Long Term Follow-Up Post Allogeneic HSCT
Immunodeficiency

Updated: October 2010

Antigen-specific T and B cell responses are profoundly deficient early after HSCT and gradual reconstitution occurs over 1-2 years. However recovery can take significantly longer due to ongoing immunosuppressive therapy, CGVHD, in HLA-mismatched transplants and with T-cell depleted grafts. Some physicians follow CD4 counts and CD4/8 ratios as a way to asses need for prophylactic antimicrobial therapy. Concurrent hypogamaglobulinaemia also increases the risk of infections in this group of patients.

Infections by capsulated bacteria (S. pneumoniae, H. influenza, and N. meningitides) remain a significant problem along with recurrent sino-pulmonary infections related to hypogamaglobulinaemia. The most common fungal infections are caused by Aspergillus species (lung/sinuses). However infections by Candida and Mucor species can also be seen. In terms of viral infections herpes viruses including VZV (particularly in the first year) and CMV (late reactivations and disease can occur in the presence of significant immunocompromise if early reactivations/disease have been an issue) infections can be problematic. Pneumocystis jirovicii (PCP) and Toxoplasma gondii infections are seen even several months post transplant and prophylaxis ideally with Co-trimoxazole should be continued until the patient is off all immunosuppression.

Recommendations:

• Penicillin V 300mg bid should be commenced in all non-allergic patients on therapy for CGVHD.
• Fungal prophylaxis with an azole should be considered whilst patients are on systemic corticosteroid therapy
• Pneumocystis prophylaxis (with Septra DS one tablet bid twice weekly in non-allergic patients) should be continued for as long as patients are on immunosuppressive therapy
• Valaciclovir prophylaxis should be continued for at least one year post-transplant and continued on in patients on ongoing immunosuppressive therapy for CGVHD.
• Immunoglobulin assays should be done at yearly intervals in patients on corticosteroids or in the presence of recurrent infections and replacement therapy (IVIg 0.4g/kg monthly) commenced in patients with IgG < 4g/L.
• Please follow AHA guidelines for dental procedures (Dajani et al.)
• Post transplant vaccination with inactivated vaccines should be commenced at 1 year post-transplant or when a patient is considered to be able to respond to the same i.e., off most immunosuppressive therapy (vaccination schedule in L/BMT Manual). Live attenuated vaccines should be avoided for the first 2 years and in those with CGVHD.

The information contained in these guidelines is a statement of consensus of Leukemia/BMT Program of BC professionals regarding their views of currently accepted approaches to treatment. Any clinician seeking to apply or consult these documents is expected to use independent medical judgment in the context of individual clinical circumstances to determine any patient’s care or treatment. Use of these guidelines and documents is at your own risk and is subject to the Leukemia/BMT Program of BC’s terms of use available at Terms of Use.