LWBK1006-42 LWW-Govindan-Review December 12, 2011 20:38
Chapter 42•Stem Cell Transplantation 535Answer 42.20. The answer is C.
Some 40% to 60% of CMV-seropositive allogeneic HCT recipients
undergo CMV reactivation posttransplant. Asymptomatic CMV viremia
is often detected by regular PCR monitoring of peripheral blood, although
it may be heralded by an unexplained decline in white blood cell or platelet
counts. Pneumonitis is the most common manifestation of CMV-mediated
disease after allogeneic HCT and is associated with a significant mortality
rate. CMV colitis may mimic gastrointestinal GVHD and usually requires
colonoscopic biopsy to distinguish. CMV retinitis, a common manifesta-
tion of CMV reactivation among patients with AIDS, is relatively uncom-
mon among allogeneic HCT recipients.Answer 42.21. The answer is B.
Autologous HCT is associated with a higher risk of relapse than allogeneic
HCT, likely resulting from a combination of the potential for tumor cell
contamination of the autologous graft and the absence of an immune-
mediated graft-versus-tumor effect associated with the latter. The major
advantage of autologous HCT is its relatively low treatment-related mor-
bidity and mortality (3% to 5% in most cases).Answer 42.22. The answer is D.
The choice of conditioning regimen is driven by multiple factors, includ-
ing, for both autologous and allogeneic HCT recipients, the underlying
malignancy and its predicted responsiveness to various therapeutic agents.
Similarly, the age and comorbidities of the recipient may dictate the use of
a regimen with a lower predicted toxicity profile. For recipients of allo-
geneic HCT, donor : recipient HLA mismatching may influence the use
of a more immunosuppressive conditioning regimen to lower the risk of
graft rejection.Answer 42.23. The answer is B.
Reduced-intensity conditioning regimens for allogeneic HCT were devel-
oped to exploit the curative potential of the GVL effect with reduced tox-
icity among older, sicker patients who might not otherwise be candidates
for traditional myeloablative conditioning. Because reduced-intensity reg-
imens are generally less myelosuppressive, a period of mixed myeloid
chimerism often persists during the peritransplant period that may atten-
uate the period of absolute neutropenia. A potential limitation of these
regimens is that their reduced cytotoxicity limits the tumor cell kill, render-
ing them less effective in the setting of refractory disease with significant
tumor burdens.Answer 42.24. The answer is C.
Retrospective studies of allogeneic transplant recipients have demon-
strated that the highest incidence of relapse is among patients who expe-
rienced either acute or chronic GVHD were the recipients of T-depleted