2.4 Pre-Transplant Risk Stratification & Organ Suitability Assessment
Key Takeaways
- The Hematopoietic Cell Transplantation-Comorbidity Index (HCT-CI / Sorror Score) supports non-relapse mortality risk estimation, but it does not by itself select a conditioning intensity or make a patient eligible or ineligible for transplantation.
- The HCT-CI weights comorbidities at 1, 2, or 3 points; qualifying reduced ejection fraction sits inside the one-point cardiac definition, and there is no separate three-point 'severe cardiac' item to add.
- The HCT-CI scores patient comorbidity while the Disease Risk Index scores malignancy biology - disease type, cytogenetics, and remission status - to predict relapse and progression-free survival, so the two indices answer different questions.
- Karnofsky (0-100%) and ECOG (0-5) performance scales describe functional vulnerability but create no universal eligibility cutoff; interpret them with frailty, disease risk, planned regimen, and center criteria.
- Pre-treatment suitability is a multidisciplinary, disease- and protocol-specific judgment integrating performance status, organ testing, infection assessment, comorbidities, disease risk, donor or product factors, patient goals, and the center's validated criteria rather than universal numeric cutoffs.
1. Pre-Transplant Risk Stratification: HCT-CI, DRI & Performance Status
Patient eligibility and conditioning intensity selection rely on objective prognostic scoring systems to balance therapeutic efficacy against treatment-related toxicity.
Hematopoietic Cell Transplantation-Comorbidity Index (HCT-CI)
The HCT-CI assigns the following validated weights; use the original definitions or validated calculator when scoring:
| Score | Comorbidities |
|---|---|
| 1 | Arrhythmia; cardiac disease (including qualifying CAD/CHF/MI or LVEF <=50%); inflammatory bowel disease; diabetes requiring medication; cerebrovascular disease; psychiatric disturbance requiring treatment; mild hepatic disease; BMI >35; active infection requiring treatment. |
| 2 | Rheumatologic disease; peptic-ulcer disease requiring treatment; qualifying renal disease; moderate pulmonary disease (commonly corrected DLCO or FEV1 66%–80% or qualifying dyspnea). |
| 3 | Prior treated solid tumor; moderate/severe heart-valve disease; severe pulmonary disease (commonly corrected DLCO or FEV1 <=65%, dyspnea at rest or oxygen); moderate/severe hepatic disease. |
Do not add a separate three-point “severe cardiac” item; qualifying reduced ejection fraction is part of the one-point cardiac definition. Verify how active disease, laboratory upper limits, pulmonary correction and overlapping conditions are handled. A higher total is associated with non-relapse risk at a population level but does not independently choose MAC/RIC/NMA or exclude HCT.
Disease Risk Index (DRI)
While the HCT-CI assesses patient comorbidity, the Disease Risk Index (DRI) assesses malignancy biology. DRI integrates disease type, cytogenetics, and remission status (Low, Intermediate, High, Very High risk), directly predicting post-transplant relapse and progression-free survival (PFS).
Performance Status Scales
- Karnofsky Performance Scale (KPS): Scores range from 0% (death) to 100% (normal); a lower score signals greater functional vulnerability.
- ECOG Performance Status: Scores range from 0 (fully active) to 5 (death).
Neither scale creates a universal eligibility cutoff. Interpret function with frailty, disease risk, planned regimen, rehabilitation potential, and center criteria.
2. Pre-Treatment Organ and Support Assessment
Before conditioning or cellular therapy, the team evaluates organ reserve, active risks, support needs, and whether the planned regimen can be delivered safely. Exact tests and thresholds vary with treatment, label, protocol, and center:
Multi-System Suitability Assessment
┌───────────────────────┬──────────────────────────────────────────────────┐
│ Domain │ Common assessment and clinical question │
├───────────────────────┼──────────────────────────────────────────────────┤
│ Cardiac │ History/exam, ECG, echo or other testing as │
│ │ indicated: can the planned regimen be tolerated? │
│ Pulmonary │ Symptoms, oxygen need and PFTs when indicated: │
│ │ is reserve adequate and risk modifiable? │
│ Renal/hepatic │ Chemistry, eGFR/CrCl, urinalysis and liver tests:│
│ │ are dose changes or another regimen required? │
│ Infection/immunity │ Exposure, serology/PCR and active-infection plan │
│ Oral/dental │ Identify infection or bleeding hazards early │
│ Function/nutrition │ Performance, frailty, nutrition, rehabilitation │
│ Psychosocial/support │ Understanding, access, caregiver/transport plan │
└───────────────────────┴──────────────────────────────────────────────────┘
Infectious Disease Surveillance Panel
- Hepatitis B virus (HBV): Check the required HBV serologies and assess HBV DNA when indicated. HBsAg-positive or anti-HBc-positive patients need a hepatology/infectious-disease reactivation plan; antiviral choice, start, and duration depend on DNA status, planned immunosuppression/cellular therapy, renal function, and current guidance rather than an automatic entecavir rule.
- Hepatitis C Virus (HCV): Anti-HCV and HCV RNA PCR. If positive, direct-acting antivirals (DAAs) are considered pre-transplant.
- Cytomegalovirus (CMV): donor and recipient CMV IgG serostatus for risk stratification; IgM is not the routine matching test.
- Toxoplasmosis & Fungi: Toxoplasma gondii IgG, Coccidioides / Histoplasma serologies in endemic geographic regions, and QuantiFERON-TB Gold for latent tuberculosis.
3. Sequencing the Workup: What Actually Delays a Start Date
Risk stratification tools produce a number, but the transplant calendar is set by whichever evaluation finishes last. Nurses who coordinate this workup protect the start date by knowing which items have long lead times and which are hard stops.
Fertility preservation is the most time-sensitive item in the entire workup. Sperm banking, oocyte or embryo cryopreservation, and ovarian tissue preservation must occur before gonadotoxic conditioning begins, and oocyte retrieval in particular requires a stimulation cycle measured in weeks. Referral cannot wait until the pre-admission visit. Raise fertility at the first evaluation for every patient of reproductive potential regardless of relationship status, sex, or stated intentions, document the discussion, and escalate immediately when insurance or cost creates a delay, because the window closes permanently.
Dental evaluation is a common and avoidable cause of postponement. Untreated caries, periodontal disease, and abscesses are infection sources during aplasia, and extractions need healing time before conditioning while the platelet count still supports the procedure.
Vascular access planning must match the regimen. Apheresis needs a device that tolerates high flow rates, which is not the same as a standard implanted port, and placement scheduling competes with the conditioning start date.
Infectious findings can either delay or redirect the plan. An active infection requiring treatment is itself a scored comorbidity, positive hepatitis serologies trigger a reactivation plan, and latent tuberculosis requires a treatment decision before immunosuppression.
4. Turning the Numbers into a Conversation
Scores are for clinicians; patients need meaning. When a comorbidity index or performance measure is discussed, the nursing task is translating population-level risk into what this person can expect and decide.
Explain that the HCT-CI describes how a group of patients with similar comorbidities has fared, not what will happen to this individual, and that a high score prompts a different plan rather than a closed door. Confirm that the patient has heard the alternatives, including non-transplant therapy and supportive care, and that advance care planning has been offered rather than deferred to a crisis. Document the patient's own stated goals - function, time at home, a specific event - because those goals legitimately change conditioning intensity and care-setting decisions later, and they are frequently the only part of the evaluation nobody wrote down.
A 62-year-old male with acute myeloid leukemia in first complete remission is evaluated for allogeneic HCT. His pre-transplant workup reveals: history of coronary artery bypass grafting 4 years ago with normal current activity, baseline LVEF 55%, pulmonary function testing with corrected DLCO of 58% and FEV1 of 72%, mild type 2 diabetes managed with metformin, and serum creatinine 1.1 mg/dL. What is his HCT-CI (Sorror Comorbidity Index) score and recommended clinical management?