It's becoming more and more common to use immunosuppressant
drugs such as azathioprine and methotrexate to alleviate
the ills of Crohn's disease.
But has this intervention's increasing
popularity had any effect on the natural course of the
ailment, especially when it comes to the need for surgery?
The answer, unfortunately, seems to be 'no,' according
to the results of a study published in the February
issue of Gut.
INADEQUATE
INTERVENTION
"This does not mean that immunosuppressants have no
impact on the natural history of the disease," commented
lead researcher Dr Jacques Cosnes of the H�pital Saint-Antoine
in Paris, to Reuters Health. The benefit of the therapy
in Crohn's disease "is clearly established," he added.
What it does mean is "that we do not use them adequately."
His conclusion stems from an analysis
of the medical records of 2,573 Crohn's patients. The
records dated back 25 years. Subjects were divided into
five groups based on the date they were first diagnosed
with Crohn's disease (1978-82, 1983-87, 1988-92, 1993-97
and 1998-2002). All the records were checked for the
use of azathioprine or methotrexate, the occurrence
of intestinal resection corrective surgery and records
of intestinal complications.
In 565 patients who were examined
within three months of being diagnosed with Crohn's,
the five-year cumulative probability of being treated
with the immunosuppressants progressively rose over
time, from 0 in the 1978-82 cohort to 0.25 in the 1988-92
and 1993-97 cohorts, and finally to 0.56 in the 1998-2002
cohort. Despite the increasing popularity of immunosuppressants,
however, statistical analysis showed that the year of
diagnosis had no significant effect on the incidence
of intestinal surgery. Similarly, the cumulative risk
of strictures or penetrations of the small intestine
did not change over time.
IT'S
ALL IN HOW YOU USE IT
"Although immunosuppressants have been used more frequently
over the last 25 years, there was no significant decrease
of the need for surgery, or of intestinal complications
of Crohn's disease," concluded the authors in the Gut
paper.
The explanation, according to Dr
Cosnes, lies in the inadequate use of immunosuppressants.
"In most cases, immunosuppressants [are] started one,
two, or three years after diagnosis — not within
the first few months. Our hypothesis is that, if immunosuppressants
had been started very early — for example, within
the first six months following diagnosis — this
could have changed the natural history of the disease
and prevented complications needing surgery."
According to the Crohn's and Colitis
Foundation of Canada, approximately 170,000 Canadians
have irritable bowel disease, of which Crohn's is one
of the most common forms. Though Dr Cosnes' revelations
may come too late to help these patients avoid the need
for surgery, those who have yet to be diagnosed may
benefit from earlier immunosuppressant prescriptions.
Gut Feb, 2005 54: 237-41
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