Evidence of opportunistic infection with natalizumab
Patients with relapsing-remitting MS treated with natalizumab have a high rate of John Cunningham virus (JCV) seroconversion.
A study of 1,001 patients in Australia and Brazil found a durable positive seroconversion rate of 24.1% or 7.3% per year in initially JCV-negative patients. Seroconversion was more common in males than females.
The study said this rate exceeds that noted in registration and post-marketing studies for natalizumab and greatly exceeds that predicted by epidemiological studies of JCV seroconversion in healthy populations.
“This finding supports the contention that this otherwise highly effective agent causes important off-target changes in the immune system that may be trophic for JCV seroconversion. This may limit natalizumab’s ability to provide long-term control of the inflammatory aspects of RRMS.”
Therapeutic Advances in Neurological Disorders
Renal risk factor for stroke
Renal impairment is an important risk factor for stroke, particularly in younger patients, and is associated with more severe stroke and worse outcomes.
According to the international INTERSTROKE study of first acute stroke in over 21,000 participants from 27 countries including Australia, the prevalence of renal impairment – defined as eGFR <60 mL/min/1.73 m2 – was higher in cases than controls (22.9% v 17.7%, p < 0.001).
Renal impairment was associated with increased odds of all stroke (OR 1.35), with higher odds for intracerebral haemorrhage (OR 1.60) than ischaemic stroke (OR 1.29).
The strongest effect was seen in younger participants and those living in Africa, South Asia, or South America.
Renal impairment was also associated with poorer clinical outcome (RRR 2.97; 95% CI: 2.50–3.54 for death within 1 month).
Budget funds for brain magnetic stimulation therapy
The federal Budget is providing $288.5 million for Medicare-subsidised access to repetitive transcranial magnetic stimulation (rTMS) therapy for depression.
Psychiatrists have welcomed the announcement of new MBS items that will allow clinics to provide the noninvasive brain stimulation therapy for adults with an antidepressant medication resistant major depressive disorder.
The procedure, pioneered by Australian psychiatrists such as Professor Paul Fitzgerald of Monash University, delivers large, brief pulses of magnetic current to the left dorsolateral prefrontal cortex. It is thought to act by altering neuronal excitability at the synapses. A recent registry study found response rates of 58–83% and remission rates of 28–62% with rTMS in people with depression.