autologous blood and marrow transplantation - Blog Science ...

712 Chapter 15: New Avenues
Among adult transplant recipients, only sporadic cases of serious RSV disease
in adults had been reported until 1988. 9
Since then, studies of RSV infections in
BMT recipients reported from several centers have established a fairly consistent
picture of the epidemiology, frequency, and clinical course of RSV infections in
BMT recipients. 10
" 13
These studies have established that RSV is a frequent cause
of acute respiratory disease in autologous as well as allogeneic pediatric and adult
BMT recipients during community outbreaks. Devastating nosocomial outbreaks
have occurred, highlighting the need for aggressive hospital infection control
strategies. For instance, at M.D. Anderson Cancer Center (MDACC), 19 (17%) of
111 hospitalized adult BMT recipients were diagnosed with RSV infections during
a 9-week winter outbreak in 1992-1993. These 19 patients constituted 45% of the
adult BMT recipients hospitalized with an acute respiratory illness. Two-thirds of
the infections were acquired nosocomially, and nine (56%) of 16 pneumonias were
fatal. In subsequent years, the frequency of infections declined dramatically, due to
an aggressive multifaceted infection control strategy and a new policy of
postponing transplants in patients with URIs.
RSV infections in BMT recipients follow the same clinical sequence as in
children: pneumonia is preceded by signs and symptoms of URI such as rhinorrhea,
sinus congestion, sore throat, and otitis media. The frequency of progression of
URI to pneumonia is highest in patients who are early (2 months) posttransplant or postengrafted, the
frequency is reported to be 25—40%. These latter figures are an overestimate, since
patients are followed less closely in the late posttransplant period, and primarily
severe cases come to medical attention. Once RSV disease has progressed to
pneumonia, however, the mortality is more than 80% whether the patient is pre- or
postengraftment, and the mortality of patients who have required mechanical
ventilation has approached 100% regardless of the therapeutic intervention.
The therapeutic options for RSV disease are limited. The only drug approved
for the treatment of RSV disease is aerosolized ribavirin. 14
Aerosolized ribavirin
has been shown in controlled trials to be effective in the treatment of RSV
pneumonia and bronchiolitis in high-risk children. Controlled trials of therapy for
RSV disease in immunocompromised patients have not been conducted. In BMT
recipients with RSV disease, favorable responses have been reported primarily
when therapy has been initiated at an early stage of the respiratory illness (URIs,
tracheobronchitis, or lower respiratory tract disease without radiographic
infiltrates). 10
In contrast, in BMT recipients with radiographically visible RSV
pneumonia, monotherapy with aerosolized ribavirin has been associated with a
70% mortality. 11
Because monotherapy with aerosolized ribavirin alone did not appear to be of
benefit in established pneumonia, the approach at MDACC since 1992 has been to
combine aerosolized ribavirin with IVIG which contained substantial neutralizing