CurrentBlue Cross Blue Shield - MassachusettsPolicy 182

Immune cell function assay testing in transplantation

Governs coverage of immune cell function assays (eg, ImmuKnow, Pleximmune) to monitor or predict immune function in solid organ and hematopoietic stem cell transplant settings for Blue Cross Blue Shield - Massachusetts members.

Policy Summary

PayerBlue Cross Blue Shield - Massachusetts

PolicyImmune cell function assay testing in transplantation

Policy CodePolicy 182

Change TypeNo material change

Effective Date

Next Review Date

Key ActionObtain precertification/preauthorization when the described service is performed inpatient; outpatient use is not a covered service for specified products.

SourceLink

POLICY UPDATE CHANGES

No material clinical or coverage changes in this revision.

InvestigationalPolicy stance

Required (inpatient)Precertification

81560, 86352Codes listed

No statement changePolicy history

Coverage Criteria

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Not medically necessary / Investigational

Covered when ALL of the following are met:

Investigational coverage statement: Use of immune cell function assay testing to monitor and predict immune function after solid organ transplantation is considered INVESTIGATIONAL.

Hematopoietic stem cell transplant: Use of immune cell function assay testing to monitor and predict immune function after hematopoietic stem cell transplantation is considered INVESTIGATIONAL.

Other indications: Use of immune cell function assay testing for all other indications in the setting of transplantation medicine is considered INVESTIGATIONAL.

Provider Actions and Billing

Prior Authorization

Prior Authorization Required

Precertification/preauthorization is required for services described in this policy when performed inpatient. Outpatient use of immune cell function assay testing in the transplant setting is not a covered service for Commercial Managed Care (HMO and POS), Commercial PPO and Indemnity, Medicare HMO Blue, and Medicare PPO Blue.

Preauthorization required for inpatient procedures for all products.
Outpatient testing is not covered for Commercial Managed Care (HMO and POS), Commercial PPO and Indemnity, Medicare HMO Blue, and Medicare PPO Blue.

Documentation Required

Action Required by Provider

Providers must obtain precertification/preauthorization before scheduling or performing inpatient immune cell function assay testing related to transplantation. Failure to obtain required authorization may result in claim denial or nonpayment.

Obtain authorization prior to inpatient service.
Verify member benefits and authorization requirements specific to product.

Denial Risk

Investigational / Not Covered — Outpatient

Use of immune cell function assay testing to monitor or predict immune function after solid organ transplantation or hematopoietic stem cell transplantation, and for all other transplantation-related indications, is considered investigational and is not a covered outpatient service.

Investigational / Not covered for transplant monitoring and prediction: solid organ and hematopoietic stem cell transplantation.
Outpatient use explicitly listed as not a covered service for listed product types.

Billing Rule

Coding and Claim Documentation

Report services using current industry-standard CPT, HCPCS, revenue, and diagnosis codes and include modifiers where applicable. Inclusion of a code in informational lists does not guarantee coverage; verify member contract benefits at time of service.

Providers should report all services with up-to-date procedure, revenue, and diagnosis codes and applicable modifiers.
Inclusion of codes is informational only — check member benefits for coverage determination.

Evaluation Requirements

Documentation Required

Assay description and intended use; evidence insufficient

Assays (for example, ImmuKnow and Pleximmune) are intended to assess net immune function to support individualized immunosuppression decisions, but evidence is insufficient to demonstrate clinical utility for this purpose.

ImmuKnow measures ATP concentration in CD4-positive T lymphocytes after mitogenic stimulation to characterize cellular immune response ranges.
Pleximmune measures CD154 expression on T‑cytotoxic memory cells and reports an Immunoreactivity Index (IR); posttransplant IR > 1.1 indicates increased rejection risk (pretransplant threshold 1.23).

Post-Transplant Coverage

Immune cell function assay testing (eg, ImmuKnow, Pleximmune) — coverage stance

Policy stanceUse of immune cell function assay testing (eg, ImmuKnow, Pleximmune) to monitor or predict immune function after solid organ or hematopoietic stem cell transplantation is considered INVESTIGATIONAL and not medically necessary.

Outpatient coverageOutpatient use of these services is not a covered service for specified Commercial and Medicare products.

RationaleEvidence is insufficient to demonstrate clinical utility across transplant types; predictive characteristics and impact on net health outcomes are uncertain.

Implication for providersTesting is considered investigational — coverage is not supported for monitoring or predicting immune function post-transplant.

Definitions

ImmuKnow — assay definition and ATP interpretation

Assay descriptionImmuKnow measures ATP concentration in CD4-positive T lymphocytes after mitogenic stimulation (15–18 hour incubation with phytohemagglutinin); CD4+ cells are immunoselected and intracellular ATP is quantified by luminescence.

Result interpretationATP concentration is compared with fixed ATP production ranges to characterize cellular immune response; higher ATP suggests stronger immune response, lower ATP suggests increased infection risk.

Specimen handlingWhole blood is incubated with and without stimulant to assess stimulated and basal ATP activity; CD4+ cells are selected with anti-CD4 monoclonal antibody-coated magnetic particles prior to ATP measurement.

Pleximmune — assay definition and Immunoreactivity Index

Assay descriptionPleximmune measures CD154 expression on T‑cytotoxic memory cells in peripheral blood lymphocytes; the patient’s donor-induced inflammatory response is expressed as a ratio to third‑party response (Immunoreactivity Index, IR).

Immunoreactivity Index thresholdsPosttransplant: IR > 1.1 indicates increased risk of rejection; IR < 1.1 indicates decreased risk. Pretransplant threshold: IR = 1.23.

MethodologyCells are cultured and analyzed with fluorochrome‑stained antibodies to identify CD154‑expressing cells; donor response divided by third‑party response yields the IR.

Background

Therapeutic drug monitoring and observation of clinical toxicity are current tools used to guide immunosuppression management after transplantation but have recognized limitations in precisely reflecting a patient’s net immune status. Commercially available immune cell function assays (for example, tests that measure CD4 ATP levels or assays reporting CD154-mediated donor response indices) have been proposed to individualize immunosuppression by assessing cellular immune function and thereby balancing rejection versus infection risk. However, the evidence remains insufficient to demonstrate consistent clinical utility of these assays for guiding therapy decisions after solid organ or hematopoietic cell transplantation, and therefore their use is classified as investigational.