One Step Closer to Unlocking Lupus Mystery
WebMD News Archive
When cells in the body die, they break down into DNA, protein, and other
debris, which needs to be cleared away in order for systems to function
properly. The substance responsible for clearing away "cellular trash"
is known as Dnase1, and German scientists have shown the first direct evidence
that a deficiency in Dnase1 functioning may be one of the causes of lupus. This
is because the "cellular trash" may cause the body to mount an immune
response to it and to begin attacking its own cells.
The researchers found that Dnase1 levels were lower in people with lupus and
in animal experiments, stopping the production of Dnase1 resulted in lupus-like
But whether the lack of Dnase1 actually leads to disease, or simply makes
the disease worse for those who already have it, is difficult for experts to
It also is unknown what causes people to lack Dnase1. Several possibilities
are under investigation, says study author Tarik MÃ¶rÃ¶y, PhD, a professor of
cell biology at the Institut fÃ¼r Zellbiologie in Essen, Germany. "There may
be a loss of the Dnase1 gene" which sparks production of the enzyme, he
says. "Or we may inherit a Dnase1 gene that is less effective in producing
the enzyme. Environmental factors that inhibit Dnase1 activity in the [blood]
is also a possibility."
The researchers also examined blood samples of 10 patients with kidney
disease. Four of them had lupus, and tests showed significantly decreased
Whether or not treating lupus patients with Dnase1 will be effective still
remains to be seen. Animal experiments have shown good results, but the outcome
was less optimistic with actual lupus patients. The form of Dnase1 available
leaves the body almost immediately, which makes it less effective for
MÃ¶rÃ¶y feels that Dnase1 might have a better effect if used early on in the
disease or to prevent it rather than in patients with full-blown lupus.
But the study evidence is not definitive, and even if the scientists are
correct, lupus is too complex a disease to have just one cause. "It's right
now still in the stage of hypothesis and conjecture, which is based on
suggestive evidence but I wouldn't go so far as to say its proven yet,"