Intrathecal interferon in the treatment of multiple sclerosis. Patient follow-up
L. Jacobs, J. A. O'Malley, A. Freeman, R. Ekes and P. A. Reese
Follow-up observations on patients with multiple sclerosis who were treated
with human fibroblast interferon (interferon beta) administered
intrathecally for six months revealed a persisting beneficial effect in
terms of a reduction in exacerbation rates. At the time of our last report
in 1982, ten interferon beta recipients had shown a reduction in their mean
exacerbation rate from 1.8/yr before the study to 0.2/yr during the study
while ten control patients with multiple sclerosis showed no change in
their rates during the study (0.69/yr) compared with before it (0.68/yr).
That report was based on observations made for means of 1.9 years in the
recipients and 1.6 years in the controls. The recipient patients have now
been followed up for 4.4 years (mean) and their exacerbation rates have
continued to decrease to a current mean level of 0.16/yr. The control
patients were "crossed over" and began receiving interferon beta
intrathecally after they had been in the study for two years without
showing any change in their rate. During the 2.0 years since crossover they
also have shown a reduction in exacerbation rate to a mean of 0.30/yr. The
toxic side effects of interferon beta administered intrathecally were
acceptable in view of the benefit achieved. Interferon was identified in
the cerebrospinal fluid (but not the serum) of two patients prior to
treatment, which is probably a manifestation of de novo production of
interferon by the central nervous system in response to the multiple
sclerosis disease process.
