Ordering Recommendation

Aids in diagnosis of limbic encephalitis. May be used to monitor treatment response in individuals who initially test positive for DPPX antibodies. The presence of DPPX antibodies may be associated with hyperexcitability, pleocytosis, and frequent diarrhea. DPPX encephalitis may be paraneoplastic; hematologic malignancies are reported in a subset of patients. Serum is the preferred specimen; see Dipeptidyl Aminopeptidase-Like Protein 6 (DPPX) Antibody, IgG by IFA With Reflex to Titer, Serum (3004359).

Mnemonic

DPPX CSF

Methodology

Semi-Quantitative Indirect Fluorescent Antibody

Performed

Wed

Reported

1-8 days

New York DOH Approval Status

Specimens from New York clients will be sent out to a New York DOH approved laboratory, if possible.

Specimen Required

Patient Preparation
Collect

Separate CSF.

Specimen Preparation

Transfer 0.5 mL CSF to an ARUP Standard Transport Tube. (Min: 0.15 mL)

Storage/Transport Temperature

Refrigerated.

Unacceptable Conditions

Hemolyzed, contaminated, or severely lipemic specimens.

Remarks
Stability

Ambient: 48 hours; Refrigerated: 2 weeks; Frozen: 1 month

Reference Interval

Less than 1:1

Interpretive Data

Anti-DPPX IgG antibody is found in a subset of patients with autoimmune encephalitis and may occur with or without associated tumor. Decreasing antibody levels may be associated with therapeutic response; therefore, clinical correlation must be strongly considered. A negative test result does not rule out a diagnosis of autoimmune limbic encephalitis.

This indirect fluorescent antibody cell-based assay (CBA) utilizes dipeptidyl aminopeptidase-like protein 6 (DPPX) transfected cells for the detection of the DPPX IgG antibody.

This test was developed and its performance characteristics determined by ARUP Laboratories. It has not been cleared or approved by the U.S. Food and Drug Administration. This test was performed in a CLIA-certified laboratory and is intended for clinical purposes..

Compliance Category

Laboratory Developed Test (LDT)

Note

If DPPX antibody IgG is positive, then DPPX antibody IgG titer will be added. Additional charges apply.

Hotline History

N/A

CPT Codes

86255; if reflexed, add 86256

Components

Component Test Code* Component Chart Name LOINC
3004513 DPPX Ab IgG CBA IFA Screen, CSF 94283-9
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.

Aliases

Dipeptidyl Aminopeptidase-Like Protein 6 (DPPX) Antibody, IgG by IFA With Reflex to Titer, CSF