Ever wondered why Dr. House and his staff suspect Lupus so frequently? Until this week, I always considered that to be very odd, and probably a quirk of the script-writers. Until we learned about Lupus!
Systemic lupus erythematosus (SLE) is an autoimmune disease of the connective tissue. ‘Autoimmune’ means that it occurs when a dysfunction in your immune system causes your immune cells to start reacting against your own body. Essentially, your body starts fighting itself. There are many different autoimmune disorders, but in SLE, the attack is mounted against components of connective tissue. Unfortunately, connective tissue is found virtually everywhere in your body. This means that SLE can affect virtually any organ system.
Seriously – you should see my textbook, and all of the hundred presentations of lupus that are listed there. It is understandable then, that given a systemic disease involving multiple organ systems, you might reasonably suspect lupus.
As you saw in the clip, there’s a sensitive blood test available for lupus: ANA. The clip explains how 95% of people with lupus are positive for ANA, which means that a negative ANA is a sufficiently good indication that you don’t have lupus. The problem occurs when your ANA is positive! Because although the test is sensitive, it’s not very specific and so a few different conditions may present with a postive ANA. So when the ANA is positive, you still have some sleuthing to do… or should I say Dr-House-ing.
