Summary & Overview

CPT 0526U: CXCL10 Urine Test for Kidney Transplant Monitoring

CPT code 0526U designates a proprietary laboratory test — the CXCL10 Urine Test from One Lambda™ Inc. — that measures urinary CXCL10 via flow cytometry and reports values as pg/mL of creatinine for monitoring kidney transplant patients. This PLA code is specific to one manufacturer’s assay and is used when serial biomarker measurements inform assessment of rejection risk. Nationally, PLA codes like 0526U matter because they identify single-source diagnostics that can affect coverage, laboratory adoption, and clinical workflows for transplant surveillance.

Key payers in this review include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of the code’s clinical purpose, where the service is typically performed, and which payers are considered. The publication outlines benchmarks and policy-relevant context for proprietary lab tests, summarizes payer coverage considerations and typical billing components, and provides clinical context for use of urinary CXCL10 in transplant monitoring. Data not available in the input is noted where applicable.

AetnaBlue Cross Blue ShieldCigna HealthUnitedHealthcareMedicare0526UCPTProprietary Laboratory Analysesurine biomarkerkidney transplantCXCL10flow cytometrylaboratory medicinetransplant surveillance

Billing Code Overview

CPT code 0526U is a Proprietary Laboratory Analyses (PLA) code that applies exclusively to the CXCL10 Urine Test from One Lambda™ Inc. The test quantifies the chemokine CXCL10 in urine using flow cytometry and reports results as pg/mL of creatinine. It is intended for serial measurement to monitor kidney transplant patients for changes in immune activity associated with transplant rejection risk.

Service Type: Proprietary laboratory diagnostic test (urine biomarker assay)

Typical Site of Service: Clinical laboratory or hospital laboratory

Clinical & Coding Specifications

Clinical Context

A typical patient is a kidney transplant recipient in routine post‑transplant surveillance or with signs/symptoms suggestive of allograft dysfunction (rising serum creatinine, decreased urine output, new proteinuria, or nonspecific systemic symptoms). The transplant nephrologist orders the CXCL10 Urine Test (0526U) to quantify urinary CXCL10 expressed as pg/mL of creatinine using flow cytometry. A urine specimen is collected during an outpatient clinic visit or ambulatory lab draw and sent to the performing laboratory (One Lambda™ Inc.). The laboratory performs the assay and reports a value normalized to urine creatinine; serial measurements over time are compared to prior results to assess trends in immune activation and risk of acute rejection. Results are reviewed by the transplant team and correlated with clinical assessment, serum laboratory studies (including serum creatinine, tacrolimus level), urine studies, and, when indicated, noninvasive imaging or allograft biopsy.

Coding Specifications

Modifier	Description	When to Use
`22`	Increased procedural services	Use when test requires substantially greater technical effort or documentation than usual (e.g., additional specimen handling or extended analysis time).
`26`	Professional component	Use when only the interpretation or professional portion of the laboratory report is billed separately.
`52`	Reduced services	Use when the laboratory performed a modified or partial version of the test.
`53`	Discontinued procedure	Use when testing was started but discontinued for clinical reasons before completion.
`TC`	Technical component	Use when billing only the laboratory technical component (instrumentation and processing) without the professional interpretation.
`90`	Reference (outside) laboratory	Use when the specimen is sent to a different independent laboratory for testing.
`59`	Distinct procedural service	Use when multiple unrelated tests or procedures are billed on the same day and must be reported separately.
`76`	Repeat procedure by same physician/lab	Use when the same test is repeated later the same day by the same lab because of specimen issues.
`77`	Repeat procedure by another physician/lab	Use when the test is repeated by a different laboratory for validation or confirmation.
`91`	Repeat clinical diagnostic laboratory test	Use when the exact same quantitative test is repeated on the same day to obtain multiple measurements.

Taxonomy Code	Specialty	Notes
2080S0400X	Nephrology	Transplant nephrologists order and interpret results for kidney transplant surveillance.
207L00000X	Pathology & Laboratory Medicine	Clinical laboratory directors and pathologists oversee assay validation and reporting.
207RC0000X	Clinical Laboratory	Clinical laboratory technologists and directors perform the technical testing.
207K00000X	Clinical Cytogenetics/Flow Cytometry	Laboratories specialized in flow cytometry applications for clinical testing.

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`T86.10`	Unspecified complication of kidney transplant	General code used for complications including suspected rejection prompting urinary CXCL10 testing.
`T86.11`	Acute rejection of kidney transplant	Directly relevant when assessing immune activation and risk of acute rejection.
`T86.12`	Chronic rejection of kidney transplant	Relevant for monitoring chronic immune-mediated graft injury where CXCL10 trends may assist risk assessment.
`N18.9`	Chronic kidney disease, unspecified	Used when monitoring graft function in patients with chronic kidney disease post-transplant.
`R94.31`	Abnormal results of renal function studies	Applied when abnormal renal tests prompt adjunctive biomarker testing such as urinary CXCL10.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`80053`	Comprehensive metabolic panel	Baseline and trend data (including serum creatinine) used alongside urinary CXCL10 to assess graft function.
`82565`	Urinary creatinine, quantitative	Measurement used to normalize urinary CXCL10 results to creatinine (pg/mL per creatinine).
`82570`	Creatinine; other source (e.g., urine)	Alternate urinary creatinine assay code used when specific method differs.
`82043`	Creatinine, urine (qualitative or semi-quantitative)	Used in some facilities for urine creatinine assessment accompanying biomarker assays.
`88305`	Level IV surgical pathology, gross and microscopic exam (includes renal biopsy)	Allograft biopsy performed when urinary CXCL10 and clinical data suggest rejection; provides histologic confirmation.