Magnetization transfer ratio in new MS lesions before and during therapy with IFNbeta-1a.
OBJECTIVE
The authors examined the effect of 6.0 MIU interferon beta-1a (IFNbeta-1a) administered IM each week on the evolution of monthly magnetization transfer ratio (MTR) within new gadolinium-enhancing (Gd+) lesions in patients with very early relapsing-remitting (RR) MS.


BACKGROUND
IFNbeta is an effective disease-modifying treatment for patients with RRMS. Among other effects, it has been shown to decrease the number of new Gd+ and T2-weighted lesions. MTR is a putative marker for irreversible tissue damage and evolution of MTR within a lesion may reflect recovery of tissue damage. It is not known whether IFNbeta-1a affects the recovery phase of lesions.


METHODS
Eight untreated patients with RRMS who completed up to 14 monthly brain MRI sessions elected to initiate treatment with IFNbeta-1a. Four out of eight patients developed new Gd+ lesions during treatment. MTR of lesions at the time of appearance and subsequent rate of change of monthly MTR were compared before and after treatment (stratified Mann-Whitney test).


RESULTS
The difference between MTR at appearance of 47 new Gd+ lesions before treatment versus 23 new Gd+ lesions during treatment was not significant. Twenty-two of 47 new Gd+ lesions before treatment and 11 of 23 new Gd+ lesions after treatment were monitored for up to 6 months. After appearance of new Gd+ lesions, the rate of increase in MTR was faster during therapy (p = 0.037).


CONCLUSIONS
MTR abnormalities within new Gd+ lesions evolve at a faster rate during treatment with IFNbeta-1a than before initiating therapy. This is consistent with the hypothesis that IFNbeta-1a promotes resolution of new Gd+ lesions.
Kita
M
M
UCSF/Mt. Zion Multiple Sclerosis Center, University of California at San Francisco, USA.
Goodkin
D E
DE
Bacchetti
P
P
Waubant
E
E
Nelson
S J
SJ
Majumdar
S
S
D000276:Adjuvants, Immunologic / Q000008:administration & dosage* / Q000009:adverse effects; D000328:Adult; D001921:Brain / Q000187:drug effects / Q000473:pathology; D003287:Contrast Media; D004185:Disability Evaluation; D005260:Female; D005500:Follow-Up Studies; D019786:Gadolinium DTPA; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007273:Injections, Intramuscular; D000068556:Interferon beta-1a; D016899:Interferon-beta / Q000008:administration & dosage* / Q000009:adverse effects; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000175:diagnosis / Q000188:drug therapy*; D016896:Treatment Outcome
D000276:Adjuvants, Immunologic; D003287:Contrast Media; D016899:Interferon-beta; D019786:Gadolinium DTPA; D000068556:Interferon beta-1a