. This sample is crucial for the subsequent analysis of AQP4 antibodies.
Preparation of Antigen Substrate Human embryonic kidney (HEK) cells that have been transfected with green fluorescent protein (GFP)-tagged AQP4 are fixed onto slides. These cells serve as the antigen substrate for the immunofluorescence assay.
Incubation with Serum The patient’s serum sample is incubated with the prepared HEK cells. This allows any AQP4 antibodies present in the serum to bind to the antigen on the cells.
Secondary Antibody Addition After incubation, a secondary anti-human IgG antibody conjugated with fluorescein isothiocyanate is added to the mixture. This secondary antibody binds to any AQP4 antibodies that have attached to the HEK cells.
Washing and Observation The cells are then washed to remove unbound antibodies, and the slides are examined under a fluorescent microscope. The presence of fluorescence indicates the binding of AQP4 antibodies.
Scoring and Titration The fluorescent signal is scored qualitatively to determine the presence of AQP4 antibodies. Additionally, titration studies may be performed to identify the dilution factor at which the specific fluorescence is detectable, yielding a semi-quantitative result.

3. Post-Procedure

After the procedure, the patient may not require any specific post-procedure care, as the blood draw is a routine procedure. However, it is essential to monitor the patient for any immediate adverse reactions to the blood draw, such as bruising or discomfort at the puncture site. The results of the AQP4 antibody test will be analyzed and reported, and further clinical correlation may be necessary to interpret the findings in the context of the patient's symptoms and medical history. If the test is positive, additional diagnostic tests may be recommended to support the diagnosis of neuromyelitis optica or to rule out other conditions.

Short Descr	AQUAPORIN-4 ANTB CBA EACH
Medium Descr	AQUAPORIN-4 ANTIBODY CELL-BASED IMFLUOR ASSAY EA
Long Descr	Aquaporin-4 (neuromyelitis optica [NMO]) antibody; cell-based immunofluorescence assay (CBA), each
Status Code	Statutory Exclusion (from MPFS, may be paid under other methodologies)
Global Days	XXX - Global Concept Does Not Apply
PC/TC Indicator (26, TC)	9 - Not Applicable
Multiple Procedures (51)	9 - Concept does not apply.
Bilateral Surgery (50)	9 - Concept does not apply.
Physician Supervisions	09 - Concept does not apply.
Assistant Surgeon (80, 82)	9 - Concept does not apply.
Co-Surgeons (62)	9 - Concept does not apply.
Team Surgery (66)	9 - Concept does not apply.
Diagnostic Imaging Family	99 - Concept Does Not Apply
CLIA Waived (QW)	No
APC Status Indicator	Conditionally packaged laboratory tests
Type of Service (TOS)	5 - Diagnostic Laboratory
Berenson-Eggers TOS (BETOS)	none
MUE	1

90	Reference (outside) laboratory: when laboratory procedures are performed by a party other than the treating or reporting physician or other qualified health care professional, the procedure may be identified by adding modifier 90 to the usual procedure number.
26	Professional component: certain procedures are a combination of a physician or other qualified health care professional component and a technical component. when the physician or other qualified health care professional component is reported separately, the service may be identified by adding modifier 26 to the usual procedure number.
59	Distinct procedural service: under certain circumstances, it may be necessary to indicate that a procedure or service was distinct or independent from other non-e/m services performed on the same day. modifier 59 is used to identify procedures/services, other than e/m services, that are not normally reported together, but are appropriate under the circumstances. documentation must support a different session, different procedure or surgery, different site or organ system, separate incision/excision, separate lesion, or separate injury (or area of injury in extensive injuries) not ordinarily encountered or performed on the same day by the same individual. however, when another already established modifier is appropriate it should be used rather than modifier 59. only if no more descriptive modifier is available, and the use of modifier 59 best explains the circumstances, should modifier 59 be used. note: modifier 59 should not be appended to an e/m service. to report a separate and distinct e/m service with a non-e/m service performed on the same date, see modifier 25.
GA	Waiver of liability statement issued as required by payer policy, individual case