T86.01 Bone marrow transplant rejection

Name of the Condition

• Bone marrow transplant rejection

Summary

Bone marrow transplant rejection occurs when the recipient's immune system attacks the transplanted bone marrow cells, preventing engraftment or leading to graft failure. This can happen in allogeneic transplants, where the donor and recipient are not genetically identical. Rejection may present acutely or chronically and can compromise the success of the transplant.

Causes

Rejection is primarily driven by the recipient's immune system recognizing the transplanted cells as foreign. Mismatched human leukocyte antigens (HLA) between donor and recipient increase this risk. Other factors include inadequate immunosuppression, prior sensitization to donor antigens, or underlying immune disorders.

Risk Factors

• HLA mismatch between donor and recipient
• Inadequate or interrupted immunosuppressive therapy
• Prior blood transfusions or pregnancies (sensitization)
• Underlying autoimmune conditions
• Younger recipient age (in some cases)

Symptoms

• Fever or chills
• Fatigue or weakness
• Low blood cell counts (anemia, thrombocytopenia, neutropenia)
• Graft failure signs (e.g., persistent cytopenias)
• Skin rash or organ dysfunction (if related to graft-versus-host disease)

Diagnosis

Diagnosis involves monitoring engraftment through blood tests (e.g., chimerism analysis to detect donor cell presence), bone marrow biopsies, and assessing immune responses. Imaging or additional tests may evaluate organ involvement if rejection is suspected.

Treatment Options

• Intensified immunosuppression (e.g., higher doses of anti-rejection drugs)
• Donor lymphocyte infusion (DLI) to boost graft acceptance
• Second transplant (in severe or persistent rejection)
• Supportive care for cytopenias or infections

Prognosis and Follow-Up

Prognosis depends on the speed of diagnosis and response to treatment. Early intervention improves outcomes, but severe rejection may lead to graft failure. Long-term follow-up monitors for recurrence, infections, or late complications like secondary malignancies.

Complications

• Graft failure (inability to produce blood cells)
• Increased infection risk due to immunosuppression
• Organ damage from rejection or treatment side effects
• Chronic graft-versus-host disease (if overlapping)

Lifestyle & Prevention

• Strict adherence to immunosuppressive regimens
• Avoiding exposure to infections (e.g., crowds, sick contacts)
• Regular monitoring of blood counts and immune function
• Prompt reporting of new symptoms to the transplant team

When to Seek Professional Help

Seek immediate care for:

• Persistent fever or signs of infection
• Unusual bleeding or bruising
• Severe fatigue or shortness of breath
• Rash, jaundice, or abdominal pain
• Sudden drop in blood cell counts

Tips for Medical Coders

Document the type of transplant (allogeneic vs. autologous), timing of rejection (acute/chronic), and any contributing factors (e.g., HLA mismatch, non-adherence). Specify if rejection is isolated or part of graft-versus-host disease. Ensure clinical correlation with lab results (e.g., chimerism) to support coding.