Autologous Bone Marrow Transplantation - Blog Science Connections

666 IVIg in ABMT
in autologous transplant recipients. One recent study of 70 patients with
leukemia or lymphoma who received ABMT showed a 10% incidence of IP;
three were due to CMV, one to Pneumocystis carinii, and three were
idiopathic. The incidence seemed to be correlated with prior radiation (28).
Another review identified CMV pneumonitis in 1 of 14 patients after ABMT, a
patient who received granulocyte transfusions (29). We have recently
compiled data on 34 patients who received ABMT as treatment for a variety of
malignancies; half of them received prophylactic Mg (manuscript in preparation).
One patient who did not receive Mg died of transfusion-related
CMV pneumonitis, and three had self-limited nonpneumonitic infections; only
one in the latter group had received IVIg. The infection rate is obviously too
low to detect a role for IVIg in CMV prophylaxis.
Nevertheless, immunologic problems still exist in conjunction with
ABMT, including other infections, fevers, and gastrointestinal difficulties. In
our patient population, over half of the ABMT recipients have an episode of
fever with bacteremia some time during treatment (unpublished data).
Gastrointestinal problems, including debilitating mucositis and diarrhea,
occur in up to 45%. Especially when radiotherapy is combined with intensive
chemotherapy, diffuse mucosal changes have occurred within 10 days of
initiation of therapy. Changes include severe cellular atypia in villous and
crypt epithelium and eventually necrosis of damaged tissue; repair begins
between days 16 and 20. Damage to the mucosal barrier and decreased
intestinal motility, mucus production, and acid production (30,31) increase
the potential for bacterial attachment to the mucosa (32). Furthermore, this
damage to the mucosal barrier, immunodeficiency and neutropenia resulting
from the cytoreductive therapy, and changes in flora due to antibiotic therapy
may place the marrow recipients at high risk of developing potentially severe
gastrointestinal and systemic infections, a large proportion of which arise
from abdominal sources (33). Enteric viruses, including rotaviruses (34),
adenoviruses (34,35), CMV (34-37), Coxsackie Al, and herpes simplex
(38,39), have been problematic in causing enteritis among patients who
receive transplants; it is unclear how many of these viruses are acquired (35)
or reactivated (34) in the hospital.
Theoretically, therefore, orally administered immune globulin could
serve a prophylactic function. Locally produced antiviral IgA appears to be
critical protection from bowel and systemic infections (40), and it, like all
other antibodies, is deficient in the posttransplant period. Research has
shown that intestinal antibody helps to inhibit the adherence of Vibrio
bacteria to rabbit intestinal mucosa (41). In another study, a systemic
antibody response alone to polio vaccine, without a concomitant response in
the intestinal tract, did not necessarily inhibit continued intestinal carriage of
the organism (40). These two studies point to a role for exogenous oral
immune globulin in prophylaxis against enteric infections. Since patients'
acid production is reduced when the immune globulin is given orally, it is not