Clinical Context
A 6-month-old infant with a confirmed genetic diagnosis of Wiskott-Aldrich syndrome (or another single-gene hematopoietic disorder approved for atidarsagene autotemcel) is scheduled for administration of J3391 (injection, atidarsagene autotemcel, per treatment). The patient presents to an outpatient hospital-based ambulatory infusion center or an inpatient transplant/oncology unit for a single-dose gene-modified autologous hematopoietic stem cell infusion.
Pre-procedure workflow includes verification of identity and informed consent, review of prior leukapheresis/collection records, confirmation of product matching (chain-of-custody), baseline vital signs and laboratory assessment (CBC, chemistry panel, infectious disease screening), and documentation of eligibility criteria and payer authorization. The cell therapy product is thawed and prepared in an appropriate sterile compounding area. The infusion is administered intravenously by an experienced infusion nurse under physician supervision with continuous monitoring for acute infusion reactions and cytokine release. Post-infusion monitoring occurs in the same setting for several hours to days depending on institutional protocol, with scheduled follow-up for graft function, immune reconstitution, and long-term surveillance for treatment response and adverse events.
Typical sites of service are outpatient hospital infusion centers and inpatient hematology/oncology or bone marrow transplant units. Common payors include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, BUCA, and Medicare. Common modifiers used in billing include 22, 52, 53, 78, 80, 82, AS, SH, and TG to capture unusual circumstances, reduced services, surgical team participation, or site-specific billing requirements.