autologous blood and marrow transplantation - Blog Science ...

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antibody titers to RSV (1:2048 to 1:8192). 1315
" 18
The overall mortality in BMT
recipients with RSV pneumonia treated with this combination has been approximately
30% among patients in whom therapy was initiated prior to mechanical
ventilation. In contrast, the mortality among patients who were treated after the
onset of respiratory failure has approached 100%, as has the mortality of patients
who were not treated. Because of this favorable response rate during the early years
of the study, we have continued to use combination therapy, though in recent years
standard IVIG has been substituted for high RSV titered IVIG.
Other treatment regimens for RSV pneumonia have been tried with varying
success, including intravenous ribavirin and combinations of aerosolized and
intravenous ribavirin. 19-21
The ease of administering intravenous ribavirin
compared with aerosolized ribavirin is attractive. However, in an open trial of
intravenous ribavirin in 10 BMT recipients with RSV pneumonia, the mortality
was 80% and two patients developed severe hemolytic anemia, 20
suggesting that
monotherapy with intravenous ribavirin is neither effective nor benign.
In spite of a high cognizance and an intensive surveillance for RSV, many
pneumonias are only diagnosed after the onset of profound respiratory failure or
death, and even with aggressive therapy prior to profound respiratory failure, the
mortality is still high. The need for empiric therapy or for prophylaxis or early
therapy of URIs before the onset of viral pneumonia is apparent.
Various approaches to the therapy of RSV-URIs in BMT recipients are
currently being investigated, including aerosolized ribavirin and/or high RSV
4 5 1 9 2 0
titered IVIG or standard IVIG. Aerosolized ribavirin is being studied at
different daily dosages (ranging from 2 to 6 grams), at different concentrations
(ranging from 20 to 60 mg/mL) and for different daily durations (ranging from 2 to
18 hours a day). The overall preliminary findings suggest that the frequency of
pneumonia and death may be decreased, but far from eliminated, by promptly
treating URIs. Whether higher daily doses and longer daily durations of therapy are
more effective remains to be determined. Since so many RSV-URIs are selflimited,
interpretation of the response to therapy in these studies has been limited
by lack of controls.
The decision to initiate therapy with aerosolized ribavirin and/or IVIG for a
simple RSV-URI is complex and needs to take into consideration many factors
including the patient's risk of developing serious lower respiratory tract disease
(with regard to underlying disease, type of transplant, immunosuppressive therapy
being administered, and time posttransplant); the presence of underlying lung
disease such as bronchiolitis pneumonia obliterans or radiation pneumonitis; the
stage of the URI such as whether the illness has already progressed to a deep
tracheobronchitis; whether the respiratory illness is improving or worsening; the
unproven efficacy of these drugs in transplant recipients; the potential for environmental
contamination and exposure of health care workers; the psychological and